add ssh askpass implementation

pkgs/clan-cli/clan_lib/ssh/password_prompt.py

@@ -0,0 +1,51 @@
+"""
+Password prompt utilities for SSH and sudo operations.
+
+This module provides functions to create password prompts using either
+GUI (zenity) or terminal (dialog) interfaces based on the environment.
+"""
+
+import os
+import sys
+
+from clan_lib.nix import nix_shell
+
+
+def get_password_command(title: str = "SSH Password", message: str = "") -> list[str]:
+    """
+    Determine the appropriate password prompt command based on environment.
+
+    This function checks if a GUI environment is available and selects either zenity (for GUI)
+    or dialog (for terminal) to create a password prompt. It then returns a command that will
+    execute the selected tool within a Nix shell with the necessary dependencies.
+
+    Args:
+        title: Title for the password dialog
+        message: Optional message for the dialog (only used by dialog, not zenity)
+
+    Returns:
+        A list of strings representing the shell command to execute the password prompt
+    """
+    if (
+        os.environ.get("DISPLAY")
+        or os.environ.get("WAYLAND_DISPLAY")
+        or sys.platform == "darwin"
+    ):
+        # GUI environment - use zenity
+        cmd = ["zenity", "--password", "--title", title]
+        dependencies = ["zenity"]
+    else:
+        # Terminal environment - use dialog
+        cmd = [
+            "dialog",
+            "--stdout",
+            "--insecure",
+            "--title",
+            title,
+            "--passwordbox",
+            message or "Enter password:",
+            "10",
+            "50",
+        ]
+        dependencies = ["dialog"]
+    return nix_shell(dependencies, cmd)

pkgs/clan-cli/clan_lib/ssh/remote.py

@@ -20,6 +20,7 @@ from clan_lib.errors import ClanError  # Assuming these are available
 from clan_lib.nix import nix_shell
 from clan_lib.ssh.host_key import HostKeyCheck, hostkey_to_ssh_opts
 from clan_lib.ssh.parse import parse_ssh_uri
+from clan_lib.ssh.password_prompt import get_password_command
 from clan_lib.ssh.sudo_askpass_proxy import SudoAskpassProxy
 
 cmdlog = logging.getLogger(__name__)
@@ -27,6 +28,9 @@ cmdlog = logging.getLogger(__name__)
 # Seconds until a message is printed when _run produces no output.
 NO_OUTPUT_TIMEOUT = 20
 
+# Path to the SSH_ASKPASS script (direct path to the script)
+SSH_ASKPASS_PATH = str(Path(__file__).parent / "ssh_askpass")
+
 
 @dataclass(frozen=True)
 class Remote:
@@ -183,27 +187,8 @@ class Remote:
             yield self
             return
 
-        if (
-            os.environ.get("DISPLAY")
-            or os.environ.get("WAYLAND_DISPLAY")
-            or sys.platform == "darwin"
-        ):
-            command = ["zenity", "--password", "--title", "%title%"]
-            dependencies = ["zenity"]
-        else:
-            command = [
-                "dialog",
-                "--stdout",
-                "--insecure",
-                "--title",
-                "%title%",
-                "--passwordbox",
-                "",
-                "10",
-                "50",
-            ]
-            dependencies = ["dialog"]
-        proxy = SudoAskpassProxy(self, nix_shell(dependencies, command))
+        cmd = get_password_command(title="%title%", message="")
+        proxy = SudoAskpassProxy(self, cmd)
         try:
             askpass_path = proxy.run()
             yield Remote(
@@ -243,6 +228,12 @@ class Remote:
         if opts is None:
             opts = RunOpts()
 
+        if not self.password:
+            # Set up environment for SSH_ASKPASS if we don't have a password
+            opts.env = opts.env or os.environ.copy()
+            opts.env["SSH_ASKPASS"] = SSH_ASKPASS_PATH
+            opts.env["SSH_ASKPASS_REQUIRE"] = "force"
+
         sudo = []
         if self._askpass_path is not None:
             sudo = [
@@ -306,11 +297,14 @@ class Remote:
         env: dict[str, str] | None = None,
         control_master: bool = True,
     ) -> dict[str, str]:
+        """Return environment variables for nix commands that use SSH."""
         if env is None:
             env = {}
-        env["NIX_SSHOPTS"] = " ".join(
-            self.ssh_cmd_opts(control_master=control_master)  # Renamed
-        )
+        env["NIX_SSHOPTS"] = " ".join(self.ssh_cmd_opts(control_master=control_master))
+        # Set SSH_ASKPASS environment variable if not using password directly
+        if not self.password:
+            env["SSH_ASKPASS"] = SSH_ASKPASS_PATH
+            env["SSH_ASKPASS_REQUIRE"] = "force"
         return env
 
     def ssh_cmd_opts(
@@ -360,6 +354,8 @@ class Remote:
     ) -> list[str]:
         packages = []
         password_args = []
+
+        # If we have a password, use sshpass for direct entry
         if self.password:
             packages.append("sshpass")
             password_args = ["sshpass", "-p", self.password]
@@ -419,8 +415,16 @@ class Remote:
                 raise ClanError(msg)
 
     def interactive_ssh(self) -> None:
+        """Run an interactive SSH session to the remote host."""
         cmd_list = self.ssh_cmd(tty=True, control_master=False)
-        res = subprocess.run(cmd_list, check=False)
+
+        # Set SSH_ASKPASS environment variable if no password is provided
+        env = os.environ.copy()
+        if not self.password:
+            env["SSH_ASKPASS"] = SSH_ASKPASS_PATH
+            env["SSH_ASKPASS_REQUIRE"] = "force"
+
+        res = subprocess.run(cmd_list, check=False, env=env)
 
         self.check_sshpass_errorcode(res)
 

pkgs/clan-cli/clan_lib/ssh/ssh_askpass

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""
+Clan SSH Askpass - Password prompt utility for SSH
+
+This script can be used as SSH_ASKPASS for SSH password prompts when a terminal
+is not available. It automatically selects the appropriate GUI or terminal-based
+password prompt based on the environment.
+
+Usage:
+  1. As SSH_ASKPASS environment variable:
+     $ export SSH_ASKPASS=/path/to/this/script
+     $ ssh-add
+
+  2. Directly (only for testing):
+     $ ./ssh_askpass
+
+The script will prompt for a password using:
+  - Zenity for GUI environments (DISPLAY/WAYLAND_DISPLAY set or on macOS)
+  - Dialog for terminal environments (no display detected)
+
+Dependencies are automatically installed via nix-shell as needed.
+"""
+
+import subprocess
+import sys
+import os
+from pathlib import Path
+
+# Add parent directory to path when script is executed directly
+script_dir = Path(__file__).parent
+clan_cli_dir = script_dir.parent.parent  # pkgs/clan-cli
+if str(clan_cli_dir) not in sys.path:
+    sys.path.insert(0, str(clan_cli_dir))
+
+# Import the actual implementation
+from clan_lib.ssh.password_prompt import get_password_command
+
+
+def main() -> int:
+    """Execute password prompt and print password to stdout."""
+    try:
+        # Get the appropriate command for the environment
+        cmd = get_password_command()
+
+        # Run the command and capture the password
+        result = subprocess.run(cmd, stdout=subprocess.PIPE, text=True, check=True)
+
+        # Print the password to stdout (will be read by SSH)
+        print(result.stdout.strip())
+    except subprocess.CalledProcessError:
+        # User canceled the password dialog
+        return 1
+    except Exception as e:
+        print(f"Error: {e}", file=sys.stderr)
+        return 1
+    else:
+        return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

pkgs/clan-cli/pyproject.toml

@@ -7,7 +7,7 @@ name = "clan"
 description = "clan cli tool"
 dynamic = ["version"]
 scripts = { clan = "clan_cli:main" }
-license = { text = "MIT" }
+license = "MIT"
 
 [project.urls]
 Homepage = "https://clan.lol/"
@@ -29,6 +29,7 @@ clan_lib = [
     "clan_core_templates/**/*",
     "**/allowed-packages.json",
     "ssh/*.sh",
+    "ssh/ssh_askpass",
 ]
 
 [tool.pytest.ini_options]