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
|
// Copyright 2017 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.
//go:build boringcrypto && linux && amd64 && !android && !cmd_go_bootstrap && !msan
// +build boringcrypto,linux,amd64,!android,!cmd_go_bootstrap,!msan
package boring
// #include "goboringcrypto.h"
import "C"
import (
"crypto"
"hash"
"runtime"
"unsafe"
)
// hashToMD converts a hash.Hash implementation from this package
// to a BoringCrypto *C.GO_EVP_MD.
func hashToMD(h hash.Hash) *C.GO_EVP_MD {
switch h.(type) {
case *sha1Hash:
return C._goboringcrypto_EVP_sha1()
case *sha224Hash:
return C._goboringcrypto_EVP_sha224()
case *sha256Hash:
return C._goboringcrypto_EVP_sha256()
case *sha384Hash:
return C._goboringcrypto_EVP_sha384()
case *sha512Hash:
return C._goboringcrypto_EVP_sha512()
}
return nil
}
// cryptoHashToMD converts a crypto.Hash
// to a BoringCrypto *C.GO_EVP_MD.
func cryptoHashToMD(ch crypto.Hash) *C.GO_EVP_MD {
switch ch {
case crypto.MD5:
return C._goboringcrypto_EVP_md5()
case crypto.MD5SHA1:
return C._goboringcrypto_EVP_md5_sha1()
case crypto.SHA1:
return C._goboringcrypto_EVP_sha1()
case crypto.SHA224:
return C._goboringcrypto_EVP_sha224()
case crypto.SHA256:
return C._goboringcrypto_EVP_sha256()
case crypto.SHA384:
return C._goboringcrypto_EVP_sha384()
case crypto.SHA512:
return C._goboringcrypto_EVP_sha512()
}
return nil
}
// NewHMAC returns a new HMAC using BoringCrypto.
// The function h must return a hash implemented by
// BoringCrypto (for example, h could be boring.NewSHA256).
// If h is not recognized, NewHMAC returns nil.
func NewHMAC(h func() hash.Hash, key []byte) hash.Hash {
ch := h()
md := hashToMD(ch)
if md == nil {
return nil
}
// Note: Could hash down long keys here using EVP_Digest.
hkey := make([]byte, len(key))
copy(hkey, key)
hmac := &boringHMAC{
md: md,
size: ch.Size(),
blockSize: ch.BlockSize(),
key: hkey,
}
hmac.Reset()
return hmac
}
type boringHMAC struct {
md *C.GO_EVP_MD
ctx C.GO_HMAC_CTX
ctx2 C.GO_HMAC_CTX
size int
blockSize int
key []byte
sum []byte
needCleanup bool
}
func (h *boringHMAC) Reset() {
if h.needCleanup {
C._goboringcrypto_HMAC_CTX_cleanup(&h.ctx)
} else {
h.needCleanup = true
// Note: Because of the finalizer, any time h.ctx is passed to cgo,
// that call must be followed by a call to runtime.KeepAlive(h),
// to make sure h is not collected (and finalized) before the cgo
// call returns.
runtime.SetFinalizer(h, (*boringHMAC).finalize)
}
C._goboringcrypto_HMAC_CTX_init(&h.ctx)
if C._goboringcrypto_HMAC_Init(&h.ctx, unsafe.Pointer(base(h.key)), C.int(len(h.key)), h.md) == 0 {
panic("boringcrypto: HMAC_Init failed")
}
if int(C._goboringcrypto_HMAC_size(&h.ctx)) != h.size {
println("boringcrypto: HMAC size:", C._goboringcrypto_HMAC_size(&h.ctx), "!=", h.size)
panic("boringcrypto: HMAC size mismatch")
}
runtime.KeepAlive(h) // Next line will keep h alive too; just making doubly sure.
h.sum = nil
}
func (h *boringHMAC) finalize() {
C._goboringcrypto_HMAC_CTX_cleanup(&h.ctx)
}
func (h *boringHMAC) Write(p []byte) (int, error) {
if len(p) > 0 {
C._goboringcrypto_HMAC_Update(&h.ctx, (*C.uint8_t)(unsafe.Pointer(&p[0])), C.size_t(len(p)))
}
runtime.KeepAlive(h)
return len(p), nil
}
func (h *boringHMAC) Size() int {
return h.size
}
func (h *boringHMAC) BlockSize() int {
return h.blockSize
}
func (h *boringHMAC) Sum(in []byte) []byte {
if h.sum == nil {
size := h.Size()
h.sum = make([]byte, size)
}
// Make copy of context because Go hash.Hash mandates
// that Sum has no effect on the underlying stream.
// In particular it is OK to Sum, then Write more, then Sum again,
// and the second Sum acts as if the first didn't happen.
C._goboringcrypto_HMAC_CTX_init(&h.ctx2)
if C._goboringcrypto_HMAC_CTX_copy_ex(&h.ctx2, &h.ctx) == 0 {
panic("boringcrypto: HMAC_CTX_copy_ex failed")
}
C._goboringcrypto_HMAC_Final(&h.ctx2, (*C.uint8_t)(unsafe.Pointer(&h.sum[0])), nil)
C._goboringcrypto_HMAC_CTX_cleanup(&h.ctx2)
return append(in, h.sum...)
}
|
