0,0 → 1,104 |
#! /usr/bin/env python |
""" crypto.cipher.aes_sbox_analysis |
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AES Sbox Analysis - a simple analysis of the AES Sbox that determines |
the number and size of the permutation subgroups in the transformation. |
Could be extended to examine any Sbox ... |
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Copyright © (c) 2002 by Paul A. Lambert |
Read LICENSE.txt for license information. |
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2002-12-05 Added validation of equation form of AES |
2002-06-01 Original |
""" |
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# The AES Sbox |
sbbytes = (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) |
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def groups(subbytes): |
gdict={} # a dictionary of the cycles indexed by the first cycle element |
touched=[0 for i in range(len(subbytes))] |
for i in range(len(sbbytes)): |
touched.append(0) |
for i in range(len(sbbytes)): |
element = i |
cycle = [] |
if not touched[element]: |
for j in range (i,len(sbbytes)): |
touched[element] = 1 |
cycle.append(element) |
element = sbbytes[element] |
if element == i: |
break |
gdict[cycle[1]]=cycle |
else: |
pass |
return gdict |
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def grpv(subbytes): |
"""" Returns a list of tuples (cycle start, cycle size) """ |
v=[] |
z=groups(subbytes) |
for i in z.keys(): |
v.append( [i, len(z[i])] ) |
return v |
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def sgv(subbytes): |
x = grpv(subbytes) |
sum = 0 |
for i in x: |
sum = sum + i[1] |
return sum |
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def main(): |
cycles = grpv(sbbytes) |
print 'The AES sbox contains ', |
print len(cycles), |
print 'permutation subgroups' |
print 'The AES sbox subgroups (start, length) are:' |
print cycles |
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# Make this test module runnable from the command prompt |
if __name__ == "__main__": |
main() |
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