Python Crypto.Cipher.AES.MODE_CBC Examples

def decrypt_chunk(chunk, password=None):
    """Decrypts the given encrypted chunk with the given password and returns the decrypted chunk.
       If password is None then saq.ENCRYPTION_PASSWORD is used instead.
       password must be a byte string 32 bytes in length."""

    if password is None:
        password = saq.ENCRYPTION_PASSWORD

    assert isinstance(password, bytes)
    assert len(password) == 32


    _buffer = io.BytesIO(chunk)
    original_size = struct.unpack('<Q', _buffer.read(struct.calcsize('Q')))[0]
    iv = _buffer.read(16)
    chunk = _buffer.read()

    #original_size = struct.unpack('<Q', chunk[0:struct.calcsize('Q')])[0]
    #iv = chunk[struct.calcsize('Q'):struct.calcsize('Q') + 16]
    #chunk = chunk[struct.calcsize('Q') + 16:]
    decryptor = AES.new(password, AES.MODE_CBC, iv)
    result = decryptor.decrypt(chunk)
    return result[:original_size] 

def decrypt_credential(enc, secret=None):
    """
    Decodes data

    :param data: Data to be decoded
    :type data: str
    :returns:  string -- Decoded data
    """
    # pylint: disable=invalid-name,import-error
    import base64
    try:  # The crypto package depends on the library installed (see Wiki)
        from Crypto.Cipher import AES
        from Crypto.Util import Padding
    except ImportError:
        from Cryptodome.Cipher import AES
        from Cryptodome.Util import Padding
    enc = base64.b64decode(enc)
    iv = enc[:AES.block_size]
    cipher = AES.new(secret or get_crypt_key(), AES.MODE_CBC, iv)
    decoded = Padding.unpad(
        padded_data=cipher.decrypt(enc[AES.block_size:]),
        block_size=__BLOCK_SIZE__)
    return decoded 

def encrypt_credential(raw):
    """
    Encodes data

    :param data: Data to be encoded
    :type data: str
    :returns:  string -- Encoded data
    """
    # pylint: disable=invalid-name,import-error
    import base64
    try:  # The crypto package depends on the library installed (see Wiki)
        from Crypto import Random
        from Crypto.Cipher import AES
        from Crypto.Util import Padding
    except ImportError:
        from Cryptodome import Random
        from Cryptodome.Cipher import AES
        from Cryptodome.Util import Padding
    raw = bytes(Padding.pad(data_to_pad=raw.encode('utf-8'), block_size=__BLOCK_SIZE__))
    iv = Random.new().read(AES.block_size)
    cipher = AES.new(get_crypt_key(), AES.MODE_CBC, iv)
    return base64.b64encode(iv + cipher.encrypt(raw)).decode('utf-8') 

def encrypt_file(key, in_filename, out_filename=None, chunksize=64*1024):

    if not out_filename:
        out_filename = in_filename + '.crypt'

    iv = ''.join(chr(random.randint(0, 0xFF)) for i in range(16))
    encryptor = AES.new(key, AES.MODE_CBC, iv)
    filesize = os.path.getsize(in_filename)

    with open(in_filename, 'rb') as infile:
        with open(out_filename, 'wb') as outfile:
            outfile.write(struct.pack('<Q', filesize))
            outfile.write(iv)

            while True:
                chunk = infile.read(chunksize)
                if len(chunk) == 0:
                    break
                elif len(chunk) % 16 != 0:
                    chunk += ' ' * (16 - len(chunk) % 16)

                outfile.write(encryptor.encrypt(chunk)) 

def decrypt_file(key, in_filename, out_filename=None, chunksize=24*1024):

    # Split .crypt extension to restore file format
    if not out_filename:
        out_filename = os.path.splitext(in_filename)[0]

    with open(in_filename, 'rb') as infile:
        origsize = struct.unpack('<Q', infile.read(struct.calcsize('Q')))[0]
        iv = infile.read(16)
        decryptor = AES.new(key, AES.MODE_CBC, iv)

        with open(out_filename, 'wb') as outfile:
            while True:
                chunk = infile.read(chunksize)
                if len(chunk) == 0:
                    break
                outfile.write(decryptor.decrypt(chunk))
	    
	    # Truncate file to original size
            outfile.truncate(origsize) 

def encrypt_chunk(chunk, password=None):
    """Encrypts the given chunk of data and returns the encrypted chunk.
       If password is None then saq.ENCRYPTION_PASSWORD is used instead.
       password must be a byte string 32 bytes in length."""

    if password is None:
        password = saq.ENCRYPTION_PASSWORD

    assert isinstance(password, bytes)
    assert len(password) == 32

    iv = Crypto.Random.OSRNG.posix.new().read(AES.block_size)
    encryptor = AES.new(password, AES.MODE_CBC, iv)

    original_size = len(chunk)

    if len(chunk) % 16 != 0:
        chunk += b' ' * (16 - len(chunk) % 16)

    result = struct.pack('<Q', original_size) + iv + encryptor.encrypt(chunk)
    return result 

def decrypt(key, filename):
	chunksize = 64 * 1024
	outputFile = filename.split('.hacklab')[0]


	with open(filename, 'rb') as infile:
		filesize = int(infile.read(16))
		IV = infile.read(16)
		decryptor = AES.new(key, AES.MODE_CBC, IV)

		with open(outputFile, 'wb') as outfile:

			while True:
				chunk = infile.read(chunksize)

				if len(chunk) == 0:
					break

				chunk = str(decryptor.decrypt(chunk))
				chunk = chunk.replace("0000hack1lab0000", "")
				outfile.write(chunk)
			outfile.truncate(filesize) 

def decrypt_file(key, filename, chunk_size=24*1024):
        
    output_filename = os.path.splitext(filename)[0]

    with open(filename, 'rb') as infile:
        origsize = struct.unpack('<Q', infile.read(struct.calcsize('Q')))[0]
        iv = infile.read(16)
        decryptor = AES.new(key, AES.MODE_CBC, iv)

        with open(output_filename, 'wb') as outfile:
            while True:
                chunk = infile.read(chunk_size)
                if len(chunk) == 0:
                    break
                outfile.write(decryptor.decrypt(chunk))

            outfile.truncate(origsize) 

def decrypt_hash(edata, nlkm, ch, xp = True):
    if xp:
        hmac_md5 = HMAC.new(nlkm, ch)
        rc4key = hmac_md5.digest()

        rc4 = ARC4.new(rc4key)
        data = rc4.encrypt(edata)
    else:
        # based on  Based on code from http://lab.mediaservice.net/code/cachedump.rb
        aes = AES.new(nlkm[16:32], AES.MODE_CBC, ch)
        data = ""
        for i in range(0, len(edata), 16):
            buf = edata[i : i + 16]
            if len(buf) < 16:
                buf += (16 - len(buf)) * "\00"
            data += aes.decrypt(buf)
    return data 

def decrypt_aes(secret, key):
    """
    Based on code from http://lab.mediaservice.net/code/cachedump.rb
    """
    sha = SHA256.new()
    sha.update(key)
    for _i in range(1, 1000 + 1):
        sha.update(secret[28:60])
    aeskey = sha.digest()

    data = ""
    for i in range(60, len(secret), 16):
        aes = AES.new(aeskey, AES.MODE_CBC, '\x00' * 16)
        buf = secret[i : i + 16]
        if len(buf) < 16:
            buf += (16 - len(buf)) * "\00"
        data += aes.decrypt(buf)

    return data 

def aes_decrypt(key, iv, content):
    """
    AES解密
     key,iv使用同一个
    模式cbc
    去填充pkcs7
    :param key:
    :param content:
    :return:
    """
    cipher = AES.new(key, AES.MODE_CBC, iv)
    # base64解码
    encrypt_bytes = base64.b64decode(content)
    # 解密
    decrypt_bytes = cipher.decrypt(encrypt_bytes)
    # 重新编码
    result = str(decrypt_bytes, encoding='utf8')
    # 去除填充内容
    result = pkcs7unpadding(result)
    return result 

def aes_encrypt(key, iv, content):
    """
    AES加密
    key,iv使用同一个
    模式cbc
    填充pkcs7
    :param key: 密钥
    :param content: 加密内容
    :return:
    """
    cipher = AES.new(key, AES.MODE_CBC, iv)
    # 处理明文
    content_padding = pkcs7padding(content)
    # 加密
    encrypt_bytes = cipher.encrypt(bytes(content_padding, encoding='utf-8'))
    # 重新编码
    result = str(base64.b64encode(encrypt_bytes), encoding='utf-8')
    return result 

def encryptBlocks(img):
	cyphertext = []
	for i in range(numBlocks(img)):
		block = img[i*1024:(i+1)*1024]
		cyphertext.append(AES.new(key, AES.MODE_CBC, iv).encrypt(block))
	return b''.join(cyphertext) 

def encrypt(key, filename, ig):
	chunksize = 64*1024
	outputFile = filename+".hacklab"
	size = os.path.getsize(filename) #+ 16
	filesize = str(size).zfill(16)
	IV = Random.new().read(16)
	secret = "0000hack1lab0000"

	encryptor = AES.new(key, AES.MODE_CBC, IV)

	with open(filename, 'rb') as infile:
		with open(outputFile, 'wb') as outfile:
			outfile.write(filesize.encode('utf-8'))
			outfile.write(IV)
			if ig != 'True':
				outfile.write(encryptor.encrypt(secret))

			while True:
				chunk = infile.read(chunksize)

				if len(chunk) == 0:
					break
				elif len(chunk) % 16 != 0:
					chunk += b' ' * (16 - (len(chunk) % 16))

				outfile.write(encryptor.encrypt(chunk)) 

def __init__(self, stream):
            hash_iterations = 1234
            password = "x" * 8
            salt = "\0" * 8
            key, iv = generate_key(password, salt, hash_iterations)
            self.cipher = AES.new(key, AES.MODE_CBC, iv) 

def try_use_pycrypto_or_pycryptodome_module():
    from Crypto.Cipher import AES
    from Crypto.Util import Counter

    def create_aes_ctr(key, iv):
        ctr = Counter.new(128, initial_value=iv)
        return AES.new(key, AES.MODE_CTR, counter=ctr)

    def create_aes_cbc(key, iv):
        return AES.new(key, AES.MODE_CBC, iv)

    return create_aes_ctr, create_aes_cbc 

def decrypt(self, init_vector, ciphertext):
        """Decrypt a ciphertext"""
        cipher = AES.new(self.encryption_key, AES.MODE_CBC, init_vector)
        return Padding.unpad(cipher.decrypt(ciphertext), 16) 

def decryptBlocks(offset, count, outfile):
    for i in range(count):
        block = infile[8+(offset+i)*1024:8+(offset+i+1)*1024]
        outfile.write(AES.new(key, AES.MODE_CBC, iv).decrypt(block)) 

def encrypt(self, plaintext, esn):
        """
        Encrypt the given Plaintext with the encryption key
        :param plaintext:
        :return: Serialized JSON String of the encryption Envelope
        """
        init_vector = get_random_bytes(16)
        cipher = AES.new(self.encryption_key, AES.MODE_CBC, init_vector)
        ciphertext = base64.standard_b64encode(
            cipher.encrypt(Padding.pad(plaintext.encode('utf-8'), 16))).decode('utf-8')
        encryption_envelope = {
            'ciphertext': ciphertext,
            'keyid': '_'.join((esn, str(self.sequence_number))),
            'sha256': 'AA==',
            'iv': base64.standard_b64encode(init_vector).decode('utf-8')
        }
        return json.dumps(encryption_envelope) 

def decrypt_story(data, key, iv):
    akey = b64decode(key)
    aiv = b64decode(iv)
    cipher = AES.new(akey, AES.MODE_CBC, aiv)
    return cipher.decrypt(pkcs5_pad(data)) 

def Encrypt(self, plainText):
        raw = self._pad(plainText)
        iv = Random.new().read(AES.block_size)
        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return base64.b64encode(iv + cipher.encrypt(raw)) 

def decrypt(source_path, target_path=None, password=None):
    """Decrypts the given file at source_path with the given password and saves the results in target_path.
       If target_path is None then output will be sent to standard output.
       If password is None then saq.ENCRYPTION_PASSWORD is used instead.
       password must be a byte string 32 bytes in length."""

    if password is None:
        password = saq.ENCRYPTION_PASSWORD

    assert isinstance(password, bytes)
    assert len(password) == 32

    with open(source_path, 'rb') as fp_in:
        original_size = struct.unpack('<Q', fp_in.read(struct.calcsize('Q')))[0]
        iv = fp_in.read(16)
        decryptor = AES.new(password, AES.MODE_CBC, iv)

        with open(target_path, 'wb') as fp_out:
            while True:
                chunk = fp_in.read(CHUNK_SIZE)
                if len(chunk) == 0:
                    break

                fp_out.write(decryptor.decrypt(chunk))

            fp_out.truncate(original_size) 

def encrypt(source_path, target_path, password=None):
    """Encrypts the given file at source_path with the given password and saves the results in target_path.
       If password is None then saq.ENCRYPTION_PASSWORD is used instead.
       password must be a byte string 32 bytes in length."""

    if password is None:
        password = saq.ENCRYPTION_PASSWORD

    assert isinstance(password, bytes)
    assert len(password) == 32

    iv = Crypto.Random.OSRNG.posix.new().read(AES.block_size)
    encryptor = AES.new(password, AES.MODE_CBC, iv)
    file_size = os.path.getsize(source_path)

    with open(source_path, 'rb') as fp_in:
        with open(target_path, 'wb') as fp_out:
            fp_out.write(struct.pack('<Q', file_size))
            fp_out.write(iv)

            while True:
                chunk = fp_in.read(CHUNK_SIZE)
                if len(chunk) == 0:
                    break
                elif len(chunk) % 16 != 0:
                    chunk += b' ' * (16 - len(chunk) % 16)

                fp_out.write(encryptor.encrypt(chunk)) 

def decrypt_response(des_key, des_iv, aes_key, aes_iv, content):
    """
    AES解密
     key,iv使用同一个
    模式cbc
    去填充pkcs7
    :param key:
    :param content:
    :return:
    """
    aes = AES.new(aes_key, AES.MODE_CBC, aes_iv)
    des = DES.new(des_key, DES.MODE_CBC, des_iv)
    # base64解码
    encrypt_bytes = base64.b64decode(content)
    # 解密
    decrypt_bytes = des.decrypt(encrypt_bytes)
    decrypt_bytes = base64.b64decode(decrypt_bytes)
    #decrypt_bytes = pkcs7padding(decrypt_bytes.decode()).encode("utf8")
    decrypt_bytes = aes.decrypt(decrypt_bytes)

    #base64解码
    decrypt_bytes = base64.b64decode(decrypt_bytes)
    # 重新编码
    result = str(decrypt_bytes, encoding='utf8')
    # 去除填充内容
    #result = pkcs7unpadding(result)
    return result 

def aes_decrypt(key, iv, content):
    """
    AES解密
     key,iv使用同一个
    模式cbc
    去填充pkcs7
    :param key:
    :param content:
    :return:
    """
    cipher = AES.new(key, AES.MODE_CBC, iv)
    # base64解码
    encrypt_bytes = base64.b64decode(content)
    # 解密
    decrypt_bytes = cipher.decrypt(encrypt_bytes)
    # 重新编码
    result = str(decrypt_bytes, encoding='utf8')
    # 去除填充内容
    result = pkcs7unpadding(result)
    return result 

def aes_encrypt(key, iv, content):
    """
    AES加密
    key,iv使用同一个
    模式cbc
    填充pkcs7
    :param key: 密钥
    :param content: 加密内容
    :return:
    """
    cipher = AES.new(key, AES.MODE_CBC, iv)
    # 处理明文
    content_padding = pkcs7padding(content)
    # 加密
    encrypt_bytes = cipher.encrypt(bytes(content_padding, encoding='utf-8'))
    # 重新编码
    result = str(base64.b64encode(encrypt_bytes), encoding='utf-8')
    return result 

def decrypt( self ):
        #print "@ Decrypting %s ..." % self.db_filename

        self.input = open( self.db_filename, 'rb' )

        magic  = self.__read_short()
        sver   = self.__read_byte()
        salt   = self.__read_bytearray()

        # print "  - [PBKDF2] Deriving first key ..."

        skey   = self.__derive( self.password, salt )
        iv     = self.__read_bytearray()
        cipher = AES.new( skey, AES.MODE_CBC, iv )
        salt2  = self.__read_bytearray()
        block  = self.__read_bytearray()
        decr   = cipher.decrypt(block)
        sub_fd = StringIO.StringIO(decr)
        iv2    = self.__read_bytearray( sub_fd )
        pass2  = self.__read_bytearray( sub_fd )
        check  = self.__read_bytearray( sub_fd )

        # print "  - [PBKDF2] Deriving second key ..."

        skey2  = self.__derive( pass2, salt2, 1000 )
        cipher = AES.new( pass2, AES.MODE_CBC, iv2 )
        data   = cipher.decrypt( self.input.read() )

        # print "@ Decompressing ..."
        decompressor = zlib.decompressobj()
        return decompressor.decompress(data) + decompressor.flush() 

def decrypt(encrypted, passphrase):
    encrypted = base64.b64decode(encrypted)
    assert encrypted[0:8] == b"Salted__"
    salt = encrypted[8:16]
    key_iv = bytes_to_key(passphrase, salt, 32+16)
    key = key_iv[:32]
    iv = key_iv[32:]
    aes = AES.new(key, AES.MODE_CBC, iv)
    return unpad(aes.decrypt(encrypted[16:])) 

def get_key():
    """Get current gateway key"""
    cipher = AES.new(config.MIHOME_GATEWAY_PASSWORD, AES.MODE_CBC, IV)
    encrypted = cipher.encrypt(get_store().get('gateway_token'))
    return binascii.hexlify(encrypted) 

def decrypt_data(key, initialization_vector, data):
        """Decrypt data"""
        cipher = AES.new(key, AES.MODE_CBC, initialization_vector)
        return cipher.decrypt(data)