aboutsummaryrefslogtreecommitdiff
path: root/main.go
blob: 498937012f132997e1d5afc3da6ac0012205aae8 (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
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
package main

import (
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"

	"github.com/hanwen/go-fuse/fuse"

	"github.com/rfjakob/gocryptfs/internal/configfile"
	"github.com/rfjakob/gocryptfs/internal/contentenc"
	"github.com/rfjakob/gocryptfs/internal/exitcodes"
	"github.com/rfjakob/gocryptfs/internal/readpassword"
	"github.com/rfjakob/gocryptfs/internal/speed"
	"github.com/rfjakob/gocryptfs/internal/stupidgcm"
	"github.com/rfjakob/gocryptfs/internal/tlog"
)

// GitVersion is the gocryptfs version according to git, set by build.bash
var GitVersion = "[GitVersion not set - please compile using ./build.bash]"

// GitVersionFuse is the go-fuse library version, set by build.bash
var GitVersionFuse = "[GitVersionFuse not set - please compile using ./build.bash]"

// BuildDate is a date string like "2017-09-06", set by build.bash
var BuildDate = "0000-00-00"

// raceDetector is set to true by race.go if we are compiled with "go build -race"
var raceDetector bool

// loadConfig loads the config file "args.config", prompting the user for the password
func loadConfig(args *argContainer) (masterkey []byte, confFile *configfile.ConfFile, err error) {
	// First check if the file can be read at all, and find out if a Trezor should
	// be used instead of a password.
	_, cf1, err := configfile.Load(args.config, nil)
	if err != nil {
		tlog.Fatal.Printf("Cannot open config file: %v", err)
		return nil, nil, err
	}
	// The user has passed the master key on the command line (probably because
	// he forgot the password).
	if args.masterkey != "" {
		masterkey = parseMasterKey(args.masterkey, false)
		return masterkey, cf1, nil
	}
	var pw []byte
	if cf1.IsFeatureFlagSet(configfile.FlagTrezor) {
		// Get binary data from from Trezor
		pw = readpassword.Trezor(cf1.TrezorPayload)
	} else {
		// Normal password entry
		pw = readpassword.Once(args.extpass, "")
	}
	tlog.Info.Println("Decrypting master key")
	masterkey, confFile, err = configfile.Load(args.config, pw)
	for i := range pw {
		pw[i] = 0
	}

	if err != nil {
		tlog.Fatal.Println(err)
		return nil, nil, err
	}
	return masterkey, confFile, nil
}

// changePassword - change the password of config file "filename"
// Does not return (calls os.Exit both on success and on error).
func changePassword(args *argContainer) {
	// Parse the config file, but do not unlock the master key. We only want to
	// know if the Trezor flag is set.
	_, cf1, err := configfile.Load(args.config, nil)
	if err != nil {
		tlog.Fatal.Printf("Cannot open config file: %v", err)
		os.Exit(exitcodes.LoadConf)
	}
	if cf1.IsFeatureFlagSet(configfile.FlagTrezor) {
		tlog.Fatal.Printf("Password change is not supported on Trezor-enabled filesystems.")
		os.Exit(exitcodes.Usage)
	}
	var confFile *configfile.ConfFile
	{
		var masterkey []byte
		masterkey, confFile, err = loadConfig(args)
		if err != nil {
			exitcodes.Exit(err)
		}
		if len(masterkey) == 0 {
			panic("empty masterkey")
		}
		tlog.Info.Println("Please enter your new password.")
		newPw := readpassword.Twice(args.extpass)
		readpassword.CheckTrailingGarbage()
		confFile.EncryptKey(masterkey, newPw, confFile.ScryptObject.LogN())
		for i := range newPw {
			newPw[i] = 0
		}
		for i := range masterkey {
			masterkey[i] = 0
		}
		// masterkey and newPw run out of scope here
	}
	// Are we resetting the password without knowing the old one using
	// "-masterkey"?
	if args.masterkey != "" {
		bak := args.config + ".bak"
		err = os.Link(args.config, bak)
		if err != nil {
			tlog.Fatal.Printf("Could not create backup file: %v", err)
			os.Exit(exitcodes.Init)
		}
		tlog.Info.Printf(tlog.ColorGrey+
			"A copy of the old config file has been created at %q.\n"+
			"Delete it after you have verified that you can access your files with the new password."+
			tlog.ColorReset, bak)
	}
	err = confFile.WriteFile()
	if err != nil {
		tlog.Fatal.Println(err)
		os.Exit(exitcodes.WriteConf)
	}
	tlog.Info.Printf(tlog.ColorGreen + "Password changed." + tlog.ColorReset)
}

// printVersion prints a version string like this:
// gocryptfs v0.12-36-ge021b9d-dirty; go-fuse a4c968c; 2016-07-03 go1.6.2
func printVersion() {
	buildFlags := ""
	if stupidgcm.BuiltWithoutOpenssl {
		buildFlags = " without_openssl"
	}
	built := fmt.Sprintf("%s %s", BuildDate, runtime.Version())
	if raceDetector {
		built += " -race"
	}
	fmt.Printf("%s %s%s; go-fuse %s; %s\n",
		tlog.ProgramName, GitVersion, buildFlags, GitVersionFuse, built)
}

func main() {
	mxp := runtime.GOMAXPROCS(0)
	if mxp < 4 {
		// On a 2-core machine, setting maxprocs to 4 gives 10% better performance
		runtime.GOMAXPROCS(4)
	}
	// mount(1) unsets PATH. Since exec.Command does not handle this case, we set
	// PATH to a default value if it's empty or unset.
	if os.Getenv("PATH") == "" {
		os.Setenv("PATH", "/usr/sbin:/usr/bin:/sbin:/bin")
	}
	var err error
	// Parse all command-line options (i.e. arguments starting with "-")
	// into "args". Path arguments are parsed below.
	args := parseCliOpts()
	// Fork a child into the background if "-fg" is not set AND we are mounting
	// a filesystem. The child will do all the work.
	if !args.fg && flagSet.NArg() == 2 {
		ret := forkChild()
		os.Exit(ret)
	}
	if args.debug {
		tlog.Debug.Enabled = true
	}
	// "-v"
	if args.version {
		tlog.Debug.Printf("openssl=%v\n", args.openssl)
		tlog.Debug.Printf("on-disk format %d\n", contentenc.CurrentVersion)
		printVersion()
		os.Exit(0)
	}
	// "-hh"
	if args.hh {
		helpLong()
		os.Exit(0)
	}
	// "-speed"
	if args.speed {
		speed.Run()
		os.Exit(0)
	}
	if args.wpanic {
		tlog.Warn.Wpanic = true
		tlog.Debug.Printf("Panicking on warnings")
	}
	// Every operation below requires CIPHERDIR. Exit if we don't have it.
	if flagSet.NArg() == 0 {
		if flagSet.NFlag() == 0 {
			// Naked call to "gocryptfs". Just print the help text.
			helpShort()
		} else {
			// The user has passed some flags, but CIPHERDIR is missing. State
			// what is wrong.
			tlog.Fatal.Printf("CIPHERDIR argument is missing")
		}
		os.Exit(exitcodes.Usage)
	}
	// Check that CIPHERDIR exists
	args.cipherdir, _ = filepath.Abs(flagSet.Arg(0))
	err = isDir(args.cipherdir)
	if err != nil {
		tlog.Fatal.Printf("Invalid cipherdir: %v", err)
		os.Exit(exitcodes.CipherDir)
	}
	// "-q"
	if args.quiet {
		tlog.Info.Enabled = false
	}
	// "-reverse" implies "-aessiv"
	if args.reverse {
		args.aessiv = true
	}
	// "-config"
	if args.config != "" {
		args.config, err = filepath.Abs(args.config)
		if err != nil {
			tlog.Fatal.Printf("Invalid \"-config\" setting: %v", err)
			os.Exit(exitcodes.Init)
		}
		tlog.Info.Printf("Using config file at custom location %s", args.config)
		args._configCustom = true
	} else if args.reverse {
		args.config = filepath.Join(args.cipherdir, configfile.ConfReverseName)
	} else {
		args.config = filepath.Join(args.cipherdir, configfile.ConfDefaultName)
	}
	// "-force_owner"
	if args.force_owner != "" {
		var uidNum, gidNum int64
		ownerPieces := strings.SplitN(args.force_owner, ":", 2)
		if len(ownerPieces) != 2 {
			tlog.Fatal.Printf("force_owner must be in form UID:GID")
			os.Exit(exitcodes.Usage)
		}
		uidNum, err = strconv.ParseInt(ownerPieces[0], 0, 32)
		if err != nil || uidNum < 0 {
			tlog.Fatal.Printf("force_owner: Unable to parse UID %v as positive integer", ownerPieces[0])
			os.Exit(exitcodes.Usage)
		}
		gidNum, err = strconv.ParseInt(ownerPieces[1], 0, 32)
		if err != nil || gidNum < 0 {
			tlog.Fatal.Printf("force_owner: Unable to parse GID %v as positive integer", ownerPieces[1])
			os.Exit(exitcodes.Usage)
		}
		args._forceOwner = &fuse.Owner{Uid: uint32(uidNum), Gid: uint32(gidNum)}
	}
	// "-cpuprofile"
	if args.cpuprofile != "" {
		onExitFunc := setupCpuprofile(args.cpuprofile)
		defer onExitFunc()
	}
	// "-memprofile"
	if args.memprofile != "" {
		onExitFunc := setupMemprofile(args.memprofile)
		defer onExitFunc()
	}
	// "-trace"
	if args.trace != "" {
		onExitFunc := setupTrace(args.trace)
		defer onExitFunc()
	}
	if args.cpuprofile != "" || args.memprofile != "" || args.trace != "" {
		tlog.Info.Printf("Note: You must unmount gracefully, otherwise the profile file(s) will stay empty!\n")
	}
	// "-openssl"
	if !args.openssl {
		tlog.Debug.Printf("OpenSSL disabled, using Go GCM")
	} else {
		tlog.Debug.Printf("OpenSSL enabled")
	}
	// Operation flags
	nOps := countOpFlags(&args)
	if nOps == 0 {
		// Default operation: mount.
		if flagSet.NArg() != 2 {
			prettyArgs := prettyArgs()
			tlog.Info.Printf("Wrong number of arguments (have %d, want 2). You passed: %s",
				flagSet.NArg(), prettyArgs)
			tlog.Fatal.Printf("Usage: %s [OPTIONS] CIPHERDIR MOUNTPOINT [-o COMMA-SEPARATED-OPTIONS]", tlog.ProgramName)
			os.Exit(exitcodes.Usage)
		}
		doMount(&args)
		// Don't call os.Exit to give deferred functions a chance to run
		return
	}
	if nOps > 1 {
		tlog.Fatal.Printf("At most one of -info, -init, -passwd, -fsck is allowed")
		os.Exit(exitcodes.Usage)
	}
	if flagSet.NArg() != 1 {
		tlog.Fatal.Printf("The options -info, -init, -passwd, -fsck take exactly one argument, %d given",
			flagSet.NArg())
		os.Exit(exitcodes.Usage)
	}
	// "-info"
	if args.info {
		info(args.config)
		os.Exit(0)
	}
	// "-init"
	if args.init {
		initDir(&args)
		os.Exit(0)
	}
	// "-passwd"
	if args.passwd {
		changePassword(&args)
		os.Exit(0)
	}
	// "-fsck"
	if args.fsck {
		fsck(&args)
		os.Exit(0)
	}
}