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Protect Netlify execution ledger writes #69

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Protect Netlify execution ledger writes #69

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32 changes: 32 additions & 0 deletions netlify/functions/execution-ledger.ts
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
import { connectLambda, getStore } from "@netlify/blobs";
import { Redis } from "@upstash/redis";
import { timingSafeEqual } from "node:crypto";

type NetlifyEvent = {
blobs?: string;
Expand Down Expand Up @@ -58,6 +59,29 @@ function normalizeLambdaHeaders(headers: NetlifyEvent["headers"]) {
);
}

function getHeader(headers: NetlifyEvent["headers"], name: string) {
const direct = headers[name];
const lower = headers[name.toLowerCase()];
return direct ?? lower;
}

function safeTokenEquals(actual: string, expected: string) {
const actualBuffer = Buffer.from(actual);
const expectedBuffer = Buffer.from(expected);
return actualBuffer.length === expectedBuffer.length && timingSafeEqual(actualBuffer, expectedBuffer);
}

function isWriteAuthorized(event: NetlifyEvent) {
const expectedToken = process.env.EXECUTION_LEDGER_WRITE_TOKEN;
if (!expectedToken) return false;

const authHeader = getHeader(event.headers, "authorization");
const bearerToken = authHeader?.match(/^Bearer\s+(.+)$/i)?.[1];
const token = bearerToken ?? getHeader(event.headers, "x-execution-ledger-token");

return Boolean(token && safeTokenEquals(token, expectedToken));
}

function isLedgerRows(value: unknown): value is HistoricalExecutionLedgerEntry[] {
return Array.isArray(value);
}
Expand Down Expand Up @@ -177,6 +201,14 @@ function parseBody(event: NetlifyEvent) {
}

export const handler = async (event: NetlifyEvent) => {
if (event.httpMethod === "POST" && !isWriteAuthorized(event)) {

@chatgpt-codex-connector chatgpt-codex-connector Bot Jun 18, 2026

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P2 Badge Restore a server-side path for ledger writes

On Netlify, /api/* is redirected to this function, and the only in-repo ledger writer I found is the browser call in src/lib/executionLedgerStore.ts, which sends only Content-Type. With this new check, normal board syncs now always get 403 because the server-only EXECUTION_LEDGER_WRITE_TOKEN cannot be safely attached from the browser, so the shared proof ledger stops accumulating rows and silently falls back to per-browser storage. Add a trusted server-side writer/proxy before enforcing the token on this endpoint.

Useful? React with 👍 / 👎.

return response(403, {
configured: true,
rows: [],
message: "Shared execution ledger writes require a server-side write token.",
});
}

const store = getLedgerStore(event);

if (!store) {
Expand Down
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