forked from rot256/fugl
/
pgp.go
79 lines (70 loc) · 1.96 KB
/
pgp.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
package fugl
import (
"bytes"
"errors"
"golang.org/x/crypto/openpgp"
"golang.org/x/crypto/openpgp/armor"
"golang.org/x/crypto/openpgp/clearsign"
"golang.org/x/crypto/openpgp/packet"
)
func PGPLoadPrivateKey(key []byte) (*openpgp.Entity, error) {
block, err := armor.Decode(bytes.NewReader([]byte(key)))
if err != nil {
return nil, err
} else if block.Type != openpgp.PrivateKeyType {
return nil, errors.New("Not a OpenPGP public key")
}
return openpgp.ReadEntity(packet.NewReader(block.Body))
}
func PGPLoadPublicKey(key []byte) (*openpgp.Entity, error) {
block, err := armor.Decode(bytes.NewReader([]byte(key)))
if err != nil {
return nil, err
} else if block.Type != openpgp.PublicKeyType {
return nil, errors.New("Not a OpenPGP private key")
}
return openpgp.ReadEntity(packet.NewReader(block.Body))
}
func PGPSign(entity *openpgp.Entity, message []byte) (string, error) {
if entity.PrivateKey == nil {
return "", errors.New("invalid private key")
}
// create signature writer
var outSig bytes.Buffer
writer, err := clearsign.Encode(&outSig, entity.PrivateKey, nil)
if err != nil {
return "", err
}
// sign entire message and flush
_, err = writer.Write(message)
if err != nil {
return "", err
}
err = writer.Close()
if err != nil {
return "", err
}
return outSig.String(), err
}
func PGPVerify(entity *openpgp.Entity, signature []byte) (*clearsign.Block, error) {
if entity == nil {
return nil, errors.New("invalid public key")
}
// parse clear signature
block, rest := clearsign.Decode(signature)
if len(rest) > 0 {
return nil, errors.New("Proof contains junk")
}
if block == nil {
return nil, errors.New("Unable to read pgp block")
}
// verify signature
keyring := make(openpgp.EntityList, 1)
keyring[0] = entity
content := bytes.NewReader(block.Bytes)
_, err := openpgp.CheckDetachedSignature(keyring, content, block.ArmoredSignature.Body)
if err != nil {
return nil, errors.New("Invalid signature")
}
return block, nil
}