"""
Password Authentication Implementation

Implements SSH password authentication method according to RFC 4252.
"""

from typing import Any
from ..exceptions import AuthenticationException


class PasswordAuth:
    """
    SSH password authentication implementation.
    
    Handles password-based authentication with secure credential handling
    and protection against timing attacks.
    """
    
    def __init__(self, transport: Any) -> None:
        """
        Initialize password authentication.
        
        Args:
            transport: SSH transport instance
        """
        self._transport = transport
    
    def authenticate(self, username: str, password: str) -> bool:
        """
        Perform password authentication.
        
        Args:
            username: Username for authentication
            password: Password for authentication
            
        Returns:
            True if authentication successful
            
        Raises:
            AuthenticationException: If authentication fails
        """
        # Implementation will be added in later tasks
        raise NotImplementedError("PasswordAuth.authenticate will be implemented in task 4.2")