forked from hashicorp/consul
-
Notifications
You must be signed in to change notification settings - Fork 0
/
generate.go
216 lines (185 loc) · 5.83 KB
/
generate.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
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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
package tls
import (
"bytes"
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/sha256"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"fmt"
"math/big"
"net"
"strings"
"time"
)
// GenerateSerialNumber returns random bigint generated with crypto/rand
func GenerateSerialNumber() (*big.Int, error) {
l := new(big.Int).Lsh(big.NewInt(1), 128)
s, err := rand.Int(rand.Reader, l)
if err != nil {
return nil, err
}
return s, nil
}
// GeneratePrivateKey generates a new ecdsa private key
func GeneratePrivateKey() (crypto.Signer, string, error) {
pk, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
if err != nil {
return nil, "", fmt.Errorf("error generating private key: %s", err)
}
bs, err := x509.MarshalECPrivateKey(pk)
if err != nil {
return nil, "", fmt.Errorf("error generating private key: %s", err)
}
var buf bytes.Buffer
err = pem.Encode(&buf, &pem.Block{Type: "EC PRIVATE KEY", Bytes: bs})
if err != nil {
return nil, "", fmt.Errorf("error encoding private key: %s", err)
}
return pk, buf.String(), nil
}
// GenerateCA generates a new CA for agent TLS (not to be confused with Connect TLS)
func GenerateCA(signer crypto.Signer, sn *big.Int, days int, constraints []string) (string, error) {
id, err := keyID(signer.Public())
if err != nil {
return "", err
}
name := fmt.Sprintf("Consul Agent CA %d", sn)
// Create the CA cert
template := x509.Certificate{
SerialNumber: sn,
Subject: pkix.Name{
Country: []string{"US"},
PostalCode: []string{"94105"},
Province: []string{"CA"},
Locality: []string{"San Francisco"},
StreetAddress: []string{"101 Second Street"},
Organization: []string{"HashiCorp Inc."},
CommonName: name,
},
BasicConstraintsValid: true,
KeyUsage: x509.KeyUsageCertSign | x509.KeyUsageCRLSign | x509.KeyUsageDigitalSignature,
IsCA: true,
NotAfter: time.Now().AddDate(0, 0, days),
NotBefore: time.Now(),
AuthorityKeyId: id,
SubjectKeyId: id,
}
if len(constraints) > 0 {
template.PermittedDNSDomainsCritical = true
template.PermittedDNSDomains = constraints
}
bs, err := x509.CreateCertificate(
rand.Reader, &template, &template, signer.Public(), signer)
if err != nil {
return "", fmt.Errorf("error generating CA certificate: %s", err)
}
var buf bytes.Buffer
err = pem.Encode(&buf, &pem.Block{Type: "CERTIFICATE", Bytes: bs})
if err != nil {
return "", fmt.Errorf("error encoding private key: %s", err)
}
return buf.String(), nil
}
// GenerateCert generates a new certificate for agent TLS (not to be confused with Connect TLS)
func GenerateCert(signer crypto.Signer, ca string, sn *big.Int, name string, days int, DNSNames []string, IPAddresses []net.IP, extKeyUsage []x509.ExtKeyUsage) (string, string, error) {
parent, err := parseCert(ca)
if err != nil {
return "", "", err
}
signee, pk, err := GeneratePrivateKey()
if err != nil {
return "", "", err
}
id, err := keyID(signee.Public())
if err != nil {
return "", "", err
}
template := x509.Certificate{
SerialNumber: sn,
Subject: pkix.Name{CommonName: name},
BasicConstraintsValid: true,
KeyUsage: x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment,
ExtKeyUsage: extKeyUsage,
IsCA: false,
NotAfter: time.Now().AddDate(0, 0, days),
NotBefore: time.Now(),
SubjectKeyId: id,
DNSNames: DNSNames,
IPAddresses: IPAddresses,
}
bs, err := x509.CreateCertificate(rand.Reader, &template, parent, signee.Public(), signer)
if err != nil {
return "", "", err
}
var buf bytes.Buffer
err = pem.Encode(&buf, &pem.Block{Type: "CERTIFICATE", Bytes: bs})
if err != nil {
return "", "", fmt.Errorf("error encoding private key: %s", err)
}
return buf.String(), pk, nil
}
// KeyId returns a x509 KeyId from the given signing key.
func keyID(raw interface{}) ([]byte, error) {
switch raw.(type) {
case *ecdsa.PublicKey:
default:
return nil, fmt.Errorf("invalid key type: %T", raw)
}
// This is not standard; RFC allows any unique identifier as long as they
// match in subject/authority chains but suggests specific hashing of DER
// bytes of public key including DER tags.
bs, err := x509.MarshalPKIXPublicKey(raw)
if err != nil {
return nil, err
}
// String formatted
kID := sha256.Sum256(bs)
return []byte(strings.Replace(fmt.Sprintf("% x", kID), " ", ":", -1)), nil
}
func parseCert(pemValue string) (*x509.Certificate, error) {
// The _ result below is not an error but the remaining PEM bytes.
block, _ := pem.Decode([]byte(pemValue))
if block == nil {
return nil, fmt.Errorf("no PEM-encoded data found")
}
if block.Type != "CERTIFICATE" {
return nil, fmt.Errorf("first PEM-block should be CERTIFICATE type")
}
return x509.ParseCertificate(block.Bytes)
}
// ParseSigner parses a crypto.Signer from a PEM-encoded key. The private key
// is expected to be the first block in the PEM value.
func ParseSigner(pemValue string) (crypto.Signer, error) {
// The _ result below is not an error but the remaining PEM bytes.
block, _ := pem.Decode([]byte(pemValue))
if block == nil {
return nil, fmt.Errorf("no PEM-encoded data found")
}
switch block.Type {
case "EC PRIVATE KEY":
return x509.ParseECPrivateKey(block.Bytes)
default:
return nil, fmt.Errorf("unknown PEM block type for signing key: %s", block.Type)
}
}
func Verify(caString, certString, dns string) error {
roots := x509.NewCertPool()
ok := roots.AppendCertsFromPEM([]byte(caString))
if !ok {
return fmt.Errorf("failed to parse root certificate")
}
cert, err := parseCert(certString)
if err != nil {
return fmt.Errorf("failed to parse certificate")
}
opts := x509.VerifyOptions{
DNSName: fmt.Sprintf(dns),
Roots: roots,
}
_, err = cert.Verify(opts)
return err
}