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import os
from binascii import unhexlify, hexlify
import csv
def load_samples(folder):
msgs, crcs, rawhex = [], [], []
for fn in os.listdir(folder):
path = os.path.join(folder, fn)
with open(path, 'r') as f:
for line in f:
if '=' not in line:
continue
try:
h, c = line.strip().split('=')
data = list(unhexlify(h))
chk = int(c, 16)
msgs.append(data)
crcs.append(chk)
rawhex.append(h.upper())
except Exception:
continue
return msgs, crcs, rawhex
def bit_diff(a, b):
return ''.join(['↑' if (a ^ b) & (1 << i) else '.' for i in reversed(range(8))])
def analyze(msgs, crcs, rawhex):
base_msg, base_crc = msgs[0], crcs[0]
base_hex = rawhex[0]
rows = []
for idx, (msg, crc, raw) in enumerate(zip(msgs[1:], crcs[1:], rawhex[1:]), start=1):
maxlen = max(len(base_msg), len(msg))
for i in range(maxlen):
b0 = base_msg[i] if i < len(base_msg) else None
b1 = msg[i] if i < len(msg) else None
if b0 != b1:
delta_crc = (crc - base_crc) & 0xFF
xor_crc = crc ^ base_crc
b0_str = f"{b0:02X}" if b0 is not None else "--"
b1_str = f"{b1:02X}" if b1 is not None else "--"
bitdiff = bit_diff(b0 or 0, b1 or 0)
print(f"Sample {idx} | Byte {i} | {b0_str} → {b1_str} | ΔCRC={crc:02X} | BitDiff={bitdiff}")
rows.append([
idx,
i,
b0_str,
b1_str,
bitdiff,
f"{base_crc:02X}",
f"{crc:02X}",
f"{delta_crc:02X}",
f"{xor_crc:02X}",
raw,
f"{crc:02X}"
])
return rows
# 📂 Point this to your folder
input_folder = "C:/Users/crt/Documents/bodeting/research/bad-bruteforcing/reveng-formatted"
# 🧠 Do the work
msgs, crcs, rawhex = load_samples(input_folder)
rows = analyze(msgs, crcs, rawhex)
# 📝 Save CSV
out_path = os.path.join(os.getcwd(), "crc_analysis_output.csv")
with open(out_path, 'w', newline='', encoding='utf-8') as f:
writer = csv.writer(f)
writer.writerow([
"Sample", "Byte Index", "Base Byte", "Other Byte", "Bit Diff",
"Base CRC", "Other CRC", "CRC_DIFF", "CRC_XOR",
"HEX Input", "Original CRC"
])
writer.writerows(rows)
print(f"\n✅ Analysis saved to: {out_path}")
os.system(f'start notepad "{out_path}"')
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