-
Notifications
You must be signed in to change notification settings - Fork 0
/
generate.go
105 lines (101 loc) · 2.84 KB
/
generate.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
package josex
import (
"crypto"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"errors"
"fmt"
"github.com/go-jose/go-jose/v3"
)
// NewSigningKey generates a keypair for corresponding SignatureAlgorithm.
func NewSigningKey(alg jose.SignatureAlgorithm, bits int) (crypto.PublicKey, crypto.PrivateKey, error) {
switch alg {
case jose.ES256, jose.ES384, jose.ES512, jose.EdDSA:
keylen := map[jose.SignatureAlgorithm]int{
jose.ES256: 256,
jose.ES384: 384,
jose.ES512: 521, // sic!
jose.EdDSA: 256,
}
if bits != 0 && bits != keylen[alg] {
return nil, nil, errors.New("invalid elliptic curve key size, this algorithm does not support arbitrary size")
}
case jose.RS256, jose.RS384, jose.RS512, jose.PS256, jose.PS384, jose.PS512:
if bits == 0 {
bits = 2048
}
if bits < 2048 {
return nil, nil, errors.New("invalid key size for RSA key, 2048 or more is required")
}
}
switch alg {
case jose.ES256:
key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
if err != nil {
return nil, nil, err
}
return key.Public(), key, err
case jose.ES384:
key, err := ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
if err != nil {
return nil, nil, err
}
return key.Public(), key, err
case jose.ES512:
key, err := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
if err != nil {
return nil, nil, err
}
return key.Public(), key, err
case jose.EdDSA:
pub, key, err := ed25519.GenerateKey(rand.Reader)
return pub, key, err
case jose.RS256, jose.RS384, jose.RS512, jose.PS256, jose.PS384, jose.PS512:
key, err := rsa.GenerateKey(rand.Reader, bits)
if err != nil {
return nil, nil, err
}
return key.Public(), key, err
default:
return nil, nil, fmt.Errorf("unknown algorithm %s for signing key", alg)
}
}
// NewEncryptionKey generates a keypair for corresponding KeyAlgorithm.
func NewEncryptionKey(alg jose.KeyAlgorithm, bits int) (crypto.PublicKey, crypto.PrivateKey, error) {
switch alg {
case jose.RSA1_5, jose.RSA_OAEP, jose.RSA_OAEP_256:
if bits == 0 {
bits = 2048
}
if bits < 2048 {
return nil, nil, errors.New("invalid key size for RSA key, 2048 or more is required")
}
key, err := rsa.GenerateKey(rand.Reader, bits)
if err != nil {
return nil, nil, err
}
return key.Public(), key, err
case jose.ECDH_ES, jose.ECDH_ES_A128KW, jose.ECDH_ES_A192KW, jose.ECDH_ES_A256KW:
var crv elliptic.Curve
switch bits {
case 0, 256:
crv = elliptic.P256()
case 384:
crv = elliptic.P384()
case 521:
crv = elliptic.P521()
default:
return nil, nil, errors.New("invalid elliptic curve key size, use one of 256, 384, or 521")
}
key, err := ecdsa.GenerateKey(crv, rand.Reader)
if err != nil {
return nil, nil, err
}
return key.Public(), key, err
default:
return nil, nil, fmt.Errorf("unknown algorithm %s for encryption key", alg)
}
}