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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls#7

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Merged
bordumb merged 2 commits into from
Mar 18, 2026
Merged

feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls #7

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5cf3735
feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…
bordumb Mar 18, 2026
8f53fa4
fix: remove - from comments
bordumb Mar 18, 2026
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107 changes: 103 additions & 4 deletions crates/capsec-core/src/has.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
fn cap_ref(&self) -> Cap<P> {
Cap::new()
}
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
([$($a:ident),+]; $all:tt) => {
$( impl_tuple_has_first!(@inner $a; $all); )+
};
(@inner $a:ident; [$($b:ident),+]) => {
$(
impl Has<$a> for Cap<($a, $b)> {
fn cap_ref(&self) -> Cap<$a> { Cap::new() }
}
)+
};
}

macro_rules! impl_tuple_has_second {
($first:ident $(, $rest:ident)+) => {
$(
impl Has<$first> for Cap<($rest, $first)> {
fn cap_ref(&self) -> Cap<$first> { Cap::new() }
}
impl Has<$rest> for Cap<($first, $rest)> {
fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
}
)+
impl_tuple_has_second!($($rest),+);
};
($single:ident) => {};
}

impl_tuple_has_first!(
[FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
[FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
let net = root.grant::<NetConnect>();
sync_data(&fs, &net);
}

#[test]
fn tuple_cap_satisfies_both_has() {
let root = test_root();
let cap = root.grant::<(FsRead, NetConnect)>();
fn needs_fs(_: &impl Has<FsRead>) {}
fn needs_net(_: &impl Has<NetConnect>) {}
needs_fs(&cap);
needs_net(&cap);
}

#[test]
fn tuple_self_pair() {
let root = test_root();
let cap = root.grant::<(FsRead, FsRead)>();
fn needs_fs(_: &impl Has<FsRead>) {}
needs_fs(&cap);
}

#[test]
fn tuple_with_subsumption_type() {
let root = test_root();
let cap = root.grant::<(FsAll, NetConnect)>();
fn needs_fs_all(_: &impl Has<FsAll>) {}
fn needs_net(_: &impl Has<NetConnect>) {}
needs_fs_all(&cap);
needs_net(&cap);
}

#[test]
fn tuple_cap_ref_returns_correct_type() {
let root = test_root();
let cap = root.grant::<(FsRead, NetConnect)>();
let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
}

#[test]
fn tuple_is_zst() {
use std::mem::size_of;
assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
}
}
33 changes: 25 additions & 8 deletions crates/capsec-core/src/permission.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
impl Sealed for super::EnvWrite {}
impl Sealed for super::Spawn {}
impl Sealed for super::Ambient {}
impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
// Compile-time proof that subsumption relationships hold:
fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

#[test]
fn tuple_permission_is_zst() {
assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
}

#[test]
fn subsumption_relationships() {
_assert_subsumes::<FsAll, FsRead>();
Expand Down
4 changes: 4 additions & 0 deletions crates/capsec-core/src/root.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
/// # use capsec_core::permission::{FsRead, NetConnect};
/// let root = test_root();
///
/// // Individual capabilities:
/// let fs_cap = root.grant::<FsRead>();
/// let net_cap = root.grant::<NetConnect>();
///
/// // Or bundle multiple permissions in one token:
/// let combo = root.grant::<(FsRead, NetConnect)>();
/// ```
pub fn grant<P: Permission>(&self) -> Cap<P> {
Cap::new()
Expand Down
6 changes: 3 additions & 3 deletions crates/capsec/src/lib.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down
3 changes: 3 additions & 0 deletions crates/capsec/tests/compile_fail/cap_is_not_send.stderr
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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
= help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
--> $RUST/core/src/marker.rs
|
| pub struct PhantomData<T: PointeeSized>;
| ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
--> $WORKSPACE/crates/capsec-core/src/cap.rs
|
Expand Down
3 changes: 3 additions & 0 deletions crates/capsec/tests/compile_fail/cap_is_not_sync.stderr
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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
= help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
--> $RUST/core/src/marker.rs
|
| pub struct PhantomData<T: PointeeSized>;
| ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
--> $WORKSPACE/crates/capsec-core/src/cap.rs
|
Expand Down
16 changes: 8 additions & 8 deletions crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr
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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
| required by a bound introduced by this call
|
= help: the following other types implement trait `Has<P>`:
`Cap<Ambient>` implements `Has<EnvRead>`
`Cap<Ambient>` implements `Has<EnvWrite>`
`Cap<Ambient>` implements `Has<FsAll>`
`Cap<Ambient>` implements `Has<FsRead>`
`Cap<Ambient>` implements `Has<FsWrite>`
`Cap<Ambient>` implements `Has<NetAll>`
`Cap<Ambient>` implements `Has<NetBind>`
`Cap<Ambient>` implements `Has<Spawn>`
`Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
`Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
`Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
`Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
`Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
`Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
`Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
`Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
and $N others
note: required by a bound in `capsec::fs::read_to_string`
--> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down
2 changes: 1 addition & 1 deletion crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr
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Original file line numberDiff line numberDiff line change
Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
| ^^^^^^^^^^^^^
= help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
(A, B)
Ambient
EnvRead
EnvWrite
FsAll
FsRead
FsWrite
NetAll
NetBind
and $N others
note: required by a bound in `capsec::Permission`
--> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down
16 changes: 8 additions & 8 deletions crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr
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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
| required by a bound introduced by this call
|
= help: the following other types implement trait `capsec::Has<P>`:
`Cap<Ambient>` implements `capsec::Has<EnvRead>`
`Cap<Ambient>` implements `capsec::Has<EnvWrite>`
`Cap<Ambient>` implements `capsec::Has<FsAll>`
`Cap<Ambient>` implements `capsec::Has<FsWrite>`
`Cap<Ambient>` implements `capsec::Has<NetAll>`
`Cap<Ambient>` implements `capsec::Has<NetBind>`
`Cap<Ambient>` implements `capsec::Has<Spawn>`
`Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
`Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
`Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
`Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
`Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
and $N others
note: required by a bound in `needs_net`
--> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down
16 changes: 8 additions & 8 deletions crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr
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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
| required by a bound introduced by this call
|
= help: the following other types implement trait `capsec::Has<P>`:
`Cap<Ambient>` implements `capsec::Has<EnvRead>`
`Cap<Ambient>` implements `capsec::Has<EnvWrite>`
`Cap<Ambient>` implements `capsec::Has<FsWrite>`
`Cap<Ambient>` implements `capsec::Has<NetAll>`
`Cap<Ambient>` implements `capsec::Has<NetBind>`
`Cap<Ambient>` implements `capsec::Has<NetConnect>`
`Cap<Ambient>` implements `capsec::Has<Spawn>`
`Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
`Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
`Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
`Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
`Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
`Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
and $N others
note: required by a bound in `needs_fs_all`
--> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls#7

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 Merged

bordumb
merged 2 commits into

from

Mar 18, 2026
 Merged


feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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5cf3735

feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
8f53fa4

fix: remove - from comments


bordumb Mar 18, 2026

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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

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Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down

2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
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 Merged

bordumb
merged 2 commits into

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Mar 18, 2026
 Merged


feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down

2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls#7

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 Merged

bordumb
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Mar 18, 2026
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down

2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
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} catch (e) {
return url;
}
}
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document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
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observer.observe(document.body, { childList: true, subtree: true });
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})();
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try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls#7

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Mar 18, 2026
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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5cf3735

feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
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fix: remove - from comments


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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down

2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
Skip to content
feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls#7

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 Merged

bordumb
merged 2 commits into

from

Mar 18, 2026
 Merged


feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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5cf3735

feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
8f53fa4

fix: remove - from comments


bordumb Mar 18, 2026

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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down

2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
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var __m = "*";
var __re = new RegExp('^' + ".*" + '
feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
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 Merged

bordumb
merged 2 commits into

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Mar 18, 2026
 Merged


feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
Expand Down

2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
Expand Down
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls by bordumb · Pull Request #7 · auths-dev/capsec · GitHub
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls#7

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bordumb
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Mar 18, 2026
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-generated concrete impls
#7
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feat: implement Has<A> + Has<B> for tuple Cap<(A, B)> via macro-gener…


bordumb Mar 18, 2026
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107 changes: 103 additions & 4 deletions
crates/capsec-core/src/has.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -8,7 +8,17 @@
//!
//! # Multiple capabilities
//!
//! For functions that need multiple permissions, use multiple parameters:
//! Bundle permissions in a single token with a tuple:
//!
//! ```rust,ignore
//! fn sync_data(cap: &(impl Has<FsRead> + Has<NetConnect>)) { ... }
//!
//! let root = test_root();
//! let cap = root.grant::<(FsRead, NetConnect)>();
//! sync_data(&cap);
//! ```
//!
//! Or use separate parameters:
//!
//! ```rust,ignore
//! fn sync_data(fs: &impl Has<FsRead>, net: &impl Has<NetConnect>) { ... }
Expand DownExpand Up@@ -49,15 +59,15 @@ pub trait Has<P: Permission> {
 fn cap_ref(&self) -> Cap<P>;
}

// ── Direct: Cap<P> implements Has<P> ────────────────────────────
// Direct: Cap<P> implements Has<P>

impl<P: Permission> Has<P> for Cap<P> {
 fn cap_ref(&self) -> Cap<P> {
 Cap::new()
 }
}

// ── Subsumption: FsAll, NetAll ──────────────────────────────────
// Subsumption: FsAll, NetAll

macro_rules! impl_subsumes {
 ($super:ty => $($sub:ty),+) => {
Expand All@@ -72,7 +82,7 @@ macro_rules! impl_subsumes {
impl_subsumes!(FsAll => FsRead, FsWrite);
impl_subsumes!(NetAll => NetConnect, NetBind);

// ── Ambient: satisfies everything ───────────────────────────────
// Ambient: satisfies everything

macro_rules! impl_ambient {
 ($($perm:ty),+) => {
Expand All@@ -88,6 +98,53 @@ impl_ambient!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn
);

// Tuples: Cap<(A, B)> satisfies Has<A> and Has<B>
//
// Because Rust's coherence rules reject overlapping generic impls when A == B,
// we enumerate all concrete permission pairs via two macros.
//
// Macro 1: Has<first_element> for all (A, B) pairs including self-pairs (100 impls).
// Macro 2: Has<second_element> for distinct pairs only (90 impls).
//
// Total: 190 unique impls. No conflicts. No changes to the Has<P> trait signature.

macro_rules! impl_tuple_has_first {
 ([$($a:ident),+]; $all:tt) => {
 $( impl_tuple_has_first!(@inner $a; $all); )+
 };
 (@inner $a:ident; [$($b:ident),+]) => {
 $(
 impl Has<$a> for Cap<($a, $b)> {
 fn cap_ref(&self) -> Cap<$a> { Cap::new() }
 }
 )+
 };
}

macro_rules! impl_tuple_has_second {
 ($first:ident $(, $rest:ident)+) => {
 $(
 impl Has<$first> for Cap<($rest, $first)> {
 fn cap_ref(&self) -> Cap<$first> { Cap::new() }
 }
 impl Has<$rest> for Cap<($first, $rest)> {
 fn cap_ref(&self) -> Cap<$rest> { Cap::new() }
 }
 )+
 impl_tuple_has_second!($($rest),+);
 };
 ($single:ident) => {};
}

impl_tuple_has_first!(
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient];
 [FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient]
);

impl_tuple_has_second!(
 FsRead, FsWrite, FsAll, NetConnect, NetBind, NetAll, EnvRead, EnvWrite, Spawn, Ambient
);

#[cfg(test)]
mod tests {
 use super::*;
Expand DownExpand Up@@ -141,4 +198,46 @@ mod tests {
 let net = root.grant::<NetConnect>();
 sync_data(&fs, &net);
 }

 #[test]
 fn tuple_cap_satisfies_both_has() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_self_pair() {
 let root = test_root();
 let cap = root.grant::<(FsRead, FsRead)>();
 fn needs_fs(_: &impl Has<FsRead>) {}
 needs_fs(&cap);
 }

 #[test]
 fn tuple_with_subsumption_type() {
 let root = test_root();
 let cap = root.grant::<(FsAll, NetConnect)>();
 fn needs_fs_all(_: &impl Has<FsAll>) {}
 fn needs_net(_: &impl Has<NetConnect>) {}
 needs_fs_all(&cap);
 needs_net(&cap);
 }

 #[test]
 fn tuple_cap_ref_returns_correct_type() {
 let root = test_root();
 let cap = root.grant::<(FsRead, NetConnect)>();
 let _fs: Cap<FsRead> = Has::<FsRead>::cap_ref(&cap);
 let _net: Cap<NetConnect> = Has::<NetConnect>::cap_ref(&cap);
 }

 #[test]
 fn tuple_is_zst() {
 use std::mem::size_of;
 assert_eq!(size_of::<Cap<(FsRead, NetConnect)>>(), 0);
 }
}

33 changes: 25 additions & 8 deletions
crates/capsec-core/src/permission.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,6 +19,13 @@
//! | [`Spawn`] | Process | Execute subprocesses |
//! | [`Ambient`] | Everything | Full ambient authority — the "god token" |
//!
//! # Tuples
//!
//! Two permissions can be bundled via a tuple: `(FsRead, NetConnect)` is itself
//! a `Permission`, and `Cap<(FsRead, NetConnect)>` satisfies both `Has<FsRead>`
//! and `Has<NetConnect>`. All 2-tuple combinations of built-in permissions are
//! supported.
//!
//! # Subsumption
//!
//! Some permissions imply others. [`FsAll`] subsumes both [`FsRead`] and [`FsWrite`],
Expand All@@ -32,7 +39,7 @@
/// can be used as capability tokens — external crates cannot forge new permissions.
pub trait Permission: sealed::Sealed + 'static {}

// ── Filesystem ──────────────────────────────────────────────────
// Filesystem

/// Permission to read files, list directories, and check metadata.
pub struct FsRead;
Expand All@@ -43,7 +50,7 @@ pub struct FsWrite;
/// Permission for all filesystem operations. Subsumes [`FsRead`] and [`FsWrite`].
pub struct FsAll;

// ── Network ─────────────────────────────────────────────────────
// Network

/// Permission to open outbound TCP and UDP connections.
pub struct NetConnect;
Expand All@@ -54,28 +61,28 @@ pub struct NetBind;
/// Permission for all network operations. Subsumes [`NetConnect`] and [`NetBind`].
pub struct NetAll;

// ── Environment ─────────────────────────────────────────────────
// Environment

/// Permission to read environment variables.
pub struct EnvRead;

/// Permission to modify or remove environment variables.
pub struct EnvWrite;

// ── Process ─────────────────────────────────────────────────────
// Process

/// Permission to spawn and execute subprocesses via `std::process::Command`.
pub struct Spawn;

// ── Ambient ─────────────────────────────────────────────────────
// Ambient

/// Full ambient authority — grants every permission.
///
/// This is the "god token." A `Cap<Ambient>` satisfies any `Has<P>` bound.
/// Use sparingly and only at the capability root.
pub struct Ambient;

// ── Permission impls ────────────────────────────────────────────
// Permission impls

impl Permission for FsRead {}
impl Permission for FsWrite {}
Expand All@@ -88,7 +95,11 @@ impl Permission for EnvWrite {}
impl Permission for Spawn {}
impl Permission for Ambient {}

// ── Subsumption ─────────────────────────────────────────────────
// Tuple permissions

impl<A: Permission, B: Permission> Permission for (A, B) {}

// Subsumption

/// Indicates that `Self` implies permission `P`.
///
Expand All@@ -103,7 +114,7 @@ impl Subsumes<NetConnect> for NetAll {}
impl Subsumes<NetBind> for NetAll {}
impl<P: Permission> Subsumes<P> for Ambient {}

// ── Sealed ──────────────────────────────────────────────────────
// Sealed

mod sealed {
 pub trait Sealed {}
Expand All@@ -117,6 +128,7 @@ mod sealed {
 impl Sealed for super::EnvWrite {}
 impl Sealed for super::Spawn {}
 impl Sealed for super::Ambient {}
 impl<A: Sealed, B: Sealed> Sealed for (A, B) {}
}

#[cfg(test)]
Expand All@@ -141,6 +153,11 @@ mod tests {
 // Compile-time proof that subsumption relationships hold:
 fn _assert_subsumes<Super: Subsumes<Sub>, Sub: Permission>() {}

 #[test]
 fn tuple_permission_is_zst() {
 assert_eq!(size_of::<(FsRead, NetConnect)>(), 0);
 }

 #[test]
 fn subsumption_relationships() {
 _assert_subsumes::<FsAll, FsRead>();
Expand Down

4 changes: 4 additions & 0 deletions
crates/capsec-core/src/root.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -83,8 +83,12 @@ impl CapRoot {
 /// # use capsec_core::permission::{FsRead, NetConnect};
 /// let root = test_root();
 ///
 /// // Individual capabilities:
 /// let fs_cap = root.grant::<FsRead>();
 /// let net_cap = root.grant::<NetConnect>();
 ///
 /// // Or bundle multiple permissions in one token:
 /// let combo = root.grant::<(FsRead, NetConnect)>();
 /// ```
 pub fn grant<P: Permission>(&self) -> Cap<P> {
 Cap::new()
Expand Down

6 changes: 3 additions & 3 deletions
crates/capsec/src/lib.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -28,7 +28,7 @@
//! - **`capsec-macro`** — `#[requires]` and `#[deny]` proc macros
//! - **`capsec-std`** — capability-gated `std` wrappers

// ── Re-exports from capsec-core ─────────────────────────────────
// Re-exports from capsec-core

pub use capsec_core::cap::{Cap, SendCap};
pub use capsec_core::error::CapSecError;
Expand All@@ -44,11 +44,11 @@ pub use capsec_core::root::test_root;

pub use capsec_core::attenuate::{Attenuated, DirScope, HostScope, Scope};

// ── Re-exports from capsec-macro ────────────────────────────────
// Re-exports from capsec-macro

pub use capsec_macro::{deny, requires};

// ── Capability-gated std wrappers ───────────────────────────────
// Capability-gated std wrappers

/// Capability-gated filesystem operations. See [`capsec_std::fs`].
pub mod fs {
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_send.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be sent between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Send` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

3 changes: 3 additions & 0 deletions
crates/capsec/tests/compile_fail/cap_is_not_sync.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,6 +7,9 @@ error[E0277]: `*const ()` cannot be shared between threads safely
 = help: within `capsec::Cap<capsec::FsRead>`, the trait `Sync` is not implemented for `*const ()`
note: required because it appears within the type `PhantomData<*const ()>`
 --> $RUST/core/src/marker.rs
 |
 | pub struct PhantomData<T: PointeeSized>;
 | ^^^^^^^^^^^
note: required because it appears within the type `capsec::Cap<capsec::FsRead>`
 --> $WORKSPACE/crates/capsec-core/src/cap.rs
 |
Expand Down

16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/capsec_std_wrong_cap.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::NetConnect>: Has<FsRead>` is not sati
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `Has<P>`:
 `Cap<Ambient>` implements `Has<EnvRead>`
 `Cap<Ambient>` implements `Has<EnvWrite>`
 `Cap<Ambient>` implements `Has<FsAll>`
 `Cap<Ambient>` implements `Has<FsRead>`
 `Cap<Ambient>` implements `Has<FsWrite>`
 `Cap<Ambient>` implements `Has<NetAll>`
 `Cap<Ambient>` implements `Has<NetBind>`
 `Cap<Ambient>` implements `Has<Spawn>`
 `Cap<(Ambient, Ambient)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `Has<FsAll>`
 `Cap<(Ambient, FsRead)>` implements `Has<Ambient>`
 and $N others
note: required by a bound in `capsec::fs::read_to_string`
 --> $WORKSPACE/crates/capsec-std/src/fs.rs
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2 changes: 1 addition & 1 deletion
crates/capsec/tests/compile_fail/sealed_permission_no_external_impl.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -10,14 +10,14 @@ help: the trait `capsec_core::permission::sealed::Sealed` is not implemented for
5 | struct MyPerm;
 | ^^^^^^^^^^^^^
 = help: the following other types implement trait `capsec_core::permission::sealed::Sealed`:
 (A, B)
 Ambient
 EnvRead
 EnvWrite
 FsAll
 FsRead
 FsWrite
 NetAll
 NetBind
 and $N others
note: required by a bound in `capsec::Permission`
 --> $WORKSPACE/crates/capsec-core/src/permission.rs
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16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/sendcap_cannot_grant_wrong_perm.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::NetConne
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsAll>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsRead>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsAll)>` implements `capsec::Has<FsAll>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_net`
 --> tests/compile_fail/sendcap_cannot_grant_wrong_perm.rs:5:23
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16 changes: 8 additions & 8 deletions
crates/capsec/tests/compile_fail/subsumption_not_reversed.stderr

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Original file line numberDiff line numberDiff line change
Expand Up@@ -7,14 +7,14 @@ error[E0277]: the trait bound `Cap<capsec::FsRead>: capsec::Has<capsec::FsAll>`
 | required by a bound introduced by this call
 |
 = help: the following other types implement trait `capsec::Has<P>`:
 `Cap<Ambient>` implements `capsec::Has<EnvRead>`
 `Cap<Ambient>` implements `capsec::Has<EnvWrite>`
 `Cap<Ambient>` implements `capsec::Has<FsWrite>`
 `Cap<Ambient>` implements `capsec::Has<NetAll>`
 `Cap<Ambient>` implements `capsec::Has<NetBind>`
 `Cap<Ambient>` implements `capsec::Has<NetConnect>`
 `Cap<Ambient>` implements `capsec::Has<Spawn>`
 `Cap<Ambient>` implements `capsec::Has<capsec::FsAll>`
 `Cap<(Ambient, Ambient)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvRead)>` implements `capsec::Has<EnvRead>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, EnvWrite)>` implements `capsec::Has<EnvWrite>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<Ambient>`
 `Cap<(Ambient, FsWrite)>` implements `capsec::Has<FsWrite>`
 `Cap<(Ambient, NetAll)>` implements `capsec::Has<Ambient>`
 and $N others
note: required by a bound in `needs_fs_all`
 --> tests/compile_fail/subsumption_not_reversed.rs:5:26
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