1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
"""
Lilliput TBC
"""
import constants
import multiplications
BLOCK_BITS = 128
KEY_BITS = 128
TWEAK_BITS = 192
LANE_BITS = 64
LANE_BYTES = LANE_BITS / 8
LANES = int((TWEAK_BITS+KEY_BITS) / LANE_BITS)
BLOCK_BYTES = int(BLOCK_BITS / 8)
TWEAKEY_BITS = KEY_BITS + TWEAK_BITS
KEY_BYTES = int(KEY_BITS / 8)
TWEAK_BYTES = int(TWEAK_BITS / 8)
TWEAKEY_BYTES = int(TWEAKEY_BITS / 8)
Sbox = constants.Sbox
MultiplyM = multiplications.MultiplyM
MultiplyM2 = multiplications.MultiplyM2
MultiplyM3 = multiplications.MultiplyM3
MultiplyMR = multiplications.MultiplyMR
MultiplyMR2 = multiplications.MultiplyMR2
MultiplyMR3 = multiplications.MultiplyMR3
permutation = [14, 11, 12, 10, 8, 9, 13, 15, 3, 1, 4, 5, 6, 0, 2, 7]
permutationInv = [13, 9, 14, 8, 10, 11, 12, 15, 4, 5, 3, 1, 2, 6 ,0 ,7]
################################################################################
def BuildTweakey(tweak, key) :
tweakey = [0 for byte in range(0, TWEAKEY_BYTES)]
for byte in range(0, TWEAK_BYTES) :
tweakey[byte] = tweak[byte]
for byte in range(0, KEY_BYTES) :
tweakey[byte + TWEAK_BYTES] = key[byte]
return tweakey
#############################
def RoundTweakeySchedule(tweakey) :
# Multiplication
lanes = [tweakey[word * 8:(word+1) * 8] for word in range(0, LANES)]
tweakey_multiplied = []
for word in range(0, LANES) :
if word == 0 :
tweakey_multiplied += list(lanes[0])
elif word == 1 :
tweakey_multiplied += MultiplyM(lanes[1])
elif word == 2 :
tweakey_multiplied += MultiplyM2(lanes[2])
elif word == 3 :
tweakey_multiplied += MultiplyM3(lanes[3])
elif word == 4 :
tweakey_multiplied += MultiplyMR(lanes[4])
elif word == 5 :
tweakey_multiplied += MultiplyMR2(lanes[5])
elif word == 6 :
tweakey_multiplied += MultiplyMR3(lanes[6])
return tweakey_multiplied ;
def SubTweakeyExtract(tweakey, Ci):
subtweakey = [0 for byte in range(0, 8)]
for byte in range(0, TWEAKEY_BYTES) :
subtweakey[byte % 8] ^= tweakey[byte]
subtweakey[0] ^= Ci
return subtweakey
def TweakeyScheduleWhole(tweakey, r):
# store main tweakey in TKs[0]
# and corresponding RTKs[0]
TKs = [tweakey]
RTKs = [SubTweakeyExtract(TKs[0], 0)]
for i in range(1, r) :
TKs.append(RoundTweakeySchedule(TKs[i-1]))
RTKs.append(SubTweakeyExtract(TKs[i], i))
return RTKs
################################################################################
def NonLinearLayer(state, subtweakey) :
variables_xored = [0 for byte in range(0, 8)]
for byte in range(0,8) :
variables_xored[byte] = state[byte] ^ subtweakey[byte]
variables_sboxed = [0 for byte in range(0, 8)]
for byte in range(0, 8) :
variables_sboxed[byte] = Sbox[variables_xored[byte]]
state_output = [0 for byte in range(0, BLOCK_BYTES)]
for byte in range(0,BLOCK_BYTES) :
state_output[byte] = state[byte]
for byte in range(0, 8) :
state_output[15 - byte] ^= variables_sboxed[byte]
return state_output
def LinearLayer(state) :
state_output = [0 for byte in range(0, BLOCK_BYTES)]
for byte in range(0, BLOCK_BYTES) :
state_output[byte] = state[byte]
for byte in range(1, 8) :
state_output[15] ^= state[byte]
for byte in range(9, 15) :
state_output[byte] ^= state[7]
return state_output
def PermutationLayerEnc(state) :
state_output = [0 for byte in range(0, BLOCK_BYTES)]
for byte in range(0, BLOCK_BYTES) :
state_output[byte] = state[permutation[byte]]
return state_output
def PermutationLayerDec(state) :
state_output = [0 for byte in range(0, BLOCK_BYTES)]
for byte in range(0, BLOCK_BYTES) :
state_output[byte] = state[permutationInv[byte]]
return state_output
def OneRoundEGFNEnc(state, subtweakey) :
state_non_linear = NonLinearLayer(state, subtweakey)
state_linear = LinearLayer(state_non_linear)
state_permutation = PermutationLayerEnc(state_linear)
return state_permutation
def LastRoundEGFN(state, subtweakey) :
state_non_linear = NonLinearLayer(state, subtweakey)
state_linear = LinearLayer(state_non_linear)
return state_linear
def OneRoundEGFNDec(state, subtweakey) :
state_non_linear = NonLinearLayer(state, subtweakey)
state_linear = LinearLayer(state_non_linear)
state_permutation = PermutationLayerDec(state_linear)
return state_permutation
def _rounds(key_bytes):
rounds = {
128: 32,
192: 36,
256: 42
}
return rounds[key_bytes*8]
################################################################################
# Lilliput TBC
def LilliputTBCEnc(tweak, key, message) :
r = _rounds(len(key))
tweakey = BuildTweakey(tweak, key)
RTKs = TweakeyScheduleWhole(tweakey, r)
state = [0 for byte in range(0, BLOCK_BYTES)]
for byte in range(0, BLOCK_BYTES) :
state[byte] = message[byte]
for i in range(0, r-1) :
state_output = OneRoundEGFNEnc(state, RTKs[i])
for byte in range(0, BLOCK_BYTES) :
state[byte] = state_output[byte]
state_output = LastRoundEGFN(state, RTKs[r-1])
return state_output
def LilliputTBCDec(tweak, key, cipher) :
r = _rounds(len(key))
tweakey = BuildTweakey(tweak, key)
RTKs = TweakeyScheduleWhole(tweakey, r)
state = [0 for byte in range(0, BLOCK_BYTES)]
for byte in range(0, BLOCK_BYTES) :
state[byte] = cipher[byte]
for i in range(0, r-1) :
state_output = OneRoundEGFNDec(state, RTKs[r-i-1])
for byte in range(0, BLOCK_BYTES) :
state[byte] = state_output[byte]
state_output = LastRoundEGFN(state, RTKs[0])
return state_output
|
