# Blocker S00-019

- Original task: S00-003
- Root task: S00-003
- Reporter: auto-protocol-dcdf92cd067e
- Role: protocol
- Original owner: auto-protocol-dcdf92cd067e
- Waits for user/external condition: False

## Cause

Stanza 12.22.1 browser HMAC sha-512 fails RFC 4231 Test Case 1: wrong 64-byte block selection. SCRAM-SHA-512 derives that hyphenated algorithm; private algorithm mutation/vendor patches are unsupported. Parent cannot attest browser strongest-mechanism compatibility from Node-only success.

## One remediation outcome

One isolated runnable independently reviewed browser-compatible SCRAM-SHA-512 integration uses vetted existing crypto through a supported public mechanism API and validates proof/server-final without vendor/private-field patching or custom primitives.

## Evidence / reproduction

Run the inline diagnostic in state/evidence/S00-003-auto-protocol-dcdf92cd067e.md using accepted Node runtime; sha-512 mismatches fixed RFC/Node digest while sha512 alias and SHA-256/SHA-1 controls match. Source Hmac.js uses alg === sha512 for 128-byte blocks.

The reporting agent must stop now. A new agent implements only S00-019.