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package main
import (
"flag"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"runtime"
"runtime/pprof"
"time"
"github.com/rfjakob/gocryptfs/cryptfs"
"github.com/rfjakob/gocryptfs/pathfs_frontend"
"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 usageText() {
fmt.Printf("Usage: %s [OPTIONS] CIPHERDIR MOUNTPOINT\n", PROGRAM_NAME)
fmt.Printf("\nOptions:\n")
flag.PrintDefaults()
}
func main() {
runtime.GOMAXPROCS(4)
// Parse command line arguments
var debug, init, zerokey, fusedebug, openssl, passwd bool
var masterkey string
flag.Usage = usageText
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")
flag.BoolVar(&passwd, "passwd", false, "Change password")
flag.StringVar(&masterkey, "masterkey", "", "Mount with explicit master key")
var cpuprofile = flag.String("cpuprofile", "", "Write cpu profile to specified 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))
} else if passwd {
if flag.NArg() != 1 {
fmt.Printf("Usage: %s --passwd CIPHERDIR\n", PROGRAM_NAME)
os.Exit(ERREXIT_USAGE)
}
} else if flag.NArg() < 2 {
usageText()
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)
}
var cf *cryptfs.ConfFile
var currentPassword string
key := make([]byte, cryptfs.KEY_LEN)
if zerokey {
fmt.Printf("Zerokey mode active: using all-zero dummy master key.\n")
} else if len(masterkey) > 0 {
key = parseMasterKey(masterkey)
fmt.Printf("Using explicit master key.\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)
}
if passwd == true {
fmt.Printf("Old password: ")
} else {
fmt.Printf("Password: ")
}
currentPassword = readPassword()
fmt.Printf("\nDecrypting master key... ")
cryptfs.Warn.Disable() // Silence DecryptBlock() error messages on incorrect password
key, cf, err = cryptfs.LoadConfFile(cfname, currentPassword)
cryptfs.Warn.Enable()
if err != nil {
fmt.Println(err)
fmt.Println("Password incorrect.")
os.Exit(ERREXIT_LOADCONF)
}
fmt.Printf("done.\n")
}
if passwd == true {
fmt.Printf("Please enter the new password.\n")
newPassword := readPasswordTwice()
if newPassword == currentPassword {
fmt.Printf("New and old passwords are identical\n")
os.Exit(1)
}
cf.EncryptKey(key, newPassword)
err := cf.WriteFile()
if err != nil {
fmt.Println(err)
os.Exit(ERREXIT_INIT)
}
fmt.Printf("Password changed.\n")
os.Exit(0)
}
srv := pathfsFrontend(key, cipherdir, mountpoint, fusedebug, openssl)
if zerokey == false && len(masterkey) == 0 {
printMasterKey(key)
} else if zerokey == true {
fmt.Printf("ZEROKEY MODE PROVIDES NO SECURITY AT ALL AND SHOULD ONLY BE USED FOR TESTING.\n")
} else if len(masterkey) > 0 {
fmt.Printf("THE MASTER KEY IS VISIBLE VIA \"ps -auxwww\", ONLY USE THIS MODE FOR EMERGENCIES.\n")
}
fmt.Println("Filesystem ready.")
// Send notification to our parent
sendSig()
// Jump into server loop
srv.Serve()
}
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
}
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