Magcard Write Read Utility Program Access

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]

It simulates the low-level track data manipulation for magnetic stripe cards (tracks 1, 2, 3) as per ISO 7811, and includes functions to , write , encode , and decode card data.

if args.write or args.read: cli_mode(args) return magcard write read utility program

#!/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:;<=>?")

# 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") python magcard_util

For real hardware (e.g., MagTek, ID Tech readers), you would replace the simulated I/O with serial/USB HID commands.

python magcard_util.py --write "2:1234567890" Read track 1: = TRACK_MAX_LEN[3] return False

def is_valid_track(self, track_num, data): if track_num == 1: return all(ch in TRACK1_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[1] elif track_num == 2: return all(ch in TRACK2_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[2] elif track_num == 3: return all(ch in TRACK3_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[3] return False