Allow empty password

cmd/restic/cmd_init.go

@@ -36,6 +36,7 @@ type InitOptions struct {
 	secondaryRepoOptions
 	CopyChunkerParameters bool
 	RepositoryVersion     string
+	AllowEmptyPassword    bool
 }
 
 var initOptions InitOptions
@@ -47,6 +48,7 @@ func init() {
 	initSecondaryRepoOptions(f, &initOptions.secondaryRepoOptions, "secondary", "to copy chunker parameters from")
 	f.BoolVar(&initOptions.CopyChunkerParameters, "copy-chunker-params", false, "copy chunker parameters from the secondary repository (useful with the copy command)")
 	f.StringVar(&initOptions.RepositoryVersion, "repository-version", "stable", "repository format version to use, allowed values are a format version, 'latest' and 'stable'")
+	f.BoolVar(&initOptions.AllowEmptyPassword, "allow-empty-password", false, "allow an empty password (feel beeing warned)")
 }
 
 func runInit(ctx context.Context, opts InitOptions, gopts GlobalOptions, args []string) error {
@@ -82,7 +84,8 @@ func runInit(ctx context.Context, opts InitOptions, gopts GlobalOptions, args []
 
 	gopts.password, err = ReadPasswordTwice(gopts,
 		"enter password for new repository: ",
-		"enter password again: ")
+		"enter password again: ",
+		opts.AllowEmptyPassword)
 	if err != nil {
 		return err
 	}

cmd/restic/cmd_key_add.go

@@ -29,9 +29,10 @@ Exit status is 0 if the command is successful, and non-zero if there was any err
 }
 
 type KeyAddOptions struct {
-	NewPasswordFile string
-	Username        string
-	Hostname        string
+	NewPasswordFile    string
+	AllowEmptyPassword bool
+	Username           string
+	Hostname           string
 }
 
 var keyAddOpts KeyAddOptions
@@ -41,6 +42,7 @@ func init() {
 
 	flags := cmdKeyAdd.Flags()
 	flags.StringVarP(&keyAddOpts.NewPasswordFile, "new-password-file", "", "", "`file` from which to read the new password")
+	flags.BoolVar(&keyAddOpts.AllowEmptyPassword, "allow-empty-password", false, "allow an empty password (feel beeing warned)")
 	flags.StringVarP(&keyAddOpts.Username, "user", "", "", "the username for new key")
 	flags.StringVarP(&keyAddOpts.Hostname, "host", "", "", "the hostname for new key")
 }
@@ -65,7 +67,7 @@ func runKeyAdd(ctx context.Context, gopts GlobalOptions, opts KeyAddOptions, arg
 }
 
 func addKey(ctx context.Context, repo *repository.Repository, gopts GlobalOptions, opts KeyAddOptions) error {
-	pw, err := getNewPassword(gopts, opts.NewPasswordFile)
+	pw, err := getNewPassword(gopts, opts.NewPasswordFile, opts.AllowEmptyPassword)
 	if err != nil {
 		return err
 	}
@@ -88,7 +90,7 @@ func addKey(ctx context.Context, repo *repository.Repository, gopts GlobalOption
 // testKeyNewPassword is used to set a new password during integration testing.
 var testKeyNewPassword string
 
-func getNewPassword(gopts GlobalOptions, newPasswordFile string) (string, error) {
+func getNewPassword(gopts GlobalOptions, newPasswordFile string, allowAllowEmptyPassword bool) (string, error) {
 	if testKeyNewPassword != "" {
 		return testKeyNewPassword, nil
 	}
@@ -104,7 +106,8 @@ func getNewPassword(gopts GlobalOptions, newPasswordFile string) (string, error)
 
 	return ReadPasswordTwice(newopts,
 		"enter new password: ",
-		"enter password again: ")
+		"enter password again: ",
+		allowAllowEmptyPassword)
 }
 
 func loadPasswordFromFile(pwdFile string) (string, error) {

cmd/restic/cmd_key_passwd.go

@@ -38,6 +38,7 @@ func init() {
 
 	flags := cmdKeyPasswd.Flags()
 	flags.StringVarP(&keyPasswdOpts.NewPasswordFile, "new-password-file", "", "", "`file` from which to read the new password")
+	flags.BoolVar(&keyPasswdOpts.AllowEmptyPassword, "allow-empty-password", false, "allow an empty password (feel beeing warned)")
 	flags.StringVarP(&keyPasswdOpts.Username, "user", "", "", "the username for new key")
 	flags.StringVarP(&keyPasswdOpts.Hostname, "host", "", "", "the hostname for new key")
 }
@@ -62,7 +63,7 @@ func runKeyPasswd(ctx context.Context, gopts GlobalOptions, opts KeyPasswdOption
 }
 
 func changePassword(ctx context.Context, repo *repository.Repository, gopts GlobalOptions, opts KeyPasswdOptions) error {
-	pw, err := getNewPassword(gopts, opts.NewPasswordFile)
+	pw, err := getNewPassword(gopts, opts.NewPasswordFile, opts.AllowEmptyPassword)
 	if err != nil {
 		return err
 	}

cmd/restic/global.go

@@ -313,7 +313,11 @@ func resolvePassword(opts GlobalOptions, envStr string) (string, error) {
 		if errors.Is(err, os.ErrNotExist) {
 			return "", errors.Fatalf("%s does not exist", opts.PasswordFile)
 		}
-		return strings.TrimSpace(string(s)), errors.Wrap(err, "Readfile")
+		pwd := strings.TrimSpace(string(s))
+		if pwd == "" {
+			pwd = emptyPassword
+		}
+		return pwd, errors.Wrap(err, "Readfile")
 	}
 
 	if pwd := os.Getenv(envStr); pwd != "" {
@@ -348,9 +352,11 @@ func readPasswordTerminal(in *os.File, out io.Writer, prompt string) (password s
 	return password, nil
 }
 
+const emptyPassword = "\xff"
+
 // ReadPassword reads the password from a password file, the environment
 // variable RESTIC_PASSWORD or prompts the user.
-func ReadPassword(opts GlobalOptions, prompt string) (string, error) {
+func ReadPassword(opts GlobalOptions, prompt string, allowAllowEmptyPassword bool) (string, error) {
 	if opts.password != "" {
 		return opts.password, nil
 	}
@@ -372,21 +378,26 @@ func ReadPassword(opts GlobalOptions, prompt string) (string, error) {
 	}
 
 	if len(password) == 0 {
-		return "", errors.Fatal("an empty password is not a password")
+		if allowAllowEmptyPassword {
+			Warnf("using an empty password is bad security practice\n")
+			return emptyPassword, nil
+		} else {
+			return "", errors.Fatal("an empty password is not a password")
+		}
 	}
 
 	return password, nil
 }
 
 // ReadPasswordTwice calls ReadPassword two times and returns an error when the
 // passwords don't match.
-func ReadPasswordTwice(gopts GlobalOptions, prompt1, prompt2 string) (string, error) {
-	pw1, err := ReadPassword(gopts, prompt1)
+func ReadPasswordTwice(gopts GlobalOptions, prompt1, prompt2 string, allowAllowEmptyPassword bool) (string, error) {
+	pw1, err := ReadPassword(gopts, prompt1, allowAllowEmptyPassword)
 	if err != nil {
 		return "", err
 	}
 	if stdinIsTerminal() {
-		pw2, err := ReadPassword(gopts, prompt2)
+		pw2, err := ReadPassword(gopts, prompt2, allowAllowEmptyPassword)
 		if err != nil {
 			return "", err
 		}
@@ -469,7 +480,7 @@ func OpenRepository(ctx context.Context, opts GlobalOptions) (*repository.Reposi
 	}
 
 	for ; passwordTriesLeft > 0; passwordTriesLeft-- {
-		opts.password, err = ReadPassword(opts, "enter password for repository: ")
+		opts.password, err = ReadPassword(opts, "enter password for repository: ", true)
 		if err != nil && passwordTriesLeft > 1 {
 			opts.password = ""
 			fmt.Printf("%s. Try again\n", err)

cmd/restic/secondary_repo.go

@@ -109,7 +109,8 @@ func fillSecondaryGlobalOpts(opts secondaryRepoOptions, gopts GlobalOptions, rep
 			return GlobalOptions{}, false, err
 		}
 	}
-	dstGopts.password, err = ReadPassword(dstGopts, "enter password for "+repoPrefix+" repository: ")
+	//FIXME: constant true okay?
+	dstGopts.password, err = ReadPassword(dstGopts, "enter password for "+repoPrefix+" repository: ", true)
 	if err != nil {
 		return GlobalOptions{}, false, err
 	}

doc/bash-completion.sh

@@ -1442,6 +1442,7 @@ _restic_init()
     two_word_flags+=("--from-password-file")
     local_nonpersistent_flags+=("--from-password-file")
     local_nonpersistent_flags+=("--from-password-file=")
+    flags+=("--allow-empty-password")
     flags+=("--from-repo=")
     two_word_flags+=("--from-repo")
     local_nonpersistent_flags+=("--from-repo")
@@ -1512,6 +1513,10 @@ _restic_key()
     command_aliases=()
 
     commands=()
+    commands+=("add")
+    commands+=("list")
+    commands+=("passwd")
+    commands+=("remove")
 
     flags=()
     two_word_flags=()
@@ -1582,6 +1587,74 @@ _restic_key()
     noun_aliases=()
 }
 
+_restic_key_add()
+{
+    last_command="restic_key_add"
+
+    command_aliases=()
+
+    commands=()
+
+    flags_with_completion=()
+    flags_completion=()
+
+    flags+=("--allow-empty-password")
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+    noun_aliases=()
+}
+
+_restic_key_list()
+{
+    last_command="restic_key_list"
+
+    command_aliases=()
+
+    commands=()
+
+    flags_with_completion=()
+    flags_completion=()
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+    noun_aliases=()
+}
+
+_restic_key_passwd()
+{
+    last_command="restic_key_passwd"
+
+    command_aliases=()
+
+    commands=()
+
+    flags_with_completion=()
+    flags_completion=()
+
+    flags+=("--allow-empty-password")
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+    noun_aliases=()
+}
+
+_restic_key_remove()
+{
+    last_command="restic_key_remove"
+
+    command_aliases=()
+
+    commands=()
+
+    flags_with_completion=()
+    flags_completion=()
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+    noun_aliases=()
+}
+
 _restic_list()
 {
     last_command="restic_list"