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: / usr / share / doc / python2-cryptography-1.7.2 / docs / development / custom-vectors / seed /
Filename : generate_seed.py
back
import binascii

from cryptography.hazmat.backends.openssl.backend import backend
from cryptography.hazmat.primitives.ciphers import algorithms, base, modes


def encrypt(mode, key, iv, plaintext):
    cipher = base.Cipher(
        algorithms.SEED(binascii.unhexlify(key)),
        mode(binascii.unhexlify(iv)),
        backend
    )
    encryptor = cipher.encryptor()
    ct = encryptor.update(binascii.unhexlify(plaintext))
    ct += encryptor.finalize()
    return binascii.hexlify(ct)


def build_vectors(mode, filename):
    with open(filename, "r") as f:
        vector_file = f.read().splitlines()

    count = 0
    output = []
    key = None
    iv = None
    plaintext = None
    for line in vector_file:
        line = line.strip()
        if line.startswith("KEY"):
            if count != 0:
                output.append("CIPHERTEXT = {0}".format(
                    encrypt(mode, key, iv, plaintext))
                )
            output.append("\nCOUNT = {0}".format(count))
            count += 1
            name, key = line.split(" = ")
            output.append("KEY = {0}".format(key))
        elif line.startswith("IV"):
            name, iv = line.split(" = ")
            output.append("IV = {0}".format(iv))
        elif line.startswith("PLAINTEXT"):
            name, plaintext = line.split(" = ")
            output.append("PLAINTEXT = {0}".format(plaintext))

    output.append("CIPHERTEXT = {0}".format(encrypt(mode, key, iv, plaintext)))
    return "\n".join(output)


def write_file(data, filename):
    with open(filename, "w") as f:
        f.write(data)


OFB_PATH = "vectors/cryptography_vectors/ciphers/AES/OFB/OFBMMT128.rsp"
write_file(build_vectors(modes.OFB, OFB_PATH), "seed-ofb.txt")
CFB_PATH = "vectors/cryptography_vectors/ciphers/AES/CFB/CFB128MMT128.rsp"
write_file(build_vectors(modes.CFB, CFB_PATH), "seed-cfb.txt")