feat: Add an option to let the user provide the entire key PEM data as the answer

common/sshkeys/sshkeys.go

@@ -33,6 +33,10 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
+const (
+	userProvidedKey = "user_provided_key"
+)
+
 var (
 	// DomainToPublicKeys maps domains to public keys gathered with known-hosts/get-public-keys.sh
 	DomainToPublicKeys = map[string][]string{
@@ -101,37 +105,67 @@ func loadSSHKeysOfCurrentUser() {
 	privateKeyDir = filepath.Join(home, ".ssh")
 	logrus.Debugf("Looking in ssh directory at path %q for keys.", privateKeyDir)
 
-	// Ask if we should look at the private keys
+	// Ask whether to load private keys or provide own key
+	options := []string{
+		"Load private ssh keys from " + privateKeyDir,
+		"Provide your own key",
+		"No, I will add them later if necessary.",
+	}
 	message := `The CI/CD pipeline needs access to the git repos in order to clone, build and push.
 If any of the repos require ssh keys you will need to provide them.
-Do you want to load the private ssh keys from [%s]?:`
-	ans := qaengine.FetchBoolAnswer(common.ConfigRepoLoadPrivKey, fmt.Sprintf(message, privateKeyDir), []string{"No, I will add them later if necessary."}, false, nil)
-	if !ans {
+Select an option:`
+	selectedOption := qaengine.FetchSelectAnswer(common.ConfigRepoLoadPrivKey, message, nil, "", options, nil)
+
+	switch selectedOption {
+	case options[0]:
+		if err := loadKeysFromDirectory(privateKeyDir); err != nil {
+			logrus.Warn("Can't load keys from directory. Error:", err)
+			return
+		}
+
+	case options[1]:
+		privateKeysToConsider = []string{userProvidedKey}
+
+	default:
 		logrus.Debug("Don't read private keys. They will be added later if necessary.")
 		return
 	}
 
-	// Ask which keys we should consider
-	finfos, err := os.ReadDir(privateKeyDir)
+}
+
+func loadKeysFromDirectory(directory string) error {
+	finfos, err := os.ReadDir(directory)
 	if err != nil {
-		logrus.Errorf("Failed to read the ssh directory at path %q Error: %q", privateKeyDir, err)
-		return
+		return fmt.Errorf("failed to read the SSH directory at path %q: %w", directory, err)
 	}
+
 	if len(finfos) == 0 {
-		logrus.Warn("No key files where found in", privateKeyDir)
-		return
+		logrus.Warn("No key files were found in", directory)
+		return nil
 	}
+
 	filenames := []string{}
 	for _, finfo := range finfos {
 		filenames = append(filenames, finfo.Name())
 	}
-	filenames = qaengine.FetchMultiSelectAnswer(common.ConfigRepoKeyPathsKey, fmt.Sprintf("These are the files we found in %q . Which keys should we consider?", privateKeyDir), []string{"Select all the keys that give access to git repos."}, filenames, filenames, nil)
-	if len(filenames) == 0 {
+
+	selectedFilenames := qaengine.FetchMultiSelectAnswer(
+		common.ConfigRepoKeyPathsKey,
+		fmt.Sprintf("These are the files found in %q. Select the keys to consider:", directory),
+		[]string{"Select all the keys that give access to git repos."},
+		filenames,
+		filenames,
+		nil,
+	)
+
+	if len(selectedFilenames) == 0 {
 		logrus.Info("All key files ignored.")
-		return
+		return nil
 	}
+
 	// Save the filenames for now. We will decrypt them if and when we need them.
-	privateKeysToConsider = filenames
+	privateKeysToConsider = selectedFilenames
+	return nil
 }
 
 func marshalRSAIntoPEM(key *rsa.PrivateKey) string {
@@ -195,6 +229,18 @@ func GetSSHKey(domain string) (string, bool) {
 	if len(privateKeysToConsider) == 0 {
 		return "", false
 	}
+	if privateKeysToConsider[0] == userProvidedKey {
+		key := qaengine.FetchStringAnswer(common.ConfigRepoPrivKey, "Provide your own PEM-formatted private key:", []string{"Should not be empty"}, "", nil)
+		if key == "" {
+			logrus.Error("User-provided private key is empty.")
+			return "", false
+		}
+		if err := validatePEMPrivateKey(key); err != nil {
+			logrus.Error("Can't validate the PEM-formatted private key. Error:", err)
+			return "", false
+		}
+		return key, true
+	}
 
 	filenames := privateKeysToConsider
 	noAnswer := "none of the above"
@@ -216,3 +262,17 @@ func GetSSHKey(domain string) (string, bool) {
 	}
 	return key, true
 }
+
+func validatePEMPrivateKey(key string) error {
+	block, _ := pem.Decode([]byte(key))
+	if block == nil || block.Type != "RSA PRIVATE KEY" {
+		return fmt.Errorf("invalid PEM private key format")
+	}
+
+	_, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}