Repository navigation
Expand file tree
/
Copy pathbitrot.go
More file actions
194 lines (173 loc) · 5.71 KB
/
Copy pathbitrot.go
File metadata and controls
194 lines (173 loc) · 5.71 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
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
194
/*
* Minio Cloud Storage, (C) 2018 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 cmd
import (
"context"
"errors"
"hash"
"github.com/minio/highwayhash"
"github.com/minio/minio/cmd/logger"
sha256 "github.com/minio/sha256-simd"
"golang.org/x/crypto/blake2b"
)
// magic HH-256 key as HH-256 hash of the first 100 decimals of π as utf-8 string with a zero key.
var magicHighwayHash256Key = []byte("\x4b\xe7\x34\xfa\x8e\x23\x8a\xcd\x26\x3e\x83\xe6\xbb\x96\x85\x52\x04\x0f\x93\x5d\xa3\x9f\x44\x14\x97\xe0\x9d\x13\x22\xde\x36\xa0")
// BitrotAlgorithm specifies a algorithm used for bitrot protection.
type BitrotAlgorithm uint
const (
// SHA256 represents the SHA-256 hash function
SHA256 BitrotAlgorithm = 1 + iota
// HighwayHash256 represents the HighwayHash-256 hash function
HighwayHash256
// BLAKE2b512 represents the BLAKE2b-512 hash function
BLAKE2b512
)
// DefaultBitrotAlgorithm is the default algorithm used for bitrot protection.
const (
DefaultBitrotAlgorithm = HighwayHash256
)
var bitrotAlgorithms = map[BitrotAlgorithm]string{
SHA256: "sha256",
BLAKE2b512: "blake2b",
HighwayHash256: "highwayhash256",
}
// New returns a new hash.Hash calculating the given bitrot algorithm.
func (a BitrotAlgorithm) New() hash.Hash {
switch a {
case SHA256:
return sha256.New()
case BLAKE2b512:
b2, _ := blake2b.New512(nil) // New512 never returns an error if the key is nil
return b2
case HighwayHash256:
hh, _ := highwayhash.New(magicHighwayHash256Key) // New will never return error since key is 256 bit
return hh
default:
logger.CriticalIf(context.Background(), errors.New("Unsupported bitrot algorithm"))
return nil
}
}
// Available reports whether the given algorithm is available.
func (a BitrotAlgorithm) Available() bool {
_, ok := bitrotAlgorithms[a]
return ok
}
// String returns the string identifier for a given bitrot algorithm.
// If the algorithm is not supported String panics.
func (a BitrotAlgorithm) String() string {
name, ok := bitrotAlgorithms[a]
if !ok {
logger.CriticalIf(context.Background(), errors.New("Unsupported bitrot algorithm"))
}
return name
}
// NewBitrotVerifier returns a new BitrotVerifier implementing the given algorithm.
func NewBitrotVerifier(algorithm BitrotAlgorithm, checksum []byte) *BitrotVerifier {
return &BitrotVerifier{algorithm, checksum}
}
// BitrotVerifier can be used to verify protected data.
type BitrotVerifier struct {
algorithm BitrotAlgorithm
sum []byte
}
// BitrotAlgorithmFromString returns a bitrot algorithm from the given string representation.
// It returns 0 if the string representation does not match any supported algorithm.
// The zero value of a bitrot algorithm is never supported.
func BitrotAlgorithmFromString(s string) (a BitrotAlgorithm) {
for alg, name := range bitrotAlgorithms {
if name == s {
return alg
}
}
return
}
// To read bit-rot verified data.
type bitrotReader struct {
disk StorageAPI
volume string
filePath string
verifier *BitrotVerifier // Holds the bit-rot info
endOffset int64 // Affects the length of data requested in disk.ReadFile depending on Read()'s offset
buf []byte // Holds bit-rot verified data
}
// newBitrotReader returns bitrotReader.
// Note that the buffer is allocated later in Read(). This is because we will know the buffer length only
// during the bitrotReader.Read(). Depending on when parallelReader fails-over, the buffer length can be different.
func newBitrotReader(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm, endOffset int64, sum []byte) *bitrotReader {
return &bitrotReader{
disk: disk,
volume: volume,
filePath: filePath,
verifier: &BitrotVerifier{algo, sum},
endOffset: endOffset,
buf: nil,
}
}
// ReadChunk returns requested data.
func (b *bitrotReader) ReadChunk(offset int64, length int64) ([]byte, error) {
if b.buf == nil {
b.buf = make([]byte, b.endOffset-offset)
if _, err := b.disk.ReadFile(b.volume, b.filePath, offset, b.buf, b.verifier); err != nil {
ctx := context.Background()
logger.GetReqInfo(ctx).AppendTags("disk", b.disk.String())
logger.LogIf(ctx, err)
return nil, err
}
}
if int64(len(b.buf)) < length {
logger.LogIf(context.Background(), errLessData)
return nil, errLessData
}
retBuf := b.buf[:length]
b.buf = b.buf[length:]
return retBuf, nil
}
// To calculate the bit-rot of the written data.
type bitrotWriter struct {
disk StorageAPI
volume string
filePath string
h hash.Hash
}
// newBitrotWriter returns bitrotWriter.
func newBitrotWriter(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm) *bitrotWriter {
return &bitrotWriter{
disk: disk,
volume: volume,
filePath: filePath,
h: algo.New(),
}
}
// Append appends the data and while calculating the hash.
func (b *bitrotWriter) Append(buf []byte) error {
n, err := b.h.Write(buf)
if err != nil {
return err
}
if n != len(buf) {
logger.LogIf(context.Background(), errUnexpected)
return errUnexpected
}
if err = b.disk.AppendFile(b.volume, b.filePath, buf); err != nil {
logger.LogIf(context.Background(), err)
return err
}
return nil
}
// Sum returns bit-rot sum.
func (b *bitrotWriter) Sum() []byte {
return b.h.Sum(nil)
}