diff options
Diffstat (limited to 'frozen_deps/Crypto/Protocol')
| -rw-r--r-- | frozen_deps/Crypto/Protocol/AllOrNothing.py | 320 | ||||
| -rw-r--r-- | frozen_deps/Crypto/Protocol/Chaffing.py | 245 | ||||
| -rw-r--r-- | frozen_deps/Crypto/Protocol/KDF.py | 123 | ||||
| -rw-r--r-- | frozen_deps/Crypto/Protocol/__init__.py | 41 |
4 files changed, 729 insertions, 0 deletions
diff --git a/frozen_deps/Crypto/Protocol/AllOrNothing.py b/frozen_deps/Crypto/Protocol/AllOrNothing.py new file mode 100644 index 0000000..dd20536 --- /dev/null +++ b/frozen_deps/Crypto/Protocol/AllOrNothing.py @@ -0,0 +1,320 @@ +# +# AllOrNothing.py : all-or-nothing package transformations +# +# Part of the Python Cryptography Toolkit +# +# Written by Andrew M. Kuchling and others +# +# =================================================================== +# The contents of this file are dedicated to the public domain. To +# the extent that dedication to the public domain is not available, +# everyone is granted a worldwide, perpetual, royalty-free, +# non-exclusive license to exercise all rights associated with the +# contents of this file for any purpose whatsoever. +# No rights are reserved. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# =================================================================== + +"""This file implements all-or-nothing package transformations. + +An all-or-nothing package transformation is one in which some text is +transformed into message blocks, such that all blocks must be obtained before +the reverse transformation can be applied. Thus, if any blocks are corrupted +or lost, the original message cannot be reproduced. + +An all-or-nothing package transformation is not encryption, although a block +cipher algorithm is used. The encryption key is randomly generated and is +extractable from the message blocks. + +This class implements the All-Or-Nothing package transformation algorithm +described in: + +Ronald L. Rivest. "All-Or-Nothing Encryption and The Package Transform" +http://theory.lcs.mit.edu/~rivest/fusion.pdf + +""" + +__revision__ = "$Id$" + +import operator +import sys +from Crypto.Util.number import bytes_to_long, long_to_bytes +from Crypto.Util.py3compat import * +from functools import reduce + +def isInt(x): + test = 0 + try: + test += x + except TypeError: + return 0 + return 1 + +class AllOrNothing: + """Class implementing the All-or-Nothing package transform. + + Methods for subclassing: + + _inventkey(key_size): + Returns a randomly generated key. Subclasses can use this to + implement better random key generating algorithms. The default + algorithm is probably not very cryptographically secure. + + """ + + def __init__(self, ciphermodule, mode=None, IV=None): + """AllOrNothing(ciphermodule, mode=None, IV=None) + + ciphermodule is a module implementing the cipher algorithm to + use. It must provide the PEP272 interface. + + Note that the encryption key is randomly generated + automatically when needed. Optional arguments mode and IV are + passed directly through to the ciphermodule.new() method; they + are the feedback mode and initialization vector to use. All + three arguments must be the same for the object used to create + the digest, and to undigest'ify the message blocks. + """ + + self.__ciphermodule = ciphermodule + self.__mode = mode + self.__IV = IV + self.__key_size = ciphermodule.key_size + if not isInt(self.__key_size) or self.__key_size==0: + self.__key_size = 16 + + __K0digit = bchr(0x69) + + def digest(self, text): + """digest(text:string) : [string] + + Perform the All-or-Nothing package transform on the given + string. Output is a list of message blocks describing the + transformed text, where each block is a string of bit length equal + to the ciphermodule's block_size. + """ + + # generate a random session key and K0, the key used to encrypt the + # hash blocks. Rivest calls this a fixed, publically-known encryption + # key, but says nothing about the security implications of this key or + # how to choose it. + key = self._inventkey(self.__key_size) + K0 = self.__K0digit * self.__key_size + + # we need two cipher objects here, one that is used to encrypt the + # message blocks and one that is used to encrypt the hashes. The + # former uses the randomly generated key, while the latter uses the + # well-known key. + mcipher = self.__newcipher(key) + hcipher = self.__newcipher(K0) + + # Pad the text so that its length is a multiple of the cipher's + # block_size. Pad with trailing spaces, which will be eliminated in + # the undigest() step. + block_size = self.__ciphermodule.block_size + padbytes = block_size - (len(text) % block_size) + text = text + b(' ') * padbytes + + # Run through the algorithm: + # s: number of message blocks (size of text / block_size) + # input sequence: m1, m2, ... ms + # random key K' (`key' in the code) + # Compute output sequence: m'1, m'2, ... m's' for s' = s + 1 + # Let m'i = mi ^ E(K', i) for i = 1, 2, 3, ..., s + # Let m's' = K' ^ h1 ^ h2 ^ ... hs + # where hi = E(K0, m'i ^ i) for i = 1, 2, ... s + # + # The one complication I add is that the last message block is hard + # coded to the number of padbytes added, so that these can be stripped + # during the undigest() step + s = divmod(len(text), block_size)[0] + blocks = [] + hashes = [] + for i in range(1, s+1): + start = (i-1) * block_size + end = start + block_size + mi = text[start:end] + assert len(mi) == block_size + cipherblock = mcipher.encrypt(long_to_bytes(i, block_size)) + mticki = bytes_to_long(mi) ^ bytes_to_long(cipherblock) + blocks.append(mticki) + # calculate the hash block for this block + hi = hcipher.encrypt(long_to_bytes(mticki ^ i, block_size)) + hashes.append(bytes_to_long(hi)) + + # Add the padbytes length as a message block + i = i + 1 + cipherblock = mcipher.encrypt(long_to_bytes(i, block_size)) + mticki = padbytes ^ bytes_to_long(cipherblock) + blocks.append(mticki) + + # calculate this block's hash + hi = hcipher.encrypt(long_to_bytes(mticki ^ i, block_size)) + hashes.append(bytes_to_long(hi)) + + # Now calculate the last message block of the sequence 1..s'. This + # will contain the random session key XOR'd with all the hash blocks, + # so that for undigest(), once all the hash blocks are calculated, the + # session key can be trivially extracted. Calculating all the hash + # blocks requires that all the message blocks be received, thus the + # All-or-Nothing algorithm succeeds. + mtick_stick = bytes_to_long(key) ^ reduce(operator.xor, hashes) + blocks.append(mtick_stick) + + # we convert the blocks to strings since in Python, byte sequences are + # always represented as strings. This is more consistent with the + # model that encryption and hash algorithms always operate on strings. + return [long_to_bytes(i,self.__ciphermodule.block_size) for i in blocks] + + + def undigest(self, blocks): + """undigest(blocks : [string]) : string + + Perform the reverse package transformation on a list of message + blocks. Note that the ciphermodule used for both transformations + must be the same. blocks is a list of strings of bit length + equal to the ciphermodule's block_size. + """ + + # better have at least 2 blocks, for the padbytes package and the hash + # block accumulator + if len(blocks) < 2: + raise ValueError("List must be at least length 2.") + + # blocks is a list of strings. We need to deal with them as long + # integers + blocks = list(map(bytes_to_long, blocks)) + + # Calculate the well-known key, to which the hash blocks are + # encrypted, and create the hash cipher. + K0 = self.__K0digit * self.__key_size + hcipher = self.__newcipher(K0) + block_size = self.__ciphermodule.block_size + + # Since we have all the blocks (or this method would have been called + # prematurely), we can calculate all the hash blocks. + hashes = [] + for i in range(1, len(blocks)): + mticki = blocks[i-1] ^ i + hi = hcipher.encrypt(long_to_bytes(mticki, block_size)) + hashes.append(bytes_to_long(hi)) + + # now we can calculate K' (key). remember the last block contains + # m's' which we don't include here + key = blocks[-1] ^ reduce(operator.xor, hashes) + + # and now we can create the cipher object + mcipher = self.__newcipher(long_to_bytes(key, self.__key_size)) + + # And we can now decode the original message blocks + parts = [] + for i in range(1, len(blocks)): + cipherblock = mcipher.encrypt(long_to_bytes(i, block_size)) + mi = blocks[i-1] ^ bytes_to_long(cipherblock) + parts.append(mi) + + # The last message block contains the number of pad bytes appended to + # the original text string, such that its length was an even multiple + # of the cipher's block_size. This number should be small enough that + # the conversion from long integer to integer should never overflow + padbytes = int(parts[-1]) + text = b('').join(map(long_to_bytes, parts[:-1])) + return text[:-padbytes] + + def _inventkey(self, key_size): + # Return key_size random bytes + from Crypto import Random + return Random.new().read(key_size) + + def __newcipher(self, key): + if self.__mode is None and self.__IV is None: + return self.__ciphermodule.new(key) + elif self.__IV is None: + return self.__ciphermodule.new(key, self.__mode) + else: + return self.__ciphermodule.new(key, self.__mode, self.__IV) + + + +if __name__ == '__main__': + import sys + import getopt + import base64 + + usagemsg = '''\ +Test module usage: %(program)s [-c cipher] [-l] [-h] + +Where: + --cipher module + -c module + Cipher module to use. Default: %(ciphermodule)s + + --aslong + -l + Print the encoded message blocks as long integers instead of base64 + encoded strings + + --help + -h + Print this help message +''' + + ciphermodule = 'AES' + aslong = 0 + + def usage(code, msg=None): + if msg: + print(msg) + print(usagemsg % {'program': sys.argv[0], + 'ciphermodule': ciphermodule}) + sys.exit(code) + + try: + opts, args = getopt.getopt(sys.argv[1:], + 'c:l', ['cipher=', 'aslong']) + except getopt.error as msg: + usage(1, msg) + + if args: + usage(1, 'Too many arguments') + + for opt, arg in opts: + if opt in ('-h', '--help'): + usage(0) + elif opt in ('-c', '--cipher'): + ciphermodule = arg + elif opt in ('-l', '--aslong'): + aslong = 1 + + # ugly hack to force __import__ to give us the end-path module + module = __import__('Crypto.Cipher.'+ciphermodule, None, None, ['new']) + + x = AllOrNothing(module) + print('Original text:\n==========') + print(__doc__) + print('==========') + msgblocks = x.digest(b(__doc__)) + print('message blocks:') + for i, blk in zip(list(range(len(msgblocks))), msgblocks): + # base64 adds a trailing newline + print(' %3d' % i, end=' ') + if aslong: + print(bytes_to_long(blk)) + else: + print(base64.encodestring(blk)[:-1]) + # + # get a new undigest-only object so there's no leakage + y = AllOrNothing(module) + text = y.undigest(msgblocks) + if text == b(__doc__): + print('They match!') + else: + print('They differ!') diff --git a/frozen_deps/Crypto/Protocol/Chaffing.py b/frozen_deps/Crypto/Protocol/Chaffing.py new file mode 100644 index 0000000..bbfcbda --- /dev/null +++ b/frozen_deps/Crypto/Protocol/Chaffing.py @@ -0,0 +1,245 @@ +# +# Chaffing.py : chaffing & winnowing support +# +# Part of the Python Cryptography Toolkit +# +# Written by Andrew M. Kuchling, Barry A. Warsaw, and others +# +# =================================================================== +# The contents of this file are dedicated to the public domain. To +# the extent that dedication to the public domain is not available, +# everyone is granted a worldwide, perpetual, royalty-free, +# non-exclusive license to exercise all rights associated with the +# contents of this file for any purpose whatsoever. +# No rights are reserved. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# =================================================================== +# +"""This file implements the chaffing algorithm. + +Winnowing and chaffing is a technique for enhancing privacy without requiring +strong encryption. In short, the technique takes a set of authenticated +message blocks (the wheat) and adds a number of chaff blocks which have +randomly chosen data and MAC fields. This means that to an adversary, the +chaff blocks look as valid as the wheat blocks, and so the authentication +would have to be performed on every block. By tailoring the number of chaff +blocks added to the message, the sender can make breaking the message +computationally infeasible. There are many other interesting properties of +the winnow/chaff technique. + +For example, say Alice is sending a message to Bob. She packetizes the +message and performs an all-or-nothing transformation on the packets. Then +she authenticates each packet with a message authentication code (MAC). The +MAC is a hash of the data packet, and there is a secret key which she must +share with Bob (key distribution is an exercise left to the reader). She then +adds a serial number to each packet, and sends the packets to Bob. + +Bob receives the packets, and using the shared secret authentication key, +authenticates the MACs for each packet. Those packets that have bad MACs are +simply discarded. The remainder are sorted by serial number, and passed +through the reverse all-or-nothing transform. The transform means that an +eavesdropper (say Eve) must acquire all the packets before any of the data can +be read. If even one packet is missing, the data is useless. + +There's one twist: by adding chaff packets, Alice and Bob can make Eve's job +much harder, since Eve now has to break the shared secret key, or try every +combination of wheat and chaff packet to read any of the message. The cool +thing is that Bob doesn't need to add any additional code; the chaff packets +are already filtered out because their MACs don't match (in all likelihood -- +since the data and MACs for the chaff packets are randomly chosen it is +possible, but very unlikely that a chaff MAC will match the chaff data). And +Alice need not even be the party adding the chaff! She could be completely +unaware that a third party, say Charles, is adding chaff packets to her +messages as they are transmitted. + +For more information on winnowing and chaffing see this paper: + +Ronald L. Rivest, "Chaffing and Winnowing: Confidentiality without Encryption" +http://theory.lcs.mit.edu/~rivest/chaffing.txt + +""" + +__revision__ = "$Id$" + +from Crypto.Util.number import bytes_to_long + +class Chaff: + """Class implementing the chaff adding algorithm. + + Methods for subclasses: + + _randnum(size): + Returns a randomly generated number with a byte-length equal + to size. Subclasses can use this to implement better random + data and MAC generating algorithms. The default algorithm is + probably not very cryptographically secure. It is most + important that the chaff data does not contain any patterns + that can be used to discern it from wheat data without running + the MAC. + + """ + + def __init__(self, factor=1.0, blocksper=1): + """Chaff(factor:float, blocksper:int) + + factor is the number of message blocks to add chaff to, + expressed as a percentage between 0.0 and 1.0. blocksper is + the number of chaff blocks to include for each block being + chaffed. Thus the defaults add one chaff block to every + message block. By changing the defaults, you can adjust how + computationally difficult it could be for an adversary to + brute-force crack the message. The difficulty is expressed + as: + + pow(blocksper, int(factor * number-of-blocks)) + + For ease of implementation, when factor < 1.0, only the first + int(factor*number-of-blocks) message blocks are chaffed. + """ + + if not (0.0<=factor<=1.0): + raise ValueError("'factor' must be between 0.0 and 1.0") + if blocksper < 0: + raise ValueError("'blocksper' must be zero or more") + + self.__factor = factor + self.__blocksper = blocksper + + + def chaff(self, blocks): + """chaff( [(serial-number:int, data:string, MAC:string)] ) + : [(int, string, string)] + + Add chaff to message blocks. blocks is a list of 3-tuples of the + form (serial-number, data, MAC). + + Chaff is created by choosing a random number of the same + byte-length as data, and another random number of the same + byte-length as MAC. The message block's serial number is + placed on the chaff block and all the packet's chaff blocks + are randomly interspersed with the single wheat block. This + method then returns a list of 3-tuples of the same form. + Chaffed blocks will contain multiple instances of 3-tuples + with the same serial number, but the only way to figure out + which blocks are wheat and which are chaff is to perform the + MAC hash and compare values. + """ + + chaffedblocks = [] + + # count is the number of blocks to add chaff to. blocksper is the + # number of chaff blocks to add per message block that is being + # chaffed. + count = len(blocks) * self.__factor + blocksper = list(range(self.__blocksper)) + for i, wheat in zip(list(range(len(blocks))), blocks): + # it shouldn't matter which of the n blocks we add chaff to, so for + # ease of implementation, we'll just add them to the first count + # blocks + if i < count: + serial, data, mac = wheat + datasize = len(data) + macsize = len(mac) + addwheat = 1 + # add chaff to this block + for j in blocksper: + import sys + chaffdata = self._randnum(datasize) + chaffmac = self._randnum(macsize) + chaff = (serial, chaffdata, chaffmac) + # mix up the order, if the 5th bit is on then put the + # wheat on the list + if addwheat and bytes_to_long(self._randnum(16)) & 0x40: + chaffedblocks.append(wheat) + addwheat = 0 + chaffedblocks.append(chaff) + if addwheat: + chaffedblocks.append(wheat) + else: + # just add the wheat + chaffedblocks.append(wheat) + return chaffedblocks + + def _randnum(self, size): + from Crypto import Random + return Random.new().read(size) + + +if __name__ == '__main__': + text = """\ +We hold these truths to be self-evident, that all men are created equal, that +they are endowed by their Creator with certain unalienable Rights, that among +these are Life, Liberty, and the pursuit of Happiness. That to secure these +rights, Governments are instituted among Men, deriving their just powers from +the consent of the governed. That whenever any Form of Government becomes +destructive of these ends, it is the Right of the People to alter or to +abolish it, and to institute new Government, laying its foundation on such +principles and organizing its powers in such form, as to them shall seem most +likely to effect their Safety and Happiness. +""" + print('Original text:\n==========') + print(text) + print('==========') + + # first transform the text into packets + blocks = [] ; size = 40 + for i in range(0, len(text), size): + blocks.append( text[i:i+size] ) + + # now get MACs for all the text blocks. The key is obvious... + print('Calculating MACs...') + from Crypto.Hash import HMAC, SHA + key = 'Jefferson' + macs = [HMAC.new(key, block, digestmod=SHA).digest() + for block in blocks] + + assert len(blocks) == len(macs) + + # put these into a form acceptable as input to the chaffing procedure + source = [] + m = list(zip(list(range(len(blocks))), blocks, macs)) + print(m) + for i, data, mac in m: + source.append((i, data, mac)) + + # now chaff these + print('Adding chaff...') + c = Chaff(factor=0.5, blocksper=2) + chaffed = c.chaff(source) + + from base64 import encodestring + + # print the chaffed message blocks. meanwhile, separate the wheat from + # the chaff + + wheat = [] + print('chaffed message blocks:') + for i, data, mac in chaffed: + # do the authentication + h = HMAC.new(key, data, digestmod=SHA) + pmac = h.digest() + if pmac == mac: + tag = '-->' + wheat.append(data) + else: + tag = ' ' + # base64 adds a trailing newline + print(tag, '%3d' % i, \ + repr(data), encodestring(mac)[:-1]) + + # now decode the message packets and check it against the original text + print('Undigesting wheat...') + # PY3K: This is meant to be text, do not change to bytes (data) + newtext = "".join(wheat) + if newtext == text: + print('They match!') + else: + print('They differ!') diff --git a/frozen_deps/Crypto/Protocol/KDF.py b/frozen_deps/Crypto/Protocol/KDF.py new file mode 100644 index 0000000..af4e2a6 --- /dev/null +++ b/frozen_deps/Crypto/Protocol/KDF.py @@ -0,0 +1,123 @@ +# +# KDF.py : a collection of Key Derivation Functions +# +# Part of the Python Cryptography Toolkit +# +# =================================================================== +# The contents of this file are dedicated to the public domain. To +# the extent that dedication to the public domain is not available, +# everyone is granted a worldwide, perpetual, royalty-free, +# non-exclusive license to exercise all rights associated with the +# contents of this file for any purpose whatsoever. +# No rights are reserved. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# =================================================================== + +"""This file contains a collection of standard key derivation functions. + +A key derivation function derives one or more secondary secret keys from +one primary secret (a master key or a pass phrase). + +This is typically done to insulate the secondary keys from each other, +to avoid that leakage of a secondary key compromises the security of the +master key, or to thwart attacks on pass phrases (e.g. via rainbow tables). + +:undocumented: __revision__ +""" + +__revision__ = "$Id$" + +import math +import struct + +from Crypto.Util.py3compat import * +from Crypto.Hash import SHA as SHA1, HMAC +from Crypto.Util.strxor import strxor + +def PBKDF1(password, salt, dkLen, count=1000, hashAlgo=None): + """Derive one key from a password (or passphrase). + + This function performs key derivation according an old version of + the PKCS#5 standard (v1.5). + + This algorithm is called ``PBKDF1``. Even though it is still described + in the latest version of the PKCS#5 standard (version 2, or RFC2898), + newer applications should use the more secure and versatile `PBKDF2` instead. + + :Parameters: + password : string + The secret password or pass phrase to generate the key from. + salt : byte string + An 8 byte string to use for better protection from dictionary attacks. + This value does not need to be kept secret, but it should be randomly + chosen for each derivation. + dkLen : integer + The length of the desired key. Default is 16 bytes, suitable for instance for `Crypto.Cipher.AES`. + count : integer + The number of iterations to carry out. It's recommended to use at least 1000. + hashAlgo : module + The hash algorithm to use, as a module or an object from the `Crypto.Hash` package. + The digest length must be no shorter than ``dkLen``. + The default algorithm is `SHA1`. + + :Return: A byte string of length `dkLen` that can be used as key. + """ + if not hashAlgo: + hashAlgo = SHA1 + password = tobytes(password) + pHash = hashAlgo.new(password+salt) + digest = pHash.digest_size + if dkLen>digest: + raise ValueError("Selected hash algorithm has a too short digest (%d bytes)." % digest) + if len(salt)!=8: + raise ValueError("Salt is not 8 bytes long.") + for i in range(count-1): + pHash = pHash.new(pHash.digest()) + return pHash.digest()[:dkLen] + +def PBKDF2(password, salt, dkLen=16, count=1000, prf=None): + """Derive one or more keys from a password (or passphrase). + + This performs key derivation according to the PKCS#5 standard (v2.0), + by means of the ``PBKDF2`` algorithm. + + :Parameters: + password : string + The secret password or pass phrase to generate the key from. + salt : string + A string to use for better protection from dictionary attacks. + This value does not need to be kept secret, but it should be randomly + chosen for each derivation. It is recommended to be at least 8 bytes long. + dkLen : integer + The cumulative length of the desired keys. Default is 16 bytes, suitable for instance for `Crypto.Cipher.AES`. + count : integer + The number of iterations to carry out. It's recommended to use at least 1000. + prf : callable + A pseudorandom function. It must be a function that returns a pseudorandom string + from two parameters: a secret and a salt. If not specified, HMAC-SHA1 is used. + + :Return: A byte string of length `dkLen` that can be used as key material. + If you wanted multiple keys, just break up this string into segments of the desired length. +""" + password = tobytes(password) + if prf is None: + prf = lambda p,s: HMAC.new(p,s,SHA1).digest() + key = b('') + i = 1 + while len(key)<dkLen: + U = previousU = prf(password,salt+struct.pack(">I", i)) + for j in range(count-1): + previousU = t = prf(password,previousU) + U = strxor(U,t) + key += U + i = i + 1 + return key[:dkLen] + diff --git a/frozen_deps/Crypto/Protocol/__init__.py b/frozen_deps/Crypto/Protocol/__init__.py new file mode 100644 index 0000000..cacc685 --- /dev/null +++ b/frozen_deps/Crypto/Protocol/__init__.py @@ -0,0 +1,41 @@ +# -*- coding: utf-8 -*- +# +# =================================================================== +# The contents of this file are dedicated to the public domain. To +# the extent that dedication to the public domain is not available, +# everyone is granted a worldwide, perpetual, royalty-free, +# non-exclusive license to exercise all rights associated with the +# contents of this file for any purpose whatsoever. +# No rights are reserved. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# =================================================================== + +"""Cryptographic protocols + +Implements various cryptographic protocols. (Don't expect to find +network protocols here.) + +Crypto.Protocol.AllOrNothing + Transforms a message into a set of message blocks, such that the blocks + can be recombined to get the message back. + +Crypto.Protocol.Chaffing + Takes a set of authenticated message blocks (the wheat) and adds a number + of randomly generated blocks (the chaff). + +Crypto.Protocol.KDF + A collection of standard key derivation functions. + +:undocumented: __revision__ +""" + +__all__ = ['AllOrNothing', 'Chaffing', 'KDF'] +__revision__ = "$Id$" |