- branch
- Py2 comp.
- changeset 3057
- 10516539f238
- parent 2525
- 8b507a9a2d40
- parent 2997
- 7f0ef975da9e
- child 3058
- 0a02c433f52d

--- a/Utilities/crypto/py3AES.py Tue Oct 15 22:03:54 2013 +0200 +++ b/Utilities/crypto/py3AES.py Fri Oct 18 23:00:41 2013 +0200 @@ -6,7 +6,8 @@ # Copyright (c) 2008 Josh Davis ( http://www.josh-davis.org ), # Alex Martelli ( http://www.aleax.it ) # -# Ported from C code written by Laurent Haan ( http://www.progressive-coding.com ) +# Ported from C code written by Laurent Haan +# ( http://www.progressive-coding.com ) # # Licensed under the Apache License, Version 2.0 # http://www.apache.org/licenses/ @@ -48,10 +49,12 @@ @return stripped data (bytes) """ if len(b) % 16 or not b: - raise ValueError("Data of len {0} can't be PCKS7-padded".format(len(b))) + raise ValueError( + "Data of len {0} can't be PCKS7-padded".format(len(b))) numpads = b[-1] if numpads > 16: - raise ValueError("Data ending with {0} can't be PCKS7-padded".format(b[-1])) + raise ValueError( + "Data ending with {0} can't be PCKS7-padded".format(b[-1])) return b[:-numpads] @@ -166,7 +169,8 @@ """ Private method performing Rijndael's key schedule rotate operation. - Rotate the data word eight bits to the left: eg, rotate(1d2c3a4f) == 2c3a4f1d. + Rotate the data word eight bits to the left: eg, + rotate(1d2c3a4f) == 2c3a4f1d. @param data data of size 4 (bytearray) """ @@ -230,12 +234,14 @@ t = self.__core(t, rconIteration) rconIteration += 1 # For 256-bit keys, we add an extra sbox to the calculation - if size == self.KeySize["SIZE_256"] and ((currentSize % size) == 16): + if size == self.KeySize["SIZE_256"] and \ + ((currentSize % size) == 16): for l in range(4): t[l] = self.__getSBoxValue(t[l]) # We XOR t with the four-byte block 16, 24, 32 bytes before the new - # expanded key. This becomes the next four bytes in the expanded key. + # expanded key. This becomes the next four bytes in the expanded + # key. for m in range(4): expandedKey[currentSize] = \ expandedKey[currentSize - size] ^ t[m] @@ -272,7 +278,8 @@ def __galois_multiplication(self, a, b): """ - Private method to perform a Galois multiplication of 8 bit characters a and b. + Private method to perform a Galois multiplication of 8 bit characters + a and b. @param a first factor (byte) @param b second factor (byte) @@ -293,8 +300,8 @@ def __subBytes(self, state, isInv): """ - Private method to substitute all the values from the state with the value in - the SBox using the state value as index for the SBox. + Private method to substitute all the values from the state with the + value in the SBox using the state value as index for the SBox. @param state state to be worked on (bytearray) @param isInv flag indicating an inverse operation (boolean) @@ -368,7 +375,8 @@ # galois multiplication of 1 column of the 4x4 matrix def __mixColumn(self, column, isInv): """ - Private method to perform a galois multiplication of 1 column the 4x4 matrix. + Private method to perform a galois multiplication of 1 column the + 4x4 matrix. @param column column to be worked on (bytearray) @param isInv flag indicating an inverse operation (boolean) @@ -394,7 +402,8 @@ def __aes_round(self, state, roundKey): """ - Private method to apply the 4 operations of the forward round in sequence. + Private method to apply the 4 operations of the forward round in + sequence. @param state state to be worked on (bytearray) @param roundKey round key to be used (bytearray) @@ -408,7 +417,8 @@ def __aes_invRound(self, state, roundKey): """ - Private method to apply the 4 operations of the inverse round in sequence. + Private method to apply the 4 operations of the inverse round in + sequence. @param state state to be worked on (bytearray) @param roundKey round key to be used (bytearray) @@ -422,15 +432,19 @@ def __aes_main(self, state, expandedKey, nbrRounds): """ - Private method to perform the initial operations, the standard round, and the - final operations of the forward AES, creating a round key for each round. + Private method to do the AES encryption for one round. + + Perform the initial operations, the standard round, and the + final operations of the forward AES, creating a round key for + each round. @param state state to be worked on (bytearray) @param expandedKey expanded key to be used (bytearray) @param nbrRounds number of rounds to be done (integer) @return modified state (bytearray) """ - state = self.__addRoundKey(state, self.__createRoundKey(expandedKey, 0)) + state = self.__addRoundKey( + state, self.__createRoundKey(expandedKey, 0)) i = 1 while i < nbrRounds: state = self.__aes_round( @@ -444,8 +458,11 @@ def __aes_invMain(self, state, expandedKey, nbrRounds): """ - Private method to perform the initial operations, the standard round, and the - final operations of the inverse AES, creating a round key for each round. + Private method to do the inverse AES encryption for one round. + + Perform the initial operations, the standard round, and the + final operations of the inverse AES, creating a round key for + each round. @param state state to be worked on (bytearray) @param expandedKey expanded key to be used (bytearray) @@ -461,13 +478,14 @@ i -= 1 state = self.__shiftRows(state, True) state = self.__subBytes(state, True) - state = self.__addRoundKey(state, self.__createRoundKey(expandedKey, 0)) + state = self.__addRoundKey( + state, self.__createRoundKey(expandedKey, 0)) return state def encrypt(self, iput, key, size): """ - Public method to encrypt a 128 bit input block against the given key of size - specified. + Public method to encrypt a 128 bit input block against the given key + of size specified. @param iput input data (bytearray) @param key key to be used (bytes or bytearray) @@ -522,8 +540,8 @@ # decrypts a 128 bit input block against the given key of size specified def decrypt(self, iput, key, size): """ - Public method to decrypt a 128 bit input block against the given key of size - specified. + Public method to decrypt a 128 bit input block against the given key + of size specified. @param iput input data (bytearray) @param key key to be used (bytes or bytearray) @@ -803,7 +821,8 @@ if mode == AESModeOfOperation.ModeOfOperation["CBC"]: data = append_PKCS7_padding(data) keysize = len(key) - assert keysize in AES.KeySize.values(), 'invalid key size: {0}'.format(keysize) + assert keysize in AES.KeySize.values(), \ + 'invalid key size: {0}'.format(keysize) # create a new iv using random data iv = bytearray([i for i in os.urandom(16)]) moo = AESModeOfOperation() @@ -819,7 +838,8 @@ Module function to decrypt the given data with the given key. @param key key to be used for decryption (bytes) - @param data data to be decrypted (with initialization vector prepended) (bytes) + @param data data to be decrypted (with initialization vector prepended) + (bytes) @param mode mode of operations (0, 1 or 2) @return decrypted data (bytes) @exception ValueError key size is invalid or decrypted data is invalid