truelayer-signing

Rust crate to produce & verify TrueLayer API requests signatures.

// `Tl-Signature` value to send with the request.
let tl_signature = truelayer_signing::sign_with_pem(kid, private_key)
    .method(Method::Post)
    .path("/payouts")
    .header("Idempotency-Key", idempotency_key)
    .body(body)
    .build_signer()
    .sign()?;

See full example.

Prerequisites

• OpenSSL (see here for instructions).

Verifying webhooks

The verify_with_jwks function may be used to verify webhook Tl-Signature header signatures.

// `jku` field is included in webhook signatures
let jku = truelayer_signing::extract_jws_header(webhook_signature)?.jku?;

// check `jku` is an allowed TrueLayer url & fetch jwks JSON (not provided by this lib)
ensure_jku_allowed(jku)?;
let jwks = fetch_jwks(jku);

// jwks may be used directly to verify a signature
truelayer_signing::verify_with_jwks(jwks)
    .method(Method::Post)
    .path(path)
    .headers(all_webhook_headers)
    .body(body)
    .build_verifier()
    .verify(webhook_signature)?;

See webhook server example.