#!/usr/bin/env python3 # -*- coding: utf-8 -*- #======================================================================= # # sha1.py # --------- # Simple, pure Python model of the SHA-1 function. Used as a # reference for the HW implementation. The code follows the structure # of the HW implementation as much as possible. # # # Author: Joachim Strömbergson # (c) 2014, SUNET # # Redistribution and use in source and binary forms, with or # without modification, are permitted provided that the following # conditions are met: # # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in # the documentation and/or other materials provided with the # distribution. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, # STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF # ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # #======================================================================= #------------------------------------------------------------------- # Python module imports. #------------------------------------------------------------------- import sys #------------------------------------------------------------------- # Constants. #------------------------------------------------------------------- #------------------------------------------------------------------- # ChaCha() #------------------------------------------------------------------- class SHA1(): def __init__(self, verbose = 0): self.verbose = verbose self.H = [0] * 5 self.T = 0 self.a = 0 self.b = 0 self.c = 0 self.d = 0 self.e = 0 self.W = [0] * 80 self.k = 0 def init(self): self.H = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0] def next(self, block): self._W_schedule(block) self._copy_digest() for i in range(80): self._sha1_round(i) self._update_digest() def get_digest(self): return self.H def _copy_digest(self): self.a = self.H[0] self.b = self.H[1] self.c = self.H[2] self.d = self.H[3] self.e = self.H[4] def _update_digest(self): self.H[0] = (self.H[0] + self.a) & 0xffffffff self.H[1] = (self.H[1] + self.b) & 0xffffffff self.H[2] = (self.H[2] + self.c) & 0xffffffff self.H[3] = (self.H[3] + self.d) & 0xffffffff self.H[4] = (self.H[4] + self.e) & 0xffffffff def _sha1_round(self, round): if round <= 19: self.k = 0x5a827999 self.f = self._Ch(self.b, self.c, self.d) elif 20 <= round <= 39: self.k = 0x6ed9eba1 self.f = self._Parity(self.b, self.c, self.d) elif 40 <= round <= 59: self.k = 0x8f1bbcdc self.f = self._Maj(self.b, self.c, self.d) elif 60 <= round <= 79: self.k = 0xca62c1d6 self.f = self._Parity(self.b, self.c, self.d) if self.verbose: print("Round %0d" % round) print("Round input values:") print("a = 0x%08x, b = 0x%08x, c = 0x%08x" % (self.a, self.b, self.c)) print("d = 0x%08x, e = 0x%08x" % (self.d, self.e)) print("f = 0x%08x, k = 0x%08x, w = 0x%08x" % (self.f, self.k, self.W[round])) self.T = (self._rotl32(self.a, 5) + self.f + self.e + self.k + self.W[round]) & 0xffffffff self.e = self.d self.d = self.c self.c = self._rotl32(self.b, 30) self.b = self.a self.a = self.T if self.verbose: print("Round output values:") print("a = 0x%08x, b = 0x%08x, c = 0x%08x" % (self.a, self.b, self.c)) print("d = 0x%08x, e = 0x%08x" % (self.d, self.e)) print("") def _W_schedule(self, block): # Expand the block into 80 words before round operations. for i in range(80): if (i < 16): self.W[i] = block[i] else: self.W[i] = self._rotl32((self.W[(i - 3)] ^ self.W[(i - 8)] ^ self.W[(i - 14)] ^ self.W[(i - 16)]), 1) if (self.verbose): print("W after schedule:") for i in range(80): print("W[%02d] = 0x%08x" % (i, self.W[i])) print("") def _Ch(self, x, y, z): return (x & y) ^ (~x & z) def _Maj(self, x, y, z): return (x & y) ^ (x & z) ^ (y & z) def _Parity(self, x, y, z): return (x ^ y ^ z) def _rotl32(self, n, r): return ((n << r) | (n >> (32 - r))) & 0xffffffff def compare_digests(digest, expected): if (digest != expected): print("Error:") print("Got:") print(digest) print("Expected:") print(expected) else: print("Test case ok.") #------------------------------------------------------------------- # main() # # If executed tests the ChaCha class using known test vectors. #------------------------------------------------------------------- def main(): print("Testing the SHA-1 Python model.") print("-------------------------------") print my_sha1 = SHA1(verbose=0); # TC1: NIST testcase with message "abc" print("TC1: Single block NIST test case.") TC1_block = [0x61626380, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000018] TC1_expected = [0xa9993e36, 0x4706816a, 0xba3e2571, 0x7850c26c, 0x9cd0d89d] my_sha1.init() my_sha1.next(TC1_block) my_digest = my_sha1.get_digest() compare_digests(my_digest, TC1_expected) print("") # TC2: NIST testcase with message two block message. print("TC2: Dual block NIST test case.") TC2_1_block = [0x61626364, 0x62636465, 0x63646566, 0x64656667, 0x65666768, 0x66676869, 0x6768696A, 0x68696A6B, 0x696A6B6C, 0x6A6B6C6D, 0x6B6C6D6E, 0x6C6D6E6F, 0x6D6E6F70, 0x6E6F7071, 0x80000000, 0x00000000] TC2_2_block = [0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x000001C0] TC2_1_expected = [0xF4286818, 0xC37B27AE, 0x0408F581, 0x84677148, 0x4A566572] TC2_2_expected = [0x84983E44, 0x1C3BD26E, 0xBAAE4AA1, 0xF95129E5, 0xE54670F1] my_sha1.init() my_sha1.next(TC2_1_block) my_digest = my_sha1.get_digest() compare_digests(my_digest, TC2_1_expected) my_sha1.next(TC2_2_block) my_digest = my_sha1.get_digest() compare_digests(my_digest, TC2_2_expected) print("") # TC3: Huge message with n blocks n = 10000 print("TC3: Huge message with %d blocks test case." % n) TC3_block = [0xaa55aa55, 0xdeadbeef, 0x55aa55aa, 0xf00ff00f, 0xaa55aa55, 0xdeadbeef, 0x55aa55aa, 0xf00ff00f, 0xaa55aa55, 0xdeadbeef, 0x55aa55aa, 0xf00ff00f, 0xaa55aa55, 0xdeadbeef, 0x55aa55aa, 0xf00ff00f] TC3_expected = [0xea2ebc79, 0x35516705, 0xde1e1467, 0x31e55587, 0xa0038725] my_sha1.init() for i in range(n): my_sha1.next(TC3_block) my_digest = my_sha1.get_digest() compare_digests(my_digest, TC3_expected) #------------------------------------------------------------------- # __name__ # Python thingy which allows the file to be run standalone as # well as parsed from within a Python interpreter. #------------------------------------------------------------------- if __name__=="__main__": # Run the main function. sys.exit(main()) #======================================================================= # EOF sha1.py #=======================================================================