Adding the Python keywrap model from sw/libhal/unit-tests.py to modify as needed to get intermediate values. Removed the aes model taken from the aes core.

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()
 
 
 #-------------------------------------------------------------------