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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
// Copyright © 2021 rsiddharth <s@ricketyspace.net>
// SPDX-License-Identifier: ISC
package lib
// MD4 implementation.
// Reference https://datatracker.ietf.org/doc/html/rfc1320
type Md4 struct {
hvs []uint32
Msg []byte
MsgLen int
}
// Initial hash value.
var md4IHashValues []uint32 = []uint32{
0x67452301,
0xefcdab89,
0x98badcfe,
0x10325476,
}
func md4F(x, y, z uint32) uint32 {
return (x & y) | (^x & z)
}
func md4G(x, y, z uint32) uint32 {
return (x & y) | (x & z) | (y & z)
}
func md4H(x, y, z uint32) uint32 {
return x ^ y ^ z
}
func md4RoundOneFunc(a, b, c, d, x uint32, s uint) uint32 {
a = shaAdd(a, md4F(b, c, d), x)
a = shaRotl(a, s)
return a
}
func md4RoundTwoFunc(a, b, c, d, x uint32, s uint) uint32 {
a = shaAdd(a, md4G(b, c, d), x, 0x5A827999)
a = shaRotl(a, s)
return a
}
func md4RoundThreeFunc(a, b, c, d, x uint32, s uint) uint32 {
a = shaAdd(a, md4H(b, c, d), x, 0x6ED9EBA1)
a = shaRotl(a, s)
return a
}
func Md4Padding(l int) []byte {
l = l * 8 // msg size in bits
// Reckon value of `k`
k := 0
for ((l + 1 + k) % 512) != 448 {
k += 1
}
// Initialize padding bytes
pbs := make([]byte, 0)
// Add bit `1` as byte block.
pbs = append(pbs, 0x80)
f := 7 // unclaimed bits in last byte of `pbs`
// Add `k` bit `0`s
for i := 0; i < k; i++ {
if f == 0 {
pbs = append(pbs, 0x0)
f = 8
}
f = f - 1
}
// Add `l` in a 64 bit block in `pbs`
l64 := uint64(l)
b64 := make([]byte, 8) // last 64-bits
for i := 0; i <= 7; i++ {
// Get 8 last bits.
b64[i] = byte(l64 & 0xFF)
// Get rid of the last 8 bits.
l64 = l64 >> 8
}
pbs = append(pbs, b64...)
return pbs
}
func md4MessageBlocks(pm []byte) [][]uint32 {
// Break into 512-bit blocks
bs := BreakIntoBlocks(pm, 64)
mbs := make([][]uint32, 0) // Message blocks.
for i := 0; i < len(bs); i++ {
ws := make([]uint32, 0) // 32-bit words.
// Break 512-bit (64 bytes) into 32-bit words.
for j := 0; j < 64; j = j + 4 {
// Pack 4 bytes into a 32-bit word.
w := (uint32(bs[i][j]) |
uint32(bs[i][j+1])<<8 |
uint32(bs[i][j+2])<<16 |
uint32(bs[i][j+3])<<24)
ws = append(ws, w)
}
mbs = append(mbs, ws)
}
return mbs
}
func (md *Md4) Init(hvs []uint32) {
// Set Initial Hash Values.
h := make([]uint32, 4)
if len(hvs) == 4 {
copy(h, hvs)
md.hvs = h
} else {
copy(h, md4IHashValues)
md.hvs = h
}
}
func (md *Md4) Message(m []byte) {
md.Msg = m
md.MsgLen = len(m)
}
// MD4 - Pad message such that its length is a multiple of 512.
func (md *Md4) Pad() []byte {
// Initialize padded message
pm := make([]byte, len(md.Msg))
copy(pm, md.Msg)
// Add padding.
pm = append(pm, Md4Padding(md.MsgLen)...)
return pm
}
func (md *Md4) Hash() []byte {
// Pad message.
pm := md.Pad()
// Break into message blocks.
mbs := md4MessageBlocks(pm)
// Initialize hash values.
h := make([]uint32, 4)
copy(h, md.hvs) // Initial hash values.
// Process each message block.
for _, mb := range mbs {
// Initialize working variables.
a := h[0]
b := h[1]
c := h[2]
d := h[3]
// Round 1.
a = md4RoundOneFunc(a, b, c, d, mb[0], 3)
d = md4RoundOneFunc(d, a, b, c, mb[1], 7)
c = md4RoundOneFunc(c, d, a, b, mb[2], 11)
b = md4RoundOneFunc(b, c, d, a, mb[3], 19)
a = md4RoundOneFunc(a, b, c, d, mb[4], 3)
d = md4RoundOneFunc(d, a, b, c, mb[5], 7)
c = md4RoundOneFunc(c, d, a, b, mb[6], 11)
b = md4RoundOneFunc(b, c, d, a, mb[7], 19)
a = md4RoundOneFunc(a, b, c, d, mb[8], 3)
d = md4RoundOneFunc(d, a, b, c, mb[9], 7)
c = md4RoundOneFunc(c, d, a, b, mb[10], 11)
b = md4RoundOneFunc(b, c, d, a, mb[11], 19)
a = md4RoundOneFunc(a, b, c, d, mb[12], 3)
d = md4RoundOneFunc(d, a, b, c, mb[13], 7)
c = md4RoundOneFunc(c, d, a, b, mb[14], 11)
b = md4RoundOneFunc(b, c, d, a, mb[15], 19)
// Round 2
a = md4RoundTwoFunc(a, b, c, d, mb[0], 3)
d = md4RoundTwoFunc(d, a, b, c, mb[4], 5)
c = md4RoundTwoFunc(c, d, a, b, mb[8], 9)
b = md4RoundTwoFunc(b, c, d, a, mb[12], 13)
a = md4RoundTwoFunc(a, b, c, d, mb[1], 3)
d = md4RoundTwoFunc(d, a, b, c, mb[5], 5)
c = md4RoundTwoFunc(c, d, a, b, mb[9], 9)
b = md4RoundTwoFunc(b, c, d, a, mb[13], 13)
a = md4RoundTwoFunc(a, b, c, d, mb[2], 3)
d = md4RoundTwoFunc(d, a, b, c, mb[6], 5)
c = md4RoundTwoFunc(c, d, a, b, mb[10], 9)
b = md4RoundTwoFunc(b, c, d, a, mb[14], 13)
a = md4RoundTwoFunc(a, b, c, d, mb[3], 3)
d = md4RoundTwoFunc(d, a, b, c, mb[7], 5)
c = md4RoundTwoFunc(c, d, a, b, mb[11], 9)
b = md4RoundTwoFunc(b, c, d, a, mb[15], 13)
// Round 3
a = md4RoundThreeFunc(a, b, c, d, mb[0], 3)
d = md4RoundThreeFunc(d, a, b, c, mb[8], 9)
c = md4RoundThreeFunc(c, d, a, b, mb[4], 11)
b = md4RoundThreeFunc(b, c, d, a, mb[12], 15)
a = md4RoundThreeFunc(a, b, c, d, mb[2], 3)
d = md4RoundThreeFunc(d, a, b, c, mb[10], 9)
c = md4RoundThreeFunc(c, d, a, b, mb[6], 11)
b = md4RoundThreeFunc(b, c, d, a, mb[14], 15)
a = md4RoundThreeFunc(a, b, c, d, mb[1], 3)
d = md4RoundThreeFunc(d, a, b, c, mb[9], 9)
c = md4RoundThreeFunc(c, d, a, b, mb[5], 11)
b = md4RoundThreeFunc(b, c, d, a, mb[13], 15)
a = md4RoundThreeFunc(a, b, c, d, mb[3], 3)
d = md4RoundThreeFunc(d, a, b, c, mb[11], 9)
c = md4RoundThreeFunc(c, d, a, b, mb[7], 11)
b = md4RoundThreeFunc(b, c, d, a, mb[15], 15)
// Compute intermediate hash values.
h[0] = shaAdd(a, h[0])
h[1] = shaAdd(b, h[1])
h[2] = shaAdd(c, h[2])
h[3] = shaAdd(d, h[3])
}
// Slurp md4 digest from hash values.
d := make([]byte, 0) // md4 digest
for i := 0; i < 4; i++ {
// Break 32-bit hash value into 4 bytes.
hb := make([]byte, 4)
for j := 0; j <= 3; j++ {
// Get last 8 bits.
hb[j] = byte(h[i] & 0xFF)
// Get rid of last 8 bits.
h[i] = h[i] >> 8
}
d = append(d, hb...)
}
return d
}
|
