-
Notifications
You must be signed in to change notification settings - Fork 420
/
softcas.go
296 lines (259 loc) · 9.02 KB
/
softcas.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
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
package softcas
import (
"context"
"crypto"
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"time"
"github.com/pkg/errors"
"go.step.sm/crypto/kms"
kmsapi "go.step.sm/crypto/kms/apiv1"
"go.step.sm/crypto/x509util"
"github.com/smallstep/certificates/cas/apiv1"
)
func init() {
apiv1.Register(apiv1.SoftCAS, func(ctx context.Context, opts apiv1.Options) (apiv1.CertificateAuthorityService, error) {
return New(ctx, opts)
})
}
var now = time.Now
// SoftCAS implements a Certificate Authority Service using Golang or KMS
// crypto. This is the default CAS used in step-ca.
type SoftCAS struct {
CertificateChain []*x509.Certificate
Signer crypto.Signer
CertificateSigner func() ([]*x509.Certificate, crypto.Signer, error)
KeyManager kms.KeyManager
}
// New creates a new CertificateAuthorityService implementation using Golang or KMS
// crypto.
func New(_ context.Context, opts apiv1.Options) (*SoftCAS, error) {
if !opts.IsCreator {
switch {
case len(opts.CertificateChain) == 0 && opts.CertificateSigner == nil:
return nil, errors.New("softCAS 'CertificateChain' cannot be nil")
case opts.Signer == nil && opts.CertificateSigner == nil:
return nil, errors.New("softCAS 'signer' cannot be nil")
}
}
return &SoftCAS{
CertificateChain: opts.CertificateChain,
Signer: opts.Signer,
CertificateSigner: opts.CertificateSigner,
KeyManager: opts.KeyManager,
}, nil
}
// Type returns the type of this CertificateAuthorityService.
func (c *SoftCAS) Type() apiv1.Type {
return apiv1.SoftCAS
}
// GetSigner implements [apiv1.CertificateAuthoritySigner] and returns a
// [crypto.Signer] with the intermediate key.
func (c *SoftCAS) GetSigner() (crypto.Signer, error) {
_, signer, err := c.getCertSigner()
return signer, err
}
// CreateCertificate signs a new certificate using Golang or KMS crypto.
func (c *SoftCAS) CreateCertificate(req *apiv1.CreateCertificateRequest) (*apiv1.CreateCertificateResponse, error) {
switch {
case req.Template == nil:
return nil, errors.New("createCertificateRequest `template` cannot be nil")
case req.Lifetime == 0:
return nil, errors.New("createCertificateRequest `lifetime` cannot be 0")
}
t := now()
// Provisioners can also set specific values.
if req.Template.NotBefore.IsZero() {
req.Template.NotBefore = t.Add(-1 * req.Backdate)
}
if req.Template.NotAfter.IsZero() {
req.Template.NotAfter = t.Add(req.Lifetime)
}
chain, signer, err := c.getCertSigner()
if err != nil {
return nil, err
}
req.Template.Issuer = chain[0].Subject
cert, err := createCertificate(req.Template, chain[0], req.Template.PublicKey, signer)
if err != nil {
return nil, err
}
return &apiv1.CreateCertificateResponse{
Certificate: cert,
CertificateChain: chain,
}, nil
}
// RenewCertificate signs the given certificate template using Golang or KMS crypto.
func (c *SoftCAS) RenewCertificate(req *apiv1.RenewCertificateRequest) (*apiv1.RenewCertificateResponse, error) {
switch {
case req.Template == nil:
return nil, errors.New("createCertificateRequest `template` cannot be nil")
case req.Lifetime == 0:
return nil, errors.New("createCertificateRequest `lifetime` cannot be 0")
}
t := now()
req.Template.NotBefore = t.Add(-1 * req.Backdate)
req.Template.NotAfter = t.Add(req.Lifetime)
chain, signer, err := c.getCertSigner()
if err != nil {
return nil, err
}
req.Template.Issuer = chain[0].Subject
cert, err := createCertificate(req.Template, chain[0], req.Template.PublicKey, signer)
if err != nil {
return nil, err
}
return &apiv1.RenewCertificateResponse{
Certificate: cert,
CertificateChain: chain,
}, nil
}
// RevokeCertificate revokes the given certificate in step-ca. In SoftCAS this
// operation is a no-op as the actual revoke will happen when we store the entry
// in the db.
func (c *SoftCAS) RevokeCertificate(req *apiv1.RevokeCertificateRequest) (*apiv1.RevokeCertificateResponse, error) {
chain, _, err := c.getCertSigner()
if err != nil {
return nil, err
}
return &apiv1.RevokeCertificateResponse{
Certificate: req.Certificate,
CertificateChain: chain,
}, nil
}
// CreateCRL will create a new CRL based on the RevocationList passed to it
func (c *SoftCAS) CreateCRL(req *apiv1.CreateCRLRequest) (*apiv1.CreateCRLResponse, error) {
certChain, signer, err := c.getCertSigner()
if err != nil {
return nil, err
}
revocationListBytes, err := x509.CreateRevocationList(rand.Reader, req.RevocationList, certChain[0], signer)
if err != nil {
return nil, err
}
return &apiv1.CreateCRLResponse{CRL: revocationListBytes}, nil
}
// CreateCertificateAuthority creates a root or an intermediate certificate.
func (c *SoftCAS) CreateCertificateAuthority(req *apiv1.CreateCertificateAuthorityRequest) (*apiv1.CreateCertificateAuthorityResponse, error) {
switch {
case req.Template == nil:
return nil, errors.New("createCertificateAuthorityRequest `template` cannot be nil")
case req.Lifetime == 0:
return nil, errors.New("createCertificateAuthorityRequest `lifetime` cannot be 0")
case req.Type == apiv1.IntermediateCA && req.Parent == nil:
return nil, errors.New("createCertificateAuthorityRequest `parent` cannot be nil")
case req.Type == apiv1.IntermediateCA && req.Parent.Certificate == nil:
return nil, errors.New("createCertificateAuthorityRequest `parent.template` cannot be nil")
case req.Type == apiv1.IntermediateCA && req.Parent.Signer == nil:
return nil, errors.New("createCertificateAuthorityRequest `parent.signer` cannot be nil")
}
key, err := c.createKey(req.CreateKey)
if err != nil {
return nil, err
}
signer, err := c.createSigner(&key.CreateSignerRequest)
if err != nil {
return nil, err
}
t := now()
if req.Template.NotBefore.IsZero() {
req.Template.NotBefore = t.Add(-1 * req.Backdate)
}
if req.Template.NotAfter.IsZero() {
req.Template.NotAfter = t.Add(req.Lifetime)
}
var cert *x509.Certificate
switch req.Type {
case apiv1.RootCA:
cert, err = createCertificate(req.Template, req.Template, signer.Public(), signer)
if err != nil {
return nil, err
}
case apiv1.IntermediateCA:
cert, err = createCertificate(req.Template, req.Parent.Certificate, signer.Public(), req.Parent.Signer)
if err != nil {
return nil, err
}
default:
return nil, errors.Errorf("createCertificateAuthorityRequest `type=%d' is invalid or not supported", req.Type)
}
// Add the parent
var chain []*x509.Certificate
if req.Parent != nil {
chain = append(chain, req.Parent.Certificate)
chain = append(chain, req.Parent.CertificateChain...)
}
return &apiv1.CreateCertificateAuthorityResponse{
Name: cert.Subject.CommonName,
Certificate: cert,
CertificateChain: chain,
KeyName: key.Name,
PublicKey: key.PublicKey,
PrivateKey: key.PrivateKey,
Signer: signer,
}, nil
}
// initializeKeyManager initializes the default key manager if was not given.
func (c *SoftCAS) initializeKeyManager() (err error) {
if c.KeyManager == nil {
c.KeyManager, err = kms.New(context.Background(), kmsapi.Options{
Type: kmsapi.DefaultKMS,
})
}
return
}
// getCertSigner returns the certificate chain and signer to use.
func (c *SoftCAS) getCertSigner() ([]*x509.Certificate, crypto.Signer, error) {
if c.CertificateSigner != nil {
return c.CertificateSigner()
}
return c.CertificateChain, c.Signer, nil
}
// createKey uses the configured kms to create a key.
func (c *SoftCAS) createKey(req *kmsapi.CreateKeyRequest) (*kmsapi.CreateKeyResponse, error) {
if err := c.initializeKeyManager(); err != nil {
return nil, err
}
if req == nil {
req = &kmsapi.CreateKeyRequest{
SignatureAlgorithm: kmsapi.ECDSAWithSHA256,
}
}
return c.KeyManager.CreateKey(req)
}
// createSigner uses the configured kms to create a singer
func (c *SoftCAS) createSigner(req *kmsapi.CreateSignerRequest) (crypto.Signer, error) {
if err := c.initializeKeyManager(); err != nil {
return nil, err
}
return c.KeyManager.CreateSigner(req)
}
// createCertificate sets the SignatureAlgorithm of the template if necessary
// and calls x509util.CreateCertificate.
func createCertificate(template, parent *x509.Certificate, pub crypto.PublicKey, signer crypto.Signer) (*x509.Certificate, error) {
// Signers can specify the signature algorithm. This is especially important
// when x509.CreateCertificate attempts to validate a RSAPSS signature.
if template.SignatureAlgorithm == 0 {
if sa, ok := signer.(apiv1.SignatureAlgorithmGetter); ok {
template.SignatureAlgorithm = sa.SignatureAlgorithm()
} else if _, ok := parent.PublicKey.(*rsa.PublicKey); ok {
// For RSA issuers, only overwrite the default algorithm is the
// intermediate is signed with an RSA signature scheme.
if isRSA(parent.SignatureAlgorithm) {
template.SignatureAlgorithm = parent.SignatureAlgorithm
}
}
}
return x509util.CreateCertificate(template, parent, pub, signer)
}
func isRSA(sa x509.SignatureAlgorithm) bool {
switch sa {
case x509.SHA256WithRSA, x509.SHA384WithRSA, x509.SHA512WithRSA:
return true
case x509.SHA256WithRSAPSS, x509.SHA384WithRSAPSS, x509.SHA512WithRSAPSS:
return true
default:
return false
}
}