-
Notifications
You must be signed in to change notification settings - Fork 56
/
eia256.go
239 lines (222 loc) · 5.11 KB
/
eia256.go
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
package zuc
import (
"encoding/binary"
"fmt"
)
type ZUC256Mac struct {
zucState32
k0 [8]uint32
t []uint32
x [chunk]byte
nx int
len uint64
tagSize int
initState zucState32
}
// NewHash256 create hash for zuc-256 eia, with arguments key, iv and tagSize.
// Key size is 32 in bytes, iv size is 23 in bytes, tagSize supports 4/8/16 in bytes.
// The larger the tag size, the worse the performance.
func NewHash256(key, iv []byte, tagSize int) (*ZUC256Mac, error) {
k := len(key)
ivLen := len(iv)
mac := &ZUC256Mac{}
var d []byte
switch tagSize {
default:
return nil, fmt.Errorf("zuc/eia: invalid tag size %d, support 4/8/16 in bytes", tagSize)
case 4:
d = zuc256_d[0][:]
case 8:
d = zuc256_d[1][:]
case 16:
d = zuc256_d[2][:]
}
mac.tagSize = tagSize
mac.t = make([]uint32, mac.tagSize/4)
switch k {
default:
return nil, fmt.Errorf("zuc/eia: invalid key size %d, expect 32 in bytes", k)
case 32: // ZUC-256
if ivLen != IVSize256 {
return nil, fmt.Errorf("zuc/eia: invalid iv size %d, expect %d in bytes", ivLen, IVSize256)
}
mac.loadKeyIV32(key, iv, d)
}
// initialization
for i := 0; i < 32; i++ {
mac.bitReorganization()
w := mac.f32()
mac.enterInitMode(w >> 1)
}
// work state
mac.bitReorganization()
mac.f32()
mac.enterWorkMode()
mac.initState.r1 = mac.r1
mac.initState.r2 = mac.r2
copy(mac.initState.lfsr[:], mac.lfsr[:])
mac.Reset()
return mac, nil
}
func (m *ZUC256Mac) Size() int {
return m.tagSize
}
func (m *ZUC256Mac) BlockSize() int {
return chunk
}
// Reset resets the Hash to its initial state.
func (m *ZUC256Mac) Reset() {
m.nx = 0
m.len = 0
m.r1 = m.initState.r1
m.r2 = m.initState.r2
copy(m.lfsr[:], m.initState.lfsr[:])
m.genKeywords(m.t)
m.genKeywords(m.k0[:4])
}
func block256Generic(m *ZUC256Mac, p []byte) {
var k64, t64 uint64
if m.tagSize == 4 {
t64 = uint64(m.t[0]) << 32
}
tagWords := m.tagSize / 4
for len(p) >= chunk {
m.genKeywords(m.k0[4:])
for l := 0; l < 4; l++ {
w := binary.BigEndian.Uint32(p[l*4:])
switch m.tagSize {
case 4:
k64 = uint64(m.k0[l])<<32 | uint64(m.k0[l+1])
for j := 0; j < 32; j++ {
t64 ^= ^(uint64(w>>31) - 1) & k64
w <<= 1
k64 <<= 1
}
default:
k1 := m.k0[tagWords+l]
for i := 0; i < 32; i++ {
wBit := ^(w>>31 - 1)
for j := 0; j < tagWords; j++ {
m.t[j] ^= wBit & m.k0[j]
}
w <<= 1
var j int
for j = 0; j < tagWords-1; j++ {
m.k0[j] = (m.k0[j] << 1) | (m.k0[j+1] >> 31)
}
m.k0[j] = (m.k0[j] << 1) | (k1 >> 31)
k1 <<= 1
}
}
}
if tagWords != 4 {
copy(m.k0[:4], m.k0[4:])
}
p = p[chunk:]
}
if m.tagSize == 4 {
m.t[0] = uint32(t64 >> 32)
}
}
func (m *ZUC256Mac) Write(p []byte) (nn int, err error) {
nn = len(p)
m.len += uint64(nn)
if m.nx > 0 {
n := copy(m.x[m.nx:], p)
m.nx += n
if m.nx == chunk {
block256(m, m.x[:])
m.nx = 0
}
p = p[n:]
}
if len(p) >= chunk {
n := len(p) &^ (chunk - 1)
block256(m, p[:n])
p = p[n:]
}
if len(p) > 0 {
m.nx = copy(m.x[:], p)
}
return
}
func (m *ZUC256Mac) checkSum(additionalBits int, b byte) []byte {
if m.nx >= chunk {
panic("m.nx >= 16")
}
kIdx := 0
if m.nx > 0 || additionalBits > 0 {
m.x[m.nx] = b
m.genKeywords(m.k0[4:])
nRemainBits := 8*m.nx + additionalBits
words := (nRemainBits + 31) / 32
for l := 0; l < words-1; l++ {
w := binary.BigEndian.Uint32(m.x[l*4:])
k1 := m.k0[m.tagSize/4+l]
for i := 0; i < 32; i++ {
wBit := ^(w>>31 - 1)
for j := 0; j < m.tagSize/4; j++ {
m.t[j] ^= wBit & m.k0[j]
}
w <<= 1
var j int
for j = 0; j < m.tagSize/4-1; j++ {
m.k0[j] = (m.k0[j] << 1) | (m.k0[j+1] >> 31)
}
m.k0[j] = (m.k0[j] << 1) | (k1 >> 31)
k1 <<= 1
}
}
nRemainBits -= (words - 1) * 32
kIdx = words - 1
if nRemainBits > 0 {
w := binary.BigEndian.Uint32(m.x[(words-1)*4:])
for i := 0; i < nRemainBits; i++ {
wBit := ^(w>>31 - 1)
for j := 0; j < m.tagSize/4; j++ {
m.t[j] ^= wBit & m.k0[j+kIdx]
}
w <<= 1
var j int
for j = 0; j < m.tagSize/4; j++ {
m.k0[j+kIdx] = (m.k0[j+kIdx] << 1) | (m.k0[kIdx+j+1] >> 31)
}
m.k0[j+kIdx] <<= 1
}
}
}
digest := make([]byte, m.tagSize)
for j := 0; j < m.tagSize/4; j++ {
m.t[j] ^= m.k0[j+kIdx]
binary.BigEndian.PutUint32(digest[j*4:], m.t[j])
}
return digest
}
// Finish this function hash nbits data in p and return mac value
// In general, we will use byte level function, this is just for test/verify.
func (m *ZUC256Mac) Finish(p []byte, nbits int) []byte {
if len(p) < (nbits+7)/8 {
panic("invalid p length")
}
nbytes := nbits / 8
nRemainBits := nbits - nbytes*8
if nbytes > 0 {
m.Write(p[:nbytes])
}
var b byte
if nRemainBits > 0 {
b = p[nbytes]
}
digest := m.checkSum(nRemainBits, b)
return digest[:]
}
// Sum appends the current hash to in and returns the resulting slice.
// It does not change the underlying hash state.
func (m *ZUC256Mac) Sum(in []byte) []byte {
// Make a copy of d so that caller can keep writing and summing.
d0 := *m
d0.t = make([]uint32, len(m.t))
copy(d0.t, m.t)
hash := d0.checkSum(0, 0)
return append(in, hash[:]...)
}