Keyserver Operations

def recv_keys(self, keyserver, *keyids, **kwargs):
    """
    Retrieve one or more keys from a keyserver.
    
    Parameters:
    - keyserver (str): Keyserver URL or hostname
    - *keyids: Variable number of key IDs, fingerprints, or email addresses
    - extra_args (list): Additional GPG arguments
    - passphrase (str): Passphrase if needed for key import
    
    Returns:
    ImportResult: Result with imported key information and statistics
    """

def auto_locate_key(self, email, mechanisms=None, **kwargs):
    """
    Automatically locate a public key by email address using various mechanisms.
    
    Parameters:
    - email (str): Email address to locate key for
    - mechanisms (list): Location mechanisms ('keyserver', 'pka', 'cert', 'dane', 'wkd', 'ldap')
    - extra_args (list): Additional GPG arguments
    
    Returns:
    AutoLocateKey: Result with located key information
    """

def send_keys(self, keyserver, *keyids, **kwargs):
    """
    Send one or more keys to a keyserver for public distribution.
    
    Parameters:
    - keyserver (str): Keyserver URL or hostname to send keys to
    - *keyids: Variable number of key IDs, fingerprints, or email addresses to send
    - extra_args (list): Additional GPG arguments
    
    Returns:
    SendResult: Result with send operation status
    """

def search_keys(self, query, keyserver='pgp.mit.edu', extra_args=None):
    """
    Search a keyserver for keys matching the query.
    
    Parameters:
    - query (str): Search query (name, email, or key ID)
    - keyserver (str): Keyserver to search (default: 'pgp.mit.edu')
    - extra_args (list): Additional GPG arguments
    
    Returns:
    SearchKeys: List of matching keys with metadata
    """

class ImportResult(StatusHandler):
    count: int              # Total keys processed
    imported: int          # Keys successfully imported
    not_imported: int      # Keys that failed to import
    unchanged: int         # Keys already in keyring unchanged
    new_user_ids: int      # New user IDs added to existing keys
    new_signatures: int    # New signatures added
    new_subkeys: int       # New subkeys added
    secret_imported: int   # Secret keys imported
    secret_unchanged: int  # Secret keys unchanged
    fingerprints: list     # List of processed key fingerprints
    
    def summary(self):
        """Return human-readable import summary."""

class SendResult(StatusHandler):
    # Status information for key sending operations
    pass

class AutoLocateKey(StatusHandler):
    email: str             # Email address that was searched
    display_name: str      # Display name from located key
    created_at: datetime   # Key creation timestamp
    key_length: int        # Key length in bits
    fingerprint: str       # Key fingerprint
    
class SearchKeys(list):
    # List of key dictionaries containing:
    # - keyid: Key ID
    # - algo: Algorithm number
    # - length: Key length in bits
    # - date: Creation date
    # - expires: Expiration date (if any)
    # - uids: List of user IDs
    # - revoked: Whether key is revoked
    # - disabled: Whether key is disabled
    # - invalid: Whether key is invalid
    pass

import gnupg

gpg = gnupg.GPG()

# Retrieve key by email address
result = gpg.recv_keys('keyserver.ubuntu.com', 'alice@example.com')

if result.imported > 0:
    print(f"Successfully imported {result.imported} keys")
    print(f"Key fingerprints: {result.fingerprints}")
else:
    print(f"No keys imported: {result.status}")

# Retrieve multiple keys by ID
key_ids = ['DEADBEEF', 'CAFEBABE', '12345678']
result = gpg.recv_keys('pgp.mit.edu', *key_ids)

print(f"Processed {result.count} keys")
print(f"Imported: {result.imported}")
print(f"Already had: {result.unchanged}")

# Various keyserver formats
keyservers = [
    'keyserver.ubuntu.com',
    'pgp.mit.edu', 
    'hkp://pool.sks-keyservers.net',
    'hkps://hkps.pool.sks-keyservers.net',
    'ldap://keyserver.pgp.com'
]

# Try multiple keyservers for reliability
def retrieve_key_with_fallback(gpg_instance, key_identifier, keyservers):
    for keyserver in keyservers:
        try:
            result = gpg_instance.recv_keys(keyserver, key_identifier)
            if result.imported > 0:
                print(f"Retrieved key from {keyserver}")
                return result
        except Exception as e:
            print(f"Failed to retrieve from {keyserver}: {e}")
            continue
    
    print("Failed to retrieve key from all keyservers")
    return None

# Usage
result = retrieve_key_with_fallback(gpg, 'user@example.com', keyservers)

# Auto-locate key using multiple mechanisms
result = gpg.auto_locate_key(
    'colleague@company.com',
    mechanisms=['wkd', 'keyserver', 'pka']  # Web Key Directory, keyserver, Public Key Association
)

if result.fingerprint:
    print(f"Found key for {result.email}")
    print(f"Display name: {result.display_name}")
    print(f"Fingerprint: {result.fingerprint}")
    print(f"Key length: {result.key_length} bits")
    print(f"Created: {result.created_at}")
else:
    print(f"Could not locate key for {result.email}")

# Auto-locate with specific mechanisms
wkd_result = gpg.auto_locate_key('user@example.org', mechanisms=['wkd'])
keyserver_result = gpg.auto_locate_key('user@example.org', mechanisms=['keyserver'])

# Send public key to keyserver
result = gpg.send_keys('keyserver.ubuntu.com', 'alice@example.com')

if result.status == 'key sent':
    print("Key successfully published to keyserver")
else:
    print(f"Failed to send key: {result.status}")

# Send multiple keys
my_keys = ['alice@example.com', 'work@alice.org']
result = gpg.send_keys('pgp.mit.edu', *my_keys)

# Send by fingerprint
result = gpg.send_keys('hkp://pool.sks-keyservers.net', 'DEADBEEFCAFEBABE12345678')

# Search by name
results = gpg.search_keys('John Smith', keyserver='keyserver.ubuntu.com')

print(f"Found {len(results)} matching keys:")
for key in results:
    print(f"Key ID: {key['keyid']}")
    print(f"Algorithm: {key['algo']}")
    print(f"Length: {key['length']} bits")
    print(f"Created: {key['date']}")
    print(f"User IDs: {', '.join(key['uids'])}")
    if key['expires']:
        print(f"Expires: {key['expires']}")
    if key['revoked']:
        print("WARNING: Key is revoked")
    print("---")

# Search by email
email_results = gpg.search_keys('alice@example.com')

# Search by partial key ID
keyid_results = gpg.search_keys('DEADBEEF')

def find_best_key(gpg_instance, search_query, keyserver='keyserver.ubuntu.com'):
    """Find the best key from search results based on various criteria."""
    
    results = gpg_instance.search_keys(search_query, keyserver=keyserver)
    
    if not results:
        return None
    
    # Filter and rank keys
    valid_keys = []
    
    for key in results:
        # Skip revoked, disabled, or invalid keys
        if key.get('revoked') or key.get('disabled') or key.get('invalid'):
            continue
        
        # Skip expired keys
        if key.get('expires'):
            from datetime import datetime
            try:
                expires = datetime.strptime(key['expires'], '%Y-%m-%d')
                if expires < datetime.now():
                    continue
            except:
                pass  # Skip date parsing errors
        
        # Prefer longer keys
        key_score = key.get('length', 0)
        
        # Prefer more recent keys
        try:
            created = datetime.strptime(key['date'], '%Y-%m-%d')
            days_old = (datetime.now() - created).days
            key_score += max(0, 3650 - days_old)  # Bonus for newer keys (up to 10 years)
        except:
            pass
        
        valid_keys.append((key_score, key))
    
    if not valid_keys:
        return None
    
    # Return highest scoring key
    valid_keys.sort(key=lambda x: x[0], reverse=True)
    return valid_keys[0][1]

# Usage
best_key = find_best_key(gpg, 'alice@example.com')
if best_key:
    print(f"Best key: {best_key['keyid']}")
    print(f"Length: {best_key['length']} bits")
    print(f"User IDs: {', '.join(best_key['uids'])}")
    
    # Import the selected key
    import_result = gpg.recv_keys('keyserver.ubuntu.com', best_key['keyid'])
    if import_result.imported > 0:
        print("Key imported successfully")

# Configure default keyserver options
def setup_keyserver_options(gpg_instance):
    """Configure GPG instance with keyserver preferences."""
    
    # Set keyserver options for reliability
    keyserver_options = [
        '--keyserver-options', 'timeout=30',           # 30 second timeout
        '--keyserver-options', 'import-clean',         # Clean imported keys
        '--keyserver-options', 'export-clean',         # Clean exported keys
        '--keyserver-options', 'auto-key-retrieve',    # Auto-retrieve missing keys
    ]
    
    if gpg_instance.options:
        gpg_instance.options.extend(keyserver_options)
    else:
        gpg_instance.options = keyserver_options

# Create GPG instance with keyserver configuration
gpg = gnupg.GPG(options=[
    '--keyserver', 'hkps://keys.openpgp.org',
    '--keyserver-options', 'timeout=30'
])

# Test keyserver connectivity
def test_keyserver_connectivity(gpg_instance, keyserver):
    """Test if a keyserver is accessible."""
    
    try:
        # Try to search for a common key (GPG itself)
        results = gpg_instance.search_keys('gnupg', keyserver=keyserver)
        return len(results) > 0
    except Exception as e:
        print(f"Keyserver {keyserver} not accessible: {e}")
        return False

# Test multiple keyservers
keyservers_to_test = [
    'keys.openpgp.org',
    'keyserver.ubuntu.com', 
    'pgp.mit.edu'
]

working_keyservers = []
for ks in keyservers_to_test:
    if test_keyserver_connectivity(gpg, ks):
        working_keyservers.append(ks)
        print(f"✓ {ks} is accessible")
    else:
        print(f"✗ {ks} is not accessible")

print(f"Working keyservers: {working_keyservers}")

def reliable_key_operation(operation_func, *args, max_retries=3, **kwargs):
    """Wrapper for reliable keyserver operations with retry logic."""
    
    for attempt in range(max_retries):
        try:
            result = operation_func(*args, **kwargs)
            
            # Check if operation was successful
            if hasattr(result, 'imported') and result.imported > 0:
                return result
            elif hasattr(result, 'status') and 'success' in result.status.lower():
                return result
            elif not hasattr(result, 'imported'):  # Search operations
                return result
            
            print(f"Attempt {attempt + 1} had no results, retrying...")
            
        except Exception as e:
            print(f"Attempt {attempt + 1} failed: {e}")
            if attempt == max_retries - 1:
                raise
            
            # Wait before retry (exponential backoff)
            import time
            time.sleep(2 ** attempt)
    
    return None

# Usage with retry logic
result = reliable_key_operation(
    gpg.recv_keys, 
    'keyserver.ubuntu.com', 
    'user@example.com',
    max_retries=3
)

if result and result.imported > 0:
    print("Key retrieved successfully with retry logic")