Repository navigation
Expand file tree
/
Copy pathmain.go
More file actions
379 lines (355 loc) · 10.3 KB
/
Copy pathmain.go
File metadata and controls
379 lines (355 loc) · 10.3 KB
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
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
package main
import (
"bytes"
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/sha1"
"crypto/x509"
"crypto/x509/pkix"
"encoding/asn1"
"encoding/hex"
"encoding/pem"
"flag"
"fmt"
"log"
"math"
"math/big"
"net"
"os"
"regexp"
"strings"
"time"
)
func main() {
err := main2()
if err != nil {
log.Fatal(err)
}
}
type issuer struct {
key crypto.Signer
cert *x509.Certificate
}
func getIssuer(keyFile, certFile string, alg x509.PublicKeyAlgorithm) (*issuer, error) {
keyContents, keyErr := os.ReadFile(keyFile)
certContents, certErr := os.ReadFile(certFile)
if os.IsNotExist(keyErr) && os.IsNotExist(certErr) {
err := makeIssuer(keyFile, certFile, alg)
if err != nil {
return nil, err
}
return getIssuer(keyFile, certFile, alg)
} else if keyErr != nil {
return nil, fmt.Errorf("%s (but %s exists)", keyErr, certFile)
} else if certErr != nil {
return nil, fmt.Errorf("%s (but %s exists)", certErr, keyFile)
}
key, err := readPrivateKey(keyContents)
if err != nil {
return nil, fmt.Errorf("reading private key from %s: %s", keyFile, err)
}
cert, err := readCert(certContents)
if err != nil {
return nil, fmt.Errorf("reading CA certificate from %s: %s", certFile, err)
}
equal, err := publicKeysEqual(key.Public(), cert.PublicKey)
if err != nil {
return nil, fmt.Errorf("comparing public keys: %s", err)
} else if !equal {
return nil, fmt.Errorf("public key in CA certificate %s doesn't match private key in %s",
certFile, keyFile)
}
return &issuer{key, cert}, nil
}
func readPrivateKey(keyContents []byte) (crypto.Signer, error) {
block, _ := pem.Decode(keyContents)
if block == nil {
return nil, fmt.Errorf("no PEM found")
} else if block.Type == "PRIVATE KEY" {
signer, err := x509.ParsePKCS8PrivateKey(block.Bytes)
if err != nil {
return nil, fmt.Errorf("failed to parse PKCS8: %w", err)
}
switch t := signer.(type) {
case *rsa.PrivateKey:
return signer.(*rsa.PrivateKey), nil
case *ecdsa.PrivateKey:
return signer.(*ecdsa.PrivateKey), nil
default:
return nil, fmt.Errorf("unsupported PKCS8 key type: %t", t)
}
} else if block.Type == "RSA PRIVATE KEY" {
return x509.ParsePKCS1PrivateKey(block.Bytes)
} else if block.Type == "EC PRIVATE KEY" || block.Type == "ECDSA PRIVATE KEY" {
return x509.ParseECPrivateKey(block.Bytes)
}
return nil, fmt.Errorf("incorrect PEM type %s", block.Type)
}
func readCert(certContents []byte) (*x509.Certificate, error) {
block, _ := pem.Decode(certContents)
if block == nil {
return nil, fmt.Errorf("no PEM found")
} else if block.Type != "CERTIFICATE" {
return nil, fmt.Errorf("incorrect PEM type %s", block.Type)
}
return x509.ParseCertificate(block.Bytes)
}
func makeIssuer(keyFile, certFile string, alg x509.PublicKeyAlgorithm) error {
key, err := makeKey(keyFile, alg)
if err != nil {
return err
}
_, err = makeRootCert(key, certFile)
if err != nil {
return err
}
return nil
}
func makeKey(filename string, alg x509.PublicKeyAlgorithm) (crypto.Signer, error) {
var key crypto.Signer
var err error
switch {
case alg == x509.RSA:
key, err = rsa.GenerateKey(rand.Reader, 2048)
if err != nil {
return nil, err
}
case alg == x509.ECDSA:
key, err = ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
if err != nil {
return nil, err
}
}
der, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return nil, err
}
file, err := os.OpenFile(filename, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0600)
if err != nil {
return nil, err
}
defer file.Close()
err = pem.Encode(file, &pem.Block{
Type: "PRIVATE KEY",
Bytes: der,
})
if err != nil {
return nil, err
}
return key, nil
}
func makeRootCert(key crypto.Signer, filename string) (*x509.Certificate, error) {
serial, err := rand.Int(rand.Reader, big.NewInt(math.MaxInt64))
if err != nil {
return nil, err
}
skid, err := calculateSKID(key.Public())
if err != nil {
return nil, err
}
template := &x509.Certificate{
Subject: pkix.Name{
CommonName: "minica root ca " + hex.EncodeToString(serial.Bytes()[:3]),
},
SerialNumber: serial,
NotBefore: time.Now(),
NotAfter: time.Now().AddDate(100, 0, 0),
SubjectKeyId: skid,
AuthorityKeyId: skid,
KeyUsage: x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
BasicConstraintsValid: true,
IsCA: true,
MaxPathLenZero: true,
}
der, err := x509.CreateCertificate(rand.Reader, template, template, key.Public(), key)
if err != nil {
return nil, err
}
file, err := os.OpenFile(filename, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0600)
if err != nil {
return nil, err
}
defer file.Close()
err = pem.Encode(file, &pem.Block{
Type: "CERTIFICATE",
Bytes: der,
})
if err != nil {
return nil, err
}
return x509.ParseCertificate(der)
}
func parseIPs(ipAddresses []string) ([]net.IP, error) {
var parsed []net.IP
for _, s := range ipAddresses {
p := net.ParseIP(s)
if p == nil {
return nil, fmt.Errorf("invalid IP address %s", s)
}
parsed = append(parsed, p)
}
return parsed, nil
}
func publicKeysEqual(a, b interface{}) (bool, error) {
aBytes, err := x509.MarshalPKIXPublicKey(a)
if err != nil {
return false, err
}
bBytes, err := x509.MarshalPKIXPublicKey(b)
if err != nil {
return false, err
}
return bytes.Compare(aBytes, bBytes) == 0, nil
}
func calculateSKID(pubKey crypto.PublicKey) ([]byte, error) {
spkiASN1, err := x509.MarshalPKIXPublicKey(pubKey)
if err != nil {
return nil, err
}
var spki struct {
Algorithm pkix.AlgorithmIdentifier
SubjectPublicKey asn1.BitString
}
_, err = asn1.Unmarshal(spkiASN1, &spki)
if err != nil {
return nil, err
}
skid := sha1.Sum(spki.SubjectPublicKey.Bytes)
return skid[:], nil
}
func sign(iss *issuer, domains []string, ipAddresses []string, alg x509.PublicKeyAlgorithm) (*x509.Certificate, error) {
var cn string
if len(domains) > 0 {
cn = domains[0]
} else if len(ipAddresses) > 0 {
cn = ipAddresses[0]
} else {
return nil, fmt.Errorf("must specify at least one domain name or IP address")
}
var cnFolder = strings.Replace(cn, "*", "_", -1)
err := os.Mkdir(cnFolder, 0700)
if err != nil && !os.IsExist(err) {
return nil, err
}
key, err := makeKey(fmt.Sprintf("%s/key.pem", cnFolder), alg)
if err != nil {
return nil, err
}
parsedIPs, err := parseIPs(ipAddresses)
if err != nil {
return nil, err
}
serial, err := rand.Int(rand.Reader, big.NewInt(math.MaxInt64))
if err != nil {
return nil, err
}
template := &x509.Certificate{
DNSNames: domains,
IPAddresses: parsedIPs,
Subject: pkix.Name{
CommonName: cn,
},
SerialNumber: serial,
NotBefore: time.Now(),
// Set the validity period to 2 years and 30 days, to satisfy the iOS and
// macOS requirements that all server certificates must have validity
// shorter than 825 days:
// https://derflounder.wordpress.com/2019/06/06/new-tls-security-requirements-for-ios-13-and-macos-catalina-10-15/
NotAfter: time.Now().AddDate(2, 0, 30),
KeyUsage: x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
BasicConstraintsValid: true,
IsCA: false,
}
der, err := x509.CreateCertificate(rand.Reader, template, iss.cert, key.Public(), iss.key)
if err != nil {
return nil, err
}
file, err := os.OpenFile(fmt.Sprintf("%s/cert.pem", cnFolder), os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0600)
if err != nil {
return nil, err
}
defer file.Close()
err = pem.Encode(file, &pem.Block{
Type: "CERTIFICATE",
Bytes: der,
})
if err != nil {
return nil, err
}
return x509.ParseCertificate(der)
}
func split(s string) (results []string) {
if len(s) > 0 {
return strings.Split(s, ",")
}
return nil
}
func main2() error {
var caKey = flag.String("ca-key", "minica-key.pem", "Root private key filename, PEM encoded.")
var caCert = flag.String("ca-cert", "minica.pem", "Root certificate filename, PEM encoded.")
var caAlg = flag.String("ca-alg", "ecdsa", "Algorithm for any new keypairs: RSA or ECDSA.")
var domains = flag.String("domains", "", "Comma separated domain names to include as Server Alternative Names.")
var ipAddresses = flag.String("ip-addresses", "", "Comma separated IP addresses to include as Server Alternative Names.")
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
fmt.Fprintf(os.Stderr, `
Minica is a simple CA intended for use in situations where the CA operator
also operates each host where a certificate will be used. It automatically
generates both a key and a certificate when asked to produce a certificate.
It does not offer OCSP or CRL services. Minica is appropriate, for instance,
for generating certificates for RPC systems or microservices.
On first run, minica will generate a keypair and a root certificate in the
current directory, and will reuse that same keypair and root certificate
unless they are deleted.
On each run, minica will generate a new keypair and sign an end-entity (leaf)
certificate for that keypair. The certificate will contain a list of DNS names
and/or IP addresses from the command line flags. The key and certificate are
placed in a new directory whose name is chosen as the first domain name from
the certificate, or the first IP address if no domain names are present. It
will not overwrite existing keys or certificates.
`)
flag.PrintDefaults()
}
flag.Parse()
if *domains == "" && *ipAddresses == "" {
flag.Usage()
os.Exit(1)
}
alg := x509.RSA
if strings.ToLower(*caAlg) == "ecdsa" {
alg = x509.ECDSA
} else if strings.ToLower(*caAlg) != "rsa" {
fmt.Printf("Unrecognized algorithm: %s (use RSA or ECDSA)\n", *caAlg)
os.Exit(1)
}
if len(flag.Args()) > 0 {
fmt.Printf("Extra arguments: %s (maybe there are spaces in your domain list?)\n", flag.Args())
os.Exit(1)
}
domainSlice := split(*domains)
domainRe := regexp.MustCompile("^[A-Za-z0-9.*-]+$")
for _, d := range domainSlice {
if !domainRe.MatchString(d) {
fmt.Printf("Invalid domain name %q\n", d)
os.Exit(1)
}
}
ipSlice := split(*ipAddresses)
for _, ip := range ipSlice {
if net.ParseIP(ip) == nil {
fmt.Printf("Invalid IP address %q\n", ip)
os.Exit(1)
}
}
issuer, err := getIssuer(*caKey, *caCert, alg)
if err != nil {
return err
}
_, err = sign(issuer, domainSlice, ipSlice, alg)
return err
}