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
|
// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package autocert
import (
"crypto/tls"
"log"
"net"
"os"
"path/filepath"
"runtime"
"time"
)
// NewListener returns a net.Listener that listens on the standard TLS
// port (443) on all interfaces and returns *tls.Conn connections with
// LetsEncrypt certificates for the provided domain or domains.
//
// It enables one-line HTTPS servers:
//
// log.Fatal(http.Serve(autocert.NewListener("example.com"), handler))
//
// NewListener is a convenience function for a common configuration.
// More complex or custom configurations can use the autocert.Manager
// type instead.
//
// Use of this function implies acceptance of the LetsEncrypt Terms of
// Service. If domains is not empty, the provided domains are passed
// to HostWhitelist. If domains is empty, the listener will do
// LetsEncrypt challenges for any requested domain, which is not
// recommended.
//
// Certificates are cached in a "golang-autocert" directory under an
// operating system-specific cache or temp directory. This may not
// be suitable for servers spanning multiple machines.
//
// The returned Listener also enables TCP keep-alives on the accepted
// connections. The returned *tls.Conn are returned before their TLS
// handshake has completed.
func NewListener(domains ...string) net.Listener {
m := &Manager{
Prompt: AcceptTOS,
}
if len(domains) > 0 {
m.HostPolicy = HostWhitelist(domains...)
}
dir := cacheDir()
if err := os.MkdirAll(dir, 0700); err != nil {
log.Printf("warning: autocert.NewListener not using a cache: %v", err)
} else {
m.Cache = DirCache(dir)
}
return m.Listener()
}
// Listener listens on the standard TLS port (443) on all interfaces
// and returns a net.Listener returning *tls.Conn connections.
//
// The returned Listener also enables TCP keep-alives on the accepted
// connections. The returned *tls.Conn are returned before their TLS
// handshake has completed.
//
// Unlike NewListener, it is the caller's responsibility to initialize
// the Manager m's Prompt, Cache, HostPolicy, and other desired options.
func (m *Manager) Listener() net.Listener {
ln := &listener{
m: m,
conf: &tls.Config{
GetCertificate: m.GetCertificate, // bonus: panic on nil m
},
}
ln.tcpListener, ln.tcpListenErr = net.Listen("tcp", ":443")
return ln
}
type listener struct {
m *Manager
conf *tls.Config
tcpListener net.Listener
tcpListenErr error
}
func (ln *listener) Accept() (net.Conn, error) {
if ln.tcpListenErr != nil {
return nil, ln.tcpListenErr
}
conn, err := ln.tcpListener.Accept()
if err != nil {
return nil, err
}
tcpConn := conn.(*net.TCPConn)
// Because Listener is a convenience function, help out with
// this too. This is not possible for the caller to set once
// we return a *tcp.Conn wrapping an inaccessible net.Conn.
// If callers don't want this, they can do things the manual
// way and tweak as needed. But this is what net/http does
// itself, so copy that. If net/http changes, we can change
// here too.
tcpConn.SetKeepAlive(true)
tcpConn.SetKeepAlivePeriod(3 * time.Minute)
return tls.Server(tcpConn, ln.conf), nil
}
func (ln *listener) Addr() net.Addr {
if ln.tcpListener != nil {
return ln.tcpListener.Addr()
}
// net.Listen failed. Return something non-nil in case callers
// call Addr before Accept:
return &net.TCPAddr{IP: net.IP{0, 0, 0, 0}, Port: 443}
}
func (ln *listener) Close() error {
if ln.tcpListenErr != nil {
return ln.tcpListenErr
}
return ln.tcpListener.Close()
}
func homeDir() string {
if runtime.GOOS == "windows" {
return os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")
}
if h := os.Getenv("HOME"); h != "" {
return h
}
return "/"
}
func cacheDir() string {
const base = "golang-autocert"
switch runtime.GOOS {
case "darwin":
return filepath.Join(homeDir(), "Library", "Caches", base)
case "windows":
for _, ev := range []string{"APPDATA", "CSIDL_APPDATA", "TEMP", "TMP"} {
if v := os.Getenv(ev); v != "" {
return filepath.Join(v, base)
}
}
// Worst case:
return filepath.Join(homeDir(), base)
}
if xdg := os.Getenv("XDG_CACHE_HOME"); xdg != "" {
return filepath.Join(xdg, base)
}
return filepath.Join(homeDir(), ".cache", base)
}
|
