Golang 的 RSA 公私钥方法实现

话不多说,自己看吧,比较明白。

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
package main

import ("crypto"
"crypto/rand"
"crypto/rsa"
"crypto/sha256"
"crypto/x509"
"encoding/base64"
"encoding/pem"
"errors"
"fmt"
)

func main() {signer, err := loadPrivateKey("private.pem")
if err != nil {fmt.Errorf("signer is damaged: %v", err)
}

toSign := "date: Thu, 05 Jan 2012 21:31:40 GMT"

signed, err := signer.Sign([]byte(toSign))
if err != nil {fmt.Errorf("could not sign request: %v", err)
}
sig := base64.StdEncoding.EncodeToString(signed)
fmt.Printf("Signature: %v\n", sig)

parser, perr := loadPublicKey("public.pem")
if perr != nil {fmt.Errorf("could not sign request: %v", err)
}

err = parser.Unsign([]byte(toSign), signed)
if err != nil {fmt.Errorf("could not sign request: %v", err)
}

fmt.Printf("Unsign error: %v\n", err)
}

// loadPrivateKey loads an parses a PEM encoded private key file.
func loadPublicKey(path string) (Unsigner, error) {return parsePublicKey([]byte(`-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDCFENGw33yGihy92pDjZQhl0C3
6rPJj+CvfSC8+q28hxA161QFNUd13wuCTUcq0Qd2qsBe/2hFyc2DCJJg0h1L78+6
Z4UMR7EOcpfdUE9Hf3m/hs+FUR45uBJeDK1HSFHD8bHKD6kv8FPGfJTotc+2xjJw
oYi+1hqp1fIekaxsyQIDAQAB
-----END PUBLIC KEY-----`))
}

// parsePublicKey parses a PEM encoded private key.
func parsePublicKey(pemBytes []byte) (Unsigner, error) {block, _ := pem.Decode(pemBytes)
if block == nil {return nil, errors.New("ssh: no key found")}

var rawkey interface{}
switch block.Type {case"PUBLIC KEY":
rsa, err := x509.ParsePKIXPublicKey(block.Bytes)
if err != nil {return nil, err}
rawkey = rsa
default:
return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type)
}

return newUnsignerFromKey(rawkey)
}

// loadPrivateKey loads an parses a PEM encoded private key file.
func loadPrivateKey(path string) (Signer, error) {return parsePrivateKey([]byte(`-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----`))
}

// parsePublicKey parses a PEM encoded private key.
func parsePrivateKey(pemBytes []byte) (Signer, error) {block, _ := pem.Decode(pemBytes)
if block == nil {return nil, errors.New("ssh: no key found")}

var rawkey interface{}
switch block.Type {case"RSA PRIVATE KEY":
rsa, err := x509.ParsePKCS1PrivateKey(block.Bytes)
if err != nil {return nil, err}
rawkey = rsa
default:
return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type)
}
return newSignerFromKey(rawkey)
}

// A Signer is can create signatures that verify against a public key.
type Signer interface {
// Sign returns raw signature for the given data. This method
// will apply the hash specified for the keytype to the data.
Sign(data []byte) ([]byte, error)
}

// A Signer is can create signatures that verify against a public key.
type Unsigner interface {
// Sign returns raw signature for the given data. This method
// will apply the hash specified for the keytype to the data.
Unsign(data[]byte, sig []byte) error
}

func newSignerFromKey(k interface{}) (Signer, error) {
var sshKey Signer
switch t := k.(type) {
case *rsa.PrivateKey:
sshKey = &rsaPrivateKey{t}
default:
return nil, fmt.Errorf("ssh: unsupported key type %T", k)
}
return sshKey, nil
}

func newUnsignerFromKey(k interface{}) (Unsigner, error) {
var sshKey Unsigner
switch t := k.(type) {
case *rsa.PublicKey:
sshKey = &rsaPublicKey{t}
default:
return nil, fmt.Errorf("ssh: unsupported key type %T", k)
}
return sshKey, nil
}

type rsaPublicKey struct {*rsa.PublicKey}

type rsaPrivateKey struct {*rsa.PrivateKey}

// Sign signs data with rsa-sha256
func (r *rsaPrivateKey) Sign(data []byte) ([]byte, error) {h := sha256.New()
h.Write(data)
d := h.Sum(nil)
return rsa.SignPKCS1v15(rand.Reader, r.PrivateKey, crypto.SHA256, d)
}

// Unsign verifies the message using a rsa-sha256 signature
func (r *rsaPublicKey) Unsign(message []byte, sig []byte) error {h := sha256.New()
h.Write(message)
d := h.Sum(nil)
return rsa.VerifyPKCS1v15(r.PublicKey, crypto.SHA256, d, sig)
}