restic/cmd/restic/cmd_key_add.go

package main

import (
	"context"
	"fmt"

	"github.com/restic/restic/internal/errors"
	"github.com/restic/restic/internal/repository"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
)

var cmdKeyAdd = &cobra.Command{
	Use:   "add",
	Short: "Add a new key (password) to the repository; returns the new key ID",
	Long: `
The "add" sub-command creates a new key and validates the key. Returns the new key ID.

EXIT STATUS
===========

Exit status is 0 if the command was successful.
Exit status is 1 if there was any error.
Exit status is 10 if the repository does not exist.
Exit status is 11 if the repository is already locked.
Exit status is 12 if the password is incorrect.
	`,
	DisableAutoGenTag: true,
}

type KeyAddOptions struct {
	NewPasswordFile    string
	InsecureNoPassword bool
	Username           string
	Hostname           string
}

func (opts *KeyAddOptions) Add(flags *pflag.FlagSet) {
	flags.StringVarP(&opts.NewPasswordFile, "new-password-file", "", "", "`file` from which to read the new password")
	flags.BoolVar(&opts.InsecureNoPassword, "new-insecure-no-password", false, "add an empty password for the repository (insecure)")
	flags.StringVarP(&opts.Username, "user", "", "", "the username for new key")
	flags.StringVarP(&opts.Hostname, "host", "", "", "the hostname for new key")
}

func init() {
	cmdKey.AddCommand(cmdKeyAdd)

	var keyAddOpts KeyAddOptions
	keyAddOpts.Add(cmdKeyAdd.Flags())
	cmdKeyAdd.RunE = func(cmd *cobra.Command, args []string) error {
		return runKeyAdd(cmd.Context(), globalOptions, keyAddOpts, args)
	}
}

func runKeyAdd(ctx context.Context, gopts GlobalOptions, opts KeyAddOptions, args []string) error {
	if len(args) > 0 {
		return fmt.Errorf("the key add command expects no arguments, only options - please see `restic help key add` for usage and flags")
	}

	ctx, repo, unlock, err := openWithAppendLock(ctx, gopts, false)
	if err != nil {
		return err
	}
	defer unlock()

	return addKey(ctx, repo, gopts, opts)
}

func addKey(ctx context.Context, repo *repository.Repository, gopts GlobalOptions, opts KeyAddOptions) error {
	pw, err := getNewPassword(ctx, gopts, opts.NewPasswordFile, opts.InsecureNoPassword)
	if err != nil {
		return err
	}

	id, err := repository.AddKey(ctx, repo, pw, opts.Username, opts.Hostname, repo.Key())
	if err != nil {
		return errors.Fatalf("creating new key failed: %v\n", err)
	}

	err = switchToNewKeyAndRemoveIfBroken(ctx, repo, id, pw)
	if err != nil {
		return err
	}

	Verbosef("saved new key with ID %s\n", id.ID())

	return nil
}

// testKeyNewPassword is used to set a new password during integration testing.
var testKeyNewPassword string

func getNewPassword(ctx context.Context, gopts GlobalOptions, newPasswordFile string, insecureNoPassword bool) (string, error) {
	if testKeyNewPassword != "" {
		return testKeyNewPassword, nil
	}

	if insecureNoPassword {
		if newPasswordFile != "" {
			return "", fmt.Errorf("only either --new-password-file or --new-insecure-no-password may be specified")
		}
		return "", nil
	}

	if newPasswordFile != "" {
		password, err := loadPasswordFromFile(newPasswordFile)
		if err != nil {
			return "", err
		}
		if password == "" {
			return "", fmt.Errorf("an empty password is not allowed by default. Pass the flag `--new-insecure-no-password` to restic to disable this check")
		}
		return password, nil
	}

	// Since we already have an open repository, temporary remove the password
	// to prompt the user for the passwd.
	newopts := gopts
	newopts.password = ""
	// empty passwords are already handled above
	newopts.InsecureNoPassword = false

	return ReadPasswordTwice(ctx, newopts,
		"enter new password: ",
		"enter password again: ")
}

func switchToNewKeyAndRemoveIfBroken(ctx context.Context, repo *repository.Repository, key *repository.Key, pw string) error {
	// Verify new key to make sure it really works. A broken key can render the
	// whole repository inaccessible
	err := repo.SearchKey(ctx, pw, 0, key.ID().String())
	if err != nil {
		// the key is invalid, try to remove it
		_ = repository.RemoveKey(ctx, repo, key.ID())
		return errors.Fatalf("failed to access repository with new key: %v", err)
	}
	return nil
}