diff options
Diffstat (limited to 'src')
| -rwxr-xr-x | src/model/aes.py | 1058 | ||||
| -rwxr-xr-x | src/model/keywrap.py | 125 |
2 files changed, 101 insertions, 1082 deletions
diff --git a/src/model/aes.py b/src/model/aes.py deleted file mode 100755 index 86741c0..0000000 --- a/src/model/aes.py +++ /dev/null @@ -1,1058 +0,0 @@ -#!/usr/bin/env python3 -# -*- coding: utf-8 -*- -#======================================================================= -# -# aes.py -# ------ -# Simple, pure Python, word based model of the AES cipher with -# support for 128 and 256 bit keys. -# -# -# Author: Joachim Strombergson -# Copyright (c) 2014, NORDUnet A/S -# All rights reserved. -# -# Redistribution and use in source and binary forms, with or without -# modification, are permitted provided that the following conditions are -# met: -# - Redistributions of source code must retain the above copyright notice, -# this list of conditions and the following disclaimer. -# -# - 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. -# -# - Neither the name of the NORDUnet nor the names of its contributors may -# be used to endorse or promote products derived from this software -# without specific prior written permission. -# -# 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 -# HOLDER 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. -#------------------------------------------------------------------- -VERBOSE = False -DUMP_VARS = False - -AES_128_ROUNDS = 10 -AES_256_ROUNDS = 14 - - -sbox = [0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, - 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, - 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, - 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, - 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, - 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, - 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, - 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, - 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, - 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, - 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, - 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, - 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, - 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, - 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, - 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, - 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, - 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, - 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, - 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, - 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, - 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, - 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, - 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, - 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, - 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, - 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, - 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, - 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, - 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, - 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, - 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16] - - -inv_sbox = [0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, - 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, - 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, - 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, - 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, - 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, - 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, - 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, - 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, - 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, - 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, - 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, - 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, - 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, - 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, - 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, - 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, - 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, - 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, - 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, - 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, - 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, - 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, - 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, - 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, - 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, - 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, - 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, - 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, - 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, - 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, - 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d] - - -#------------------------------------------------------------------- -# print_bytekeys() -# -# Print a set of round keys given as an array of bytes. -#------------------------------------------------------------------- -def print_bytekeys(keys): - i = 0 - print("Number of round keys: %d" % (int(len(keys) / 16))) - while i < (len(keys) - 1): - for j in range(16): - print("0x%02x " % keys[i + j], end="") - print("") - i += 16 - -#------------------------------------------------------------------- -# print_block() -# -# Print the given block as four 32 bit words. -#------------------------------------------------------------------- -def print_block(block): - (w0, w1, w2, w3) = block - print("0x%08x, 0x%08x, 0x%08x, 0x%08x" % (w0, w1, w2, w3)) - - -#------------------------------------------------------------------- -# print_key() -# -# Print the given key as on or two sets of four 32 bit words. -#------------------------------------------------------------------- -def print_key(key): - if len(key) == 8: - (k0, k1, k2, k3, k4, k5, k6, k7) = key - print_block((k0, k1, k2, k3)) - print_block((k4, k5, k6, k7)) - else: - print_block(key) - - -#------------------------------------------------------------------- -# b2w() -# -# Create a word from the given bytes. -#------------------------------------------------------------------- -def b2w(b0, b1, b2, b3): - return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3 - - -#------------------------------------------------------------------- -# w2b() -# -# Extracts the bytes in a word. -#------------------------------------------------------------------- -def w2b(w): - b0 = w >> 24 - b1 = w >> 16 & 0xff - b2 = w >> 8 & 0xff - b3 = w & 0xff - - return (b0, b1, b2, b3) - - -#------------------------------------------------------------------- -# gm2() -# -# The specific Galois Multiplication by two for a given byte. -#------------------------------------------------------------------- -def gm2(b): - return ((b << 1) ^ (0x1b & ((b >> 7) * 0xff))) & 0xff - - -#------------------------------------------------------------------- -# gm3() -# -# The specific Galois Multiplication by three for a given byte. -#------------------------------------------------------------------- -def gm3(b): - return gm2(b) ^ b - - -#------------------------------------------------------------------- -# gm4() -# -# The specific Galois Multiplication by four for a given byte. -#------------------------------------------------------------------- -def gm4(b): - return gm2(gm2(b)) - - -#------------------------------------------------------------------- -# gm8() -# -# The specific Galois Multiplication by eight for a given byte. -#------------------------------------------------------------------- -def gm8(b): - return gm2(gm4(b)) - - -#------------------------------------------------------------------- -# gm09() -# -# The specific Galois Multiplication by nine for a given byte. -#------------------------------------------------------------------- -def gm09(b): - return gm8(b) ^ b - - -#------------------------------------------------------------------- -# gm11() -# -# The specific Galois Multiplication by 11 for a given byte. -#------------------------------------------------------------------- -def gm11(b): - return gm8(b) ^ gm2(b) ^ b - - -#------------------------------------------------------------------- -# gm13() -# -# The specific Galois Multiplication by 13 for a given byte. -#------------------------------------------------------------------- -def gm13(b): - return gm8(b) ^ gm4(b) ^ b - - -#------------------------------------------------------------------- -# gm14() -# -# The specific Galois Multiplication by 14 for a given byte. -#------------------------------------------------------------------- -def gm14(b): - return gm8(b) ^ gm4(b) ^ gm2(b) - - -#------------------------------------------------------------------- -# substw() -# -# Returns a 32-bit word in which each of the bytes in the -# given 32-bit word has been used as lookup into the AES S-box. -#------------------------------------------------------------------- -def substw(w): - (b0, b1, b2, b3) = w2b(w) - - s0 = sbox[b0] - s1 = sbox[b1] - s2 = sbox[b2] - s3 = sbox[b3] - - res = b2w(s0, s1, s2, s3) - - if VERBOSE: - print("Inside substw:") - print("b0 = 0x%02x, b1 = 0x%02x, b2 = 0x%02x, b3 = 0x%02x" % - (b0, b1, b2, b3)) - print("s0 = 0x%02x, s1 = 0x%02x, s2 = 0x%02x, s3 = 0x%02x" % - (s0, s1, s2, s3)) - print("res = 0x%08x" % (res)) - - return res - - -#------------------------------------------------------------------- -# inv_substw() -# -# Returns a 32-bit word in which each of the bytes in the -# given 32-bit word has been used as lookup into -# the inverse AES S-box. -#------------------------------------------------------------------- -def inv_substw(w): - (b0, b1, b2, b3) = w2b(w) - - s0 = inv_sbox[b0] - s1 = inv_sbox[b1] - s2 = inv_sbox[b2] - s3 = inv_sbox[b3] - - res = b2w(s0, s1, s2, s3) - - if VERBOSE: - print("Inside inv_substw:") - print("b0 = 0x%02x, b1 = 0x%02x, b2 = 0x%02x, b3 = 0x%02x" % - (b0, b1, b2, b3)) - print("s0 = 0x%02x, s1 = 0x%02x, s2 = 0x%02x, s3 = 0x%02x" % - (s0, s1, s2, s3)) - print("res = 0x%08x" % (res)) - - return res - - -#------------------------------------------------------------------- -# rolx() -# -# Rotate the given 32 bit word x bits left. -#------------------------------------------------------------------- -def rolx(w, x): - return ((w << x) | (w >> (32 - x))) & 0xffffffff - - -#------------------------------------------------------------------- -# next_128bit_key() -# -# Generate the next four key words for aes-128 based on given -# rcon and previous key words. -#------------------------------------------------------------------- -def next_128bit_key(prev_key, rcon): - (w0, w1, w2, w3) = prev_key - - rol = rolx(w3, 8) - subst = substw(rol) - t = subst ^ (rcon << 24) - - k0 = w0 ^ t - k1 = w1 ^ w0 ^ t - k2 = w2 ^ w1 ^ w0 ^ t - k3 = w3 ^ w2 ^ w1 ^ w0 ^ t - - if VERBOSE: - print("Inside next 128bit key:") - print("w0 = 0x%08x, w1 = 0x%08x, w2 = 0x%08x, w3 = 0x%08x" % - (w0, w1, w2, w3)) - print("rol = 0x%08x, subst = 0x%08x, rcon = 0x%02x, t = 0x%08x" % - (rol, subst, rcon, t)) - print("k0 = 0x%08x, k1 = 0x%08x, k2 = 0x%08x, k3 = 0x%08x" % - (k0, k1, k2, k3)) - - return (k0, k1, k2, k3) - - -#------------------------------------------------------------------- -# key_gen128() -# -# Generating the keys for 128 bit keys. -#------------------------------------------------------------------- -def key_gen128(key): - print("Doing the 128 bit key expansion") - - round_keys = [] - - round_keys.append(key) - - for i in range(10): - round_keys.append(next_128bit_key(round_keys[i], get_rcon(i + 1))) - - if VERBOSE: - print("Input key:") - print_block(key) - print("") - - print("Generated keys:") - for k in round_keys: - print_block(k) - print("") - - return round_keys - - -#------------------------------------------------------------------- -# next_256bit_key_a() -# -# Generate the next four key words for aes-256 using algorithm A -# based on given rcon and the previous two keys. -#------------------------------------------------------------------- -def next_256it_key_a(key0, key1, rcon): - (w0, w1, w2, w3) = key0 - (w4, w5, w6, w7) = key1 - - sw = substw(rolx(w7, 8)) - rw = (rcon << 24) - t = sw ^ rw - - k0 = w0 ^ t - k1 = w1 ^ w0 ^ t - k2 = w2 ^ w1 ^ w0 ^ t - k3 = w3 ^ w2 ^ w1 ^ w0 ^ t - - if (DUMP_VARS): - print("next_256bit_key_a:") - print("w0 = 0x%08x, w0 = 0x%08x, w0 = 0x%08x, w0 = 0x%08x" % (w0, w1, w2, w3)) - print("w4 = 0x%08x, w5 = 0x%08x, w6 = 0x%08x, w7 = 0x%08x" % (w4, w5, w6, w7)) - print("t = 0x%08x, sw = 0x%08x, rw = 0x%08x" % (t, sw, rw)) - print("k0 = 0x%08x, k0 = 0x%08x, k0 = 0x%08x, k0 = 0x%08x" % (k0, k1, k2, k3)) - print("") - - return (k0, k1, k2, k3) - - -#------------------------------------------------------------------- -# next_256bit_key_b() -# -# Generate the next four key words for aes-256 using algorithm B -# based on given previous eight keywords. -#------------------------------------------------------------------- -def next_256it_key_b(key0, key1): - (w0, w1, w2, w3) = key0 - (w4, w5, w6, w7) = key1 - - t = substw(w7) - - k0 = w0 ^ t - k1 = w1 ^ w0 ^ t - k2 = w2 ^ w1 ^ w0 ^ t - k3 = w3 ^ w2 ^ w1 ^ w0 ^ t - - if (DUMP_VARS): - print("next_256bit_key_b:") - print("w0 = 0x%08x, w0 = 0x%08x, w0 = 0x%08x, w0 = 0x%08x" % (w0, w1, w2, w3)) - print("w4 = 0x%08x, w5 = 0x%08x, w6 = 0x%08x, w7 = 0x%08x" % (w4, w5, w6, w7)) - print("t = 0x%08x" % (t)) - print("k0 = 0x%08x, k0 = 0x%08x, k0 = 0x%08x, k0 = 0x%08x" % (k0, k1, k2, k3)) - print("") - - return (k0, k1, k2, k3) - - -#------------------------------------------------------------------- -# key_gen256() -# -# Generating the keys for 256 bit keys. -#------------------------------------------------------------------- -def key_gen256(key): - round_keys = [] - (k0, k1, k2, k3, k4, k5, k6, k7) = key - - round_keys.append((k0, k1, k2, k3)) - round_keys.append((k4, k5, k6, k7)) - - j = 1 - for i in range(0, (AES_256_ROUNDS - 2), 2): - k = next_256it_key_a(round_keys[i], round_keys[i + 1], get_rcon(j)) - round_keys.append(k) - k = next_256it_key_b(round_keys[i + 1], round_keys[i + 2]) - round_keys.append(k) - j += 1 - - # One final key needs to be generated. - k = next_256it_key_a(round_keys[12], round_keys[13], get_rcon(7)) - round_keys.append(k) - - if VERBOSE: - print("Input key:") - print_block((k0, k1, k2, k3)) - print_block((k4, k5, k6, k7)) - print("") - - print("Generated keys:") - for k in round_keys: - print_block(k) - print("") - - return round_keys - - -#------------------------------------------------------------------- -# get_rcon() -# -# Function implementation of rcon. Calculates rcon for a -# given round. This could be implemented as an iterator. -#------------------------------------------------------------------- -def get_rcon(round): - rcon = 0x8d - - for i in range(0, round): - rcon = ((rcon << 1) ^ (0x11b & - (rcon >> 7))) & 0xff - - return rcon - - -#------------------------------------------------------------------- -# addroundkey() -# -# AES AddRoundKey block operation. -# Perform XOR combination of the given block and the given key. -#------------------------------------------------------------------- -def addroundkey(key, block): - (w0, w1, w2, w3) = block - (k0, k1, k2, k3) = key - - res_block = (w0 ^ k0, w1 ^ k1, w2 ^ k2, w3 ^ k3) - - if VERBOSE: - print("AddRoundKey key, block in and block out:") - print_block(key) - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# mixw() -# -# Perform bit mixing of the given words. -#------------------------------------------------------------------- -def mixw(w): - (b0, b1, b2, b3) = w2b(w) - - mb0 = gm2(b0) ^ gm3(b1) ^ b2 ^ b3 - mb1 = b0 ^ gm2(b1) ^ gm3(b2) ^ b3 - mb2 = b0 ^ b1 ^ gm2(b2) ^ gm3(b3) - mb3 = gm3(b0) ^ b1 ^ b2 ^ gm2(b3) - - return b2w(mb0, mb1, mb2, mb3) - - -#------------------------------------------------------------------- -# mixcolumns() -# -# AES MixColumns on the given block. -#------------------------------------------------------------------- -def mixcolumns(block): - (c0, c1, c2, c3) = block - - mc0 = mixw(c0) - mc1 = mixw(c1) - mc2 = mixw(c2) - mc3 = mixw(c3) - - res_block = (mc0, mc1, mc2, mc3) - - if VERBOSE: - print("MixColumns block in and block out:") - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# subbytes() -# -# AES SubBytes operation on the given block. -#------------------------------------------------------------------- -def subbytes(block): - (w0, w1, w2, w3) = block - - res_block = (substw(w0), substw(w1), substw(w2), substw(w3)) - - if VERBOSE: - print("SubBytes block in and block out:") - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# shiftrows() -# -# AES ShiftRows block operation. -#------------------------------------------------------------------- -def shiftrows(block): - (w0, w1, w2, w3) = block - - c0 = w2b(w0) - c1 = w2b(w1) - c2 = w2b(w2) - c3 = w2b(w3) - - ws0 = b2w(c0[0], c1[1], c2[2], c3[3]) - ws1 = b2w(c1[0], c2[1], c3[2], c0[3]) - ws2 = b2w(c2[0], c3[1], c0[2], c1[3]) - ws3 = b2w(c3[0], c0[1], c1[2], c2[3]) - - res_block = (ws0, ws1, ws2, ws3) - - if VERBOSE: - print("ShiftRows block in and block out:") - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# aes_encipher() -# -# Perform AES encipher operation for the given block using the -# given key length. -#------------------------------------------------------------------- -def aes_encipher_block(key, block): - tmp_block = block[:] - - # Get round keys based on the given key. - if len(key) == 4: - round_keys = key_gen128(key) - num_rounds = AES_128_ROUNDS - else: - round_keys = key_gen256(key) - num_rounds = AES_256_ROUNDS - - # Init round - print(" Initial AddRoundKeys round.") - tmp_block4 = addroundkey(round_keys[0], block) - - # Main rounds - for i in range(1 , (num_rounds)): - print("") - print(" Round %02d" % i) - print(" ---------") - - tmp_block1 = subbytes(tmp_block4) - tmp_block2 = shiftrows(tmp_block1) - tmp_block3 = mixcolumns(tmp_block2) - tmp_block4 = addroundkey(round_keys[i], tmp_block3) - - - # Final round - print(" Final round.") - tmp_block1 = subbytes(tmp_block4) - tmp_block2 = shiftrows(tmp_block1) - tmp_block3 = addroundkey(round_keys[num_rounds], tmp_block2) - - return tmp_block3 - - -#------------------------------------------------------------------- -# inv_mixw() -# -# Perform inverse bit mixing of the given words. -#------------------------------------------------------------------- -def inv_mixw(w): - (b0, b1, b2, b3) = w2b(w) - - mb0 = gm14(b0) ^ gm11(b1) ^ gm13(b2) ^ gm09(b3) - mb1 = gm09(b0) ^ gm14(b1) ^ gm11(b2) ^ gm13(b3) - mb2 = gm13(b0) ^ gm09(b1) ^ gm14(b2) ^ gm11(b3) - mb3 = gm11(b0) ^ gm13(b1) ^ gm09(b2) ^ gm14(b3) - - return b2w(mb0, mb1, mb2, mb3) - - -#------------------------------------------------------------------- -# inv_mixcolumns() -# -# AES Inverse MixColumns on the given block. -#------------------------------------------------------------------- -def inv_mixcolumns(block): - (c0, c1, c2, c3) = block - - mc0 = inv_mixw(c0) - mc1 = inv_mixw(c1) - mc2 = inv_mixw(c2) - mc3 = inv_mixw(c3) - - res_block = (mc0, mc1, mc2, mc3) - - if VERBOSE: - print("Inverse MixColumns block in and block out:") - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# inv_shiftrows() -# -# AES inverse ShiftRows block operation. -#------------------------------------------------------------------- -def inv_shiftrows(block): - (w0, w1, w2, w3) = block - - c0 = w2b(w0) - c1 = w2b(w1) - c2 = w2b(w2) - c3 = w2b(w3) - - ws0 = b2w(c0[0], c3[1], c2[2], c1[3]) - ws1 = b2w(c1[0], c0[1], c3[2], c2[3]) - ws2 = b2w(c2[0], c1[1], c0[2], c3[3]) - ws3 = b2w(c3[0], c2[1], c1[2], c0[3]) - - res_block = (ws0, ws1, ws2, ws3) - - if VERBOSE: - print("Inverse ShiftRows block in and block out:") - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# inv_subbytes() -# -# AES inverse SubBytes operation on the given block. -#------------------------------------------------------------------- -def inv_subbytes(block): - (w0, w1, w2, w3) = block - - res_block = (inv_substw(w0), inv_substw(w1), inv_substw(w2), inv_substw(w3)) - - if VERBOSE: - print("Inverse SubBytes block in and block out:") - print_block(block) - print_block(res_block) - print("") - - return res_block - - -#------------------------------------------------------------------- -# aes_decipher() -# -# Perform AES decipher operation for the given block -# using the given key length. -#------------------------------------------------------------------- -def aes_decipher_block(key, block): - tmp_block = block[:] - - # Get round keys based on the given key. - if len(key) == 4: - round_keys = key_gen128(key) - num_rounds = AES_128_ROUNDS - else: - round_keys = key_gen256(key) - num_rounds = AES_256_ROUNDS - - # Initial round - print(" Initial, partial round.") - tmp_block1 = addroundkey(round_keys[len(round_keys) - 1], tmp_block) - tmp_block2 = inv_shiftrows(tmp_block1) - tmp_block4 = inv_subbytes(tmp_block2) - - # Main rounds - for i in range(1 , (num_rounds)): - print("") - print(" Round %02d" % i) - print(" ---------") - - tmp_block1 = addroundkey(round_keys[(len(round_keys) - i - 1)], tmp_block4) - tmp_block2 = inv_mixcolumns(tmp_block1) - tmp_block3 = inv_shiftrows(tmp_block2) - tmp_block4 = inv_subbytes(tmp_block3) - - # Final round - print(" Final AddRoundKeys round.") - res_block = addroundkey(round_keys[0], tmp_block4) - - return res_block - - -#------------------------------------------------------------------- -# test_mixcolumns() -# -# Test the mixcolumns and inverse mixcolumns operations using -# some simple test values. -#------------------------------------------------------------------- -def test_mixcolumns(): - nist_aes128_key = (0x2b7e1516, 0x28aed2a6, 0xabf71588, 0x09cf4f3c) - - print("Test of mixcolumns and inverse mixcolumns:") - mixresult = mixcolumns(nist_aes128_key) - inv_mixresult = inv_mixcolumns(mixresult) - - print("Test of mixw ochi inv_mixw:") - testw = 0xdb135345 - expw = 0x8e4da1bc - mixresult = mixw(testw) - inv_mixresult = inv_mixw(mixresult) - print("Testword: 0x%08x" % testw) - print("expexted: 0x%08x" % expw) - print("mixword: 0x%08x" % mixresult) - print("invmixword: 0x%08x" % inv_mixresult) - - -#------------------------------------------------------------------- -# test_aes() -# -# Test the AES implementation with 128 and 256 bit keys. -#------------------------------------------------------------------- -def test_aes(): - nist_aes128_key = (0x2b7e1516, 0x28aed2a6, 0xabf71588, 0x09cf4f3c) - nist_aes256_key = (0x603deb10, 0x15ca71be, 0x2b73aef0, 0x857d7781, - 0x1f352c07, 0x3b6108d7, 0x2d9810a3, 0x0914dff4) - - nist_plaintext0 = (0x6bc1bee2, 0x2e409f96, 0xe93d7e11, 0x7393172a) - nist_plaintext1 = (0xae2d8a57, 0x1e03ac9c, 0x9eb76fac, 0x45af8e51) - nist_plaintext2 = (0x30c81c46, 0xa35ce411, 0xe5fbc119, 0x1a0a52ef) - nist_plaintext3 = (0xf69f2445, 0xdf4f9b17, 0xad2b417b, 0xe66c3710) - - nist_exp128_0 = (0x3ad77bb4, 0x0d7a3660, 0xa89ecaf3, 0x2466ef97) - nist_exp128_1 = (0xf5d3d585, 0x03b9699d, 0xe785895a, 0x96fdbaaf) - nist_exp128_2 = (0x43b1cd7f, 0x598ece23, 0x881b00e3, 0xed030688) - nist_exp128_3 = (0x7b0c785e, 0x27e8ad3f, 0x82232071, 0x04725dd4) - - nist_exp256_0 = (0xf3eed1bd, 0xb5d2a03c, 0x064b5a7e, 0x3db181f8) - nist_exp256_1 = (0x591ccb10, 0xd410ed26, 0xdc5ba74a, 0x31362870) - nist_exp256_2 = (0xb6ed21b9, 0x9ca6f4f9, 0xf153e7b1, 0xbeafed1d) - nist_exp256_3 = (0x23304b7a, 0x39f9f3ff, 0x067d8d8f, 0x9e24ecc7) - - - print("Doing block encryption.") - enc_result128_0 = aes_encipher_block(nist_aes128_key, nist_plaintext0) - enc_result128_1 = aes_encipher_block(nist_aes128_key, nist_plaintext1) - enc_result128_2 = aes_encipher_block(nist_aes128_key, nist_plaintext2) - enc_result128_3 = aes_encipher_block(nist_aes128_key, nist_plaintext3) - - enc_result256_0 = aes_encipher_block(nist_aes256_key, nist_plaintext0) - enc_result256_1 = aes_encipher_block(nist_aes256_key, nist_plaintext1) - enc_result256_2 = aes_encipher_block(nist_aes256_key, nist_plaintext2) - enc_result256_3 = aes_encipher_block(nist_aes256_key, nist_plaintext3) - - print("Doing block decryption.") - dec_result128_0 = aes_decipher_block(nist_aes128_key, nist_exp128_0) - dec_result128_1 = aes_decipher_block(nist_aes128_key, nist_exp128_1) - dec_result128_2 = aes_decipher_block(nist_aes128_key, nist_exp128_2) - dec_result128_3 = aes_decipher_block(nist_aes128_key, nist_exp128_3) - - dec_result256_0 = aes_decipher_block(nist_aes256_key, nist_exp256_0) - dec_result256_1 = aes_decipher_block(nist_aes256_key, nist_exp256_1) - dec_result256_2 = aes_decipher_block(nist_aes256_key, nist_exp256_2) - dec_result256_3 = aes_decipher_block(nist_aes256_key, nist_exp256_3) - - - if VERBOSE: - print(" AES Encipher tests") - print(" ==================") - - print("Test 0 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_plaintext0) - print("Expected block out:") - print_block(nist_exp128_0) - print("Got block out:") - print_block(enc_result128_0) - print("") - - print("Test 1 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_plaintext1) - print("Expected block out:") - print_block(nist_exp128_1) - print("Got block out:") - print_block(enc_result128_1) - print("") - - print("Test 2 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_plaintext2) - print("Expected block out:") - print_block(nist_exp128_2) - print("Got block out:") - print_block(enc_result128_2) - print("") - - print("Test 3 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_plaintext3) - print("Expected block out:") - print_block(nist_exp128_3) - print("Got block out:") - print_block(enc_result128_3) - print("") - - - print("Test 0 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_plaintext0) - print("Expected block out:") - print_block(nist_exp256_0) - print("Got block out:") - print_block(enc_result256_0) - print("") - - print("Test 1 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_plaintext1) - print("Expected block out:") - print_block(nist_exp256_1) - print("Got block out:") - print_block(enc_result256_1) - print("") - - print("Test 2 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_plaintext2) - print("Expected block out:") - print_block(nist_exp256_2) - print("Got block out:") - print_block(enc_result256_2) - print("") - - print("Test 3 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_plaintext3) - print("Expected block out:") - print_block(nist_exp256_3) - print("Got block out:") - print_block(enc_result256_3) - print("") - - print("") - print(" AES Decipher tests") - print(" ==================") - - print("Test 0 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_exp128_0) - print("Expected block out:") - print_block(nist_plaintext0) - print("Got block out:") - print_block(dec_result128_0) - print("") - - print("Test 1 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_exp128_1) - print("Expected block out:") - print_block(nist_plaintext1) - print("Got block out:") - print_block(dec_result128_1) - print("") - - print("Test 2 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_exp128_2) - print("Expected block out:") - print_block(nist_plaintext2) - print("Got block out:") - print_block(dec_result128_2) - print("") - - print("Test 3 for AES-128.") - print("Key:") - print_key(nist_aes128_key) - print("Block in:") - print_block(nist_exp128_3) - print("Expected block out:") - print_block(nist_plaintext3) - print("Got block out:") - print_block(dec_result128_3) - print("") - - print("Test 0 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_exp256_0) - print("Expected block out:") - print_block(nist_plaintext0) - print("Got block out:") - print_block(dec_result256_0) - print("") - - print("Test 1 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_exp256_1) - print("Expected block out:") - print_block(nist_plaintext1) - print("Got block out:") - print_block(dec_result256_1) - print("") - - print("Test 2 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_exp256_2) - print("Expected block out:") - print_block(nist_plaintext2) - print("Got block out:") - print_block(dec_result256_2) - print("") - - print("Test 3 for AES-256.") - print("Key:") - print_key(nist_aes256_key) - print("Block in:") - print_block(nist_exp256_3) - print("Expected block out:") - print_block(nist_plaintext3) - print("Got block out:") - print_block(dec_result256_3) - print("") - - -#------------------------------------------------------------------- -# main() -# -# If executed tests the ChaCha class using known test vectors. -#------------------------------------------------------------------- -def main(): - print("Testing the AES cipher model") - print("============================") - print - - # test_mixcolumns() - test_aes() - - -#------------------------------------------------------------------- -# __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 aes_key_gen.py -#======================================================================= diff --git a/src/model/keywrap.py b/src/model/keywrap.py index 08aac9a..747f406 100755 --- a/src/model/keywrap.py +++ b/src/model/keywrap.py @@ -1,4 +1,4 @@ -#!/usr/bin/env python3 +#!/usr/bin/env python # -*- coding: utf-8 -*- #======================================================================= # @@ -43,7 +43,9 @@ # Python module imports. #------------------------------------------------------------------- import sys -import aes +import Crypto.Random +from Crypto.Cipher import AES +from struct import pack, unpack #------------------------------------------------------------------- @@ -52,37 +54,112 @@ import aes VERBOSE = True + +#------------------------------------------------------------------- +# AESKeyWrapWithPadding +#------------------------------------------------------------------- +class AESKeyWrapWithPadding(object): + """ + Implementation of AES Key Wrap With Padding from RFC 5649. + """ + + class UnwrapError(Exception): + "Something went wrong during unwrap." + + def __init__(self, key): + self.ctx = AES.new(key, AES.MODE_ECB) + + def _encrypt(self, b1, b2): + aes_block = self.ctx.encrypt(b1 + b2) + return aes_block[:8], aes_block[8:] + + def _decrypt(self, b1, b2): + aes_block = self.ctx.decrypt(b1 + b2) + return aes_block[:8], aes_block[8:] + + @staticmethod + def _start_stop(start, stop): # Syntactic sugar + step = -1 if start > stop else 1 + return xrange(start, stop + step, step) + + @staticmethod + def _xor(R0, t): + return pack(">Q", unpack(">Q", R0)[0] ^ t) + + def wrap(self, Q): + "RFC 5649 section 4.1." + m = len(Q) # Plaintext length + if m % 8 != 0: # Pad Q if needed + Q += "\x00" * (8 - (m % 8)) + R = [pack(">LL", 0xa65959a6, m)] # Magic MSB(32,A), build LSB(32,A) + R.extend(Q[i : i + 8] # Append Q + for i in xrange(0, len(Q), 8)) + n = len(R) - 1 + if n == 1: + R[0], R[1] = self._encrypt(R[0], R[1]) + else: + # RFC 3394 section 2.2.1 + for j in self._start_stop(0, 5): + for i in self._start_stop(1, n): + R[0], R[i] = self._encrypt(R[0], R[i]) + R[0] = self._xor(R[0], n * j + i) + assert len(R) == (n + 1) and all(len(r) == 8 for r in R) + return "".join(R) + + def unwrap(self, C): + "RFC 5649 section 4.2." + if len(C) % 8 != 0: + raise self.UnwrapError("Ciphertext length {} is not an integral number of blocks" + .format(len(C))) + n = (len(C) / 8) - 1 + R = [C[i : i + 8] for i in xrange(0, len(C), 8)] + if n == 1: + R[0], R[1] = self._decrypt(R[0], R[1]) + else: + # RFC 3394 section 2.2.2 steps (1), (2), and part of (3) + for j in self._start_stop(5, 0): + for i in self._start_stop(n, 1): + R[0] = self._xor(R[0], n * j + i) + R[0], R[i] = self._decrypt(R[0], R[i]) + magic, m = unpack(">LL", R[0]) + if magic != 0xa65959a6: + raise self.UnwrapError("Magic value in AIV should have been 0xa65959a6, was 0x{:02x}" + .format(magic)) + if m <= 8 * (n - 1) or m > 8 * n: + raise self.UnwrapError("Length encoded in AIV out of range: m {}, n {}".format(m, n)) + R = "".join(R[1:]) + assert len(R) == 8 * n + if any(r != "\x00" for r in R[m:]): + raise self.UnwrapError("Nonzero trailing bytes {}".format(R[m:].encode("hex"))) + return R[:m] + + #------------------------------------------------------------------- -# aes_test +# wrap_test1 # -# Check that the AES functionality is available and works -# as expected. +# First, simplest test from NIST test vectors. #------------------------------------------------------------------- -def keywrap_aes_test(): - nist_aes128_key = (0x2b7e1516, 0x28aed2a6, 0xabf71588, 0x09cf4f3c) - nist_plaintext0 = (0x6bc1bee2, 0x2e409f96, 0xe93d7e11, 0x7393172a) - nist_exp128_0 = (0x3ad77bb4, 0x0d7a3660, 0xa89ecaf3, 0x2466ef97) - enc_result128_0 = aes.aes_encipher_block(nist_aes128_key, nist_plaintext0) - - print("Test 0 for AES-128.") - print("Key:") - aes.print_key(nist_aes128_key) - print("Block in:") - aes.print_block(nist_plaintext0) - print("Expected block out:") - aes.print_block(nist_exp128_0) - print("Got block out:") - aes.print_block(enc_result128_0) - print("") +def wrap_test1(): + my_key = Crypto.Random.new().read(256/8) + my_keywrap = AESKeyWrapWithPadding(my_key) + + my_plaintext = "\x31\x32\x33" + my_wrap = my_keywrap.wrap(my_plaintext) + print(type(my_wrap)) + my_unwrap = my_keywrap.wrap(my_wrap) + print(type(my_unwrap)) + print("plaintext: %s wrapped: %s unwrapped: %s" % + (my_plaintext, my_wrap, my_unwrap)) #------------------------------------------------------------------- #------------------------------------------------------------------- def main(): - print("Testing the KEY WRAP model") - print("===========================") + print("Testing the Key Wrap Python model") + print("=================================") print - keywrap_aes_test() + # keywrap_aes_test() + wrap_test1() #------------------------------------------------------------------- |