Magcard Write Read Utility Program Info

def interactive_write(card): track = int(input("Enter track to write (1/2/3): ")) data = input(f"Enter data for track track (max TRACK_MAX_LEN[track] chars): ").strip() try: card.write_track(track, data) print(f"Track track written successfully.") except ValueError as e: print(f"Write failed: e")

#!/usr/bin/env python3 """ Magnetic Card Read/Write Utility (Simulated / Educational) Supports ISO 7811 tracks 1, 2, 3. """ import re import argparse TRACK1_CHARSET = set("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 .-+/$%*") TRACK2_CHARSET = set("0123456789:;<=>?") TRACK3_CHARSET = set("0123456789:;<=>?") magcard write read utility program

TRACK_MAX_LEN = 1: 79, 2: 40, 3: 107 class MagCard: def init (self): self.track1 = "" self.track2 = "" self.track3 = "" | | Read/Write abstraction | Easy to replace

def decode_track(encoded): """Extracts raw data and verifies LRC""" if len(encoded) < 4: return None # Expected format: S data E checksum start_sentinel = encoded[0] end_sentinel = encoded[-2] checksum = encoded[-1] data_part = encoded[1:-2] # Verify checksum calc_lrc = 0 for ch

python magcard_util.py --read 1 | Feature | Description | |--------|-------------| | ISO 7811 compliance | Enforces valid character sets and max lengths per track. | | Sentinel & LRC | Simulates magnetic stripe encoding with start/end sentinels and XOR checksum. | | Read/Write abstraction | Easy to replace MagCard class with real hardware driver (serial/HID). | | Error handling | Prevents invalid data from being written. | Extending to real hardware To use actual magnetic stripe readers/writers (e.g., MagTek, IDTECH, HID Omnikey), replace the MagCard class methods with device-specific commands – typically via serial or pyusb .

# Verify checksum calc_lrc = 0 for ch in data_part: calc_lrc ^= ord(ch) if chr(calc_lrc % 128) != checksum: raise ValueError("Checksum mismatch – possible read error") return data_part def display_card(card): print("\n=== CURRENT CARD DATA ===") print(f"Track 1: card.track1 if card.track1 else '<empty>'") print(f"Track 2: card.track2 if card.track2 else '<empty>'") print(f"Track 3: card.track3 if card.track3 else '<empty>'") print("=========================\n")

if args.write or args.read: cli_mode(args) return