Format Wycheproof ECDSA test data

format_ecdsa.py

!/usr/bin/python

import json
import hashlib
import binascii
from pyasn1.codec.der.decoder import decode as der_decoder
from pyasn1.type.univ import Sequence
from pyasn1.type.univ import Integer
from pyasn1.type.namedtype import NamedTypes
from pyasn1.type.namedtype import NamedType

def hash_msg(msg, sha):
    if sha =='SHA-224':
        h = hashlib.sha224()
    elif sha =='SHA-256':
        h = hashlib.sha256()
    elif sha =='SHA-384':
        h = hashlib.sha384()
    elif sha =='SHA-512':
        h = hashlib.sha512()
    else:
        raise Exception('what hash is ' + sha)

    h.update(binascii.unhexlify(msg))
    return h.hexdigest()

class DERSig(Sequence):
    componentType = NamedTypes(
        NamedType('r', Integer()),
        NamedType('s', Integer())
        )

def format_der_sig(sig, sz):

    sig, rest = der_decoder(binascii.unhexlify(sig), asn1Spec=DERSig())
    if len(rest) != 0:
        raise Exception('Bad encoding')

    r = sig['r']
    s = sig['s']

    r_enc = hex(r)[2:]
    s_enc = hex(s)[2:]

    r_padding = "0" * (2*sz - len(r_enc))
    s_padding = "0" * (2*sz - len(s_enc))

    return (r_padding + r_enc + s_padding + s_enc)

last_group = None
last_msg = None
last_hash = None
last_valid = None
def format_test(test):
    #print(test)
    wx = int(test['key']['wx'], 16)
    wy = int(test['key']['wy'], 16)
    sha = test['sha']
    group = test['key']['curve']
    sz = int(test['key']['keySize']) // 8

    group = group.replace('brainpoolP', 'brainpool')

    global last_group
    global last_msg
    global last_hash
    global last_valid

    if last_group != group:
        print("Group = %s" %  group)
        last_group = group

    if last_hash != sha:
        print("Hash = %s\n" % (sha))
        last_hash = sha

    print("Px = 0x%x" % wx)
    print("Py = 0x%x" % wy)

    for t in test['tests']:
        msg = t['msg']
        comment = t['comment']
        sig = t['sig']
        tcid = int(t['tcId'])
        valid = t['result'] == 'valid'

        print("# Test %d (%s)" %( tcid, comment))

        if msg != last_msg:
            print("Msg = %s" % msg)
            last_msg = msg

        if valid != last_valid:
            print("Valid = %d" % (valid))
            last_valid = valid
        print("Signature = %s" % sig)
        print()

def format_vec(vec):
    blob = json.loads(open(vec).read())

    for test in blob['testGroups']:
        format_test(test)
vecs = [
    'ecdsa_brainpoolP224r1_sha224_test.json',
    'ecdsa_brainpoolP256r1_sha256_test.json',
    'ecdsa_brainpoolP320r1_sha384_test.json',
    'ecdsa_brainpoolP384r1_sha384_test.json',
    'ecdsa_brainpoolP512r1_sha512_test.json',
    'ecdsa_secp224r1_sha224_test.json',
    'ecdsa_secp224r1_sha256_test.json',
    'ecdsa_secp256k1_sha256_test.json',
    'ecdsa_secp256r1_sha256_test.json',
    'ecdsa_secp384r1_sha384_test.json',
    'ecdsa_secp384r1_sha512_test.json',
    'ecdsa_secp521r1_sha512_test.json',
]

for vec in vecs:
    format_vec(vec)