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KrisBraun merged 2 commits into from
May 29, 2026
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Harden Gmail connector: header injection, body encoding, lost mail, dup sends #156

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3143e09
Fix BCC/CC collapse in Gmail compose
KrisBraun May 29, 2026
0cd1c19
Harden Gmail connector: header injection, body encoding, lost mail, d…
KrisBraun May 29, 2026
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5 changes: 5 additions & 0 deletions .changeset/recipient-role.md
View file
Open in desktop
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.
112 changes: 85 additions & 27 deletions connectors/gmail/src/gmail-api.ts
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
* thread IDs (with their fetched full thread payloads). On 404 (history
* window expired), returns `expired: true` so the caller can fall back to
* a per-channel full re-sync.
*
* Thread fetches that fail (transient 5xx, rate limits, network) are NOT
* silently dropped: their IDs are returned in `failedThreadIds`. The caller
* advances the `historyId` cursor as usual (so we don't re-walk the whole
* window) but must re-attempt the failed IDs on a subsequent sync by passing
* them back via `retryThreadIds` — otherwise the cursor would move past
* changes we never ingested, permanently losing that mail.
*/
export async function syncGmailMailboxIncremental(
api: GmailApi,
historyId: string
historyId: string,
retryThreadIds: string[] = []
): Promise<
| { expired: true }
| { expired: false; historyId: string; threads: GmailThread[] }
| {
expired: false;
historyId: string;
threads: GmailThread[];
failedThreadIds: string[];
}
> {
let historyResult;
try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
throw error;
}

const changedThreadIds = new Set<string>();
const changedThreadIds = new Set<string>(retryThreadIds);
for (const entry of historyResult.history) {
for (const added of entry.messagesAdded ?? []) {
changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
}

const threads: GmailThread[] = [];
const failedThreadIds: string[] = [];
for (const threadId of changedThreadIds) {
try {
threads.push(await api.getThread(threadId));
} catch (error) {
console.error(`Failed to fetch thread ${threadId}:`, error);
failedThreadIds.push(threadId);
}
}

return {
expired: false,
historyId: historyResult.historyId,
threads,
failedThreadIds,
};
}

/**
* Strips CR, LF, and NUL from a value before it is interpolated into an
* email header. Without this, an attacker-controlled subject or recipient
* (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
* into the outgoing message (RFC 5322 header injection). Header values must
* be a single unfolded line; we collapse any control characters to a space.
*/
function sanitizeHeaderValue(value: string): string {
return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
* Builds an RFC 2822 email message for a new (non-reply) email.
* Returns the base64url-encoded raw message string for the Gmail API.
*/
export function buildNewEmailMessage(options: {
to: string[];
cc?: string[];
bcc?: string[];
from: string;
subject: string;
body: string;
}): string {
const { to, cc = [], from, subject, body } = options;

const lines: string[] = [
`From: ${from}`,
`To: ${to.join(", ")}`,
];
const { to, cc = [], bcc = [], from, subject, body } = options;

// Sanitize every value interpolated into a header to prevent CRLF header
// injection (RFC 5322) via attacker-controlled subjects or addresses.
const toLine = to.map(sanitizeHeaderValue).join(", ");
const ccLine = cc.map(sanitizeHeaderValue).join(", ");
const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

// Only emit recipient headers that have addresses. A message may be
// addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
// Bcc recipients and strips the Bcc header from the copy other
// recipients receive, so listing them here does not expose them.
if (to.length > 0) {
lines.push(`To: ${toLine}`);
}

if (cc.length > 0) {
lines.push(`Cc: ${cc.join(", ")}`);
lines.push(`Cc: ${ccLine}`);
}

if (bcc.length > 0) {
lines.push(`Bcc: ${bccLine}`);
}

lines.push(`Subject: ${subject}`);
lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
lines.push(`Content-Type: text/plain; charset="UTF-8"`);
lines.push(""); // Empty line separates headers from body
lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
const { to, cc, from, subject, body, messageId, references, attachments } = options;

// Sanitize every value interpolated into a header to prevent CRLF header
// injection (RFC 5322) via attacker-controlled subjects or addresses.
const fromHeader = sanitizeHeaderValue(from);
const toHeader = to.map(sanitizeHeaderValue).join(", ");
const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
const safeMessageId = sanitizeHeaderValue(messageId);
const safeReferences = sanitizeHeaderValue(references);

// Ensure subject has "Re:" prefix
const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
const reSubject = sanitizeHeaderValue(
subject.startsWith("Re:") ? subject : `Re: ${subject}`
);

let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

const headerLines: string[] = [
`From: ${from}`,
`To: ${to.join(", ")}`,
`From: ${fromHeader}`,
`To: ${toHeader}`,
];
if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
headerLines.push(`Subject: ${reSubject}`);
headerLines.push(`In-Reply-To: ${messageId}`);
const refChain = references ? `${references} ${messageId}` : messageId;
headerLines.push(`In-Reply-To: ${safeMessageId}`);
const refChain = safeReferences
? `${safeReferences} ${safeMessageId}`
: safeMessageId;
headerLines.push(`References: ${refChain}`);
headerLines.push(`MIME-Version: 1.0`);
headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
headerLines.push(""); // end of headers

// Text body part
// Text body part. Base64-encode the UTF-8 body so the declared
// Content-Transfer-Encoding matches the bytes we emit — inserting a raw
// 8-bit body under a `quoted-printable` (or any non-identity) declaration
// corrupts non-ASCII content and breaks strict MIME parsers.
const bodyPart = [
`--${boundary}`,
`Content-Type: text/plain; charset="UTF-8"`,
`Content-Transfer-Encoding: quoted-printable`,
`Content-Transfer-Encoding: base64`,
"",
body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
];

// Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
} else {
// Simple text-only message (existing path)
const lines: string[] = [
`From: ${from}`,
`To: ${to.join(", ")}`,
`From: ${fromHeader}`,
`To: ${toHeader}`,
];

if (cc.length > 0) {
lines.push(`Cc: ${cc.join(", ")}`);
lines.push(`Cc: ${ccHeader}`);
}

lines.push(`Subject: ${reSubject}`);
lines.push(`In-Reply-To: ${messageId}`);
lines.push(`In-Reply-To: ${safeMessageId}`);

// Build References chain
const refChain = references
? `${references} ${messageId}`
: messageId;
const refChain = safeReferences
? `${safeReferences} ${safeMessageId}`
: safeMessageId;
lines.push(`References: ${refChain}`);

lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
 blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
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Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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 Merged

KrisBraun
merged 2 commits into

from

May 29, 2026
 Merged


Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
Skip to content
Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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 Merged

KrisBraun
merged 2 commits into

from

May 29, 2026
 Merged


Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
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Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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merged 2 commits into

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May 29, 2026
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Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// 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;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
Skip to content
Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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 Merged

KrisBraun
merged 2 commits into

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May 29, 2026
 Merged


Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading

, '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('^' + ".*" + '
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
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Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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 Merged

KrisBraun
merged 2 commits into

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May 29, 2026
 Merged


Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
Skip to content
Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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 Merged

KrisBraun
merged 2 commits into

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May 29, 2026
 Merged


Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
Loading
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
Harden Gmail connector: header injection, body encoding, lost mail, dup sends by KrisBraun · Pull Request #156 · plotday/plot · GitHub
Skip to content
Harden Gmail connector: header injection, body encoding, lost mail, dup sends#156

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 Merged

KrisBraun
merged 2 commits into

from

May 29, 2026
 Merged


Harden Gmail connector: header injection, body encoding, lost mail, dup sends
#156
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3143e09

Fix BCC/CC collapse in Gmail compose


KrisBraun May 29, 2026
0cd1c19

Harden Gmail connector: header injection, body encoding, lost mail, d…


KrisBraun May 29, 2026

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5 changes: 5 additions & 0 deletions
.changeset/recipient-role.md

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@plotday/twister": minor
---

Added: `ResolvedRecipient.role` so `onCreateLink` connectors can honor a contact's thread role (e.g. to/cc/bcc). The runtime resolves each recipient's role from the originating thread's `contact_meta`; connectors like Gmail use it to keep CC/BCC recipients out of the visible To header.

112 changes: 85 additions & 27 deletions
connectors/gmail/src/gmail-api.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -918,13 +918,26 @@ async function syncGmailChannelFull(
 * thread IDs (with their fetched full thread payloads). On 404 (history
 * window expired), returns `expired: true` so the caller can fall back to
 * a per-channel full re-sync.
 *
 * Thread fetches that fail (transient 5xx, rate limits, network) are NOT
 * silently dropped: their IDs are returned in `failedThreadIds`. The caller
 * advances the `historyId` cursor as usual (so we don't re-walk the whole
 * window) but must re-attempt the failed IDs on a subsequent sync by passing
 * them back via `retryThreadIds` — otherwise the cursor would move past
 * changes we never ingested, permanently losing that mail.
 */
export async function syncGmailMailboxIncremental(
 api: GmailApi,
 historyId: string
 historyId: string,
 retryThreadIds: string[] = []
): Promise<
 | { expired: true }
 | { expired: false; historyId: string; threads: GmailThread[] }
 | {
 expired: false;
 historyId: string;
 threads: GmailThread[];
 failedThreadIds: string[];
 }
> {
 let historyResult;
 try {
Expand All@@ -936,7 +949,7 @@ export async function syncGmailMailboxIncremental(
 throw error;
 }

 const changedThreadIds = new Set<string>();
 const changedThreadIds = new Set<string>(retryThreadIds);
 for (const entry of historyResult.history) {
 for (const added of entry.messagesAdded ?? []) {
 changedThreadIds.add(added.message.threadId);
Expand All@@ -952,44 +965,74 @@ export async function syncGmailMailboxIncremental(
 }

 const threads: GmailThread[] = [];
 const failedThreadIds: string[] = [];
 for (const threadId of changedThreadIds) {
 try {
 threads.push(await api.getThread(threadId));
 } catch (error) {
 console.error(`Failed to fetch thread ${threadId}:`, error);
 failedThreadIds.push(threadId);
 }
 }

 return {
 expired: false,
 historyId: historyResult.historyId,
 threads,
 failedThreadIds,
 };
}

/**
 * Strips CR, LF, and NUL from a value before it is interpolated into an
 * email header. Without this, an attacker-controlled subject or recipient
 * (e.g. `"Hi\r\nBcc: victim@example.com"`) would inject additional headers
 * into the outgoing message (RFC 5322 header injection). Header values must
 * be a single unfolded line; we collapse any control characters to a space.
 */
function sanitizeHeaderValue(value: string): string {
 return value.replace(/[\r\n\x00]+/g, " ").trim();
}

/**
 * Builds an RFC 2822 email message for a new (non-reply) email.
 * Returns the base64url-encoded raw message string for the Gmail API.
 */
export function buildNewEmailMessage(options: {
 to: string[];
 cc?: string[];
 bcc?: string[];
 from: string;
 subject: string;
 body: string;
}): string {
 const { to, cc = [], from, subject, body } = options;

 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 ];
 const { to, cc = [], bcc = [], from, subject, body } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const toLine = to.map(sanitizeHeaderValue).join(", ");
 const ccLine = cc.map(sanitizeHeaderValue).join(", ");
 const bccLine = bcc.map(sanitizeHeaderValue).join(", ");

 const lines: string[] = [`From: ${sanitizeHeaderValue(from)}`];

 // Only emit recipient headers that have addresses. A message may be
 // addressed entirely via Cc/Bcc (no To). Gmail's send API delivers to
 // Bcc recipients and strips the Bcc header from the copy other
 // recipients receive, so listing them here does not expose them.
 if (to.length > 0) {
 lines.push(`To: ${toLine}`);
 }

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccLine}`);
 }

 if (bcc.length > 0) {
 lines.push(`Bcc: ${bccLine}`);
 }

 lines.push(`Subject: ${subject}`);
 lines.push(`Subject: ${sanitizeHeaderValue(subject)}`);
 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
 lines.push(""); // Empty line separates headers from body
 lines.push(body);
Expand DownExpand Up@@ -1053,8 +1096,18 @@ export function buildReplyMessage(options: {
}): string {
 const { to, cc, from, subject, body, messageId, references, attachments } = options;

 // Sanitize every value interpolated into a header to prevent CRLF header
 // injection (RFC 5322) via attacker-controlled subjects or addresses.
 const fromHeader = sanitizeHeaderValue(from);
 const toHeader = to.map(sanitizeHeaderValue).join(", ");
 const ccHeader = cc.map(sanitizeHeaderValue).join(", ");
 const safeMessageId = sanitizeHeaderValue(messageId);
 const safeReferences = sanitizeHeaderValue(references);

 // Ensure subject has "Re:" prefix
 const reSubject = subject.startsWith("Re:") ? subject : `Re: ${subject}`;
 const reSubject = sanitizeHeaderValue(
 subject.startsWith("Re:") ? subject : `Re: ${subject}`
 );

 let rawMessage: string;

Expand All@@ -1063,25 +1116,30 @@ export function buildReplyMessage(options: {
 const boundary = `----=_PlotBoundary_${Date.now().toString(16)}`;

 const headerLines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];
 if (cc.length > 0) headerLines.push(`Cc: ${cc.join(", ")}`);
 if (cc.length > 0) headerLines.push(`Cc: ${ccHeader}`);
 headerLines.push(`Subject: ${reSubject}`);
 headerLines.push(`In-Reply-To: ${messageId}`);
 const refChain = references ? `${references} ${messageId}` : messageId;
 headerLines.push(`In-Reply-To: ${safeMessageId}`);
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 headerLines.push(`References: ${refChain}`);
 headerLines.push(`MIME-Version: 1.0`);
 headerLines.push(`Content-Type: multipart/mixed; boundary="${boundary}"`);
 headerLines.push(""); // end of headers

 // Text body part
 // Text body part. Base64-encode the UTF-8 body so the declared
 // Content-Transfer-Encoding matches the bytes we emit — inserting a raw
 // 8-bit body under a `quoted-printable` (or any non-identity) declaration
 // corrupts non-ASCII content and breaks strict MIME parsers.
 const bodyPart = [
 `--${boundary}`,
 `Content-Type: text/plain; charset="UTF-8"`,
 `Content-Transfer-Encoding: quoted-printable`,
 `Content-Transfer-Encoding: base64`,
 "",
 body,
uint8ArrayToBase64Lines(new TextEncoder().encode(body)),
 ];

 // Attachment parts
Expand DownExpand Up@@ -1109,21 +1167,21 @@ export function buildReplyMessage(options: {
 } else {
 // Simple text-only message (existing path)
 const lines: string[] = [
 `From: ${from}`,
 `To: ${to.join(", ")}`,
 `From: ${fromHeader}`,
 `To: ${toHeader}`,
 ];

 if (cc.length > 0) {
 lines.push(`Cc: ${cc.join(", ")}`);
 lines.push(`Cc: ${ccHeader}`);
 }

 lines.push(`Subject: ${reSubject}`);
 lines.push(`In-Reply-To: ${messageId}`);
 lines.push(`In-Reply-To: ${safeMessageId}`);

 // Build References chain
 const refChain = references
 ? `${references} ${messageId}`
 : messageId;
 const refChain = safeReferences
 ? `${safeReferences} ${safeMessageId}`
 : safeMessageId;
 lines.push(`References: ${refChain}`);

 lines.push(`Content-Type: text/plain; charset="UTF-8"`);
Expand Down
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