SunshineCTF 2026: Forensics Operations Dossier

import struct, zlib

with open('hereyougo.png', 'rb') as f:
    data = bytearray(f.read())

# Correct height is 418 px (0x01A2) at offset 0x14 (byte 20)
struct.pack_into('>I', data, 20, 418)

# Recalculate CRC32 for IHDR chunk (offset 12 to 29)
new_crc = zlib.crc32(data[12:29]) & 0xFFFFFFFF
struct.pack_into('>I', data, 29, new_crc)

with open('recovered.png', 'wb') as f:
    f.write(data)

print("[+] Successfully repaired IHDR height and CRC!")

import re

KEY_MAP = {
    (0,0): 'Q', (0,1): 'W', (0,2): 'E', (0,3): 'R', (0,4): 'T',
    (1,0): 'A', (1,1): 'S', (1,2): 'D', (1,3): 'F', (1,4): 'G', (1,5): 'H',
    (2,0): 'Z', (2,1): 'X', (2,2): 'C', (2,3): 'V', (2,4): 'B', (2,5): 'N'
}
COORD_MAP = {v: k for k, v in KEY_MAP.items()}

moves, payloads = {}, {}
with open('suntrail.klc', 'r', encoding='utf-16le', errors='ignore') as f:
    for line in f:
        m = re.match(r'^[0-9a-fA-F]+\s+([A-Z])\s+0\s+([0-9a-fA-F]+)\s+([0-9a-fA-F]+)', line)
        if m:
            key, arrow, char_hex = m.groups()
            moves[key] = arrow.lower()
            payloads[key] = chr(int(char_hex, 16))

curr = 'Q'
flag = []
while curr in moves:
    flag.append(payloads[curr])
    arrow = moves[curr]
    if arrow == '25a0': break
    r, c = COORD_MAP[curr]
    if arrow == '2198': curr = KEY_MAP[(r + 1, c)]
    elif arrow == '2192': curr = KEY_MAP[(r, c + 1)]
    elif arrow == '2196': curr = KEY_MAP[(r - 1, c)]

print("[+] Recovered Flag:", "".join(flag))

import re

with open('boardwriter.klc', 'r', encoding='utf-16le', errors='ignore') as f:
    content = f.read()

deadkey_blocks = re.findall(r'DEADKEY\s+([0-9a-fA-F]+)\s*\n([0-9a-fA-F]+)\s+([0-9a-fA-F]+@?)', content)

transitions = {}
for state, in_char_hex, next_state in deadkey_blocks:
    transitions[state.lower()] = (int(in_char_hex, 16), next_state.lower())

current_state = '0060'
flag_chars = []

while True:
    if current_state not in transitions: break
    in_code, next_target = transitions[current_state]
    flag_chars.append(chr(in_code))
    if next_target == '2600':
        print(f"[+] Reached Sun Symbol (U+2600)! Flag: {''.join(flag_chars)}")
        break
    current_state = next_target.rstrip('@')