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✏️ Editing: test_CFB.py

# ===================================================================
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# Copyright (c) 2014, Legrandin <helderijs@gmail.com>
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import unittest
from binascii import unhexlify

from Crypto.SelfTest.loader import load_test_vectors
from Crypto.SelfTest.st_common import list_test_cases
from Crypto.Util.py3compat import tobytes, is_string
from Crypto.Cipher import AES, DES3, DES
from Crypto.Hash import SHAKE128

from Crypto.SelfTest.Cipher.test_CBC import BlockChainingTests

def get_tag_random(tag, length):
    return SHAKE128.new(data=tobytes(tag)).read(length)

class CfbTests(BlockChainingTests):

aes_mode = AES.MODE_CFB
    des3_mode = DES3.MODE_CFB

# Redefine test_unaligned_data_128/64

def test_unaligned_data_128(self):
        plaintexts = [ b"7777777" ] * 100

cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=8)
        ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
        cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=8)
        self.assertEqual(b"".join(ciphertexts), cipher.encrypt(b"".join(plaintexts)))

cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=128)
        ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
        cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=128)
        self.assertEqual(b"".join(ciphertexts), cipher.encrypt(b"".join(plaintexts)))

def test_unaligned_data_64(self):
        plaintexts = [ b"7777777" ] * 100
        cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=8)
        ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
        cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=8)
        self.assertEqual(b"".join(ciphertexts), cipher.encrypt(b"".join(plaintexts)))

cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=64)
        ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
        cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=64)
        self.assertEqual(b"".join(ciphertexts), cipher.encrypt(b"".join(plaintexts)))

# Extra

def test_segment_size_128(self):
        for bits in range(8, 129, 8):
            cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128,
                             segment_size=bits)

for bits in 0, 7, 9, 127, 129:
            self.assertRaises(ValueError, AES.new, self.key_128, AES.MODE_CFB,
                              self.iv_128,
                              segment_size=bits)

def test_segment_size_64(self):
        for bits in range(8, 65, 8):
            cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64,
                              segment_size=bits)

for bits in 0, 7, 9, 63, 65:
            self.assertRaises(ValueError, DES3.new, self.key_192, AES.MODE_CFB,
                              self.iv_64,
                              segment_size=bits)

class NistCfbVectors(unittest.TestCase):

def _do_kat_aes_test(self, file_name, segment_size):

test_vectors = load_test_vectors(("Cipher", "AES"),
                            file_name,
                            "AES CFB%d KAT" % segment_size,
                            { "count" : lambda x: int(x) } )
        if test_vectors is None:
            return

direction = None
        for tv in test_vectors:

# The test vector file contains some directive lines
            if is_string(tv):
                direction = tv
                continue

self.description = tv.desc
            cipher = AES.new(tv.key, AES.MODE_CFB, tv.iv,
                             segment_size=segment_size)
            if direction == "[ENCRYPT]":
                self.assertEqual(cipher.encrypt(tv.plaintext), tv.ciphertext)
            elif direction == "[DECRYPT]":
                self.assertEqual(cipher.decrypt(tv.ciphertext), tv.plaintext)
            else:
                assert False

# See Section 6.4.5 in AESAVS
    def _do_mct_aes_test(self, file_name, segment_size):

test_vectors = load_test_vectors(("Cipher", "AES"),
                            file_name,
                            "AES CFB%d Montecarlo" % segment_size,
                            { "count" : lambda x: int(x) } )
        if test_vectors is None:
            return

assert(segment_size in (8, 128))

direction = None
        for tv in test_vectors:

# The test vector file contains some directive lines
            if is_string(tv):
                direction = tv
                continue

self.description = tv.desc
            cipher = AES.new(tv.key, AES.MODE_CFB, tv.iv,
                             segment_size=segment_size)

def get_input(input_text, output_seq, j):
                # CFB128
                if segment_size == 128:
                    if j >= 2:
                        return output_seq[-2]
                    return [input_text, tv.iv][j]
                # CFB8
                if j == 0:
                    return input_text
                elif j <= 16:
                    return tv.iv[j - 1:j]
                return output_seq[j - 17]

if direction == '[ENCRYPT]':
                cts = []
                for j in range(1000):
                    plaintext = get_input(tv.plaintext, cts, j)
                    cts.append(cipher.encrypt(plaintext))
                self.assertEqual(cts[-1], tv.ciphertext)
            elif direction == '[DECRYPT]':
                pts = []
                for j in range(1000):
                    ciphertext = get_input(tv.ciphertext, pts, j)
                    pts.append(cipher.decrypt(ciphertext))
                self.assertEqual(pts[-1], tv.plaintext)
            else:
                assert False

def _do_tdes_test(self, file_name, segment_size):

test_vectors = load_test_vectors(("Cipher", "TDES"),
                            file_name,
                            "TDES CFB%d KAT" % segment_size,
                            { "count" : lambda x: int(x) } )
        if test_vectors is None:
            return

direction = None
        for tv in test_vectors:

# The test vector file contains some directive lines
            if is_string(tv):
                direction = tv
                continue

self.description = tv.desc
            if hasattr(tv, "keys"):
                cipher = DES.new(tv.keys, DES.MODE_CFB, tv.iv,
                                 segment_size=segment_size)
            else:
                if tv.key1 != tv.key3:
                    key = tv.key1 + tv.key2 + tv.key3  # Option 3
                else:
                    key = tv.key1 + tv.key2            # Option 2
                cipher = DES3.new(key, DES3.MODE_CFB, tv.iv,
                                  segment_size=segment_size)
            if direction == "[ENCRYPT]":
                self.assertEqual(cipher.encrypt(tv.plaintext), tv.ciphertext)
            elif direction == "[DECRYPT]":
                self.assertEqual(cipher.decrypt(tv.ciphertext), tv.plaintext)
            else:
                assert False

# Create one test method per file
nist_aes_kat_mmt_files = (
    # KAT
    "CFB?GFSbox128.rsp",
    "CFB?GFSbox192.rsp",
    "CFB?GFSbox256.rsp",
    "CFB?KeySbox128.rsp",
    "CFB?KeySbox192.rsp",
    "CFB?KeySbox256.rsp",
    "CFB?VarKey128.rsp",
    "CFB?VarKey192.rsp",
    "CFB?VarKey256.rsp",
    "CFB?VarTxt128.rsp",
    "CFB?VarTxt192.rsp",
    "CFB?VarTxt256.rsp",
    # MMT
    "CFB?MMT128.rsp",
    "CFB?MMT192.rsp",
    "CFB?MMT256.rsp",
    )
nist_aes_mct_files = (
    "CFB?MCT128.rsp",
    "CFB?MCT192.rsp",
    "CFB?MCT256.rsp",
    )

for file_gen_name in nist_aes_kat_mmt_files:
    for bits in "8", "128":
        file_name = file_gen_name.replace("?", bits)
        def new_func(self, file_name=file_name, bits=bits):
            self._do_kat_aes_test(file_name, int(bits))
        setattr(NistCfbVectors, "test_AES_" + file_name, new_func)

for file_gen_name in nist_aes_mct_files:
    for bits in "8", "128":
        file_name = file_gen_name.replace("?", bits)
        def new_func(self, file_name=file_name, bits=bits):
            self._do_mct_aes_test(file_name, int(bits))
        setattr(NistCfbVectors, "test_AES_" + file_name, new_func)
del file_name, new_func

nist_tdes_files = (
    "TCFB?MMT2.rsp",    # 2TDES
    "TCFB?MMT3.rsp",    # 3TDES
    "TCFB?invperm.rsp", # Single DES
    "TCFB?permop.rsp",
    "TCFB?subtab.rsp",
    "TCFB?varkey.rsp",
    "TCFB?vartext.rsp",
    )

for file_gen_name in nist_tdes_files:
    for bits in "8", "64":
        file_name = file_gen_name.replace("?", bits)
        def new_func(self, file_name=file_name, bits=bits):
            self._do_tdes_test(file_name, int(bits))
    setattr(NistCfbVectors, "test_TDES_" + file_name, new_func)

# END OF NIST CBC TEST VECTORS

class SP800TestVectors(unittest.TestCase):
    """Class exercising the CFB test vectors found in Section F.3
    of NIST SP 800-3A"""

def test_aes_128_cfb8(self):
        plaintext =     '6bc1bee22e409f96e93d7e117393172aae2d'
        ciphertext =    '3b79424c9c0dd436bace9e0ed4586a4f32b9'
        key =           '2b7e151628aed2a6abf7158809cf4f3c'
        iv =            '000102030405060708090a0b0c0d0e0f'