Adding well-known prefix to encoded multiline

Signed-off-by: Ryan Nixon <[email protected]>

keyring_darwin.go

@@ -23,6 +23,9 @@ import (
 
 const (
 	execPathKeychain = "/usr/bin/security"
+
+	// encodingPrefix is a well-known prefix added to strings encoded by Set.
+	encodingPrefix = "go-keyring-encoded:"
 )
 
 type macOSXKeychain struct{}
@@ -48,15 +51,22 @@ func (k macOSXKeychain) Get(service, username string) (string, error) {
 	// if the added secret has multiple lines, osx will hex encode it
 	trimStr := strings.TrimSpace(string(out[:]))
 	dec, err := hex.DecodeString(trimStr)
-	// if there was an error hex decoding the string, assume it's not encoded
-	if err != nil {
-		return fmt.Sprintf("%s", trimStr), nil
+	// if there was no error hex decoding the string and it has the well-known prefix, assume it's encoded
+	if err == nil && strings.HasPrefix(string(dec), encodingPrefix) {
+		return fmt.Sprintf("%s", dec[len(encodingPrefix):]), nil
 	}
-	return fmt.Sprintf("%s", dec), err
+
+	return trimStr, nil
 }
 
 // Set stores a secret in the keyring given a service name and a user.
 func (k macOSXKeychain) Set(service, username, password string) error {
+	// if the added secret has multiple lines, osx will hex encode it
+	// identify this with a well-known prefix.
+	if strings.ContainsRune(password, '\n') {
+		password = hex.EncodeToString([]byte(encodingPrefix + password))
+	}
+
 	return exec.Command(
 		execPathKeychain,
 		"add-generic-password",

keyring_test.go

@@ -38,6 +38,24 @@ like osx`
 	}
 }
 
+// TestGetSingleLineHex tests getting a single line hex string password from the keyring.
+func TestGetSingleLineHex(t *testing.T) {
+	hexPassword := "abcdef123abcdef123"
+	err := Set(service, user, hexPassword)
+	if err != nil {
+		t.Errorf("Should not fail, got: %s", err)
+	}
+
+	pw, err := Get(service, user)
+	if err != nil {
+		t.Errorf("Should not fail, got: %s", err)
+	}
+
+	if hexPassword != pw {
+		t.Errorf("Expected password %s, got %s", hexPassword, pw)
+	}
+}
+
 // TestGet tests getting a password from the keyring.
 func TestGet(t *testing.T) {
 	err := Set(service, user, password)