Debrideur Fileice.net Access

# 2️⃣ Execute and filter the flag ./debrideur "$FIXED" 2>/dev/null | grep -i -E 'flag\[^]+\}' Make them executable ( chmod +x rebuild.py run_and_get_flag.sh ) and you’re ready to solve the challenge in one command:

# 1️⃣ Fix the CRC python3 rebuild.py "$FILE"

The checksum is calculated over the , i.e. bytes starting at 0x10 . 4. Re‑building the Bride (Checksum) 4.1 Compute the correct CRC‑32 Python makes this trivial: Debrideur fileice.net

if __name__ == "__main__": rebuild(sys.argv[1]) Running it:

set -euo pipefail

static const uint8_t key[16] = 0x13, 0x57, 0x9B, 0xDF, 0x02, 0x46, 0x8A, 0xCE, 0x31, 0x75, 0xB9, 0xFD, 0x40, 0x84, 0xC8, 0x0C ; Each 16‑byte chunk of the payload is XOR‑ed with this key, effectively decrypting the hidden text.

The file format is:

# run the binary and capture the flag ./debrideur "$FIXED" 2>/dev/null | grep -i flag Running this script prints:

# rebuild CRC python3 - <<PY import binascii, sys data = open("$FILE", "rb").read() crc = binascii.crc32(data[0x10:]) & 0xffffffff new = data[:0x08] + crc.to_bytes(4, 'little') + data[0x0c:] open("$FIXED", "wb").write(new) print(f"[*] Fixed CRC = 0xcrc:08x") PY # 2️⃣ Execute and filter the flag