-
Notifications
You must be signed in to change notification settings - Fork 15
/
signer.go
69 lines (58 loc) · 1.46 KB
/
signer.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
package signer
import (
"crypto"
"fmt"
"io"
"github.com/foxboron/ssh-tpm-agent/key"
"github.com/google/go-tpm/tpm2"
"github.com/google/go-tpm/tpm2/transport"
)
type TPMSigner struct {
key *key.Key
ownerPassword func() ([]byte, error)
tpm func() transport.TPMCloser
pin func(*key.Key) ([]byte, error)
}
var _ crypto.Signer = &TPMSigner{}
func NewTPMSigner(k *key.Key, ownerPassword func() ([]byte, error), tpm func() transport.TPMCloser, pin func(*key.Key) ([]byte, error)) *TPMSigner {
return &TPMSigner{
key: k,
ownerPassword: ownerPassword,
tpm: tpm,
pin: pin,
}
}
func (t *TPMSigner) Public() crypto.PublicKey {
pk, err := t.key.PublicKey()
// This shouldn't happen!
if err != nil {
panic(err)
}
return pk
}
func (t *TPMSigner) Sign(_ io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
var digestalg tpm2.TPMAlgID
auth := []byte("")
if t.key.TPMKey.HasAuth() {
p, err := t.pin(t.key)
if err != nil {
return nil, err
}
auth = p
}
switch opts.HashFunc() {
case crypto.SHA256:
digestalg = tpm2.TPMAlgSHA256
case crypto.SHA384:
digestalg = tpm2.TPMAlgSHA384
case crypto.SHA512:
digestalg = tpm2.TPMAlgSHA512
default:
return nil, fmt.Errorf("%s is not a supported hashing algorithm", opts.HashFunc())
}
ownerPassword, err := t.ownerPassword()
if err != nil {
return nil, err
}
return key.Sign(t.tpm(), ownerPassword, t.key, digest, auth, digestalg)
}