Repository navigation
Expand file tree
/
Copy pathreader.go
More file actions
154 lines (132 loc) · 4.01 KB
/
Copy pathreader.go
File metadata and controls
154 lines (132 loc) · 4.01 KB
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
/*
* Minio Cloud Storage, (C) 2017 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package hash
import (
"bytes"
"crypto/md5"
"encoding/base64"
"encoding/hex"
"errors"
"hash"
"io"
sha256 "github.com/minio/sha256-simd"
)
var errNestedReader = errors.New("Nesting of Reader detected, not allowed")
// Reader writes what it reads from an io.Reader to an MD5 and SHA256 hash.Hash.
// Reader verifies that the content of the io.Reader matches the expected checksums.
type Reader struct {
src io.Reader
size int64
actualSize int64
md5sum, sha256sum []byte // Byte values of md5sum, sha256sum of client sent values.
md5Hash, sha256Hash hash.Hash
}
// NewReader returns a new hash Reader which computes the MD5 sum and
// SHA256 sum (if set) of the provided io.Reader at EOF.
func NewReader(src io.Reader, size int64, md5Hex, sha256Hex string, actualSize int64) (*Reader, error) {
if _, ok := src.(*Reader); ok {
return nil, errNestedReader
}
sha256sum, err := hex.DecodeString(sha256Hex)
if err != nil {
return nil, SHA256Mismatch{}
}
md5sum, err := hex.DecodeString(md5Hex)
if err != nil {
return nil, BadDigest{}
}
var sha256Hash hash.Hash
if len(sha256sum) != 0 {
sha256Hash = sha256.New()
}
if size >= 0 {
src = io.LimitReader(src, size)
}
return &Reader{
md5sum: md5sum,
sha256sum: sha256sum,
src: src,
size: size,
md5Hash: md5.New(),
sha256Hash: sha256Hash,
actualSize: actualSize,
}, nil
}
func (r *Reader) Read(p []byte) (n int, err error) {
n, err = r.src.Read(p)
if n > 0 {
r.md5Hash.Write(p[:n])
if r.sha256Hash != nil {
r.sha256Hash.Write(p[:n])
}
}
// At io.EOF verify if the checksums are right.
if err == io.EOF {
if cerr := r.Verify(); cerr != nil {
return 0, cerr
}
}
return
}
// Size returns the absolute number of bytes the Reader
// will return during reading. It returns -1 for unlimited
// data.
func (r *Reader) Size() int64 { return r.size }
// ActualSize returns the pre-modified size of the object.
// DecompressedSize - For compressed objects.
func (r *Reader) ActualSize() int64 { return r.actualSize }
// MD5 - returns byte md5 value
func (r *Reader) MD5() []byte {
return r.md5sum
}
// MD5Current - returns byte md5 value of the current state
// of the md5 hash after reading the incoming content.
// NOTE: Calling this function multiple times might yield
// different results if they are intermixed with Reader.
func (r *Reader) MD5Current() []byte {
return r.md5Hash.Sum(nil)
}
// SHA256 - returns byte sha256 value
func (r *Reader) SHA256() []byte {
return r.sha256sum
}
// MD5HexString returns hex md5 value.
func (r *Reader) MD5HexString() string {
return hex.EncodeToString(r.md5sum)
}
// MD5Base64String returns base64 encoded MD5sum value.
func (r *Reader) MD5Base64String() string {
return base64.StdEncoding.EncodeToString(r.md5sum)
}
// SHA256HexString returns hex sha256 value.
func (r *Reader) SHA256HexString() string {
return hex.EncodeToString(r.sha256sum)
}
// Verify verifies if the computed MD5 sum and SHA256 sum are
// equal to the ones specified when creating the Reader.
func (r *Reader) Verify() error {
if r.sha256Hash != nil && len(r.sha256sum) > 0 {
if sum := r.sha256Hash.Sum(nil); !bytes.Equal(r.sha256sum, sum) {
return SHA256Mismatch{hex.EncodeToString(r.sha256sum), hex.EncodeToString(sum)}
}
}
if len(r.md5sum) > 0 {
if sum := r.md5Hash.Sum(nil); !bytes.Equal(r.md5sum, sum) {
return BadDigest{hex.EncodeToString(r.md5sum), hex.EncodeToString(sum)}
}
}
return nil
}