aboutsummaryrefslogtreecommitdiff
path: root/gocryptfs_main/main.go
blob: d6ce06440640e0b7ce581374d3a7a88a2a5e3ef7 (plain)
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
package main

import (
	"encoding/hex"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"runtime"
	"runtime/pprof"
	"time"

	"github.com/rfjakob/gocryptfs/cryptfs"
	"github.com/rfjakob/gocryptfs/pathfs_frontend"

	"golang.org/x/crypto/ssh/terminal"

	"github.com/hanwen/go-fuse/fuse"
	"github.com/hanwen/go-fuse/fuse/nodefs"
	"github.com/hanwen/go-fuse/fuse/pathfs"
)

const (
	USE_OPENSSL  = true
	PATHFS_DEBUG = false

	PROGRAM_NAME = "gocryptfs"

	// Exit codes
	ERREXIT_USAGE     = 1
	ERREXIT_NEWFS     = 2
	ERREXIT_MOUNT     = 3
	ERREXIT_SERVE     = 4
	ERREXIT_MOUNT2    = 5
	ERREXIT_CIPHERDIR = 6
	ERREXIT_INIT      = 7
	ERREXIT_LOADCONF  = 8
	ERREXIT_PASSWORD  = 9
)

func initDir(dirArg string) {
	dir, _ := filepath.Abs(dirArg)

	if dirEmpty(dir) == false {
		fmt.Printf("Error: Directory \"%s\" is not empty\n", dirArg)
		os.Exit(ERREXIT_INIT)
	}

	confName := filepath.Join(dir, cryptfs.ConfDefaultName)
	fmt.Printf("Choose a password for protecting your files.\n")
	password := readPasswordTwice()
	err := cryptfs.CreateConfFile(confName, password)
	if err != nil {
		fmt.Println(err)
		os.Exit(ERREXIT_INIT)
	}
	fmt.Printf("The filesystem is now ready for mounting.\n")
	os.Exit(0)
}

func main() {
	runtime.GOMAXPROCS(4)

	// Parse command line arguments
	var debug, init, zerokey, fusedebug, openssl bool

	flag.BoolVar(&debug, "debug", false, "Enable debug output")
	flag.BoolVar(&fusedebug, "fusedebug", false, "Enable fuse library debug output")
	flag.BoolVar(&init, "init", false, "Initialize encrypted directory")
	flag.BoolVar(&zerokey, "zerokey", false, "Use all-zero dummy master key")
	flag.BoolVar(&openssl, "openssl", true, "Use OpenSSL instead of built-in Go crypto")
	var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")

	flag.Parse()
	if *cpuprofile != "" {
		f, err := os.Create(*cpuprofile)
		if err != nil {
			fmt.Println(err)
			os.Exit(ERREXIT_INIT)
		}
		fmt.Printf("Writing CPU profile to %s\n", *cpuprofile)
		pprof.StartCPUProfile(f)
		defer pprof.StopCPUProfile()
	}
	if debug {
		cryptfs.Debug.Enable()
		cryptfs.Debug.Printf("Debug output enabled\n")
	}
	if openssl == false {
		fmt.Printf("Openssl disabled\n")
	}
	if init {
		if flag.NArg() != 1 {
			fmt.Printf("usage: %s --init CIPHERDIR\n", PROGRAM_NAME)
			os.Exit(ERREXIT_USAGE)
		}
		initDir(flag.Arg(0))
	}
	if flag.NArg() < 2 {
		fmt.Printf("usage: %s [OPTIONS] CIPHERDIR MOUNTPOINT\n", PROGRAM_NAME)
		os.Exit(ERREXIT_USAGE)
	}
	cipherdir, _ := filepath.Abs(flag.Arg(0))
	mountpoint, _ := filepath.Abs(flag.Arg(1))
	cryptfs.Debug.Printf("cipherdir=%s\nmountpoint=%s\n", cipherdir, mountpoint)

	_, err := os.Stat(cipherdir)
	if err != nil {
		fmt.Printf("Cipherdir: %s\n", err.Error())
		os.Exit(ERREXIT_CIPHERDIR)
	}

	key := make([]byte, cryptfs.KEY_LEN)
	if zerokey {
		fmt.Printf("Zerokey mode active: using all-zero dummy master key.\n")
		fmt.Printf("ZEROKEY MODE PROVIDES NO SECURITY AT ALL AND SHOULD ONLY BE USED FOR TESTING.\n")
	} else {
		cfname := filepath.Join(cipherdir, cryptfs.ConfDefaultName)
		_, err = os.Stat(cfname)
		if err != nil {
			fmt.Printf("Error: %s not found in CIPHERDIR\n", cryptfs.ConfDefaultName)
			fmt.Printf("Please run \"%s --init %s\" first\n", PROGRAM_NAME, flag.Arg(0))
			os.Exit(ERREXIT_LOADCONF)
		}
		fmt.Printf("Password: ")
		password := readPassword()
		fmt.Printf("\nDecrypting master key... ")
		key, err = cryptfs.LoadConfFile(cfname, password)
		if err != nil {
			fmt.Println(err)
			os.Exit(ERREXIT_LOADCONF)
		}
		fmt.Printf("done.\n")
	}

	srv := pathfsFrontend(key, cipherdir, mountpoint, fusedebug, openssl)
	fmt.Printf("Mounted.\n")

	if zerokey == false {
		printMasterKey(key)
	}

	// Send notification to our parent
	sendSig()
	// Jump into server loop
	srv.Serve()
}

// printMasterKey - remind the user that he should store the master key in
// a safe place
func printMasterKey(key []byte) {
	h := hex.EncodeToString(key)
	var hChunked string

	// Try to make it less scary by splitting it up in chunks
	for i := 0; i < len(h); i+=8 {
		hChunked += h[i:i+8]
		if i < 52 {
			hChunked += "-"
		}
		if i == 24 {
			hChunked += "\n                      "
		}
	}

	fmt.Printf(`
ATTENTION:

  Your master key is: %s

If the gocryptfs.conf file becomes corrupted or you ever forget your password,
there is only one hope for recovery: The master key. Print it to a piece of
paper and store it in a drawer.

`, hChunked)
}

func readPasswordTwice() string {
	fmt.Printf("Password: ")
	p1 := readPassword()
	fmt.Printf("\nRepeat: ")
	p2 := readPassword()
	fmt.Printf("\n")
	if p1 != p2 {
		fmt.Printf("Passwords do not match\n")
		os.Exit(ERREXIT_PASSWORD)
	}
	return p1
}

// Get password from terminal
func readPassword() string {
	fd := int(os.Stdin.Fd())
	p, err := terminal.ReadPassword(fd)
	if err != nil {
		fmt.Printf("Error: Could not read password: %v\n", err)
		os.Exit(ERREXIT_PASSWORD)
	}
	return string(p)
}

func dirEmpty(dir string) bool {
	entries, err := ioutil.ReadDir(dir)
	if err != nil {
		fmt.Println(err)
		os.Exit(ERREXIT_CIPHERDIR)
	}
	if len(entries) == 0 {
		return true
	}
	return false
}

func pathfsFrontend(key []byte, cipherdir string, mountpoint string, debug bool, openssl bool) *fuse.Server {

	finalFs := pathfs_frontend.NewFS(key, cipherdir, openssl)
	pathFsOpts := &pathfs.PathNodeFsOptions{ClientInodes: true}
	pathFs := pathfs.NewPathNodeFs(finalFs, pathFsOpts)
	fuseOpts := &nodefs.Options{
		// These options are to be compatible with libfuse defaults,
		// making benchmarking easier.
		NegativeTimeout: time.Second,
		AttrTimeout:     time.Second,
		EntryTimeout:    time.Second,
	}
	conn := nodefs.NewFileSystemConnector(pathFs.Root(), fuseOpts)
	var mOpts fuse.MountOptions
	mOpts.AllowOther = false
	// Set values shown in "df -T" and friends
	// First column, "Filesystem"
	mOpts.Options = append(mOpts.Options, "fsname="+cipherdir)
	// Second column, "Type", will be shown as "fuse." + Name
	mOpts.Name = "gocryptfs"

	srv, err := fuse.NewServer(conn.RawFS(), mountpoint, &mOpts)
	if err != nil {
		fmt.Printf("Mount failed: %v", err)
		os.Exit(1)
	}
	srv.SetDebug(debug)

	return srv
}