forked from minio/minio
-
Notifications
You must be signed in to change notification settings - Fork 0
/
certs.go
189 lines (171 loc) · 4.66 KB
/
certs.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
/*
* MinIO Cloud Storage, (C) 2018 MinIO, Inc.
*
* 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 certs
import (
"crypto/tls"
"os"
"path/filepath"
"sync"
"time"
"github.com/rjeczalik/notify"
)
// A Certs represents a certificate manager able to watch certificate
// and key pairs for changes.
type Certs struct {
sync.RWMutex
// user input params.
certFile string
keyFile string
loadCert LoadX509KeyPairFunc
// points to the latest certificate.
cert tls.Certificate
// internal param to track for events, also
// used to close the watcher.
e chan notify.EventInfo
}
// LoadX509KeyPairFunc - provides a type for custom cert loader function.
type LoadX509KeyPairFunc func(certFile, keyFile string) (tls.Certificate, error)
// New initializes a new certs monitor.
func New(certFile, keyFile string, loadCert LoadX509KeyPairFunc) (*Certs, error) {
certFileIsLink, err := checkSymlink(certFile)
if err != nil {
return nil, err
}
keyFileIsLink, err := checkSymlink(keyFile)
if err != nil {
return nil, err
}
c := &Certs{
certFile: certFile,
keyFile: keyFile,
loadCert: loadCert,
// Make the channel buffered to ensure no event is dropped. Notify will drop
// an event if the receiver is not able to keep up the sending pace.
e: make(chan notify.EventInfo, 1),
}
if certFileIsLink && keyFileIsLink {
if err := c.watchSymlinks(); err != nil {
return nil, err
}
} else {
if err := c.watch(); err != nil {
return nil, err
}
}
return c, nil
}
func checkSymlink(file string) (bool, error) {
st, err := os.Lstat(file)
if err != nil {
return false, err
}
return st.Mode()&os.ModeSymlink == os.ModeSymlink, nil
}
// watchSymlinks reloads symlinked files since fsnotify cannot watch
// on symbolic links.
func (c *Certs) watchSymlinks() (err error) {
c.Lock()
c.cert, err = c.loadCert(c.certFile, c.keyFile)
c.Unlock()
if err != nil {
return err
}
go func() {
for {
select {
case <-c.e:
// Once stopped exits this routine.
return
case <-time.After(24 * time.Hour):
cert, cerr := c.loadCert(c.certFile, c.keyFile)
if cerr != nil {
continue
}
c.Lock()
c.cert = cert
c.Unlock()
}
}
}()
return nil
}
// watch starts watching for changes to the certificate
// and key files. On any change the certificate and key
// are reloaded. If there is an issue the loading will fail
// and the old (if any) certificates and keys will continue
// to be used.
func (c *Certs) watch() (err error) {
defer func() {
if err != nil {
// Stop any watches previously setup after an error.
notify.Stop(c.e)
}
}()
// Windows doesn't allow for watching file changes but instead allows
// for directory changes only, while we can still watch for changes
// on files on other platforms. Watch parent directory on all platforms
// for simplicity.
if err = notify.Watch(filepath.Dir(c.certFile), c.e, eventWrite...); err != nil {
return err
}
if err = notify.Watch(filepath.Dir(c.keyFile), c.e, eventWrite...); err != nil {
return err
}
c.Lock()
c.cert, err = c.loadCert(c.certFile, c.keyFile)
c.Unlock()
if err != nil {
return err
}
go c.run()
return nil
}
func (c *Certs) run() {
for event := range c.e {
base := filepath.Base(event.Path())
if isWriteEvent(event.Event()) {
certChanged := base == filepath.Base(c.certFile)
keyChanged := base == filepath.Base(c.keyFile)
if certChanged || keyChanged {
cert, err := c.loadCert(c.certFile, c.keyFile)
if err != nil {
// ignore the error continue to use
// old certificates.
continue
}
c.Lock()
c.cert = cert
c.Unlock()
}
}
}
}
// GetCertificateFunc provides a GetCertificate type for custom client implementations.
type GetCertificateFunc func(hello *tls.ClientHelloInfo) (*tls.Certificate, error)
// GetCertificate returns the loaded certificate for use by
// the TLSConfig fields GetCertificate field in a http.Server.
func (c *Certs) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
c.RLock()
defer c.RUnlock()
return &c.cert, nil
}
// Stop tells loader to stop watching for changes to the
// certificate and key files.
func (c *Certs) Stop() {
if c != nil {
notify.Stop(c.e)
}
}