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
|
package keys
import (
"bytes"
"crypto"
"crypto/ed25519"
"crypto/rand"
"crypto/subtle"
"encoding/json"
"errors"
"fmt"
"io"
"github.com/theupdateframework/go-tuf/data"
)
func init() {
SignerMap.Store(data.KeyTypeEd25519, NewEd25519Signer)
VerifierMap.Store(data.KeyTypeEd25519, NewEd25519Verifier)
}
func NewEd25519Signer() Signer {
return &ed25519Signer{}
}
func NewEd25519Verifier() Verifier {
return &ed25519Verifier{}
}
type ed25519Verifier struct {
PublicKey data.HexBytes `json:"public"`
key *data.PublicKey
}
func (e *ed25519Verifier) Public() string {
return string(e.PublicKey)
}
func (e *ed25519Verifier) Verify(msg, sig []byte) error {
if !ed25519.Verify([]byte(e.PublicKey), msg, sig) {
return errors.New("tuf: ed25519 signature verification failed")
}
return nil
}
func (e *ed25519Verifier) MarshalPublicKey() *data.PublicKey {
return e.key
}
func (e *ed25519Verifier) UnmarshalPublicKey(key *data.PublicKey) error {
e.key = key
// Prepare decoder limited to 512Kb
dec := json.NewDecoder(io.LimitReader(bytes.NewReader(key.Value), MaxJSONKeySize))
// Unmarshal key value
if err := dec.Decode(e); err != nil {
if errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF) {
return fmt.Errorf("tuf: the public key is truncated or too large: %w", err)
}
return err
}
if n := len(e.PublicKey); n != ed25519.PublicKeySize {
return fmt.Errorf("tuf: unexpected public key length for ed25519 key, expected %d, got %d", ed25519.PublicKeySize, n)
}
return nil
}
type Ed25519PrivateKeyValue struct {
Public data.HexBytes `json:"public"`
Private data.HexBytes `json:"private"`
}
type ed25519Signer struct {
ed25519.PrivateKey
}
func GenerateEd25519Key() (*ed25519Signer, error) {
_, private, err := ed25519.GenerateKey(rand.Reader)
if err != nil {
return nil, err
}
if err != nil {
return nil, err
}
return &ed25519Signer{
PrivateKey: ed25519.PrivateKey(data.HexBytes(private)),
}, nil
}
func NewEd25519SignerFromKey(keyValue Ed25519PrivateKeyValue) *ed25519Signer {
return &ed25519Signer{
PrivateKey: ed25519.PrivateKey(data.HexBytes(keyValue.Private)),
}
}
func (e *ed25519Signer) SignMessage(message []byte) ([]byte, error) {
return e.Sign(rand.Reader, message, crypto.Hash(0))
}
func (e *ed25519Signer) MarshalPrivateKey() (*data.PrivateKey, error) {
valueBytes, err := json.Marshal(Ed25519PrivateKeyValue{
Public: data.HexBytes([]byte(e.PrivateKey.Public().(ed25519.PublicKey))),
Private: data.HexBytes(e.PrivateKey),
})
if err != nil {
return nil, err
}
return &data.PrivateKey{
Type: data.KeyTypeEd25519,
Scheme: data.KeySchemeEd25519,
Algorithms: data.HashAlgorithms,
Value: valueBytes,
}, nil
}
func (e *ed25519Signer) UnmarshalPrivateKey(key *data.PrivateKey) error {
keyValue := &Ed25519PrivateKeyValue{}
// Prepare decoder limited to 512Kb
dec := json.NewDecoder(io.LimitReader(bytes.NewReader(key.Value), MaxJSONKeySize))
// Unmarshal key value
if err := dec.Decode(keyValue); err != nil {
if errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF) {
return fmt.Errorf("tuf: the private key is truncated or too large: %w", err)
}
}
// Check private key length
if n := len(keyValue.Private); n != ed25519.PrivateKeySize {
return fmt.Errorf("tuf: invalid ed25519 private key length, expected %d, got %d", ed25519.PrivateKeySize, n)
}
// Generate public key from private key
pub, _, err := ed25519.GenerateKey(bytes.NewReader(keyValue.Private))
if err != nil {
return fmt.Errorf("tuf: unable to derive public key from private key: %w", err)
}
// Compare keys
if subtle.ConstantTimeCompare(keyValue.Public, pub) != 1 {
return errors.New("tuf: public and private keys don't match")
}
// Prepare signer
*e = ed25519Signer{
PrivateKey: ed25519.PrivateKey(data.HexBytes(keyValue.Private)),
}
return nil
}
func (e *ed25519Signer) PublicData() *data.PublicKey {
keyValBytes, _ := json.Marshal(ed25519Verifier{PublicKey: []byte(e.PrivateKey.Public().(ed25519.PublicKey))})
return &data.PublicKey{
Type: data.KeyTypeEd25519,
Scheme: data.KeySchemeEd25519,
Algorithms: data.HashAlgorithms,
Value: keyValBytes,
}
}
|
