This repository has been archived by the owner on Sep 6, 2022. It is now read-only.
/
ecdsa.go
167 lines (136 loc) · 4.33 KB
/
ecdsa.go
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
package crypto
import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/x509"
"encoding/asn1"
"errors"
"io"
"math/big"
pb "github.com/libp2p/go-libp2p-core/crypto/pb"
"github.com/minio/sha256-simd"
)
// ECDSAPrivateKey is an implementation of an ECDSA private key
type ECDSAPrivateKey struct {
priv *ecdsa.PrivateKey
}
// ECDSAPublicKey is an implementation of an ECDSA public key
type ECDSAPublicKey struct {
pub *ecdsa.PublicKey
}
// ECDSASig holds the r and s values of an ECDSA signature
type ECDSASig struct {
R, S *big.Int
}
var (
// ErrNotECDSAPubKey is returned when the public key passed is not an ecdsa public key
ErrNotECDSAPubKey = errors.New("not an ecdsa public key")
// ErrNilSig is returned when the signature is nil
ErrNilSig = errors.New("sig is nil")
// ErrNilPrivateKey is returned when a nil private key is provided
ErrNilPrivateKey = errors.New("private key is nil")
// ErrNilPublicKey is returned when a nil public key is provided
ErrNilPublicKey = errors.New("public key is nil")
// ECDSACurve is the default ecdsa curve used
ECDSACurve = elliptic.P256()
)
// GenerateECDSAKeyPair generates a new ecdsa private and public key
func GenerateECDSAKeyPair(src io.Reader) (PrivKey, PubKey, error) {
return GenerateECDSAKeyPairWithCurve(ECDSACurve, src)
}
// GenerateECDSAKeyPairWithCurve generates a new ecdsa private and public key with a speicified curve
func GenerateECDSAKeyPairWithCurve(curve elliptic.Curve, src io.Reader) (PrivKey, PubKey, error) {
priv, err := ecdsa.GenerateKey(curve, src)
if err != nil {
return nil, nil, err
}
return &ECDSAPrivateKey{priv}, &ECDSAPublicKey{&priv.PublicKey}, nil
}
// ECDSAKeyPairFromKey generates a new ecdsa private and public key from an input private key
func ECDSAKeyPairFromKey(priv *ecdsa.PrivateKey) (PrivKey, PubKey, error) {
if priv == nil {
return nil, nil, ErrNilPrivateKey
}
return &ECDSAPrivateKey{priv}, &ECDSAPublicKey{&priv.PublicKey}, nil
}
// MarshalECDSAPrivateKey returns x509 bytes from a private key
func MarshalECDSAPrivateKey(ePriv ECDSAPrivateKey) ([]byte, error) {
return x509.MarshalECPrivateKey(ePriv.priv)
}
// MarshalECDSAPublicKey returns x509 bytes from a public key
func MarshalECDSAPublicKey(ePub ECDSAPublicKey) ([]byte, error) {
return x509.MarshalPKIXPublicKey(ePub.pub)
}
// UnmarshalECDSAPrivateKey returns a private key from x509 bytes
func UnmarshalECDSAPrivateKey(data []byte) (PrivKey, error) {
priv, err := x509.ParseECPrivateKey(data)
if err != nil {
return nil, err
}
return &ECDSAPrivateKey{priv}, nil
}
// UnmarshalECDSAPublicKey returns the public key from x509 bytes
func UnmarshalECDSAPublicKey(data []byte) (PubKey, error) {
pubIfc, err := x509.ParsePKIXPublicKey(data)
if err != nil {
return nil, err
}
pub, ok := pubIfc.(*ecdsa.PublicKey)
if !ok {
return nil, ErrNotECDSAPubKey
}
return &ECDSAPublicKey{pub}, nil
}
// Type returns the key type
func (ePriv *ECDSAPrivateKey) Type() pb.KeyType {
return pb.KeyType_ECDSA
}
// Raw returns x509 bytes from a private key
func (ePriv *ECDSAPrivateKey) Raw() ([]byte, error) {
return x509.MarshalECPrivateKey(ePriv.priv)
}
// Equals compares two private keys
func (ePriv *ECDSAPrivateKey) Equals(o Key) bool {
return basicEquals(ePriv, o)
}
// Sign returns the signature of the input data
func (ePriv *ECDSAPrivateKey) Sign(data []byte) ([]byte, error) {
hash := sha256.Sum256(data)
r, s, err := ecdsa.Sign(rand.Reader, ePriv.priv, hash[:])
if err != nil {
return nil, err
}
return asn1.Marshal(ECDSASig{
R: r,
S: s,
})
}
// GetPublic returns a public key
func (ePriv *ECDSAPrivateKey) GetPublic() PubKey {
return &ECDSAPublicKey{&ePriv.priv.PublicKey}
}
// Type returns the key type
func (ePub *ECDSAPublicKey) Type() pb.KeyType {
return pb.KeyType_ECDSA
}
// Raw returns x509 bytes from a public key
func (ePub *ECDSAPublicKey) Raw() ([]byte, error) {
return x509.MarshalPKIXPublicKey(ePub.pub)
}
// Equals compares to public keys
func (ePub *ECDSAPublicKey) Equals(o Key) bool {
return basicEquals(ePub, o)
}
// Verify compares data to a signature
func (ePub *ECDSAPublicKey) Verify(data, sigBytes []byte) (bool, error) {
sig := new(ECDSASig)
if _, err := asn1.Unmarshal(sigBytes, sig); err != nil {
return false, err
}
if sig == nil {
return false, ErrNilSig
}
hash := sha256.Sum256(data)
return ecdsa.Verify(ePub.pub, hash[:], sig.R, sig.S), nil
}