A draft-cavage hs2019 signature leaves the hash to the key: with an RSA key it is tried with SHA-256, as nearly everyone signs, then with SHA-512, as some do; rsa-sha256 stays SHA-256 only. A Digest of SHA-512= is checked as SHA-256= is. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw