fix(cmd): prevent adding connection with invalid identities file

Signed-off-by: axel7083 <42176370+axel7083@users.noreply.github.com>

Author: axel7083

cmd/podman/system/connection/add.go

@@ -141,6 +141,14 @@ func add(cmd *cobra.Command, args []string) error {
 
 	switch uri.Scheme {
 	case "ssh":
+		// ensure the Identity provided is a valid file
+		info, err := os.Stat(entities.Identity)
+		switch {
+		case err != nil:
+			return err
+		case info.IsDir():
+			return fmt.Errorf("%q is a directory", entities.Identity)
+		}
 		return ssh.Create(entities, sshMode)
 	case "unix":
 		if cmd.Flags().Changed("identity") {