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HARP-COMPLIANCE Specification

Version: 0.2 Draft (Standards-Grade) Status: Draft Specification (Conformance & Interoperability)


HARP-COMPLIANCE defines formal conformance requirements and interoperability testing procedures for:

  • HARP-CORE
  • HARP-PROMPT
  • HARP-SESSION
  • HARP-TRANSPORT
  • HARP-KEYMGMT

This document specifies:

  • Conformance levels
  • Mandatory and optional feature matrices
  • Required test categories
  • Canonicalization validation procedures
  • Signature verification test requirements
  • Replay and idempotency validation
  • Negative test cases
  • Interoperability certification criteria

This document is REQUIRED for vendors claiming HARP compliance.


Implementations MUST declare one of the following:

Implements:

  • HARP-CORE
  • HARP-KEYMGMT

Implements:

  • HARP-CORE
  • HARP-PROMPT
  • HARP-SESSION
  • HARP-TRANSPORT
  • HARP-KEYMGMT

Implements:

  • All above
  • mTLS support
  • Key rotation enforcement
  • Revocation enforcement
  • Rate limiting
  • Audit logging

All compliant implementations MUST pass the following categories.

  • Verify deterministic JSON serialization.
  • Validate exact byte match against official test vectors.
  • Confirm hash consistency across platforms.

Failure condition:

  • Hash mismatch for official test vector.

  • Validate correct Ed25519 verification.
  • Reject modified payload with valid signature.
  • Reject modified signature.
  • Reject signature with wrong public key.

Failure condition:

  • Acceptance of invalid signature.

  • Re-submit identical Decision with same nonce.
  • Re-submit expired Decision.
  • Re-submit Decision with mismatched artifactHash.

Failure condition:

  • Execution allowed under replay conditions.

  • Validate artifact expiration enforcement.
  • Validate Decision expiration enforcement.
  • Validate snapshot expiration if implemented.

Failure condition:

  • Execution after expiration.

  • Re-submit prompt.send with same requestId + hash.
  • Re-submit session.snapshot with identical snapshotId + hash.

Expected behavior:

  • No duplicate processing.
  • Consistent acknowledgement.

Failure condition:

  • Duplicate execution.

  • Reject payload missing required fields.
  • Reject unknown enum values.
  • Reject malformed JSON.

Failure condition:

  • Acceptance of invalid schema input.

  • Validate correct HTTP status mapping.
  • Validate WebSocket framing.
  • Validate TLS enforcement.
  • Validate rejection of plaintext HTTP.

Failure condition:

  • Acceptance over insecure transport.

  • Validate secure key provisioning.
  • Validate key rotation procedure.
  • Validate revocation enforcement.
  • Validate signature rejection after revocation.

Failure condition:

  • Acceptance of revoked key.

Implementations MUST include negative tests for:

  • Truncated JSON
  • Corrupted hash field
  • Corrupted signature field
  • Future timestamp manipulation
  • Invalid algorithm identifiers
  • Oversized payloads

Systems MUST fail closed.


Vendors MUST test interoperability against:

  • At least one independent HARP Enforcer implementation
  • At least one independent Mobile Approver implementation

Test scenarios:

  • Cross-vendor Decision verification
  • Cross-vendor prompt.send handling
  • Cross-vendor session.snapshot validation

Results MUST be documented.


To claim HARP compliance:

  • Publish supported specification versions.
  • Publish supported algorithms.
  • Publish conformance level.
  • Pass official test vectors.
  • Pass negative test cases.
  • Document residual risk acknowledgement.

Certification MAY be:

  • Self-attested
  • Third-party audited
  • Community-reviewed

Implementations MUST:

  • Reject unsupported major versions.
  • Support backward-compatible minor versions where feasible.
  • Log version mismatch errors.

An official test suite SHOULD include:

  • Canonical test vector runner
  • Signature validation harness
  • Replay attack simulator
  • Expiration simulator
  • Schema fuzz tester

Implementations SHOULD integrate these tests in CI pipelines.


Compliant systems MUST log:

  • Signature failures
  • Replay rejections
  • Revocation enforcement
  • Transport security violations

Logs MUST be integrity-protected.


A compliant implementation SHOULD publish:

{ “harpVersion”: “0.2”, “conformanceLevel”: “Enterprise”, “algorithms”: [“Ed25519”, “SHA-256”], “transport”: [“HTTPS”, “WSS”], “mTLS”: true }


Testing does not guarantee absence of vulnerabilities. Operational security and code audits remain REQUIRED.


An implementation is HARP-COMPLIANCE conformant if:

  • It passes all mandatory tests.
  • It enforces fail-closed behavior.
  • It implements required cryptographic primitives.
  • It enforces replay protection.
  • It validates schemas strictly.
  • It enforces TLS.