Treat offer_amount of 0 as equivalent to None - #4324

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TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
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+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
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tests85.92% <92.30%> (+0.01%)⬆️

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
@TheBlueMatt

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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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Treat offer_amount of 0 as equivalent to None - #4324

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TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
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@jkczyzjkczyz left a comment

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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Treat offer_amount of 0 as equivalent to None - #4324

Merged
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
fuzzing37.23% <40.00%> (+1.03%)⬆️
tests85.92% <92.30%> (+0.01%)⬆️

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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Treat offer_amount of 0 as equivalent to None - #4324

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TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
fuzzing37.23% <40.00%> (+1.03%)⬆️
tests85.92% <92.30%> (+0.01%)⬆️

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
18 of 20 checks passed
@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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@vincenzopalazzo@ldk-reviews-bot@TheBlueMatt@jkczyz
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links"); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + '
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Treat offer_amount of 0 as equivalent to None - #4324

Merged
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
fuzzing37.23% <40.00%> (+1.03%)⬆️
tests85.92% <92.30%> (+0.01%)⬆️

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

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TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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@vincenzopalazzo@ldk-reviews-bot@TheBlueMatt@jkczyz
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default"); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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Treat offer_amount of 0 as equivalent to None - #4324

Merged
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
fuzzing37.23% <40.00%> (+1.03%)⬆️
tests85.92% <92.30%> (+0.01%)⬆️

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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@vincenzopalazzo@ldk-reviews-bot@TheBlueMatt@jkczyz
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Treat offer_amount of 0 as equivalent to None - #4324

Merged
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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@jkczyz
jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
fuzzing37.23% <40.00%> (+1.03%)⬆️
tests85.92% <92.30%> (+0.01%)⬆️

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@jkczyzjkczyz left a comment

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
@TheBlueMatt

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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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@vincenzopalazzo@ldk-reviews-bot@TheBlueMatt@jkczyz
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode"); } } catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); } })(); })();
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Treat offer_amount of 0 as equivalent to None - #4324

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TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0
Mar 17, 2026
Merged

Treat offer_amount of 0 as equivalent to None#4324
TheBlueMatt merged 1 commit into
lightningdevkit:mainfrom
vincenzopalazzo:macros/bolt12-offer-amount-0

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@vincenzopalazzo

@vincenzopalazzovincenzopalazzo commented Jan 20, 2026

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Summary

  • Normalize offer_amount=0 to None in both the builder and parser for consistent internal representation
  • An amount of zero has no practical meaning (you cannot pay zero), so treating it as "no amount specified" simplifies handling
  • When parsing offers with amount=0 (with or without currency), the amount is normalized to None

Motivation

Per BOLT12, if no specific minimum amount is required, the offer_amount field should be omitted rather than set to zero. This change ensures offers with amount=0 are handled gracefully rather than causing unexpected behavior downstream.

Spec clarification pending: lightning/bolts#1314

Test plan

  • Builder test: amount_msats(0) results in amount() == None and as_tlv_stream().0.amount == None
  • Roundtrip test: serialize and re-parse maintains None state
  • Parser tests: TLV with amount=0 (with and without currency) results in amount() == None
  • Invoice request tests: offer with amount=0 requires invoice request to provide amount

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@jkczyz
jkczyz requested review from jkczyz and removed request for wpaulinoJanuary 20, 2026 15:16
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Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.64%. Comparing base (09b3bef) to head (14b7f66).
⚠️ Report is 313 commits behind head on main.

Files with missing linesPatch %Lines
lightning/src/offers/offer.rs90.62%3 Missing ⚠️
lightning/src/offers/invoice_request.rs95.00%1 Missing ⚠️
Additional details and impacted files
@@ Coverage Diff @@## main #4324 +/- ##
==========================================
+ Coverage 86.61% 86.64% +0.02% 
==========================================
Files 158 158 Lines 102730 102782 +52 Branches 102730 102782 +52 ==========================================
+ Hits 88984 89052 +68 + Misses 11328 11315 -13 + Partials 2418 2415 -3 
FlagCoverage Δ
fuzzing37.23% <40.00%> (+1.03%)⬆️
tests85.92% <92.30%> (+0.01%)⬆️

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@jkczyzjkczyz left a comment

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Probably worth waiting on feedback from other implementations. Left some concerns of mine. I'd lean more towards disallowing explicit zero amounts.

Comment threadlightning/src/offers/offer.rs Outdated
return Err(Bolt12SemanticError::InvalidAmount);
},
// An amount of 0 is equivalent to not setting an amount, so default to None.
(None, Some(0)) => None,

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Hmmm... I'd rather we not use the same representation for two different serializations. It may still work because when creating the InvoiceRequest we'll serialize using Offer::bytes. If we didn't use that, the issuer may fail to authenticate the offer when receiving an InvoiceRequest.

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Fixed — this now returns Err(Bolt12SemanticError::InvalidAmount) instead of normalizing to None, so there is no representation mismatch between Offer::bytes and parsed OfferContents. Per the spec clarification (lightning/bolts#1316), readers MUST NOT respond to offers where offer_amount is zero.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +1320 to +1321
// An amount of 0 with a currency is equivalent to not setting an amount.
(Some(_), Some(0)) => None,

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This prevents the currency code check. Also, I don't think it's useful to drop information from the Offer even if we still retain it in Offer::bytes. At very least it would be surprising if viewing an Offer that is suppose to have a currency but LDK shows that it doesn't.

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Good point — fixed. The (Some(_), Some(0)) case now returns Err(Bolt12SemanticError::InvalidAmount) instead of dropping the currency info. No information is discarded since we reject the offer outright.

Comment threadlightning/src/offers/offer.rs Outdated
Comment on lines +408 to +411
// An amount of 0 is equivalent to not setting an amount, so default to None.
if amount_msats == 0 {
$self.offer.amount = None;
}

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I'm somewhat unsure about this change. It could hide an error on the user's end. It might be better to fail in this case instead of allowing them to accept any amount.

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Agreed — updated to return Err(Bolt12SemanticError::InvalidAmount) when amount_msats == 0. This aligns with the spec clarification in lightning/bolts#1316 which requires writers MUST set offer_amount greater than zero.

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Rebased on main and reworked based on review feedback. The approach now rejectsoffer_amount=0 instead of normalizing to None, which aligns with:

Changes in the updated commit:

  • Builder:amount_msats(0) returns Err(Bolt12SemanticError::InvalidAmount)
  • Parser:(None, Some(0)) and (Some(_), Some(0)) both return InvalidAmount error
  • Tests: Updated to assert rejection instead of normalization

This resolves all three inline review concerns (no silent normalization, no representation mismatch, no dropped currency info).

Force push incoming once we agree on the direction.

@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch 2 times, most recently from f329173 to 61d3509CompareMarch 9, 2026 21:04
Per the spec clarification in lightning/bolts#1316:
- Writers MUST set offer_amount greater than zero when present
- Readers MUST NOT respond to offers where offer_amount is zero
Reject amount_msats(0) in the builder with InvalidAmount, and reject
parsed offers with amount=0 (with or without currency) during TLV
deserialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@vincenzopalazzo
vincenzopalazzoforce-pushed the macros/bolt12-offer-amount-0 branch from 61d3509 to a06c446CompareMarch 9, 2026 21:08
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Alrighty.

@TheBlueMatt
TheBlueMatt merged commit 8b1dc05 into lightningdevkit:mainMar 17, 2026
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@vincenzopalazzo
vincenzopalazzo deleted the macros/bolt12-offer-amount-0 branch March 17, 2026 08:41
@TheBlueMatt

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IMO for the 0.1 and 0.2 backports we should silently accept 0 amounts and convert to None instead of rejecting and changing the semantics of the API in a point release.

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TheBlueMatt commented Mar 17, 2026

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Backported to 0.1 in #4487, 0.2 in #4488

let amount = match (currency, amount) {
(None, None) => None,
(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
(None, Some(amount_msats)) if amount_msats == 0 || amount_msats > MAX_VALUE_MSAT => {

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@TheBlueMatt We'll want to note in the changelog that we'll now reject any InvoiceRequest for offers created with 0 explicitly for the amount.

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Yep!

Comment on lines +2043 to +2047
// An offer with amount_msats(0) must be rejected by the builder per BOLT 12.
match OfferBuilder::new(recipient_pubkey()).amount_msats(0).build() {
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
}

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This is already tested in offer.rs. We really want to test that we can't parse an InvoiceRequest that has a Some(0) for the amount TLV. OfferBuilder::build_unchecked should help creating one.

Comment on lines +2017 to 2037
// BOLT 12 test vectors: verify rejection of offers with amount=0 from their
// bech32 encoding (see bolt12/offers-test.json).
match "lno1pqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq".parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}

match "lno1qcp4256ypqqq5qqkyyp4he0fg7pqje62jmnq78cr0ashv4q06qql58tyd9rhp3t2wuyugtq"
.parse::<Offer>()
{
Ok(_) => panic!("expected error"),
Err(e) => assert_eq!(
e,
Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)
),
}
}

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Could you move these to bolt12_tests?

TheBlueMatt added a commit that referenced this pull request Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (#4324).
Bug Fixes
=========
* Async `ChannelMonitorUpdate` persistence operations which complete, but are
not marked as complete in a persisted `ChannelManager` prior to restart,
followed immediately by a block connection and then another restart could
result in some channel operations hanging leading for force-closures (#4377).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (#4590).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (#4684).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (#4651).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (#4707).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (#4595).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (#4709).
* Several spurious debug assertions were fixed (#4537, #4618).
Security
========
0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. This method is called from `payment_parameters_from_invoice` and
`payment_parameters_from_variable_amount_invoice` (#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (#4716).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (#4718).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
TheBlueMatt added a commit to TheBlueMatt/rust-lightning that referenced this pull request Jun 23, 2026
v0.2.3 - Jun 18, 2026 - "Through the Loupe"
API Updates
===========
* `DefaultMessageRouter` will now always generate blinded message paths that
provide no privacy (where our node is the introduction node) for nodes with
public channels. This works around an issue which will appear for any nodes
with LND peers that enable onion messaging - such peers will refuse to
forward BOLT 12 messages from unknown third parties, which most BOLT 12
payers rely on today (lightningdevkit#4647).
* Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder`
now maps 0-amounts to an amount of `None` (lightningdevkit#4324).
Bug Fixes
=========
* `Features::supports_zero_conf` no longer clears the `ZeroConf` features and
`Features::requires_zero_conf` now correctly reports required, rather than
supported, status (lightningdevkit#4517).
* If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are
still being completed asynchronously, further channel updates (e.g.
forwarding another payment) are pending and the node restarts, the channel
could have become stuck (lightningdevkit#4520).
* The presence of unconfirmed transactions actually no longer causes
`ElectrumSyncClient` to spuriously fail to sync (lightningdevkit#4590).
* LSPS1, LSPS2, and LSPS5 persistence will no longer get stuck and refuse to
persist again after a single failure from the KVStore (lightningdevkit#4597, lightningdevkit#4282).
* Dropping the future returned by
`OutputSweeper::regenerate_and_broadcast_spend_if_necessary` no longer
results in future calls to the same method being spuriously ignored (lightningdevkit#4598).
* Used async-receive offers are no longer refreshed on every timer tick once
their refresh time is reached (lightningdevkit#4672).
* `FilesystemStore::list_all_keys` will no longer fail if there are stale
intermediate files lying around from a previous unclean shutdown (lightningdevkit#4618).
* When forwarding an HTLC while in a blinded path with proportional fees over
200%, LDK will no longer spuriously allow a forward that pays us 1 msat too
little in fees (lightningdevkit#4697).
* Fixed a rare case where a channel could get stuck on reconnect when using
both async `ChannelMonitorUpdate` persistence and async signing (lightningdevkit#4684).
* If we had exactly zero balance in a zero-fee-commitment channel, the
counterparty was able to splice all of their balance out, violating the
reserve requirements they'd otherwise be forced to keep (lightningdevkit#4580).
* Providing an `Event::HTLCIntercepted` to the `LSPS2ServiceHandler` twice no
longer results in spuriously opening a channel early (lightningdevkit#4656).
* `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where
`ChannelManager::abandon_payment` was called before the payment ultimately
completes anyway (lightningdevkit#4651).
* `AnchorDescriptor::previous_utxo` now provides the correct `script_pubkey`
for non-zero-commitment-fee anchor channels (lightningdevkit#4669).
* Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some
full `ChannelMonitor`s to disk several times per block (lightningdevkit#4544).
* `OMDomainResolver` now correctly accounts for failed queries when rate
limiting, ensuring we continue to respond to queries after failures (lightningdevkit#4591).
* Calling `ChannelManager::send_payment_with_route` without a `route_params`
and with an invalid `Route` will no longer panic (lightningdevkit#4707).
* `LSPS2ServiceHandler::channel_open_failed` now correctly fails intercepted
HTLCs rather than allowing them to fail just before expiry (lightningdevkit#4677).
* `StaticInvoice::is_offer_expired` was corrected to check offer, rather than
static invoice, expiry (lightningdevkit#4594).
* `lightning-custom-message`'s handling of `peer_connected` events now ensures
that sub-handlers will see a `peer_disconnected` event if a different
sub-handler refused the connection by `Err`ing `peer_connected` (lightningdevkit#4595).
* Replay protection for LSPS5 signatures now detects replays which are only
different in the encoded signature's case (lightningdevkit#4701).
* When `lightning-liquidity` is configured in the background processor, there
is no longer a stream of `Persisting LiquidityManager...` log spam (lightningdevkit#4246).
* Incomplete MPP keysend payments will no longer see their HTLCs held until
expiry (lightningdevkit#4558).
* `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a
BOLT 12 `Offer`, allowing any quantity up to a bound (lightningdevkit#4667).
* `lightning-custom-message` handlers that return `Ok(None)` when asked to
deserialize a message in their defined range no longer cause panics (lightningdevkit#4709).
* Several spurious debug assertions were fixed (lightningdevkit#4537, lightningdevkit#4618, lightningdevkit#4026)
Security
========
0.2.3 fixes several underestimates of the anchor reserves required to ensure we
can reliably close channels, several denial-of-service vulnerabilities and a
sanitization issue.
* `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an
invoice which set an explicit public key, rather than relying on public key
recovery. Note that this method is called from
`PaymentParameters::from_bolt11_invoice` (lightningdevkit#4717).
* Maliciously-crafted unpayable invoices which have overflowing feerates will
no longer cause an `unwrap` failure panic (lightningdevkit#4716).
* Parsing an `LSPSDateTime` which is before 1970 no longer panics. This is
reachable when parsing messages from counterparties (lightningdevkit#4715).
* `possiblyrandom` did not properly generate random data except when it was
explicitly configured to. By default this means LDK is vulnerable to various
HashDoS attacks (lightningdevkit#4719).
* `OMNameResolver` will no longer panic when looking up payment instructions
which include unicode characters at the start of a TXT record (lightningdevkit#4718).
* When using the `anchor_channel_reserves` module to calculate reserves
required to pay for fees when closing anchor channels, zero-fee-commitment
channels were not considered. This could allow a counterparty to open many
channels, leaving us unable to properly force-close (lightningdevkit#4592).
* The `anchor_channel_reserves` module overestimated the value of `Utxo`s in
the wallet by ignoring the `TxIn` cost to spend them (lightningdevkit#4670).
* `PrintableString` did not properly sanitize unicode format characters,
allowing an attacker to corrupt the rendering of logs or UI (lightningdevkit#4593, lightningdevkit#4605).
* RGS data is now limited in how large of a graph it is able to cause a client
to store in memory. Note that RGS data is still considered a DoS vector in
general and you should only use semi-trusted RGS data (lightningdevkit#4713).
* Counterparty-provided strings in failure messages are no longer logged in
full, reducing the ability of such a counterparty to spam our logs (lightningdevkit#4714).
* Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer
cause us to allocate large amounts of memory (lightningdevkit#4712).
Thanks to Project Loupe for reporting most of the issues fixed in this release.
Conflicts resolved in:
* lightning/src/chain/channelmonitor.rs
* lightning/src/events/mod.rs
* lightning/src/ln/channelmanager.rs
* lightning/src/ln/mod.rs
* lightning/src/ln/offers_tests.rs
* lightning/src/ln/onion_utils.rs
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@vincenzopalazzo@ldk-reviews-bot@TheBlueMatt@jkczyz