pci-compliance

name pci-compliance description Implement PCI DSS compliance requirements for secure handling of payment card data and payment systems. Use when securing payment processing, achieving PCI compliance, or implementing payment card security measures. PCI Compliance Master PCI DSS (Payment Card Industry Data Security Standard) compliance for secure payment processing and handling of cardholder data. When to Use This Skill Building payment processing systems Handling credit card information Implementing secure payment flows Conducting PCI compliance audits Reducing PCI compliance scope Implementing tokenization and encryption Preparing for PCI DSS assessments PCI DSS Requirements (12 Core Requirements) Build and Maintain Secure Network Install and maintain firewall configuration Don't use vendor-supplied defaults for passwords Protect Cardholder Data Protect stored cardholder data Encrypt transmission of cardholder data across public networks Maintain Vulnerability Management Protect systems against malware Develop and maintain secure systems and applications Implement Strong Access Control Restrict access to cardholder data by business need-to-know Identify and authenticate access to system components Restrict physical access to cardholder data Monitor and Test Networks Track and monitor all access to network resources and cardholder data Regularly test security systems and processes Maintain Information Security Policy Maintain a policy that addresses information security Compliance Levels Level 1 : > 6 million transactions/year (annual ROC required) Level 2 : 1-6 million transactions/year (annual SAQ) Level 3 : 20,000-1 million e-commerce transactions/year Level 4 : < 20,000 e-commerce or < 1 million total transactions Data Minimization (Never Store) # NEVER STORE THESE PROHIBITED_DATA = { 'full_track_data' : 'Magnetic stripe data' , 'cvv' : 'Card verification code/value' , 'pin' : 'PIN or PIN block' } # CAN STORE (if encrypted) ALLOWED_DATA = { 'pan' : 'Primary Account Number (card number)' , 'cardholder_name' : 'Name on card' , 'expiration_date' : 'Card expiration' , 'service_code' : 'Service code' } class PaymentData : """Safe payment data handling.""" def __init__ ( self ): self .prohibited_fields = [ 'cvv' , 'cvv2' , 'cvc' , 'pin' ] def sanitize_log ( self, data ): """Remove sensitive data from logs.""" sanitized = data.copy() # Mask PAN if 'card_number' in sanitized: card = sanitized[ 'card_number' ] sanitized[ 'card_number' ] = f" {card[: 6 ]} { '*' * ( len (card) - 10 )} {card[- 4 :]} " # Remove prohibited data for field in self .prohibited_fields: sanitized.pop(field, None ) return sanitized def validate_no_prohibited_storage ( self, data ): """Ensure no prohibited data is being stored.""" for field in self .prohibited_fields: if field in data: raise SecurityError( f"Attempting to store prohibited field: {field} " ) Tokenization Using Payment Processor Tokens import stripe class TokenizedPayment : """Handle payments using tokens (no card data on server).""" @staticmethod def create_payment_method_token ( card_details ): """Create token from card details (client-side only).""" # THIS SHOULD ONLY BE DONE CLIENT-SIDE WITH STRIPE.JS # NEVER send card details to your server """ // Frontend JavaScript const stripe = Stripe('pk_...'); const {token, error} = await stripe.createToken({ card: { number: '4242424242424242', exp_month: 12, exp_year: 2024, cvc: '123' } }); // Send token.id to server (NOT card details) """ pass @staticmethod def charge_with_token ( token_id, amount ): """Charge using token (server-side).""" # Your server only sees the token, never the card number stripe.api_key = "sk_..." charge = stripe.Charge.create( amount=amount, currency= "usd" , source=token_id, # Token instead of card details description= "Payment" ) return charge @staticmethod def store_payment_method ( customer_id, payment_method_token ): """Store payment method as token for future use.""" stripe.Customer.modify( customer_id, source=payment_method_token ) # Store only customer_id and payment_method_id in your database # NEVER store actual card details return { 'customer_id' : customer_id, 'has_payment_method' : True # DO NOT store: card number, CVV, etc. } Custom Tokenization (Advanced) import secrets from cryptography.fernet import Fernet class TokenVault : """Secure token vault for card data (if you must store it).""" def __init__ ( self, encryption_key ): self .cipher = Fernet(encryption_key) self .vault = {} # In production: use encrypted database def tokenize ( self, card_data ): """Convert card data to token.""" # Generate secure random token token = secrets.token_urlsafe( 32 ) # Encrypt card data encrypted = self .cipher.encrypt(json.dumps(card_data).encode()) # Store token -> encrypted data mapping self .vault[token] = encrypted return token def detokenize ( self, token ): """Retrieve card data from token.""" encrypted = self .vault.get(token) if not encrypted: raise ValueError( "Token not found" ) # Decrypt decrypted = self .cipher.decrypt(encrypted) return json.loads(decrypted.decode()) def delete_token ( self, token ): """Remove token from vault.""" self .vault.pop(token, None ) Encryption Data at Rest from cryptography.hazmat.primitives.ciphers.aead import AESGCM import os class EncryptedStorage : """Encrypt data at rest using AES-256-GCM.""" def __init__ ( self, encryption_key ): """Initialize with 256-bit key.""" self .key = encryption_key # Must be 32 bytes def encrypt ( self, plaintext ): """Encrypt data.""" # Generate random nonce nonce = os.urandom( 12 ) # Encrypt aesgcm = AESGCM( self .key) ciphertext = aesgcm.encrypt(nonce, plaintext.encode(), None ) # Return nonce + ciphertext return nonce + ciphertext def decrypt ( self, encrypted_data ): """Decrypt data.""" # Extract nonce and ciphertext nonce = encrypted_data[: 12 ] ciphertext = encrypted_data[ 12 :] # Decrypt aesgcm = AESGCM( self .key) plaintext = aesgcm.decrypt(nonce, ciphertext, None ) return plaintext.decode() # Usage storage = EncryptedStorage(os.urandom( 32 )) encrypted_pan = storage.encrypt( "4242424242424242" ) # Store encrypted_pan in database Data in Transit # Always use TLS 1.2 or higher # Flask/Django example app.config[ 'SESSION_COOKIE_SECURE' ] = True # HTTPS only app.config[ 'SESSION_COOKIE_HTTPONLY' ] = True app.config[ 'SESSION_COOKIE_SAMESITE' ] = 'Strict' # Enforce HTTPS from flask_talisman import Talisman Talisman(app, force_https= True ) Additional patterns and templates More detailed templates and worked examples live in references/details.md . Read that file for the full pattern library.