passage backend; add support based on pass backend

keyring.go

@@ -20,6 +20,7 @@ const (
 	WinCredBackend       BackendType = "wincred"
 	FileBackend          BackendType = "file"
 	PassBackend          BackendType = "pass"
+	PassageBackend       BackendType = "passage"
 )
 
 // This order makes sure the OS-specific backends
@@ -34,6 +35,7 @@ var backendOrder = []BackendType{
 	KWalletBackend,
 	KeyCtlBackend,
 	// General
+	PassageBackend,
 	PassBackend,
 	FileBackend,
 }

passage.go

@@ -0,0 +1,166 @@
+//go:build !windows
+// +build !windows
+
+package keyring
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func init() {
+	supportedBackends[PassageBackend] = opener(func(cfg Config) (Keyring, error) {
+		var err error
+
+		passage := &passageKeyring{
+			passcmd: cfg.PassCmd,
+			dir:     cfg.PassDir,
+			prefix:  cfg.PassPrefix,
+		}
+
+		if passage.passcmd == "" {
+			passage.passcmd = "passage"
+		}
+
+		if passage.dir == "" {
+			if passDir, found := os.LookupEnv("PASSAGE_DIR"); found {
+				passage.dir = passDir
+			} else {
+				homeDir, err := os.UserHomeDir()
+				if err != nil {
+					return nil, err
+				}
+				passage.dir = filepath.Join(homeDir, ".passage/store")
+			}
+		}
+
+		passage.dir, err = ExpandTilde(passage.dir)
+		if err != nil {
+			return nil, err
+		}
+
+		// fail if the pass program is not available
+		_, err = exec.LookPath(passage.passcmd)
+		if err != nil {
+			return nil, errors.New("The passage program is not available")
+		}
+
+		return passage, nil
+	})
+}
+
+type passageKeyring struct {
+	dir     string
+	passcmd string
+	prefix  string
+}
+
+func (k *passageKeyring) pass(args ...string) *exec.Cmd {
+	cmd := exec.Command(k.passcmd, args...)
+	if k.dir != "" {
+		cmd.Env = append(os.Environ(), fmt.Sprintf("PASSAGE_DIR=%s", k.dir))
+	}
+	cmd.Stderr = os.Stderr
+
+	return cmd
+}
+
+func (k *passageKeyring) Get(key string) (Item, error) {
+	if !k.itemExists(key) {
+		return Item{}, ErrKeyNotFound
+	}
+
+	name := filepath.Join(k.prefix, key)
+	cmd := k.pass("show", name)
+	output, err := cmd.Output()
+	if err != nil {
+		return Item{}, err
+	}
+
+	var decoded Item
+	err = json.Unmarshal(output, &decoded)
+
+	return decoded, err
+}
+
+func (k *passageKeyring) GetMetadata(key string) (Metadata, error) {
+	return Metadata{}, nil
+}
+
+func (k *passageKeyring) Set(i Item) error {
+	bytes, err := json.Marshal(i)
+	if err != nil {
+		return err
+	}
+
+	name := filepath.Join(k.prefix, i.Key)
+	cmd := k.pass("insert", "-m", "-f", name)
+	cmd.Stdin = strings.NewReader(string(bytes))
+
+	err = cmd.Run()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (k *passageKeyring) Remove(key string) error {
+	if !k.itemExists(key) {
+		return ErrKeyNotFound
+	}
+
+	name := filepath.Join(k.prefix, key)
+	cmd := k.pass("rm", "-f", name)
+	err := cmd.Run()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (k *passageKeyring) itemExists(key string) bool {
+	var path = filepath.Join(k.dir, k.prefix, key+".age")
+	_, err := os.Stat(path)
+
+	return err == nil
+}
+
+func (k *passageKeyring) Keys() ([]string, error) {
+	var keys = []string{}
+	var path = filepath.Join(k.dir, k.prefix)
+
+	info, err := os.Stat(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return keys, nil
+		}
+		return keys, err
+	}
+	if !info.IsDir() {
+		return keys, fmt.Errorf("%s is not a directory", path)
+	}
+
+	err = filepath.Walk(path, func(p string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if !info.IsDir() && filepath.Ext(p) == ".age" {
+			name := strings.TrimPrefix(p, path)
+			if name[0] == os.PathSeparator {
+				name = name[1:]
+			}
+			keys = append(keys, name[:len(name)-4])
+		}
+		return nil
+	})
+
+	return keys, err
+}