initial commit

Author: garotm

githubauthlib/github_auth.py

@@ -0,0 +1,144 @@
+#!/usr/bin/env python3
+"""
+This module provides GitHub authentication for macOS, Windows, and Linux systems.
+
+The module retrieves GitHub tokens from the system's secure storage:
+- macOS: Keychain Access
+- Windows: Credential Manager
+- Linux: libsecret
+
+Written by: Garot Conklin
+"""
+
+import subprocess
+import platform
+import logging
+import re
+from typing import Optional
+
+# Configure logging
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+)
+logger = logging.getLogger(__name__)
+
+class GitHubAuthError(Exception):
+    """Base exception for GitHub authentication errors."""
+    pass
+
+class CredentialHelperError(GitHubAuthError):
+    """Raised when there's an error with the credential helper."""
+    pass
+
+class UnsupportedPlatformError(GitHubAuthError):
+    """Raised when the operating system is not supported."""
+    pass
+
+def validate_token(token: str) -> bool:
+    """
+    Validate the format of a GitHub token.
+    
+    Args:
+        token (str): The token to validate
+        
+    Returns:
+        bool: True if the token format is valid, False otherwise
+    """
+    # GitHub tokens are 40 characters long and contain only hexadecimal characters
+    token_pattern = re.compile(r'^gh[ps]_[A-Za-z0-9_]{36}$|^[a-f0-9]{40}$')
+    return bool(token_pattern.match(token))
+
+def get_github_token() -> Optional[str]:
+    """
+    Retrieves the GitHub token from the system's secure storage.
+
+    Returns:
+        str: The GitHub token if found and valid
+        
+    Raises:
+        CredentialHelperError: If there's an error accessing the credential helper
+        UnsupportedPlatformError: If the operating system is not supported
+    """
+    system = platform.system()
+    
+    try:
+        if system == "Darwin":
+            return _get_token_macos()
+        elif system == "Windows":
+            return _get_token_windows()
+        elif system == "Linux":
+            return _get_token_linux()
+        else:
+            raise UnsupportedPlatformError(f"Unsupported operating system: {system}")
+    except subprocess.CalledProcessError as e:
+        raise CredentialHelperError(f"Error accessing credential helper: {str(e)}")
+
+def _get_token_macos() -> Optional[str]:
+    """Retrieve token from macOS keychain."""
+    output = subprocess.check_output(
+        ["git", "credential-osxkeychain", "get"],
+        input="protocol=https\nhost=github.com\n",
+        universal_newlines=True,
+        stderr=subprocess.PIPE
+    )
+    
+    for line in output.split('\n'):
+        if line.startswith('password='):
+            token = line.split('=')[1].strip()
+            if validate_token(token):
+                return token
+            else:
+                logger.warning("Retrieved token failed validation")
+                return None
+    
+    logger.info("No GitHub token found in macOS keychain")
+    return None
+
+def _get_token_windows() -> Optional[str]:
+    """Retrieve token from Windows Credential Manager."""
+    helper = subprocess.check_output(
+        ["git", "config", "--get", "credential.helper"],
+        universal_newlines=True
+    ).strip()
+    
+    if helper not in ["manager", "manager-core", "wincred"]:
+        raise CredentialHelperError("Windows credential manager not configured")
+        
+    output = subprocess.check_output(
+        ["git", "credential", "fill"],
+        input="url=https://github.com\n\n",
+        universal_newlines=True
+    )
+    
+    credentials = dict(
+        line.split('=', 1) 
+        for line in output.strip().split('\n') 
+        if '=' in line
+    )
+    
+    token = credentials.get('password')
+    if token and validate_token(token):
+        return token
+        
+    logger.info("No valid GitHub token found in Windows Credential Manager")
+    return None
+
+def _get_token_linux() -> Optional[str]:
+    """Retrieve token from Linux libsecret."""
+    try:
+        output = subprocess.check_output(
+            ["secret-tool", "lookup", "host", "github.com"],
+            universal_newlines=True
+        )
+        
+        token = output.strip()
+        if validate_token(token):
+            return token
+            
+        logger.warning("Retrieved token failed validation")
+        return None
+        
+    except FileNotFoundError:
+        logger.error("libsecret-tools not installed. Please install using your package manager.")
+        return None