HMAC-SHA256 API Request Signature Verifier
Verifies cryptographic HMAC-SHA256 message authentication codes for secure API payload validation.
Notice: engineering verification utility. Use test or de-identified data and verify results independently before relying on them.
How it works
Standard: RFC 2104 HMAC / NIST FIPS 198-1
Formula: Compare calculated HMAC-SHA256 signature against provided authorization signature
Checks: Hex-encoded signature string present
Calculated locally in browser memory; nothing leaves your browser.
Deterministic local-first client-side execution. Provided as-is without warranty.