implementation

Using one key for several purposes quietly couples their security. The scored answer explains extract and expand, shows key separation by context, and says when HKDF is the wrong tool.

URL validation is where string checks fail most visibly. The scored answer parses, resolves and allowlists, then tests the classic bypasses.

Pinning a version is not pinning content. The scored answer verifies every file against a recorded hash, treats unexpected and missing files as failures, and explains where the lockfile's own trust comes from.