From 3bef51eec2299403467e621ae660cef3f9256ac8 Mon Sep 17 00:00:00 2001 From: Determinant Date: Tue, 17 Nov 2020 18:47:40 -0500 Subject: update frozen deps --- frozen_deps/Crypto/Protocol/KDF.py | 123 +++++++++++++++++++++++++++++++++++++ 1 file changed, 123 insertions(+) create mode 100644 frozen_deps/Crypto/Protocol/KDF.py (limited to 'frozen_deps/Crypto/Protocol/KDF.py') 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)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] + -- cgit v1.2.3-70-g09d2