Add command "key add"

cmd/khepri/cmd_key.go

@@ -36,14 +36,34 @@ func list_keys(be backend.Server, key *khepri.Key) error {
 	return nil
 }
 
+func add_key(be backend.Server, key *khepri.Key) error {
+	pw := readPassword("KHEPRI_NEWPASSWORD", "enter password for new key: ")
+	pw2 := readPassword("KHEPRI_NEWPASSWORD", "enter password again: ")
+
+	if pw != pw2 {
+		errx(1, "passwords do not match")
+	}
+
+	id, err := key.AddKey(be, pw)
+	if err != nil {
+		return fmt.Errorf("creating new key failed: %v\n", err)
+	}
+
+	fmt.Printf("saved new key as %s\n", id)
+
+	return nil
+}
+
 func commandKey(be backend.Server, key *khepri.Key, args []string) error {
 	if len(args) < 1 {
-		return errors.New("usage: key [list]")
+		return errors.New("usage: key [list|add]")
 	}
 
 	switch args[0] {
 	case "list":
 		return list_keys(be, key)
+	case "add":
+		return add_key(be, key)
 	}
 
 	return nil

cmd/khepri/main.go

@@ -34,11 +34,15 @@ type commandFunc func(backend.Server, *khepri.Key, []string) error
 
 var commands map[string]commandFunc
 
-func readPassword(prompt string) string {
-	p := os.Getenv("KHEPRI_PASSWORD")
+func readPassword(env string, prompt string) string {
+
+	if env != "" {
+		p := os.Getenv(env)
+
 		if p != "" {
 			return p
 		}
+	}
 
 	fmt.Print(prompt)
 	pw, err := terminal.ReadPassword(int(os.Stdin.Fd()))
@@ -51,8 +55,8 @@ func readPassword(prompt string) string {
 }
 
 func commandInit(repo string) error {
-	pw := readPassword("enter password for new backend: ")
-	pw2 := readPassword("enter password again: ")
+	pw := readPassword("KHEPRI_PASSWORD", "enter password for new backend: ")
+	pw2 := readPassword("KHEPRI_PASSWORD", "enter password again: ")
 
 	if pw != pw2 {
 		errx(1, "passwords do not match")
@@ -188,7 +192,7 @@ func main() {
 		errx(1, "unable to open repo: %v", err)
 	}
 
-	key, err := khepri.SearchKey(repo, readPassword("Enter Password for Repository: "))
+	key, err := khepri.SearchKey(repo, readPassword("KHEPRI_PASSWORD", "Enter Password for Repository: "))
 	if err != nil {
 		errx(2, "unable to open repo: %v", err)
 	}

key.go

@@ -204,6 +204,70 @@ func SearchKey(be backend.Server, password string) (*Key, error) {
 	return nil, ErrNoKeyFound
 }
 
+// AddKey adds a new key to an already existing repository.
+func (oldkey *Key) AddKey(be backend.Server, password string) (backend.ID, error) {
+	// fill meta data about key
+	newkey := &Key{
+		Created: time.Now(),
+		KDF:     "scrypt",
+		N:       scryptN,
+		R:       scryptR,
+		P:       scryptP,
+	}
+
+	hn, err := os.Hostname()
+	if err == nil {
+		newkey.Hostname = hn
+	}
+
+	usr, err := user.Current()
+	if err == nil {
+		newkey.Username = usr.Username
+	}
+
+	// generate random salt
+	newkey.Salt = make([]byte, scryptSaltsize)
+	n, err := rand.Read(newkey.Salt)
+	if n != scryptSaltsize || err != nil {
+		panic("unable to read enough random bytes for salt")
+	}
+
+	// call scrypt() to derive user key
+	newkey.user, err = newkey.scrypt(password)
+	if err != nil {
+		return nil, err
+	}
+
+	// copy master keys from oldkey
+	newkey.master = oldkey.master
+
+	// encrypt master keys (as json) with user key
+	buf, err := json.Marshal(newkey.master)
+	if err != nil {
+		return nil, err
+	}
+
+	newkey.Data = GetChunkBuf("key")
+	n, err = newkey.EncryptUser(newkey.Data, buf)
+	newkey.Data = newkey.Data[:n]
+
+	// dump as json
+	buf, err = json.Marshal(newkey)
+	if err != nil {
+		return nil, err
+	}
+
+	// store in repository and return
+	id, err := be.Create(backend.Key, buf)
+	if err != nil {
+		return nil, err
+	}
+
+	FreeChunkBuf("key", newkey.Data)
+
+	return id, nil
+}
+
 func (k *Key) scrypt(password string) (*keys, error) {
 	if len(k.Salt) == 0 {
 		return nil, fmt.Errorf("scrypt() called with empty salt")