Function verifyVonageJwt

verifyVonageJwt(
    signatureSecret: string,
    bearerToken: string,
    nowSeconds: number,
): VonageJwtClaims
Verifies a Vonage webhook JWT (HS256, signed with the signature secret) and returns its claims, or null when the token is malformed, mis-signed, or expired. Verifies the HS256 signature + exp directly (no JWT library): split header.payload.signature, recompute HMAC-SHA256(header.payload) base64url, constant-time-compare, then check expiry.
Parameters
- signatureSecret: string
  The Vonage signature secret (the HS256 HMAC key; resolved upstream — never inlined).
- bearerToken: string
  The Authorization: Bearer <token> value (or the raw token).
- nowSeconds: number
  The current epoch seconds (injected so the check is deterministic in tests).
Returns VonageJwtClaims
The verified claims, or null when verification fails.
- Defined in Providers/Vonage/src/vonage-ingress.ts:96