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
|
go-tpm-keyfile
==============
Implements the ASN.1 Specification for TPM 2.0 Key Files.
https://www.hansenpartnership.com/draft-bottomley-tpm2-keys.html
### Implementation Status
- [x] Loadable Keys
- [x] Importable Keys
- [ ] Sealed data
# Loadable Keys
## With NewLoadableKey
```go
package main
import (
"os"
keyfile "github.com/foxboron/go-tpm-keyfiles"
"github.com/google/go-tpm/tpm2"
"github.com/google/go-tpm/tpm2/transport/simulator"
)
func main() {
tpm, _ := simulator.OpenSimulator()
defer tpm.Close()
k, _ := keyfile.NewLoadableKey(tpm, tpm2.TPMAlgECC, 256, []byte{},
keyfile.WithDescription("TPM Key"),
)
os.Writefile("key.pem", k.Bytes(), 0640)
}
```
## With NewTPMKey
```go
package main
import (
"os"
keyfile "github.com/foxboron/go-tpm-keyfiles"
"github.com/google/go-tpm/tpm2"
"github.com/google/go-tpm/tpm2/transport/simulator"
)
func main(){
tpm, _ := simulator.OpenSimulator()
defer tpm.Close()
primary, _ := tpm2.CreatePrimary{
PrimaryHandle: tpm2.TPMRHOwner,
InPublic: tpm2.New2B(tpm2.ECCSRKTemplate),
}.Execute(tpm)
eccTemplate := tpm2.TPMTPublic{
Type: tpm2.TPMAlgECC,
NameAlg: sha,
ObjectAttributes: tpm2.TPMAObject{
SignEncrypt: true,
FixedTPM: true,
FixedParent: true,
SensitiveDataOrigin: true,
UserWithAuth: true,
},
Parameters: tpm2.NewTPMUPublicParms(
tpm2.TPMAlgECC,
&tpm2.TPMSECCParms{
CurveID: ecc,
Scheme: tpm2.TPMTECCScheme{
Scheme: tpm2.TPMAlgNull,
},
},
),
}
eccKeyResponse, := tpm2.CreateLoaded{
ParentHandle: tpm2.AuthHandle{
Handle: primary.ObjectHandle,
Name: primary.Name,
Auth: tpm2.PasswordAuth([]byte(nil)),
},
InPublic: tpm2.New2BTemplate(&eccTemplate),
}.Execute(tpm)
k := keyfile.NewTPMKey(
keyfile.OIDOldLoadableKey
eccKeyResponse.OutPublic,
eccKeyResponse.OutPrivate,
keyfile.WithDescription("This is a TPM Key"),
)
os.Writefile("key.pem", k.Bytes(), 0640)
}
```
# TPMSigner
`go-tpm-keyfile` implements a `crypto.Signer` interface to be used with the keys
for easy signature creation and verification.
The `TPMKeySigner` struct implements a callback-style approach for user auth,
owner auth and for TPM fetching for easier implementation towards things that
require user-input.
```go
package main
import (
"crypto"
"os"
keyfile "github.com/foxboron/go-tpm-keyfiles"
"github.com/google/go-tpm/tpm2"
"github.com/google/go-tpm/tpm2/transport/simulator"
)
func main() {
tpm, _ := simulator.OpenSimulator()
defer tpm.Close()
k, _ := NewLoadableKey(tpm, tpm2.TPMAlgECC, 256, []byte(""))
signer, _ := k.Signer(tpm, []byte(""), []byte(""))
h := crypto.SHA256.New()
h.Write([]byte("message"))
b := h.Sum(nil)
sig, _ := signer.Sign((io.Reader)(nil), b[:], crypto.SHA256)
ok, err := k.Verify(crypto.SHA256, b[:], sig)
if !ok || err != nil {
log.Fatalf("invalid signature")
}
}
```
|
