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
|
// Copyright 2011 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 crypto collects common cryptographic constants.
package crypto
import (
"hash"
)
// Hash identifies a cryptographic hash function that is implemented in another
// package.
type Hash uint
const (
MD4 Hash = 1 + iota // in package crypto/md4
MD5 // in package crypto/md5
SHA1 // in package crypto/sha1
SHA224 // in package crypto/sha256
SHA256 // in package crypto/sha256
SHA384 // in package crypto/sha512
SHA512 // in package crypto/sha512
MD5SHA1 // no implementation; MD5+SHA1 used for TLS RSA
RIPEMD160 // in package crypto/ripemd160
maxHash
)
var digestSizes = []uint8{
MD4: 16,
MD5: 16,
SHA1: 20,
SHA224: 28,
SHA256: 32,
SHA384: 48,
SHA512: 64,
MD5SHA1: 36,
RIPEMD160: 20,
}
// Size returns the length, in bytes, of a digest resulting from the given hash
// function. It doesn't require that the hash function in question be linked
// into the program.
func (h Hash) Size() int {
if h > 0 && h < maxHash {
return int(digestSizes[h])
}
panic("crypto: Size of unknown hash function")
}
var hashes = make([]func() hash.Hash, maxHash)
// New returns a new hash.Hash calculating the given hash function. If the
// hash function is not linked into the binary, New returns nil.
func (h Hash) New() hash.Hash {
if h > 0 && h < maxHash {
f := hashes[h]
if f != nil {
return f()
}
}
return nil
}
// RegisterHash registers a function that returns a new instance of the given
// hash function. This is intended to be called from the init function in
// packages that implement hash functions.
func RegisterHash(h Hash, f func() hash.Hash) {
if h >= maxHash {
panic("crypto: RegisterHash of unknown hash function")
}
hashes[h] = f
}
|
