pyDes.py

# ############################################################################
# Documentation				    #
#############################################################################

# Author:   Todd Whiteman
# Date:     7th May, 2003
# Verion:   1.1
# Homepage: http://home.pacific.net.au/~twhitema/des.html
#
# Modifications to 3des CBC code by Matt Johnston 2004 <matt at ucc asn au>
#
# This algorithm is a pure python implementation of the DES algorithm.
# It is in pure python to avoid portability issues, since most DES 
# implementations are programmed in C (for performance reasons).
#
# Triple DES class is also implemented, utilising the DES base. Triple DES
# is either DES-EDE3 with a 24 byte key, or DES-EDE2 with a 16 byte key.
#
# See the README.txt that should come with this python module for the
# implementation methods used.

"""A pure python implementation of the DES and TRIPLE DES encryption algorithms

pyDes.des(key, [mode], [IV])
pyDes.triple_des(key, [mode], [IV])

key  -> String containing the encryption key. 8 bytes for DES, 16 or 24 bytes
	for Triple DES
mode -> Optional argument for encryption type, can be either
        pyDes.ECB (Electronic Code Book) or pyDes.CBC (Cypher Block Chaining)
IV   -> Optional argument, must be supplied if using CBC mode. Must be 8 bytes


Example:
from pyDes import *

data = "Please encrypt my string"
k = des("DESCRYPT", " ", CBC, "\0\0\0\0\0\0\0\0")
d = k.encrypt(data)
print "Encypted string: " + d
print "Decypted string: " + k.decrypt(d)

See the module source (pyDes.py) for more examples of use.
You can slo run the pyDes.py file without and arguments to see a simple test.

Note: This code was not written for high-end systems needing a fast
      implementation, but rather a handy portable solution with small usage.

"""


# Modes of crypting / cyphering
ECB = 0
CBC = 1


#############################################################################
# 				    DES					    #
#############################################################################
class des:
    """DES encryption/decrytpion class

	Supports ECB (Electronic Code Book) and CBC (Cypher Block Chaining) modes.

	pyDes.des(key,[mode], [IV])

	key  -> The encryption key string, must be exactly 8 bytes
	mode -> Optional argument for encryption type, can be either pyDes.ECB
		(Electronic Code Book), pyDes.CBC (Cypher Block Chaining)
	IV   -> Optional string argument, must be supplied if using CBC mode.
		Must be 8 bytes in length.
	"""


    # Permutation and translation tables for DES
    __pc1 = [56, 48, 40, 32, 24, 16, 8,
             0, 57, 49, 41, 33, 25, 17,
             9, 1, 58, 50, 42, 34, 26,
             18, 10, 2, 59, 51, 43, 35,
             62, 54, 46, 38, 30, 22, 14,
             6, 61, 53, 45, 37, 29, 21,
             13, 5, 60, 52, 44, 36, 28,
             20, 12, 4, 27, 19, 11, 3
    ]

    # number left rotations of pc1
    __left_rotations = [
        1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
    ]

    # permuted choice key (table 2)
    __pc2 = [
        13, 16, 10, 23, 0, 4,
        2, 27, 14, 5, 20, 9,
        22, 18, 11, 3, 25, 7,
        15, 6, 26, 19, 12, 1,
        40, 51, 30, 36, 46, 54,
        29, 39, 50, 44, 32, 47,
        43, 48, 38, 55, 33, 52,
        45, 41, 49, 35, 28, 31
    ]

    # initial permutation IP
    __ip = [57, 49, 41, 33, 25, 17, 9, 1,
            59, 51, 43, 35, 27, 19, 11, 3,
            61, 53, 45, 37, 29, 21, 13, 5,
            63, 55, 47, 39, 31, 23, 15, 7,
            56, 48, 40, 32, 24, 16, 8, 0,
            58, 50, 42, 34, 26, 18, 10, 2,
            60, 52, 44, 36, 28, 20, 12, 4,
            62, 54, 46, 38, 30, 22, 14, 6
    ]

    # Expansion table for turning 32 bit blocks into 48 bits
    __expansion_table = [
        31, 0, 1, 2, 3, 4,
        3, 4, 5, 6, 7, 8,
        7, 8, 9, 10, 11, 12,
        11, 12, 13, 14, 15, 16,
        15, 16, 17, 18, 19, 20,
        19, 20, 21, 22, 23, 24,
        23, 24, 25, 26, 27, 28,
        27, 28, 29, 30, 31, 0
    ]

    # The (in)famous S-boxes
    __sbox = [  # S1
                [14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
                 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
                 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
                 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13],  # S2
                [15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
                 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
                 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
                 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9],  # S3
                [10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
                 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
                 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
                 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12],  # S4
                [7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
                 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
                 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
                 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14],  # S5
                [2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
                 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
                 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
                 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3],  # S6
                [12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
                 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
                 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
                 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13],  # S7
                [4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
                 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
                 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
                 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12],  # S8
                [13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
                 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
                 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
                 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11],
    ]


    # 32-bit permutation function P used on the output of the S-boxes
    __p = [
        15, 6, 19, 20, 28, 11,
        27, 16, 0, 14, 22, 25,
        4, 17, 30, 9, 1, 7,
        23, 13, 31, 26, 2, 8,
        18, 12, 29, 5, 21, 10,
        3, 24
    ]

    # final permutation IP^-1
    __fp = [
        39, 7, 47, 15, 55, 23, 63, 31,
        38, 6, 46, 14, 54, 22, 62, 30,
        37, 5, 45, 13, 53, 21, 61, 29,
        36, 4, 44, 12, 52, 20, 60, 28,
        35, 3, 43, 11, 51, 19, 59, 27,
        34, 2, 42, 10, 50, 18, 58, 26,
        33, 1, 41, 9, 49, 17, 57, 25,
        32, 0, 40, 8, 48, 16, 56, 24
    ]

    # Type of crypting being done
    ENCRYPT = 0x00
    DECRYPT = 0x01

    # Initialisation
    def __init__(self, key, mode=ECB, IV=None):
        if len(key) != 8:
            raise ValueError("Invalid DES key size. Key must be exactly 8 bytes long.")
        self.block_size = 8
        self.key_size = 8
        self.__padding = ''

        # Set the passed in variables
        self.setMode(mode)
        if IV:
            self.setIV(IV)

        self.L = []
        self.R = []
        self.Kn = [[0] * 48] * 16  # 16 48-bit keys (K1 - K16)
        self.final = []

        self.setKey(key)


    def getKey(self):
        """getKey() -> string"""
        return self.__key

    def setKey(self, key):
        """Will set the crypting key for this object. Must be 8 bytes."""
        self.__key = key
        self.__create_sub_keys()

    def getMode(self):
        """getMode() -> pyDes.ECB or pyDes.CBC"""
        return self.__mode

    def setMode(self, mode):
        """Sets the type of crypting mode, pyDes.ECB or pyDes.CBC"""
        self.__mode = mode

    def getIV(self):
        """getIV() -> string"""
        return self.__iv

    def setIV(self, IV):
        """Will set the Initial Value, used in conjunction with CBC mode"""
        if not IV or len(IV) != self.block_size:
            raise ValueError("Invalid Initial Value (IV), must be a multiple of " + str(self.block_size) + " bytes")
        self.__iv = IV

    def getPadding(self):
        """getPadding() -> string of length 1. Padding character."""
        return self.__padding

    def __String_to_BitList(self, data):
        """Turn the string data, into a list of bits (1, 0)'s"""
        l = len(data) * 8
        result = [0] * l
        pos = 0
        for c in data:
            i = 7
            ch = ord(c)
            while i >= 0:
                if ch & (1 << i) != 0:
                    result[pos] = 1
                else:
                    result[pos] = 0
                pos += 1
                i -= 1

        return result

    def __BitList_to_String(self, data):
        """Turn the list of bits -> data, into a string"""
        result = ''
        pos = 0
        c = 0
        while pos < len(data):
            c += data[pos] << (7 - (pos % 8))
            if (pos % 8) == 7:
                result += chr(c)
                c = 0
            pos += 1

        return result

    def __permutate(self, table, block):
        """Permutate this block with the specified table"""
        return map(lambda x: block[x], table)

    # Transform the secret key, so that it is ready for data processing
    # Create the 16 subkeys, K[1] - K[16]
    def __create_sub_keys(self):
        """Create the 16 subkeys K[1] to K[16] from the given key"""
        key = self.__permutate(des.__pc1, self.__String_to_BitList(self.getKey()))
        i = 0
        # Split into Left and Right sections
        self.L = key[:28]
        self.R = key[28:]
        while i < 16:
            j = 0
            # Perform circular left shifts
            while j < des.__left_rotations[i]:
                self.L.append(self.L[0])
                del self.L[0]

                self.R.append(self.R[0])
                del self.R[0]

                j += 1

            # Create one of the 16 subkeys through pc2 permutation
            self.Kn[i] = self.__permutate(des.__pc2, self.L + self.R)

            i += 1

    # Main part of the encryption algorithm, the number cruncher :)
    def __des_crypt(self, block, crypt_type):
        """Crypt the block of data through DES bit-manipulation"""
        block = self.__permutate(des.__ip, block)
        self.L = block[:32]
        self.R = block[32:]

        # Encryption starts from Kn[1] through to Kn[16]
        if crypt_type == des.ENCRYPT:
            iteration = 0
            iteration_adjustment = 1
        # Decryption starts from Kn[16] down to Kn[1]
        else:
            iteration = 15
            iteration_adjustment = -1

        i = 0
        while i < 16:
            # Make a copy of R[i-1], this will later become L[i]
            tempR = self.R[:]

            # Permutate R[i - 1] to start creating R[i]
            self.R = self.__permutate(des.__expansion_table, self.R)

            # Exclusive or R[i - 1] with K[i], create B[1] to B[8] whilst here
            self.R = map(lambda x, y: x ^ y, self.R, self.Kn[iteration])
            B = [self.R[:6], self.R[6:12], self.R[12:18], self.R[18:24], self.R[24:30], self.R[30:36], self.R[36:42],
                 self.R[42:]]
            # Optimization: Replaced below commented code with above
            #j = 0
            #B = []
            #while j < len(self.R):
            #	self.R[j] = self.R[j] ^ self.Kn[iteration][j]
            #	j += 1
            #	if j % 6 == 0:
            #		B.append(self.R[j-6:j])

            # Permutate B[1] to B[8] using the S-Boxes
            j = 0
            Bn = [0] * 32
            pos = 0
            while j < 8:
                # Work out the offsets
                m = (B[j][0] << 1) + B[j][5]
                n = (B[j][1] << 3) + (B[j][2] << 2) + (B[j][3] << 1) + B[j][4]

                # Find the permutation value
                v = des.__sbox[j][(m << 4) + n]

                # Turn value into bits, add it to result: Bn
                Bn[pos] = (v & 8) >> 3
                Bn[pos + 1] = (v & 4) >> 2
                Bn[pos + 2] = (v & 2) >> 1
                Bn[pos + 3] = v & 1

                pos += 4
                j += 1

            # Permutate the concatination of B[1] to B[8] (Bn)
            self.R = self.__permutate(des.__p, Bn)

            # Xor with L[i - 1]
            self.R = map(lambda x, y: x ^ y, self.R, self.L)
            # Optimization: This now replaces the below commented code
            #j = 0
            #while j < len(self.R):
            #	self.R[j] = self.R[j] ^ self.L[j]
            #	j += 1

            # L[i] becomes R[i - 1]
            self.L = tempR

            i += 1
            iteration += iteration_adjustment

        # Final permutation of R[16]L[16]
        self.final = self.__permutate(des.__fp, self.R + self.L)
        return self.final


    # Data to be encrypted/decrypted
    def crypt(self, data, crypt_type):
        """Crypt the data in blocks, running it through des_crypt()"""

        # Error check the data
        if not data:
            return ''
        if len(data) % self.block_size != 0:
            if crypt_type == des.DECRYPT:  # Decryption must work on 8 byte blocks
                raise ValueError(
                    "Invalid data length, data must be a multiple of " + str(self.block_size) + " bytes\n.")
            if not self.getPadding():
                raise ValueError("Invalid data length, data must be a multiple of " + str(
                    self.block_size) + " bytes\n. Try setting the optional padding character")
            else:
                data += (self.block_size - (len(data) % self.block_size)) * self.getPadding()
            # print "Len of data: %f" % (len(data) / self.block_size)

        if self.getMode() == CBC:
            if self.getIV():
                iv = self.__String_to_BitList(self.getIV())
            else:
                raise ValueError("For CBC mode, you must supply the Initial Value (IV) for ciphering")

        # Split the data into blocks, crypting each one seperately
        i = 0
        dict = {}
        result = []
        #cached = 0
        #lines = 0
        while i < len(data):
            # Test code for caching encryption results
            #lines += 1
            #if dict.has_key(data[i:i+8]):
            #print "Cached result for: %s" % data[i:i+8]
            #	cached += 1
            #	result.append(dict[data[i:i+8]])
            #	i += 8
            #	continue

            block = self.__String_to_BitList(data[i:i + 8])

            # Xor with IV if using CBC mode
            if self.getMode() == CBC:
                if crypt_type == des.ENCRYPT:
                    block = map(lambda x, y: x ^ y, block, iv)
                #j = 0
                #while j < len(block):
                #	block[j] = block[j] ^ iv[j]
                #	j += 1

                processed_block = self.__des_crypt(block, crypt_type)

                if crypt_type == des.DECRYPT:
                    processed_block = map(lambda x, y: x ^ y, processed_block, iv)
                    #j = 0
                    #while j < len(processed_block):
                    #	processed_block[j] = processed_block[j] ^ iv[j]
                    #	j += 1
                    iv = block
                else:
                    iv = processed_block
            else:
                processed_block = self.__des_crypt(block, crypt_type)


            # Add the resulting crypted block to our list
            #d = self.__BitList_to_String(processed_block)
            #result.append(d)
            result.append(self.__BitList_to_String(processed_block))
            #dict[data[i:i+8]] = d
            i += 8

        # print "Lines: %d, cached: %d" % (lines, cached)

        # Remove the padding from the last block
        if crypt_type == des.DECRYPT and self.getPadding():
            #print "Removing decrypt pad"
            s = result[-1]
            while s[-1] == self.getPadding():
                s = s[:-1]
            result[-1] = s

        # Return the full crypted string
        return ''.join(result)

    def encrypt(self, data, pad=''):
        """encrypt(data, [pad]) -> string

		data : String to be encrypted
		pad  : Optional argument for encryption padding. Must only be one byte

		The data must be a multiple of 8 bytes and will be encrypted
		with the already specified key. Data does not have to be a
		multiple of 8 bytes if the padding character is supplied, the
		data will then be padded to a multiple of 8 bytes with this
		pad character.
		"""
        self.__padding = pad
        return self.crypt(data, des.ENCRYPT)

    def decrypt(self, data, pad=''):
        """decrypt(data, [pad]) -> string

		data : String to be encrypted
		pad  : Optional argument for decryption padding. Must only be one byte

		The data must be a multiple of 8 bytes and will be decrypted
		with the already specified key. If the optional padding character
		is supplied, then the un-encypted data will have the padding characters
		removed from the end of the string. This pad removal only occurs on the
		last 8 bytes of the data (last data block).
		"""
        self.__padding = pad
        return self.crypt(data, des.DECRYPT)


#############################################################################
# 				Triple DES				    #
#############################################################################
class triple_des:
    """Triple DES encryption/decrytpion class

	This algorithm uses the DES-EDE3 (when a 24 byte key is supplied) or
	the DES-EDE2 (when a 16 byte key is supplied) encryption methods.
	Supports ECB (Electronic Code Book) and CBC (Cypher Block Chaining) modes.

	pyDes.des(key, [mode], [IV])

	key  -> The encryption key string, must be either 16 or 24 bytes long
	mode -> Optional argument for encryption type, can be either pyDes.ECB
		(Electronic Code Book), pyDes.CBC (Cypher Block Chaining)
	IV   -> Optional string argument, must be supplied if using CBC mode.
		Must be 8 bytes in length.
	"""

    def __init__(self, key, mode=ECB, IV=None):
        self.block_size = 8
        self.setMode(mode)
        self.__padding = ''
        self.__iv = IV
        self.setKey(key)

    def getKey(self):
        """getKey() -> string"""
        return self.__key

    def setKey(self, key):
        """Will set the crypting key for this object. Either 16 or 24 bytes long."""
        self.key_size = 24  # Use DES-EDE3 mode
        if len(key) != self.key_size:
            if len(key) == 16:  # Use DES-EDE2 mode
                self.key_size = 16
            else:
                raise ValueError("Invalid triple DES key size. Key must be either 16 or 24 bytes long")
        if self.getMode() == CBC and (not self.getIV() or len(self.getIV()) != self.block_size):
            raise ValueError("Invalid IV, must be 8 bytes in length")  ## TODO: Check this
        # modes get handled later, since CBC goes on top of the triple-des
        self.__key1 = des(key[:8])
        self.__key2 = des(key[8:16])
        if self.key_size == 16:
            self.__key3 = self.__key1
        else:
            self.__key3 = des(key[16:])
        self.__key = key

    def getMode(self):
        """getMode() -> pyDes.ECB or pyDes.CBC"""
        return self.__mode

    def setMode(self, mode):
        """Sets the type of crypting mode, pyDes.ECB or pyDes.CBC"""
        self.__mode = mode

    def getIV(self):
        """getIV() -> string"""
        return self.__iv

    def setIV(self, IV):
        """Will set the Initial Value, used in conjunction with CBC mode"""
        self.__iv = IV

    def xorstr(self, x, y):
        """Returns the bitwise xor of the bytes in two strings"""
        if len(x) != len(y):
            raise "string lengths differ %d %d" % (len(x), len(y))

        ret = ''
        for i in range(len(x)):
            ret += chr(ord(x[i]) ^ ord(y[i]))

        return ret

    def encrypt(self, data, pad=''):
        """encrypt(data, [pad]) -> string

		data : String to be encrypted
		pad  : Optional argument for encryption padding. Must only be one byte

		The data must be a multiple of 8 bytes and will be encrypted
		with the already specified key. Data does not have to be a
		multiple of 8 bytes if the padding character is supplied, the
		data will then be padded to a multiple of 8 bytes with this
		pad character.
		"""
        if self.getMode() == ECB:
            # simple
            data = self.__key1.encrypt(data, pad)
            data = self.__key2.decrypt(data)
            return self.__key3.encrypt(data)

        if self.getMode() == CBC:
            raise "This code hasn't been tested yet"
            if len(data) % self.block_size != 0:
                raise "CBC mode needs datalen to be a multiple of blocksize (ignoring padding for now)"

            # simple
            lastblock = self.getIV()
            retdata = ''
            for i in range(0, len(data), self.block_size):
                thisblock = data[i:i + self.block_size]
                # the XOR for CBC
                thisblock = self.xorstr(lastblock, thisblock)
                thisblock = self.__key1.encrypt(thisblock)
                thisblock = self.__key2.decrypt(thisblock)
                lastblock = self.__key3.encrypt(thisblock)
                retdata += lastblock
            return retdata

        raise "Not reached"

    def decrypt(self, data, pad=''):
        """decrypt(data, [pad]) -> string

		data : String to be encrypted
		pad  : Optional argument for decryption padding. Must only be one byte

		The data must be a multiple of 8 bytes and will be decrypted
		with the already specified key. If the optional padding character
		is supplied, then the un-encypted data will have the padding characters
		removed from the end of the string. This pad removal only occurs on the
		last 8 bytes of the data (last data block).
		"""
        if self.getMode() == ECB:
            # simple
            data = self.__key3.decrypt(data)
            data = self.__key2.encrypt(data)
            return self.__key1.decrypt(data, pad)

        if self.getMode() == CBC:
            if len(data) % self.block_size != 0:
                raise "Can only decrypt multiples of blocksize"

            lastblock = self.getIV()
            retdata = ''
            for i in range(0, len(data), self.block_size):
                # can I arrange this better? probably...
                cipherchunk = data[i:i + self.block_size]
                thisblock = self.__key3.decrypt(cipherchunk)
                thisblock = self.__key2.encrypt(thisblock)
                thisblock = self.__key1.decrypt(thisblock)
                retdata += self.xorstr(lastblock, thisblock)
                lastblock = cipherchunk
            return retdata

        raise "Not reached"


#############################################################################
# 				Examples				    #
#############################################################################
def example_triple_des():
    from time import time

    # Utility module
    from binascii import unhexlify as unhex

    # example shows triple-des encryption using the des class
    # print "Example of triple DES encryption in default ECB mode (DES-EDE3)\n"

    # print "Triple des using the des class (3 times)"
    t = time()
    k1 = des(unhex("133457799BBCDFF1"))
    k2 = des(unhex("1122334455667788"))
    k3 = des(unhex("77661100DD223311"))
    d = "Triple DES test string, to be encrypted and decrypted..."
    # print "Key1:      %s" % k1.getKey()
    # print "Key2:      %s" % k2.getKey()
    # print "Key3:      %s" % k3.getKey()
    # print "Data:      %s" % d

    e1 = k1.encrypt(d)
    e2 = k2.decrypt(e1)
    e3 = k3.encrypt(e2)
    # print "Encrypted: " + e3

    d3 = k3.decrypt(e3)
    d2 = k2.encrypt(d3)
    d1 = k1.decrypt(d2)
    # print "Decrypted: " + d1
    # print "DES time taken: %f (%d crypt operations)" % (time() - t, 6 * (len(d) / 8))
    # print ""

    # Example below uses the triple-des class to achieve the same as above
    # print "Now using triple des class"
    t = time()
    t1 = triple_des(unhex("133457799BBCDFF1112233445566778877661100DD223311"))
    # print "Key:       %s" % t1.getKey()
    # print "Data:      %s" % d

    td1 = t1.encrypt(d)
    # print "Encrypted: " + td1

    td2 = t1.decrypt(td1)
    # print "Decrypted: " + td2

    # print "Triple DES time taken: %f (%d crypt operations)" % (time() - t, 6 * (len(d) / 8))


def example_des():
    from time import time

    # example of DES encrypting in CBC mode with the IV of "\0\0\0\0\0\0\0\0"
    # print "Example of DES encryption using CBC mode\n"
    t = time()
    k = des("DESCRYPT", CBC, "\0\0\0\0\0\0\0\0")
    data = "DES encryption algorithm"
    # print "Key      : " + k.getKey()
    # print "Data     : " + data

    d = k.encrypt(data)
    # print "Encrypted: " + d

    d = k.decrypt(d)
    # print "Decrypted: " + d
    # print "DES time taken: %f (6 crypt operations)" % (time() - t)
    # print ""


def __test__():
    example_des()
    example_triple_des()


def __fulltest__():
    # This should not produce any unexpected errors or exceptions
    from binascii import unhexlify as unhex
    from binascii import hexlify as dohex

    __test__()
    # print ""

    k = des("\0\0\0\0\0\0\0\0", CBC, "\0\0\0\0\0\0\0\0")
    d = k.encrypt("DES encryption algorithm")
    if k.decrypt(d) != "DES encryption algorithm":
        print "Test 1 Error: Unencypted data block does not match start data"

    k = des("\0\0\0\0\0\0\0\0", CBC, "\0\0\0\0\0\0\0\0")
    d = k.encrypt("Default string of text", '*')
    if k.decrypt(d, "*") != "Default string of text":
        print "Test 2 Error: Unencypted data block does not match start data"

    k = des("\r\n\tABC\r\n")
    d = k.encrypt("String to Pad", '*')
    if k.decrypt(d) != "String to Pad***":
        print "'%s'" % k.decrypt(d)
        print "Test 3 Error: Unencypted data block does not match start data"

    k = des("\r\n\tABC\r\n")
    d = k.encrypt(unhex("000102030405060708FF8FDCB04080"), unhex("44"))
    if k.decrypt(d, unhex("44")) != unhex("000102030405060708FF8FDCB04080"):
        print "Test 4a Error: Unencypted data block does not match start data"
    if k.decrypt(d) != unhex("000102030405060708FF8FDCB0408044"):
        print "Test 4b Error: Unencypted data block does not match start data"

    k = triple_des("MyDesKey\r\n\tABC\r\n0987*543")
    d = k.encrypt(unhex(
        "000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080"))
    if k.decrypt(d) != unhex(
            "000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080"):
        print "Test 5 Error: Unencypted data block does not match start data"

    k = triple_des("\r\n\tABC\r\n0987*543")
    d = k.encrypt(unhex(
        "000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080"))
    if k.decrypt(d) != unhex(
            "000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080000102030405060708FF8FDCB04080"):
        print "Test 6 Error: Unencypted data block does not match start data"


def __filetest__():
    from time import time

    f = open("pyDes.py", "rb+")
    d = f.read()
    f.close()

    t = time()
    k = des("MyDESKey")

    d = k.encrypt(d, " ")
    f = open("pyDes.py.enc", "wb+")
    f.write(d)
    f.close()

    d = k.decrypt(d, " ")
    f = open("pyDes.py.dec", "wb+")
    f.write(d)
    f.close()
    print "DES file test time: %f" % (time() - t)


def __profile__():
    import profile

    profile.run('__fulltest__()')

#profile.run('__filetest__()')

if __name__ == '__main__':
    __test__()
#__fulltest__()
#__filetest__()
#__profile__()