OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgo/] [go/] [crypto/] [sha256/] [sha256.go] - Blame information for rev 747

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 747 jeremybenn 
// Copyright 2009 The Go Authors. All rights reserved.
2 
// Use of this source code is governed by a BSD-style
3 
// license that can be found in the LICENSE file.
4 
 
5 
// Package sha256 implements the SHA224 and SHA256 hash algorithms as defined
6 
// in FIPS 180-2.
7 
package sha256
8 
 
9 
import (
10 
        "crypto"
11 
        "hash"
12 
)
13 
 
14 
func init() {
15 
        crypto.RegisterHash(crypto.SHA224, New224)
16 
        crypto.RegisterHash(crypto.SHA256, New)
17 
}
18 
 
19 
// The size of a SHA256 checksum in bytes.
20 
const Size = 32
21 
 
22 
// The size of a SHA224 checksum in bytes.
23 
const Size224 = 28
24 
 
25 
// The blocksize of SHA256 and SHA224 in bytes.
26 
const BlockSize = 64
27 
 
28 
const (
29 
        _Chunk     = 64
30 
        _Init0     = 0x6A09E667
31 
        _Init1     = 0xBB67AE85
32 
        _Init2     = 0x3C6EF372
33 
        _Init3     = 0xA54FF53A
34 
        _Init4     = 0x510E527F
35 
        _Init5     = 0x9B05688C
36 
        _Init6     = 0x1F83D9AB
37 
        _Init7     = 0x5BE0CD19
38 
        _Init0_224 = 0xC1059ED8
39 
        _Init1_224 = 0x367CD507
40 
        _Init2_224 = 0x3070DD17
41 
        _Init3_224 = 0xF70E5939
42 
        _Init4_224 = 0xFFC00B31
43 
        _Init5_224 = 0x68581511
44 
        _Init6_224 = 0x64F98FA7
45 
        _Init7_224 = 0xBEFA4FA4
46 
)
47 
 
48 
// digest represents the partial evaluation of a checksum.
49 
type digest struct {
50 
        h     [8]uint32
51 
        x     [_Chunk]byte
52 
        nx    int
53 
        len   uint64
54 
        is224 bool // mark if this digest is SHA-224
55 
}
56 
 
57 
func (d *digest) Reset() {
58 
        if !d.is224 {
59 
                d.h[0] = _Init0
60 
                d.h[1] = _Init1
61 
                d.h[2] = _Init2
62 
                d.h[3] = _Init3
63 
                d.h[4] = _Init4
64 
                d.h[5] = _Init5
65 
                d.h[6] = _Init6
66 
                d.h[7] = _Init7
67 
        } else {
68 
                d.h[0] = _Init0_224
69 
                d.h[1] = _Init1_224
70 
                d.h[2] = _Init2_224
71 
                d.h[3] = _Init3_224
72 
                d.h[4] = _Init4_224
73 
                d.h[5] = _Init5_224
74 
                d.h[6] = _Init6_224
75 
                d.h[7] = _Init7_224
76 
        }
77 
        d.nx = 0
78 
        d.len = 0
79 
}
80 
 
81 
// New returns a new hash.Hash computing the SHA256 checksum.
82 
func New() hash.Hash {
83 
        d := new(digest)
84 
        d.Reset()
85 
        return d
86 
}
87 
 
88 
// New224 returns a new hash.Hash computing the SHA224 checksum.
89 
func New224() hash.Hash {
90 
        d := new(digest)
91 
        d.is224 = true
92 
        d.Reset()
93 
        return d
94 
}
95 
 
96 
func (d *digest) Size() int {
97 
        if !d.is224 {
98 
                return Size
99 
        }
100 
        return Size224
101 
}
102 
 
103 
func (d *digest) BlockSize() int { return BlockSize }
104 
 
105 
func (d *digest) Write(p []byte) (nn int, err error) {
106 
        nn = len(p)
107 
        d.len += uint64(nn)
108 
        if d.nx > 0 {
109 
                n := len(p)
110 
                if n > _Chunk-d.nx {
111 
                        n = _Chunk - d.nx
112 
                }
113 
                for i := 0; i < n; i++ {
114 
                        d.x[d.nx+i] = p[i]
115 
                }
116 
                d.nx += n
117 
                if d.nx == _Chunk {
118 
                        _Block(d, d.x[0:])
119 
                        d.nx = 0
120 
                }
121 
                p = p[n:]
122 
        }
123 
        n := _Block(d, p)
124 
        p = p[n:]
125 
        if len(p) > 0 {
126 
                d.nx = copy(d.x[:], p)
127 
        }
128 
        return
129 
}
130 
 
131 
func (d0 *digest) Sum(in []byte) []byte {
132 
        // Make a copy of d0 so that caller can keep writing and summing.
133 
        d := *d0
134 
 
135 
        // Padding.  Add a 1 bit and 0 bits until 56 bytes mod 64.
136 
        len := d.len
137 
        var tmp [64]byte
138 
        tmp[0] = 0x80
139 
        if len%64 < 56 {
140 
                d.Write(tmp[0 : 56-len%64])
141 
        } else {
142 
                d.Write(tmp[0 : 64+56-len%64])
143 
        }
144 
 
145 
        // Length in bits.
146 
        len <<= 3
147 
        for i := uint(0); i < 8; i++ {
148 
                tmp[i] = byte(len >> (56 - 8*i))
149 
        }
150 
        d.Write(tmp[0:8])
151 
 
152 
        if d.nx != 0 {
153 
                panic("d.nx != 0")
154 
        }
155 
 
156 
        h := d.h[:]
157 
        size := Size
158 
        if d.is224 {
159 
                h = d.h[:7]
160 
                size = Size224
161 
        }
162 
 
163 
        var digest [Size]byte
164 
        for i, s := range h {
165 
                digest[i*4] = byte(s >> 24)
166 
                digest[i*4+1] = byte(s >> 16)
167 
                digest[i*4+2] = byte(s >> 8)
168 
                digest[i*4+3] = byte(s)
169 
        }
170 
 
171 
        return append(in, digest[:size]...)
172 
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.