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
|
package main
import (
"encoding/json"
"log/syslog"
"os"
"os/exec"
"os/signal"
"path/filepath"
"strings"
"syscall"
"time"
"github.com/hanwen/go-fuse/fuse"
"github.com/hanwen/go-fuse/fuse/nodefs"
"github.com/hanwen/go-fuse/fuse/pathfs"
"github.com/rfjakob/gocryptfs/internal/configfile"
"github.com/rfjakob/gocryptfs/internal/cryptocore"
"github.com/rfjakob/gocryptfs/internal/fusefrontend"
"github.com/rfjakob/gocryptfs/internal/fusefrontend_reverse"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
// doMount mounts an encrypted directory.
// Called from main.
func doMount(args *argContainer) int {
// Check mountpoint
if flagSet.NArg() != 2 {
tlog.Fatal.Printf("Usage: %s [OPTIONS] CIPHERDIR MOUNTPOINT", tlog.ProgramName)
os.Exit(ErrExitUsage)
}
var err error
args.mountpoint, err = filepath.Abs(flagSet.Arg(1))
if err != nil {
tlog.Fatal.Printf("Invalid mountpoint: %v", err)
os.Exit(ErrExitMountPoint)
}
if args.nonempty {
err = checkDir(args.mountpoint)
} else {
err = checkDirEmpty(args.mountpoint)
}
if err != nil {
tlog.Fatal.Printf("Invalid mountpoint: %v", err)
os.Exit(ErrExitMountPoint)
}
// Get master key
var masterkey []byte
var confFile *configfile.ConfFile
if args.masterkey != "" {
// "-masterkey"
tlog.Info.Printf("Using explicit master key.")
masterkey = parseMasterKey(args.masterkey)
tlog.Info.Printf(tlog.ColorYellow +
"THE MASTER KEY IS VISIBLE VIA \"ps ax\" AND MAY BE STORED IN YOUR SHELL HISTORY!\n" +
"ONLY USE THIS MODE FOR EMERGENCIES." + tlog.ColorReset)
} else if args.zerokey {
// "-zerokey"
tlog.Info.Printf("Using all-zero dummy master key.")
tlog.Info.Printf(tlog.ColorYellow +
"ZEROKEY MODE PROVIDES NO SECURITY AT ALL AND SHOULD ONLY BE USED FOR TESTING." +
tlog.ColorReset)
masterkey = make([]byte, cryptocore.KeyLen)
} else {
// Load master key from config file
masterkey, confFile = loadConfig(args)
printMasterKey(masterkey)
}
// Initialize FUSE server
tlog.Debug.Printf("cli args: %v", args)
srv := initFuseFrontend(masterkey, args, confFile)
tlog.Info.Println(tlog.ColorGreen + "Filesystem mounted and ready." + tlog.ColorReset)
// We have been forked into the background, as evidenced by the set
// "notifypid".
if args.notifypid > 0 {
// Chdir to the root directory so we don't block unmounting the CWD
os.Chdir("/")
// Switch to syslog
if !args.nosyslog {
tlog.Info.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_INFO)
tlog.Debug.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_DEBUG)
tlog.Warn.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_WARNING)
tlog.SwitchLoggerToSyslog(syslog.LOG_USER | syslog.LOG_WARNING)
// Daemons should close all fds (and we don't want to get killed by
// SIGPIPE if any of those get closed on the other end)
os.Stderr.Close()
os.Stdout.Close()
os.Stdin.Close()
}
// Send SIGUSR1 to our parent
sendUsr1(args.notifypid)
}
// Wait for SIGINT in the background and unmount ourselves if we get it.
// This prevents a dangling "Transport endpoint is not connected"
// mountpoint if the user hits CTRL-C.
handleSigint(srv, args.mountpoint)
// Jump into server loop. Returns when it gets an umount request from the kernel.
srv.Serve()
return 0
}
// initFuseFrontend - initialize gocryptfs/fusefrontend
// Calls os.Exit on errors
func initFuseFrontend(key []byte, args *argContainer, confFile *configfile.ConfFile) *fuse.Server {
// Reconciliate CLI and config file arguments into a fusefrontend.Args struct
// that is passed to the filesystem implementation
cryptoBackend := cryptocore.BackendGoGCM
if args.openssl {
cryptoBackend = cryptocore.BackendOpenSSL
}
if args.aessiv {
cryptoBackend = cryptocore.BackendAESSIV
}
frontendArgs := fusefrontend.Args{
Cipherdir: args.cipherdir,
Masterkey: key,
PlaintextNames: args.plaintextnames,
LongNames: args.longnames,
CryptoBackend: cryptoBackend,
}
// confFile is nil when "-zerokey" or "-masterkey" was used
if confFile != nil {
// Settings from the config file override command line args
frontendArgs.PlaintextNames = confFile.IsFeatureFlagSet(configfile.FlagPlaintextNames)
if confFile.IsFeatureFlagSet(configfile.FlagAESSIV) {
frontendArgs.CryptoBackend = cryptocore.BackendAESSIV
} else if args.reverse {
tlog.Fatal.Printf("AES-SIV is required by reverse mode, but not enabled in the config file")
os.Exit(ErrExitUsage)
}
}
// If allow_other is set and we run as root, try to give newly created files to
// the right user.
if args.allow_other && os.Getuid() == 0 {
frontendArgs.PreserveOwner = true
}
jsonBytes, _ := json.MarshalIndent(frontendArgs, "", "\t")
tlog.Debug.Printf("frontendArgs: %s", string(jsonBytes))
var finalFs pathfs.FileSystem
if args.reverse {
finalFs = fusefrontend_reverse.NewFS(frontendArgs)
} else {
finalFs = fusefrontend.NewFS(frontendArgs)
}
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
if args.allow_other {
tlog.Info.Printf(tlog.ColorYellow + "The option \"-allow_other\" is set. Make sure the file " +
"permissions protect your data from unwanted access." + tlog.ColorReset)
mOpts.AllowOther = true
// Make the kernel check the file permissions for us
mOpts.Options = append(mOpts.Options, "default_permissions")
}
if args.nonempty {
mOpts.Options = append(mOpts.Options, "nonempty")
}
// Set values shown in "df -T" and friends
// First column, "Filesystem"
mOpts.Options = append(mOpts.Options, "fsname="+args.cipherdir)
// Second column, "Type", will be shown as "fuse." + Name
mOpts.Name = "gocryptfs"
if args.reverse {
mOpts.Name += "-reverse"
}
// The kernel enforces read-only operation, we just have to pass "ro".
// Reverse mounts are always read-only
if args.ro || args.reverse {
mOpts.Options = append(mOpts.Options, "ro")
}
// Add additional mount options (if any) after the stock ones, so the user has
// a chance to override them.
if args.o != "" {
parts := strings.Split(args.o, ",")
tlog.Debug.Printf("Adding -o mount options: %v", parts)
mOpts.Options = append(mOpts.Options, parts...)
}
srv, err := fuse.NewServer(conn.RawFS(), args.mountpoint, &mOpts)
if err != nil {
tlog.Fatal.Printf("Mount failed: %v", err)
os.Exit(ErrExitMount)
}
srv.SetDebug(args.fusedebug)
// All FUSE file and directory create calls carry explicit permission
// information. We need an unrestricted umask to create the files and
// directories with the requested permissions.
syscall.Umask(0000)
return srv
}
func handleSigint(srv *fuse.Server, mountpoint string) {
ch := make(chan os.Signal, 1)
signal.Notify(ch, os.Interrupt)
signal.Notify(ch, syscall.SIGTERM)
go func() {
<-ch
err := srv.Unmount()
if err != nil {
tlog.Warn.Print(err)
tlog.Info.Printf("Trying lazy unmount")
cmd := exec.Command("fusermount", "-u", "-z", mountpoint)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
cmd.Run()
}
os.Exit(1)
}()
}
|
