libgocryptfs/main.go

339 lines
10 KiB
Go

// gocryptfs is an encrypted overlay filesystem written in Go.
// See README.md ( https://github.com/rfjakob/gocryptfs/blob/master/README.md )
// and the official website ( https://nuetzlich.net/gocryptfs/ ) for details.
package main
import (
"fmt"
"log"
"os"
"path/filepath"
"runtime"
"strconv"
"strings"
"github.com/hanwen/go-fuse/v2/fuse"
"github.com/rfjakob/gocryptfs/v2/internal/configfile"
"github.com/rfjakob/gocryptfs/v2/internal/contentenc"
"github.com/rfjakob/gocryptfs/v2/internal/exitcodes"
"github.com/rfjakob/gocryptfs/v2/internal/fido2"
"github.com/rfjakob/gocryptfs/v2/internal/readpassword"
"github.com/rfjakob/gocryptfs/v2/internal/speed"
"github.com/rfjakob/gocryptfs/v2/internal/stupidgcm"
"github.com/rfjakob/gocryptfs/v2/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` and decrypts the masterkey,
// or gets via the `-masterkey` or `-zerokey` command line options, if specified.
func loadConfig(args *argContainer) (masterkey []byte, cf *configfile.ConfFile, err error) {
// First check if the file can be read at all.
cf, err = configfile.Load(args.config)
if err != nil {
tlog.Fatal.Printf("Cannot open config file: %v", err)
return nil, nil, err
}
// The user may have passed the master key on the command line (probably because
// he forgot the password).
masterkey = handleArgsMasterkey(args)
if masterkey != nil {
return masterkey, cf, nil
}
var pw []byte
if cf.IsFeatureFlagSet(configfile.FlagFIDO2) {
if args.fido2 == "" {
tlog.Fatal.Printf("Masterkey encrypted using FIDO2 token; need to use the --fido2 option.")
return nil, nil, exitcodes.NewErr("", exitcodes.Usage)
}
pw = fido2.Secret(args.fido2, cf.FIDO2.CredentialID, cf.FIDO2.HMACSalt)
} else {
pw, err = readpassword.Once([]string(args.extpass), []string(args.passfile), "")
if err != nil {
tlog.Fatal.Println(err)
return nil, nil, exitcodes.NewErr("", exitcodes.ReadPassword)
}
}
tlog.Info.Println("Decrypting master key")
masterkey, err = cf.DecryptMasterKey(pw)
for i := range pw {
pw[i] = 0
}
if err != nil {
tlog.Fatal.Println(err)
return nil, nil, err
}
return masterkey, cf, 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) {
var confFile *configfile.ConfFile
{
var masterkey []byte
var err error
masterkey, confFile, err = loadConfig(args)
if err != nil {
exitcodes.Exit(err)
}
if len(masterkey) == 0 {
log.Panic("empty masterkey")
}
if confFile.IsFeatureFlagSet(configfile.FlagFIDO2) {
tlog.Fatal.Printf("Password change is not supported on FIDO2-enabled filesystems.")
os.Exit(exitcodes.Usage)
}
tlog.Info.Println("Please enter your new password.")
newPw, err := readpassword.Twice([]string(args.extpass), []string(args.passfile))
if err != nil {
tlog.Fatal.Println(err)
os.Exit(exitcodes.ReadPassword)
}
logN := confFile.ScryptObject.LogN()
if args._explicitScryptn {
logN = args.scryptn
}
confFile.EncryptKey(masterkey, newPw, 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 v1.7-32-gcf99cfd; go-fuse v1.0.0-174-g22a9cb9; 2019-05-12 go1.12 linux/amd64
func printVersion() {
var tagsSlice []string
if stupidgcm.BuiltWithoutOpenssl {
tagsSlice = append(tagsSlice, "without_openssl")
}
tags := ""
if tagsSlice != nil {
tags = " " + strings.Join(tagsSlice, " ")
}
built := fmt.Sprintf("%s %s", BuildDate, runtime.Version())
if raceDetector {
built += " -race"
}
fmt.Printf("%s %s%s; go-fuse %s; %s %s/%s\n",
tlog.ProgramName, GitVersion, tags, GitVersionFuse, built,
runtime.GOOS, runtime.GOARCH)
}
func main() {
mxp := runtime.GOMAXPROCS(0)
if mxp < 4 && os.Getenv("GOMAXPROCS") == "" {
// On a 2-core machine, setting maxprocs to 4 gives 10% better performance.
// But don't override an explicitly set GOMAXPROCS env variable.
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")
}
// Show microseconds in go-fuse debug output (-fusedebug)
log.SetFlags(log.Lmicroseconds)
var err error
// Parse all command-line options (i.e. arguments starting with "-")
// into "args". Path arguments are parsed below.
args := parseCliOpts(os.Args)
// 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
}
tlog.Debug.Printf("cli args: %q", os.Args)
// "-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 {
printVersion()
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
} else {
if args.exclude != nil {
tlog.Fatal.Printf("-exclude only works in reverse mode")
os.Exit(exitcodes.ExcludeError)
}
}
// "-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")
}
// 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 {
code := fsck(&args)
os.Exit(code)
}
}