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
|
// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package git
import (
"crypto/sha1"
"crypto/sha256"
"hash"
"regexp"
"strconv"
)
// sha1Pattern can be used to determine if a string is an valid sha
var sha1Pattern = regexp.MustCompile(`^[0-9a-f]{4,40}$`)
// sha256Pattern can be used to determine if a string is an valid sha
var sha256Pattern = regexp.MustCompile(`^[0-9a-f]{4,64}$`)
type ObjectFormat interface {
// Name returns the name of the object format
Name() string
// EmptyObjectID creates a new empty ObjectID from an object format hash name
EmptyObjectID() ObjectID
// EmptyTree is the hash of an empty tree
EmptyTree() ObjectID
// FullLength is the length of the hash's hex string
FullLength() int
// IsValid returns true if the input is a valid hash
IsValid(input string) bool
// MustID creates a new ObjectID from a byte slice
MustID(b []byte) ObjectID
// ComputeHash compute the hash for a given ObjectType and content
ComputeHash(t ObjectType, content []byte) ObjectID
}
func computeHash(dst []byte, hasher hash.Hash, t ObjectType, content []byte) {
_, _ = hasher.Write(t.Bytes())
_, _ = hasher.Write([]byte(" "))
_, _ = hasher.Write([]byte(strconv.Itoa(len(content))))
_, _ = hasher.Write([]byte{0})
_, _ = hasher.Write(content)
hasher.Sum(dst)
}
/* SHA1 Type */
type Sha1ObjectFormatImpl struct{}
var (
emptySha1ObjectID = &Sha1Hash{}
emptySha1Tree = &Sha1Hash{
0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60,
0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04,
}
)
func (Sha1ObjectFormatImpl) Name() string { return "sha1" }
func (Sha1ObjectFormatImpl) EmptyObjectID() ObjectID {
return emptySha1ObjectID
}
func (Sha1ObjectFormatImpl) EmptyTree() ObjectID {
return emptySha1Tree
}
func (Sha1ObjectFormatImpl) FullLength() int { return 40 }
func (Sha1ObjectFormatImpl) IsValid(input string) bool {
return sha1Pattern.MatchString(input)
}
func (Sha1ObjectFormatImpl) MustID(b []byte) ObjectID {
var id Sha1Hash
copy(id[0:20], b)
return &id
}
// ComputeHash compute the hash for a given ObjectType and content
func (h Sha1ObjectFormatImpl) ComputeHash(t ObjectType, content []byte) ObjectID {
var obj Sha1Hash
computeHash(obj[:0], sha1.New(), t, content)
return &obj
}
/* SHA256 Type */
type Sha256ObjectFormatImpl struct{}
var (
emptySha256ObjectID = &Sha256Hash{}
emptySha256Tree = &Sha256Hash{
0x6e, 0xf1, 0x9b, 0x41, 0x22, 0x5c, 0x53, 0x69, 0xf1, 0xc1,
0x04, 0xd4, 0x5d, 0x8d, 0x85, 0xef, 0xa9, 0xb0, 0x57, 0xb5,
0x3b, 0x14, 0xb4, 0xb9, 0xb9, 0x39, 0xdd, 0x74, 0xde, 0xcc,
0x53, 0x21,
}
)
func (Sha256ObjectFormatImpl) Name() string { return "sha256" }
func (Sha256ObjectFormatImpl) EmptyObjectID() ObjectID {
return emptySha256ObjectID
}
func (Sha256ObjectFormatImpl) EmptyTree() ObjectID {
return emptySha256Tree
}
func (Sha256ObjectFormatImpl) FullLength() int { return 64 }
func (Sha256ObjectFormatImpl) IsValid(input string) bool {
return sha256Pattern.MatchString(input)
}
func (Sha256ObjectFormatImpl) MustID(b []byte) ObjectID {
var id Sha256Hash
copy(id[0:32], b)
return &id
}
// ComputeHash compute the hash for a given ObjectType and content
func (h Sha256ObjectFormatImpl) ComputeHash(t ObjectType, content []byte) ObjectID {
var obj Sha256Hash
computeHash(obj[:0], sha256.New(), t, content)
return &obj
}
var (
Sha1ObjectFormat ObjectFormat = Sha1ObjectFormatImpl{}
Sha256ObjectFormat ObjectFormat = Sha256ObjectFormatImpl{}
// any addition must be reflected in IsEmptyCommitID
)
var SupportedObjectFormats = []ObjectFormat{
Sha1ObjectFormat,
}
func ObjectFormatFromName(name string) ObjectFormat {
for _, objectFormat := range SupportedObjectFormats {
if name == objectFormat.Name() {
return objectFormat
}
}
return nil
}
func IsValidObjectFormat(name string) bool {
return ObjectFormatFromName(name) != nil
}
|
