`ocra/ocra`

(no submodules)

- ocra.schema — Zod boundary schema for `OcraParams`……

ocra.schema — Zod boundary schema for OcraParams — the runtime parameter bag passed alongside a suite string and a key. Optional fi…
suite — Parse an OCRA suite string into a typed OcraSuite AST per RFC 6287 §6.1. Exposed separately so callers can validate s…
verify-ocra — Constant-time verify of an OCRA response. Recomputes the response under the supplied suite, key, and params, then compa…
ocra.schema — Zod boundary schema for OcraParams……
ocra.schema — Zod boundary schema for OcraParams — the runtime parameter bag passed alongside a suite string and a key. Optional fi…
suite — Parse an OCRA suite string into a typed OcraSuite AST per RFC 6287 §6.1. Exposed separately so callers can validate s…
verify-ocra — Constant-time verify of an OCRA response. Recomputes the response under the supplied suite, key, and params, then compa…
ocra.schema — Zod boundary schema for OcraParams……
ocra.schema — Zod boundary schema for OcraParams — the runtime parameter bag passed alongside a suite string and a key. Optional fi…
suite — Parse an OCRA suite string into a typed OcraSuite AST per RFC 6287 §6.1. Exposed separately so callers can validate s…
verify-ocra — Constant-time verify of an OCRA response. Recomputes the response under the supplied suite, key, and params, then compa…
ocra.schema — Zod boundary schema for OcraParams…
ocra.schema — Zod boundary schema for OcraParams — the runtime parameter bag passed alongside a suite string and a key. Optional fi…
suite — Parse an OCRA suite string into a typed OcraSuite AST per RFC 6287 §6.1. Exposed separately so callers can validate s…
verify-ocra — Constant-time verify of an OCRA response. Recomputes the response under the supplied suite, key, and params, then compa…
ocra.schema — Zod boundary schema for OcraParams — the runtime parameter bag passed alongside a suite string and a key. Optional fi…
suite — Parse an OCRA suite string into a typed OcraSuite AST per RFC 6287 §6.1. Exposed separately so callers can validate s…
verify-ocra — Constant-time verify of an OCRA response. Recomputes the response under the supplied suite, key, and params, then compa…

Purpose

RFC 6287 OCRA — OATH Challenge-Response Algorithm. Supports the full OCRA-1:HOTP-{H}-{N}:[C-]Q{A|N|H}NN[-PSHA{1,256,512}][-Snnn][-T{n}{S|M|H}] suite-string grammar. Validated against RFC 6287 Appendix C.1 reference vectors so call-site implementations have a known-good baseline.

Features

All hash algorithms: SHA-1 / SHA-256 / SHA-512.
Digits 4 / 6 / 7 / 8 (RFC 6287 §6.2 widens HOTP's 6/7/8 to also include 4).
Optional counter (C directive), password hash (PSHA{1,256,512}), session info (Snnn), and timestamp (T{n}{S|M|H}) blocks.
Three challenge formats: QN (decimal), QA (printable ASCII), QH (hex).
Constant-time verify via verifyOcra.

Usage: Basic Example

import { ocra } from "@suaveplan/otp/ocra";

const r = ocra("OCRA-1:HOTP-SHA1-6:QN08", key, { challenge: "12345678" });

Usage: Advanced Example

import { ocra } from "@suaveplan/otp/ocra";

// Counter + password-hashed plus timestamp-bound suite.
const r = ocra("OCRA-1:HOTP-SHA256-8:C-QN08-PSHA256-T1M", key, {
  counter: 17n,
  challenge: "12345678",
  passwordHash: sha256(passwordBytes),
  timestampMs: Date.now(),
});

API Reference

ocra(suite, key, params): string — primary computation API.
buildOcraMessage(parsed, params): Uint8Array — exposed for benchmarks and KAT harnesses that want to inspect the pre-HMAC byte stream.
OcraDigits — alias for the digit literal-union shared with HOTP.

Implementation Notes

The HMAC input layout follows RFC 6287 §5.1 exactly: suite ASCII, NUL separator, then the directive blocks in fixed order (counter, challenge, password hash, session info, timestamp). Each block is omitted if the suite does not declare it; callers supplying an unexpected block are silently ignored — the suite is the source of truth.

4.4 KiB Raw Blame History

ocra/ocra