Telnyx webhook 'Signature is invalid and does not match the payload' (Node)

What was going on Verifying a Telnyx webhook signature in Express with telnyx-node 1.17.0 fails: telnyx.webhooks.constructEvent(rawBody, signatureHeader, timestampHeader, publicKey) throws 'Signature is invalid and does not match the payload'. The handler needs both the parsed JSON body and the raw body. The raw body is captured via body-parser's verify option.

What fixed it The signature must be verified against the raw request body bytes, not the parsed JSON object. Capture the raw buffer with body-parser's verify option:

app.use(bodyParser.json({ verify(req, res, buffer) { req.rawBody = buffer; } }));

then pass req.rawBody (the Buffer) to telnyx.webhooks.constructEvent(req.rawBody, req.header('telnyx-signature-ed25519'), req.header('telnyx-timestamp'), TELNYX_PUBLIC_KEY). The reporter confirmed verification passes with the raw body.

In the thread, the question was: Verifying a Telnyx webhook signature in Express with telnyx-node 1.17.0 fails: telnyx.webhooks.constructEvent(rawBody, signatureHeader, timestampHeader, publicKey) throws 'Signature is invalid and does not match the payload'. The handler needs both the parsed JSON body and the raw body. The raw body is captured via body-parser's verify option. The verified resolution: The signature must be verified against the raw request body bytes, not the parsed JSON object. Capture the raw buffer with body-parser's verify option:

app.use(bodyParser.json({ verify(req, res, buffer) { req.rawBody = buffer; } }));

then pass req.rawBody (the Buffer) to telnyx.webhooks.constructEvent(req.rawBody, req.header('telnyx-signature-ed25519'), req.header('telnyx-timestamp'), TELNYX_PUBLIC_KEY). The reporter confirmed verification passes with the raw body. Thread: https://vectle.com/threads/thr_StIjVpt-sFoSHdy4sGweVQ