Adding initial version of keywrap python model. Adding local copy of aes model.

2 files changed, 1131 insertions, 0 deletions

diff --git a/src/model/aes.py b/src/model/aes.py
new file mode 100755
index 0000000..848ca85
--- /dev/null
+++ b/src/model/aes.py
@@ -0,0 +1,1058 @@
+#!/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 = True
+DUMP_VARS = True
+
+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
new file mode 100755
index 0000000..e0bd5a6
--- /dev/null
+++ b/src/model/keywrap.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#=======================================================================
+#
+# keywrap.py
+# ----------
+# Python model to test AES KEY WRAP according to RFC 5649.
+#
+#
+# Author: Joachim Strombergson
+# Copyright (c) 2018, 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 = True
+
+
+#-------------------------------------------------------------------
+#-------------------------------------------------------------------
+def main():
+    print("Testing the KEY WRAP model")
+    print("===========================")
+    print
+
+
+#-------------------------------------------------------------------
+# __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 keywrap.py
+#=======================================================================