|
| 1 | +importargparse# Import argparse for command-line argument parsing |
| 2 | +importre# Import re for regular expression matching |
| 3 | + |
| 4 | +# Validate credit card number using Luhn Algorithm |
| 5 | +defluhn_algorithm(card_number): |
| 6 | +defdigits_of(n): |
| 7 | +return [int(d)fordinstr(n)]# Convert each character in the number to an integer |
| 8 | + |
| 9 | +digits=digits_of(card_number)# Get all digits of the card number |
| 10 | +odd_digits=digits[-1::-2]# Get digits from the right, skipping one digit each time (odd positions) |
| 11 | +even_digits=digits[-2::-2]# Get every second digit from the right (even positions) |
| 12 | + |
| 13 | +checksum=sum(odd_digits)# Sum all odd position digits |
| 14 | +fordineven_digits: |
| 15 | +checksum+=sum(digits_of(d*2))# Double each even position digit and sum the resulting digits |
| 16 | + |
| 17 | +returnchecksum%10==0# Return True if checksum modulo 10 is 0 |
| 18 | + |
| 19 | + |
| 20 | +# Function to check credit card number using Luhn's alogorithm |
| 21 | +defcheck_credit_card_number(card_number): |
| 22 | +card_number=card_number.replace(' ','')# Remove spaces from the card number |
| 23 | +ifnotcard_number.isdigit():# Check if the card number contains only digits |
| 24 | +returnFalse |
| 25 | +returnluhn_algorithm(card_number)# Validate using the Luhn algorithm |
| 26 | + |
| 27 | +# Function to get the card type based on card number using RegEx |
| 28 | +defget_card_type(card_number): |
| 29 | +card_number=card_number.replace(' ','')# Remove spaces from the card number |
| 30 | +card_types= { |
| 31 | +"Visa":r"^4[0-9]{12}(?:[0-9]{3})?$",# Visa: Starts with 4, length 13 or 16 |
| 32 | +"MasterCard":r"^5[1-5][0-9]{14}$",# MasterCard: Starts with 51-55, length 16 |
| 33 | +"American Express":r"^3[47][0-9]{13}$",# AmEx: Starts with 34 or 37, length 15 |
| 34 | +"Discover":r"^6(?:011|5[0-9]{2})[0-9]{12}$",# Discover: Starts with 6011 or 65, length 16 |
| 35 | +"JCB":r"^(?:2131|1800|35\d{3})\d{11}$",# JCB: Starts with 2131, 1800, or 35, length 15 or 16 |
| 36 | +"Diners Club":r"^3(?:0[0-5]|[68][0-9])[0-9]{11}$",# Diners Club: Starts with 300-305, 36, or 38, length 14 |
| 37 | +"Maestro":r"^(5018|5020|5038|56|57|58|6304|6759|676[1-3])\d{8,15}$",# Maestro: Various starting patterns, length 12-19 |
| 38 | +"Verve":r"^(506[01]|507[89]|6500)\d{12,15}$"# Verve: Starts with 5060, 5061, 5078, 5079, or 6500, length 16-19 |
| 39 | + } |
| 40 | + |
| 41 | +forcard_type,patternincard_types.items(): |
| 42 | +ifre.match(pattern,card_number):# Check if card number matches the pattern |
| 43 | +returncard_type |
| 44 | +return"Unknown"# Return Unknown if no pattern matches |
| 45 | + |
| 46 | + |
| 47 | +# Processing a file containing card numbers. |
| 48 | +defprocess_file(file_path): |
| 49 | + |
| 50 | +try: |
| 51 | +withopen(file_path,'r')asfile:# Open the file for reading |
| 52 | +card_numbers=file.readlines()# Read all lines from the file |
| 53 | +results= {} |
| 54 | +forcard_numberincard_numbers: |
| 55 | +card_number=card_number.strip()# Remove any leading/trailing whitespace |
| 56 | +is_valid=check_credit_card_number(card_number)# Validate card number |
| 57 | +card_type=get_card_type(card_number)# Detect card type |
| 58 | +results[card_number]= (is_valid,card_type)# Store result |
| 59 | +returnresults |
| 60 | +exceptExceptionase: |
| 61 | +print(f"Error reading file:{e}")# Print error message if file cannot be read |
| 62 | +returnNone |
| 63 | + |
| 64 | + |
| 65 | +defmain(): |
| 66 | +parser=argparse.ArgumentParser(description="Check if a credit card number is legitimate and identify its type using the Luhn algorithm.") |
| 67 | +parser.add_argument('-n','--number',type=str,help="A single credit card number to validate.")# Argument for single card number |
| 68 | +parser.add_argument('-f','--file',type=str,help="A file containing multiple credit card numbers to validate.")# Argument for file input |
| 69 | + |
| 70 | +args=parser.parse_args()# Parse command-line arguments |
| 71 | + |
| 72 | +ifargs.number: |
| 73 | +is_valid=check_credit_card_number(args.number)# Validate single card number |
| 74 | +card_type=get_card_type(args.number)# Detect card type |
| 75 | +print(f"[!] Credit card number{args.number} is{'valid'ifis_validelse'invalid'} and is of type{card_type}.")# Print result |
| 76 | + |
| 77 | +ifargs.file: |
| 78 | +results=process_file(args.file)# Process file with card numbers |
| 79 | +ifresults: |
| 80 | +forcard_number, (is_valid,card_type)inresults.items(): |
| 81 | +print(f"[!] Credit card number{card_number} is{'valid'ifis_validelse'invalid'} and is of type{card_type}.")# Print results for each card number |
| 82 | + |
| 83 | +# Execute tha main function |
| 84 | +if__name__=='__main__': |
| 85 | +main() |