blob: d84cebf2ff2c1734ee143ee0ac3bd50ede3e2932 (
plain)
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
|
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package sha256 implements the SHA224 and SHA256 hash algorithms as defined
// in FIPS 180-4.
package sha256
import (
"crypto"
"hash"
)
func init() {
crypto.RegisterHash(crypto.SHA224, New224)
crypto.RegisterHash(crypto.SHA256, New)
}
// The size of a SHA256 checksum in bytes.
const Size = 32
// The size of a SHA224 checksum in bytes.
const Size224 = 28
// The blocksize of SHA256 and SHA224 in bytes.
const BlockSize = 64
const (
chunk = 64
init0 = 0x6A09E667
init1 = 0xBB67AE85
init2 = 0x3C6EF372
init3 = 0xA54FF53A
init4 = 0x510E527F
init5 = 0x9B05688C
init6 = 0x1F83D9AB
init7 = 0x5BE0CD19
init0_224 = 0xC1059ED8
init1_224 = 0x367CD507
init2_224 = 0x3070DD17
init3_224 = 0xF70E5939
init4_224 = 0xFFC00B31
init5_224 = 0x68581511
init6_224 = 0x64F98FA7
init7_224 = 0xBEFA4FA4
)
// digest represents the partial evaluation of a checksum.
type digest struct {
h [8]uint32
x [chunk]byte
nx int
len uint64
is224 bool // mark if this digest is SHA-224
}
func (d *digest) Reset() {
if !d.is224 {
d.h[0] = init0
d.h[1] = init1
d.h[2] = init2
d.h[3] = init3
d.h[4] = init4
d.h[5] = init5
d.h[6] = init6
d.h[7] = init7
} else {
d.h[0] = init0_224
d.h[1] = init1_224
d.h[2] = init2_224
d.h[3] = init3_224
d.h[4] = init4_224
d.h[5] = init5_224
d.h[6] = init6_224
d.h[7] = init7_224
}
d.nx = 0
d.len = 0
}
// New returns a new hash.Hash computing the SHA256 checksum.
func New() hash.Hash {
d := new(digest)
d.Reset()
return d
}
// New224 returns a new hash.Hash computing the SHA224 checksum.
func New224() hash.Hash {
d := new(digest)
d.is224 = true
d.Reset()
return d
}
func (d *digest) Size() int {
if !d.is224 {
return Size
}
return Size224
}
func (d *digest) BlockSize() int { return BlockSize }
func (d *digest) Write(p []byte) (nn int, err error) {
nn = len(p)
d.len += uint64(nn)
if d.nx > 0 {
n := copy(d.x[d.nx:], p)
d.nx += n
if d.nx == chunk {
block(d, d.x[:])
d.nx = 0
}
p = p[n:]
}
if len(p) >= chunk {
n := len(p) &^ (chunk - 1)
block(d, p[:n])
p = p[n:]
}
if len(p) > 0 {
d.nx = copy(d.x[:], p)
}
return
}
func (d0 *digest) Sum(in []byte) []byte {
// Make a copy of d0 so that caller can keep writing and summing.
d := *d0
hash := d.checkSum()
if d.is224 {
return append(in, hash[:Size224]...)
}
return append(in, hash[:]...)
}
func (d *digest) checkSum() [Size]byte {
len := d.len
// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
var tmp [64]byte
tmp[0] = 0x80
if len%64 < 56 {
d.Write(tmp[0 : 56-len%64])
} else {
d.Write(tmp[0 : 64+56-len%64])
}
// Length in bits.
len <<= 3
for i := uint(0); i < 8; i++ {
tmp[i] = byte(len >> (56 - 8*i))
}
d.Write(tmp[0:8])
if d.nx != 0 {
panic("d.nx != 0")
}
h := d.h[:]
if d.is224 {
h = d.h[:7]
}
var digest [Size]byte
for i, s := range h {
digest[i*4] = byte(s >> 24)
digest[i*4+1] = byte(s >> 16)
digest[i*4+2] = byte(s >> 8)
digest[i*4+3] = byte(s)
}
return digest
}
// Sum256 returns the SHA256 checksum of the data.
func Sum256(data []byte) [Size]byte {
var d digest
d.Reset()
d.Write(data)
return d.checkSum()
}
// Sum224 returns the SHA224 checksum of the data.
func Sum224(data []byte) (sum224 [Size224]byte) {
var d digest
d.is224 = true
d.Reset()
d.Write(data)
sum := d.checkSum()
copy(sum224[:], sum[:Size224])
return
}
|
