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
|
// Copyright 2022 The Sigstore Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
package main
import (
"bytes"
"context"
"crypto"
"crypto/tls"
"crypto/x509"
"encoding/pem"
"fmt"
"log"
"net/url"
fulciopb "github.com/sigstore/fulcio/pkg/generated/protobuf"
"github.com/sigstore/sigstore/pkg/cryptoutils"
"github.com/sigstore/sigstore/pkg/oauthflow"
"github.com/sigstore/sigstore/pkg/signature"
"github.com/sigstore/sigstore/pkg/signature/options"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/credentials/insecure"
)
var (
fulcioUrl = "https://fulcio.sigstore.dev"
oidcIssuer = "https://oauth2.sigstore.dev/auth"
oidcClientID = "sigstore"
)
// Some of this is just ripped from cosign
func GetCert(signer *signature.ECDSASignerVerifier, fc fulciopb.CAClient, oidcIssuer string, oidcClientID string) (*fulciopb.SigningCertificate, error) {
tok, err := oauthflow.OIDConnect(oidcIssuer, oidcClientID, "", "", oauthflow.DefaultIDTokenGetter)
if err != nil {
return nil, err
}
// Sign the email address as part of the request
b := bytes.NewBuffer([]byte(tok.Subject))
proof, err := signer.SignMessage(b, options.WithCryptoSignerOpts(crypto.SHA256))
if err != nil {
log.Fatal(err)
}
pubBytesPEM, err := cryptoutils.MarshalPublicKeyToPEM(signer.Public())
if err != nil {
return nil, err
}
cscr := &fulciopb.CreateSigningCertificateRequest{
Credentials: &fulciopb.Credentials{
Credentials: &fulciopb.Credentials_OidcIdentityToken{
OidcIdentityToken: tok.RawString,
},
},
Key: &fulciopb.CreateSigningCertificateRequest_PublicKeyRequest{
PublicKeyRequest: &fulciopb.PublicKeyRequest{
PublicKey: &fulciopb.PublicKey{
Content: string(pubBytesPEM),
},
ProofOfPossession: proof,
},
},
}
return fc.CreateSigningCertificate(context.Background(), cscr)
}
func NewClient(fulcioURL string) (fulciopb.CAClient, error) {
fulcioServer, err := url.Parse(fulcioURL)
if err != nil {
return nil, err
}
dialOpt := grpc.WithTransportCredentials(insecure.NewCredentials())
hostWithPort := fmt.Sprintf("%s:80", fulcioServer.Host)
if fulcioServer.Scheme == "https" {
dialOpt = grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{}))
hostWithPort = fmt.Sprintf("%s:443", fulcioServer.Host)
}
conn, err := grpc.Dial(hostWithPort, dialOpt)
if err != nil {
return nil, err
}
return fulciopb.NewCAClient(conn), nil
}
func main() {
signer, _, err := signature.NewDefaultECDSASignerVerifier()
if err != nil {
log.Fatal(err)
}
fClient, err := NewClient(fulcioUrl)
if err != nil {
log.Fatal(err)
}
certResp, err := GetCert(signer, fClient, oidcIssuer, oidcClientID)
if err != nil {
log.Fatal(err)
}
var chain *fulciopb.CertificateChain
switch cert := certResp.Certificate.(type) {
case *fulciopb.SigningCertificate_SignedCertificateDetachedSct:
chain = cert.SignedCertificateDetachedSct.GetChain()
case *fulciopb.SigningCertificate_SignedCertificateEmbeddedSct:
chain = cert.SignedCertificateEmbeddedSct.GetChain()
}
clientPEM, _ := pem.Decode([]byte(chain.Certificates[0]))
cert, err := x509.ParseCertificate(clientPEM.Bytes)
if err != nil {
log.Fatal(err)
}
fmt.Println("Received signing cerificate with serial number: ", cert.SerialNumber)
}
|
