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
|
package dns
import (
"crypto"
"crypto/dsa"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"math/big"
)
// Generate generates a DNSKEY of the given bit size.
// The public part is put inside the DNSKEY record.
// The Algorithm in the key must be set as this will define
// what kind of DNSKEY will be generated.
// The ECDSA algorithms imply a fixed keysize, in that case
// bits should be set to the size of the algorithm.
func (k *DNSKEY) Generate(bits int) (crypto.PrivateKey, error) {
switch k.Algorithm {
case DSA, DSANSEC3SHA1:
if bits != 1024 {
return nil, ErrKeySize
}
case RSAMD5, RSASHA1, RSASHA256, RSASHA1NSEC3SHA1:
if bits < 512 || bits > 4096 {
return nil, ErrKeySize
}
case RSASHA512:
if bits < 1024 || bits > 4096 {
return nil, ErrKeySize
}
case ECDSAP256SHA256:
if bits != 256 {
return nil, ErrKeySize
}
case ECDSAP384SHA384:
if bits != 384 {
return nil, ErrKeySize
}
}
switch k.Algorithm {
case DSA, DSANSEC3SHA1:
params := new(dsa.Parameters)
if err := dsa.GenerateParameters(params, rand.Reader, dsa.L1024N160); err != nil {
return nil, err
}
priv := new(dsa.PrivateKey)
priv.PublicKey.Parameters = *params
err := dsa.GenerateKey(priv, rand.Reader)
if err != nil {
return nil, err
}
k.setPublicKeyDSA(params.Q, params.P, params.G, priv.PublicKey.Y)
return priv, nil
case RSAMD5, RSASHA1, RSASHA256, RSASHA512, RSASHA1NSEC3SHA1:
priv, err := rsa.GenerateKey(rand.Reader, bits)
if err != nil {
return nil, err
}
k.setPublicKeyRSA(priv.PublicKey.E, priv.PublicKey.N)
return priv, nil
case ECDSAP256SHA256, ECDSAP384SHA384:
var c elliptic.Curve
switch k.Algorithm {
case ECDSAP256SHA256:
c = elliptic.P256()
case ECDSAP384SHA384:
c = elliptic.P384()
}
priv, err := ecdsa.GenerateKey(c, rand.Reader)
if err != nil {
return nil, err
}
k.setPublicKeyECDSA(priv.PublicKey.X, priv.PublicKey.Y)
return priv, nil
default:
return nil, ErrAlg
}
}
// Set the public key (the value E and N)
func (k *DNSKEY) setPublicKeyRSA(_E int, _N *big.Int) bool {
if _E == 0 || _N == nil {
return false
}
buf := exponentToBuf(_E)
buf = append(buf, _N.Bytes()...)
k.PublicKey = toBase64(buf)
return true
}
// Set the public key for Elliptic Curves
func (k *DNSKEY) setPublicKeyECDSA(_X, _Y *big.Int) bool {
if _X == nil || _Y == nil {
return false
}
var intlen int
switch k.Algorithm {
case ECDSAP256SHA256:
intlen = 32
case ECDSAP384SHA384:
intlen = 48
}
k.PublicKey = toBase64(curveToBuf(_X, _Y, intlen))
return true
}
// Set the public key for DSA
func (k *DNSKEY) setPublicKeyDSA(_Q, _P, _G, _Y *big.Int) bool {
if _Q == nil || _P == nil || _G == nil || _Y == nil {
return false
}
buf := dsaToBuf(_Q, _P, _G, _Y)
k.PublicKey = toBase64(buf)
return true
}
// Set the public key (the values E and N) for RSA
// RFC 3110: Section 2. RSA Public KEY Resource Records
func exponentToBuf(_E int) []byte {
var buf []byte
i := big.NewInt(int64(_E)).Bytes()
if len(i) < 256 {
buf = make([]byte, 1, 1+len(i))
buf[0] = uint8(len(i))
} else {
buf = make([]byte, 3, 3+len(i))
buf[0] = 0
buf[1] = uint8(len(i) >> 8)
buf[2] = uint8(len(i))
}
buf = append(buf, i...)
return buf
}
// Set the public key for X and Y for Curve. The two
// values are just concatenated.
func curveToBuf(_X, _Y *big.Int, intlen int) []byte {
buf := intToBytes(_X, intlen)
buf = append(buf, intToBytes(_Y, intlen)...)
return buf
}
// Set the public key for X and Y for Curve. The two
// values are just concatenated.
func dsaToBuf(_Q, _P, _G, _Y *big.Int) []byte {
t := divRoundUp(divRoundUp(_G.BitLen(), 8)-64, 8)
buf := []byte{byte(t)}
buf = append(buf, intToBytes(_Q, 20)...)
buf = append(buf, intToBytes(_P, 64+t*8)...)
buf = append(buf, intToBytes(_G, 64+t*8)...)
buf = append(buf, intToBytes(_Y, 64+t*8)...)
return buf
}
|
