Phase 1: Setup                 Phase 2: Parse Test Vectors
┌─────────────────┐          ┌─────────────────┐
│ Add Wycheproof  │    →     │ Load JSON file  │
│ as submodule    │          │ Filter by params│
└─────────────────┘          └─────────────────┘
         ↓                            ↓
Phase 4: CI Integration        Phase 3: Write Harness
┌─────────────────┐          ┌─────────────────┐
│ Auto-update     │    ←     │ Test valid &    │
│ test vectors    │          │ invalid cases   │
└─────────────────┘          └─────────────────┘

┣ 📜 README.md       : Project overview
┣ 📂 doc             : Documentation
┣ 📂 java            : Java JCE interface testing harness
┣ 📂 javascript      : JavaScript testing harness
┣ 📂 schemas         : Test vector schemas
┣ 📂 testvectors     : Test vectors
┗ 📂 testvectors_v1  : Updated test vectors (more detailed)

"algorithm"         : The name of the algorithm tested
"schema"            : The JSON schema (found in schemas folder)
"generatorVersion"  : The version number
"numberOfTests"     : The total number of test vectors in this file
"header"            : Detailed description of test vectors
"notes"             : In-depth explanation of flags in test vectors
"testGroups"        : Array of one or multiple test groups

git submodule add https://github.com/C2SP/wycheproof.git

#!/bin/bash

TMP_WYCHEPROOF_FOLDER=".wycheproof/"
TEST_VECTORS=('aes_gcm_test.json' 'aes_eax_test.json')
BASE_URL="https://raw.githubusercontent.com/C2SP/wycheproof/master/testvectors_v1/"

undefined

import json

def load_wycheproof_test_vectors(path: str):
    testVectors = []
    try:
        with open(path, "r") as f:
            wycheproof_json = json.loads(f.read())
    except FileNotFoundError:
        print(f"No Wycheproof file found at: {path}")
        return testVectors

    # Attributes that need hex-to-bytes conversion
    convert_attr = {"key", "aad", "iv", "msg", "ct", "tag"}

    for testGroup in wycheproof_json["testGroups"]:
        # Filter test groups based on implementation constraints
        if testGroup["ivSize"] < 64 or testGroup["ivSize"] > 1024:
            continue

        for tv in testGroup["tests"]:
            # Convert hex strings to bytes
            for attr in convert_attr:
                if attr in tv:
                    tv[attr] = bytes.fromhex(tv[attr])
            testVectors.append(tv)

    return testVectors

const fs = require('fs').promises;

async function loadWycheproofTestVectors(path) {
  const tests = [];

  try {
    const fileContent = await fs.readFile(path);
    const data = JSON.parse(fileContent.toString());

    data.testGroups.forEach(testGroup => {
      testGroup.tests.forEach(test => {
        // Add shared test group properties to each test
        test['pk'] = testGroup.publicKey.pk;
        tests.push(test);
      });
    });
  } catch (err) {
    console.error('Error reading or parsing file:', err);
    throw err;
  }

  return tests;
}

import pytest
from cryptography.hazmat.primitives.ciphers.aead import AESGCM

tvs = load_wycheproof_test_vectors("wycheproof/testvectors_v1/aes_gcm_test.json")

@pytest.mark.parametrize("tv", tvs, ids=[str(tv['tcId']) for tv in tvs])
def test_encryption(tv):
    try:
        aesgcm = AESGCM(tv['key'])
        ct = aesgcm.encrypt(tv['iv'], tv['msg'], tv['aad'])
    except ValueError as e:
        # Implementation raised error - verify test was expected to fail
        assert tv['result'] != 'valid', tv['comment']
        return

    if tv['result'] == 'valid':
        assert ct[:-16] == tv['ct'], f"Ciphertext mismatch: {tv['comment']}"
        assert ct[-16:] == tv['tag'], f"Tag mismatch: {tv['comment']}"
    elif tv['result'] == 'invalid' or tv['result'] == 'acceptable':
        assert ct[:-16] != tv['ct'] or ct[-16:] != tv['tag']

@pytest.mark.parametrize("tv", tvs, ids=[str(tv['tcId']) for tv in tvs])
def test_decryption(tv):
    try:
        aesgcm = AESGCM(tv['key'])
        decrypted_msg = aesgcm.decrypt(tv['iv'], tv['ct'] + tv['tag'], tv['aad'])
    except ValueError:
        assert tv['result'] != 'valid', tv['comment']
        return
    except InvalidTag:
        assert tv['result'] != 'valid', tv['comment']
        assert 'ModifiedTag' in tv['flags'], f"Expected 'ModifiedTag' flag: {tv['comment']}"
        return

    assert tv['result'] == 'valid', f"No invalid test case should pass: {tv['comment']}"
    assert decrypted_msg == tv['msg'], f"Decryption mismatch: {tv['comment']}"

const assert = require('assert');

function testFactory(tcId, tests) {
  it(`[${tcId + 1}] ${tests[tcId].comment}`, function () {
    const test = tests[tcId];
    const ed25519 = new eddsa('ed25519');
    const key = ed25519.keyFromPublic(toArray(test.pk, 'hex'));

    let sig;
    if (test.result === 'valid') {
      sig = key.verify(test.msg, test.sig);
      assert.equal(sig, true, `[${test.tcId}] ${test.comment}`);
    } else if (test.result === 'invalid') {
      try {
        sig = key.verify(test.msg, test.sig);
      } catch (err) {
        // Point could not be decoded
        sig = false;
      }
      assert.equal(sig, false, `[${test.tcId}] ${test.comment}`);
    }
  });
}

// Generate tests for all test vectors
for (var tcId = 0; tcId < tests.length; tcId++) {
  testFactory(tcId, tests);
}

Valid signature:   ...6a5c51eb6f946b30d
Invalid signature: ...6a5c51eb6f946b30d0000  (should be rejected)

undefined

**Impact:** Can lead to consensus problems when different implementations accept/reject the same signatures.

**Related Wycheproof tests:**
- EdDSA: tcId 37 - "removing 0 byte from signature"
- ECDSA: tcId 06 - "Legacy: ASN encoding of r misses leading 0"

                    ┌─────────────────────┐
                    │    wycheproof       │
                    │   (this skill)      │
                    └──────────┬──────────┘
                               │
           ┌───────────────────┼───────────────────┐
           │                   │                   │
           ▼                   ▼                   ▼
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│  pytest/mocha   │ │ constant-time   │ │   cryptofuzz    │
│ (test framework)│ │   testing       │ │   (fuzzing)     │
└────────┬────────┘ └────────┬────────┘ └────────┬────────┘
         │                   │                   │
         └───────────────────┼───────────────────┘
                             │
                             ▼
              ┌──────────────────────────┐
              │   Technique Skills       │
              │ coverage, harness, PBT   │
              └──────────────────────────┘