Key Discovery and Analysis

def scan_keys(self, filename):
    """
    Scan keys from a file without importing them to the keyring.
    
    Parameters:
    - filename (str): Path to key file to scan
    
    Returns:
    ScanKeys: List of key information found in the file
    """

def scan_keys_mem(self, key_data):
    """
    Scan keys from memory without importing them to the keyring.
    
    Parameters:
    - key_data (str): ASCII-armored or binary key data to scan
    
    Returns:
    ScanKeys: List of key information found in the data
    """

def trust_keys(self, fingerprints, trustlevel):
    """
    Set trust level for one or more keys in the web of trust.
    
    Parameters:
    - fingerprints (str|list): Key fingerprints to set trust for
    - trustlevel (str): Trust level to assign
                       '1' = I don't know or won't say
                       '2' = I do NOT trust
                       '3' = I trust marginally  
                       '4' = I trust fully
                       '5' = I trust ultimately (own keys)
    
    Returns:
    TrustResult: Result with trust operation status
    """

def add_subkey(self, master_key, master_passphrase=None, algorithm='rsa', 
               usage='encrypt', expire='-'):
    """
    Add a subkey to an existing master key.
    
    Parameters:
    - master_key (str): Master key fingerprint or ID
    - master_passphrase (str): Master key passphrase
    - algorithm (str): Subkey algorithm ('rsa', 'dsa', 'ecdsa', 'eddsa')
    - usage (str): Subkey usage ('encrypt', 'sign', 'auth')
    - expire (str): Expiration ('-' for same as master, '0' for no expiration)
    
    Returns:
    AddSubkey: Result with new subkey information
    """

class ScanKeys(ListKeys):
    # Inherits from ListKeys - same structure but for scanned keys
    # List of key dictionaries containing detailed key information:
    # - type: Key type ('pub', 'sec', 'sub', 'ssb')
    # - length: Key length in bits
    # - algo: Algorithm number
    # - keyid: Key ID (short form)
    # - date: Creation date
    # - expires: Expiration date (if any)
    # - dummy: Dummy key indicator
    # - ownertrust: Owner trust level
    # - sig_class: Signature class
    # - capabilities: Key capabilities string
    # - issuer: Key issuer
    # - flag: Key flags
    # - token: Token serial number
    # - hash_algo: Hash algorithm number
    # - curve: Curve name for ECC keys
    # - fingerprint: Full key fingerprint
    # - uids: List of user IDs associated with the key
    # - sigs: List of signatures on the key (if requested)
    # - subkeys: List of subkeys under this master key
    pass

class TrustResult(StatusHandler):
    # Result of trust level setting operations
    pass

class AddSubkey(StatusHandler):
    type: str           # Subkey type/algorithm
    fingerprint: str    # New subkey fingerprint

import gnupg

gpg = gnupg.GPG()

# Scan a key file without importing
scanned_keys = gpg.scan_keys('/path/to/keyfile.asc')

print(f"Found {len(scanned_keys)} keys in file:")
for key in scanned_keys:
    print(f"\nKey ID: {key['keyid']}")
    print(f"Fingerprint: {key['fingerprint']}")
    print(f"Algorithm: {key['algo']} ({key['length']} bits)")
    print(f"Created: {key['date']}")
    if key['expires']:
        print(f"Expires: {key['expires']}")
    
    print(f"User IDs:")
    for uid in key['uids']:
        print(f"  - {uid}")
    
    print(f"Capabilities: {key['capabilities']}")
    
    if key['subkeys']:
        print(f"Subkeys:")
        for subkey in key['subkeys']:
            print(f"  - {subkey['keyid']} ({subkey['length']} bits, {subkey['capabilities']})")

# Analyze key data received over network or from database
key_data = """-----BEGIN PGP PUBLIC KEY BLOCK-----

mQENBF... (key data here) ...
-----END PGP PUBLIC KEY BLOCK-----"""

scanned = gpg.scan_keys_mem(key_data)

def analyze_key_strength(key_info):
    """Analyze key strength and provide recommendations."""
    
    analysis = {
        'strength': 'unknown',
        'recommendations': [],
        'warnings': []
    }
    
    # Check key length
    length = key_info.get('length', 0)
    algo = key_info.get('algo', 0)
    
    if algo == 1:  # RSA
        if length < 2048:
            analysis['strength'] = 'weak'
            analysis['warnings'].append(f'RSA key length {length} is too short')
            analysis['recommendations'].append('Use RSA 2048 bits or higher')
        elif length < 3072:
            analysis['strength'] = 'acceptable'
        else:
            analysis['strength'] = 'strong'
    elif algo in [16, 20]:  # ElGamal
        if length < 2048:
            analysis['strength'] = 'weak'
            analysis['warnings'].append(f'ElGamal key length {length} is too short')
    elif algo == 17:  # DSA
        if length < 2048:
            analysis['strength'] = 'weak'
            analysis['warnings'].append('DSA-1024 is deprecated')
            analysis['recommendations'].append('Use RSA-2048 or higher')
    
    # Check expiration
    if not key_info.get('expires'):
        analysis['recommendations'].append('Consider setting an expiration date')
    else:
        from datetime import datetime
        try:
            exp_date = datetime.strptime(key_info['expires'], '%Y-%m-%d')
            if exp_date < datetime.now():
                analysis['warnings'].append('Key has expired')
        except:
            pass
    
    return analysis

# Analyze each scanned key
for key in scanned:
    analysis = analyze_key_strength(key)
    print(f"\nKey {key['keyid']} analysis:")
    print(f"Strength: {analysis['strength']}")
    
    for warning in analysis['warnings']:
        print(f"⚠️  Warning: {warning}")
    
    for rec in analysis['recommendations']:
        print(f"💡 Recommendation: {rec}")

# Set trust levels for keys
def setup_trust_relationships(gpg_instance):
    """Set up trust relationships for a set of known keys."""
    
    trust_assignments = {
        # Ultimate trust (own keys)
        '5': ['ABCD1234DEADBEEF5678CAFE'],  # Your own key
        
        # Full trust (fully trusted colleagues)
        '4': [
            'BEEF5678CAFE1234DEAD9876',  # Alice's key
            'CAFE1234DEAD5678BEEF9876',  # Bob's key
        ],
        
        # Marginal trust (somewhat trusted)
        '3': [
            'DEAD5678BEEF1234CAFE9876',  # Charlie's key
        ],
        
        # No trust
        '2': [
            'BADD0G15DEAD5678BEEF1234',  # Revoked or compromised key
        ]
    }
    
    for trust_level, fingerprints in trust_assignments.items():
        if fingerprints:
            result = gpg_instance.trust_keys(fingerprints, trust_level)
            if result.status == 'success':
                level_names = {'2': 'no trust', '3': 'marginal', '4': 'full', '5': 'ultimate'}
                print(f"Set {level_names.get(trust_level, trust_level)} trust for {len(fingerprints)} keys")

# Apply trust settings
setup_trust_relationships(gpg)

# Check current trust levels by listing keys
keys = gpg.list_keys()
for key in keys:
    trust = key.get('ownertrust', 'unknown')
    print(f"Key {key['keyid']}: trust level {trust}")

# Add encryption subkey to existing signing key
master_fingerprint = 'DEADBEEFCAFEBABE1234567890ABCDEF12345678'

# Add RSA encryption subkey
result = gpg.add_subkey(
    master_key=master_fingerprint,
    master_passphrase='master_key_passphrase',
    algorithm='rsa',
    usage='encrypt'
)

if result.fingerprint:
    print(f"Added encryption subkey: {result.fingerprint}")
else:
    print(f"Failed to add subkey: {result.status}")

# Add authentication subkey for SSH usage
auth_result = gpg.add_subkey(
    master_key=master_fingerprint,
    master_passphrase='master_key_passphrase',
    algorithm='rsa',
    usage='auth',
    expire='2y'  # Expire in 2 years
)

# Add ECC subkey for modern cryptography
ecc_result = gpg.add_subkey(
    master_key=master_fingerprint,
    master_passphrase='master_key_passphrase',
    algorithm='ecdsa',
    usage='sign'
)

def validate_key_health(gpg_instance, key_identifier):
    """Comprehensive key health check and validation."""
    
    # Get detailed key information
    keys = gpg_instance.list_keys(keys=[key_identifier])
    if not keys:
        return {'status': 'not_found', 'message': 'Key not found in keyring'}
    
    key = keys[0]
    health_report = {
        'key_id': key['keyid'],
        'fingerprint': key['fingerprint'],
        'status': 'healthy',
        'issues': [],
        'recommendations': []
    }
    
    # Check if key is expired
    if key.get('expires'):
        from datetime import datetime, timedelta
        try:
            exp_date = datetime.strptime(key['expires'], '%Y-%m-%d')
            now = datetime.now()
            
            if exp_date < now:
                health_report['status'] = 'expired'
                health_report['issues'].append('Key has expired')
            elif exp_date < now + timedelta(days=30):
                health_report['issues'].append('Key expires within 30 days')
                health_report['recommendations'].append('Consider extending expiration')
        except:
            pass
    
    # Check key strength
    length = key.get('length', 0)
    if length < 2048:
        health_report['issues'].append(f'Key length {length} is weak by current standards')
        health_report['recommendations'].append('Consider generating a new 2048+ bit key')
    
    # Check for revocation
    if key.get('revoked'):
        health_report['status'] = 'revoked'
        health_report['issues'].append('Key has been revoked')
    
    # Check subkey health
    subkey_issues = []
    for subkey in key.get('subkeys', []):
        if subkey.get('expires'):
            try:
                sub_exp = datetime.strptime(subkey['expires'], '%Y-%m-%d')
                if sub_exp < datetime.now():
                    subkey_issues.append(f"Subkey {subkey['keyid']} has expired")
            except:
                pass
        
        if subkey.get('length', 0) < 2048:
            subkey_issues.append(f"Subkey {subkey['keyid']} has weak length")
    
    if subkey_issues:
        health_report['issues'].extend(subkey_issues)
        health_report['recommendations'].append('Consider adding new subkeys')
    
    # Check user ID validity
    if not key.get('uids'):
        health_report['issues'].append('No user IDs found')
    else:
        # Check for email validation (basic check)
        valid_emails = []
        for uid in key['uids']:
            if '@' in uid and '.' in uid.split('@')[1]:
                valid_emails.append(uid)
        
        if not valid_emails:
            health_report['recommendations'].append('Consider adding a valid email address')
    
    return health_report

# Usage
health = validate_key_health(gpg, 'user@example.com')
print(f"Key health status: {health['status']}")

if health['issues']:
    print("Issues found:")
    for issue in health['issues']:
        print(f"  ⚠️  {issue}")

if health['recommendations']:
    print("Recommendations:")
    for rec in health['recommendations']:
        print(f"  💡 {rec}")

def discover_key_relationships(gpg_instance, target_keyid):
    """Discover relationships and signatures for a given key."""
    
    # Get key with signature information
    keys = gpg_instance.list_keys(keys=[target_keyid], sigs=True)
    if not keys:
        return None
    
    key = keys[0]
    relationships = {
        'key_id': key['keyid'],
        'fingerprint': key['fingerprint'],
        'signed_by': [],
        'certifications': [],
        'cross_signatures': []
    }
    
    # Analyze signatures
    for sig in key.get('sigs', []):
        sig_info = {
            'signer_id': sig.get('keyid'),
            'signer_uid': sig.get('uid'),
            'sig_class': sig.get('sig_class'),
            'creation_date': sig.get('date')
        }
        
        if sig.get('sig_class') == '10':  # Generic certification
            relationships['certifications'].append(sig_info)
        elif sig.get('sig_class') == '13':  # Positive certification
            relationships['signed_by'].append(sig_info)
        elif sig.get('sig_class') == '18':  # Subkey binding signature
            relationships['cross_signatures'].append(sig_info)
    
    return relationships

# Analyze key relationships
relationships = discover_key_relationships(gpg, 'alice@example.com')
if relationships:
    print(f"Key relationships for {relationships['key_id']}:")
    print(f"Certified by {len(relationships['signed_by'])} entities")
    print(f"Has {len(relationships['certifications'])} certifications")
    
    if relationships['signed_by']:
        print("Signed by:")
        for signer in relationships['signed_by'][:5]:  # Show first 5
            print(f"  - {signer['signer_id']} ({signer['creation_date']})")