2025宁波市第八届网络安全大赛Re方向wp

宁波市第八届网络安全大赛-Re方向wp

暑假的时候和伙伴们一起打了这个比赛，个人觉得re方向难度较简单，可能别的方向上加强度了，比如misc……

re-SEA_1

解题思路

这是AES的ECB加密

直接用IDA的插件查出来是aes

密文如下

直接写出脚本进行逆向

exp

from Crypto.Cipher import AES
from Crypto.Util.Padding import *

cipher = bytes.fromhex("29708f1980cce40f46abac148d488ca83716fe1d397202797b1999166265623e8f761285cb28e256b381167761e41094")
key = b"58453eec4d16ae234a10b597dfe1f6a6"
aes=AES.new(key,AES.MODE_ECB)
print(aes.decrypt(cipher).decode())
##DASCTF{75aab2560274ae21aa4554b993e658d1}

re-flower_world

解题思路

这里有将近300行的加密，都是加减异或等，直接逆向过去，byte-40对应的是flag的下标。密文也都有，如下

有点长哈，有点费眼🙌

exp

# 原始数据段转换成列表
data = [
    0x7F, 0x11, 0x4A, 0x9D, 0xA5, 0xD5, 0x99, 0x9F, 0xAC, 0xD3,
    0xD4, 0xBC, 0x1A, 0x53, 0x46, 0xF4, 0xE7, 0x37, 0x03, 0x60,
    0x17, 0xBA, 0x67, 0xAC, 0x09, 0xDA, 0xA0, 0xFB, 0x2D, 0x8E,
    0xCB, 0x11, 0x02, 0xC4, 0x17, 0xF7, 0x1B, 0x8F, 0x67, 0x52,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00  # 你可以继续补全原始数据长度
]

flag_index = 0x40  # 假设 flag 从 data[0x40] 开始
flag_len = 40


# 将 0x4070XX 转换为列表索引
def idx(x):
    return x - 0x40

def decrypt(data):
    # 这里按照你提供的逆向逻辑顺序处理，每一步都做 & 0xFF
    # 示例操作
    # 假设 data 已经是一个 list，idx(x) 已经定义
    data[idx(0x50)] = (data[idx(0x50)] ^ 0xD6) & 0xFF
    data[idx(0x51)] = (data[idx(0x51)] + 42) & 0xFF
    data[idx(0x68)] = (data[idx(0x68)] ^ 0x36) & 0xFF
    data[idx(0x52)] = (data[idx(0x52)] - 5) & 0xFF
    data[idx(0x7E)] = (data[idx(0x7E)] ^ 0x45) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] ^ 0xFE) & 0xFF
    data[idx(0x69)] = (data[idx(0x69)] + 2) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] + 6) & 0xFF
    data[idx(0x53)] = (data[idx(0x53)] + 120) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] + 6) & 0xFF
    data[idx(0x7B)] = (data[idx(0x7B)] + 104) & 0xFF
    data[idx(0x52)] = (data[idx(0x52)] + 74) & 0xFF
    data[idx(0x5D)] = (data[idx(0x5D)] ^ 0x1B) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] ^ 0xD1) & 0xFF
    data[idx(0x49)] = (data[idx(0x49)] - 43) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] - 56) & 0xFF
    data[idx(0x6A)] = (data[idx(0x6A)] + 82) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] - 8) & 0xFF
    data[idx(0x52)] = (data[idx(0x52)] ^ 0x43) & 0xFF
    data[idx(0x4D)] = (data[idx(0x4D)] + 4) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] - 88) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] - 92) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] + 117) & 0xFF
    data[idx(0x6D)] = (data[idx(0x6D)] + 75) & 0xFF
    data[idx(0x54)] = (data[idx(0x54)] ^ 0x68) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] + 99) & 0xFF
    data[idx(0x7D)] = (data[idx(0x7D)] - 121) & 0xFF
    data[idx(0x5A)] = (data[idx(0x5A)] ^ 0x11) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] + 32) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] ^ 0xA2) & 0xFF
    data[idx(0x7C)] = (data[idx(0x7C)] - 31) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] + 123) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] - 93) & 0xFF
    data[idx(0x6B)] = (data[idx(0x6B)] ^ 0xFA) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] + 59) & 0xFF
    data[idx(0x53)] = (data[idx(0x53)] - 101) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] - 66) & 0xFF
    data[idx(0x57)] = (data[idx(0x57)] - 75) & 0xFF
    data[idx(0x78)] = (data[idx(0x78)] + 32) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] + 15) & 0xFF
    data[idx(0x5D)] = (data[idx(0x5D)] ^ 0x4E) & 0xFF
    data[idx(0x52)] = (data[idx(0x52)] + 86) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] - 54) & 0xFF
    data[idx(0x58)] = (data[idx(0x58)] - 26) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] - 96) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] + 14) & 0xFF
    data[idx(0x45)] = (data[idx(0x45)] ^ 0x7D) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] + 6) & 0xFF
    data[idx(0x7E)] = (data[idx(0x7E)] ^ 0x99) & 0xFF
    data[idx(0x71)] = (data[idx(0x71)] + 89) & 0xFF
    data[idx(0x78)] = (data[idx(0x78)] - 42) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] + 123) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] ^ 0x58) & 0xFF
    data[idx(0x6C)] = (data[idx(0x6C)] - 64) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] - 121) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] + 127) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] + 25) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] ^ 0x4A) & 0xFF
    data[idx(0x5D)] = (data[idx(0x5D)] ^ 0x7D) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] + 77) & 0xFF
    data[idx(0x47)] = (data[idx(0x47)] - 92) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] + 81) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] ^ 0x12) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] + 91) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] - 70) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] ^ 0xD2) & 0xFF
    data[idx(0x4E)] = (data[idx(0x4E)] + 16) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] ^ 0xE2) & 0xFF
    data[idx(0x59)] = (data[idx(0x59)] ^ 0x47) & 0xFF
    data[idx(0x53)] = (data[idx(0x53)] ^ 0x10) & 0xFF
    data[idx(0x76)] = (data[idx(0x76)] ^ 0xF4) & 0xFF
    data[idx(0x44)] = (data[idx(0x44)] + 48) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] - 4) & 0xFF
    data[idx(0x6D)] = (data[idx(0x6D)] - 37) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] + 119) & 0xFF
    data[idx(0x5B)] = (data[idx(0x5B)] ^ 3) & 0xFF
    data[idx(0x71)] = (data[idx(0x71)] ^ 0x56) & 0xFF
    data[idx(0x54)] = (data[idx(0x54)] + 6) & 0xFF
    data[idx(0x4C)] = (data[idx(0x4C)] - 73) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] + 30) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] + 5) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] - 98) & 0xFF
    data[idx(0x4D)] = (data[idx(0x4D)] + 31) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] ^ 0x3F) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] + 20) & 0xFF
    data[idx(0x5C)] = (data[idx(0x5C)] ^ 0x89) & 0xFF
    data[idx(0x77)] = (data[idx(0x77)] - 16) & 0xFF
    data[idx(0x7D)] = (data[idx(0x7D)] ^ 0xF4) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] - 103) & 0xFF
    data[idx(0x6B)] = (data[idx(0x6B)] + 7) & 0xFF
    data[idx(0x65)] = (data[idx(0x65)] ^ 0x7A) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] + 111) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] ^ 0x0E) & 0xFF
    data[idx(0x69)] = (data[idx(0x69)] ^ 0x64) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] + 11) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] ^ 0xF7) & 0xFF
    data[idx(0x77)] = (data[idx(0x77)] + 72) & 0xFF
    data[idx(0x72)] = (data[idx(0x72)] + 69) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] ^ 0x7E) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] + 94) & 0xFF
    data[idx(0x67)] = (data[idx(0x67)] + 25) & 0xFF
    data[idx(0x59)] = (data[idx(0x59)] ^ 0xB6) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] ^ 0x83) & 0xFF
    data[idx(0x58)] = (data[idx(0x58)] + 65) & 0xFF
    data[idx(0x7F)] = (data[idx(0x7F)] ^ 0x0B) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] + 127) & 0xFF
    data[idx(0x59)] = (data[idx(0x59)] + 34) & 0xFF
    data[idx(0x65)] = (data[idx(0x65)] ^ 0x9B) & 0xFF
    data[idx(0x69)] = (data[idx(0x69)] + 70) & 0xFF
    data[idx(0x72)] = (data[idx(0x72)] - 116) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] + 127) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] ^ 0xDD) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] - 1) & 0xFF
    data[idx(0x5B)] = (data[idx(0x5B)] - 7) & 0xFF
    data[idx(0x78)] = (data[idx(0x78)] + 27) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] + 80) & 0xFF

    # for i in range(flag_len):
    data[idx(flag_index)] = (data[idx(flag_index)] + 27) & 0xFF  # 如果是加值

    data[idx(0x5B)] = (data[idx(0x5B)] - 26) & 0xFF
    data[idx(0x6F)] = (data[idx(0x6F)] ^ 0xF6) & 0xFF
    data[idx(0x4E)] = (data[idx(0x4E)] - 76) & 0xFF
    # for i in range(flag_len):
    data[idx(flag_index )] = (data[idx(flag_index )] ^ 0xD9) & 0xFF  # 如果是加值

    data[idx(0x6E)] = (data[idx(0x6E)] - 111) & 0xFF
    data[idx(0x7E)] = (data[idx(0x7E)] + 71) & 0xFF
    data[idx(0x7B)] = (data[idx(0x7B)] + 108) & 0xFF
    data[idx(0x63)] = (data[idx(0x63)] + 2) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] + 38) & 0xFF
    data[idx(0x6A)] = (data[idx(0x6A)] + 20) & 0xFF
    data[idx(0x7B)] = (data[idx(0x7B)] - 3) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] - 49) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] - 60) & 0xFF
    data[idx(0x7E)] = (data[idx(0x7E)] ^ 0x4D) & 0xFF
    data[idx(0x7F)] = (data[idx(0x7F)] - 50) & 0xFF

    # for i in range(flag_len):
    data[idx(flag_index )] = (data[idx(flag_index )] ^ 0xA8) & 0xFF  # 如果是加值

    data[idx(0x72)] = (data[idx(0x72)] ^ 0xA4) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] ^ 0xD3) & 0xFF
    data[idx(0x59)] = (data[idx(0x59)] + 22) & 0xFF
    data[idx(0x68)] = (data[idx(0x68)] - 3) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] - 124) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] + 1) & 0xFF
    data[idx(0x7D)] = (data[idx(0x7D)] + 8) & 0xFF
    data[idx(0x77)] = (data[idx(0x77)] - 119) & 0xFF
    data[idx(0x65)] = (data[idx(0x65)] + 91) & 0xFF
    data[idx(0x54)] = (data[idx(0x54)] ^ 0x6D) & 0xFF
    data[idx(0x49)] = (data[idx(0x49)] ^ 0xDE) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] + 46) & 0xFF
    data[idx(0x71)] = (data[idx(0x71)] - 9) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] + 16) & 0xFF
    data[idx(0x47)] = (data[idx(0x47)] + 31) & 0xFF
    data[idx(0x5D)] = (data[idx(0x5D)] ^ 0xEE) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] - 65) & 0xFF
    data[idx(0x5B)] = (data[idx(0x5B)] - 29) & 0xFF
    data[idx(0x71)] = (data[idx(0x71)] ^ 0x30) & 0xFF
    data[idx(0x7C)] = (data[idx(0x7C)] + 8) & 0xFF

    # for i in range(flag_len):
    data[idx(flag_index )] = (data[idx(flag_index )] + 6) & 0xFF  # 如果是加值
    # data[idx(0x75)] = (data[idx(0x75)] + 6) & 0xFF
    data[idx(0x4F)] = (data[idx(0x4F)] + 86) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] ^ 0xD3) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] - 51) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] - 95) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] ^ 0x76) & 0xFF
    data[idx(0x79)] = (data[idx(0x79)] + 37) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] ^ 0x88) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] - 99) & 0xFF
    data[idx(0x4E)] = (data[idx(0x4E)] - 69) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] - 114) & 0xFF
    data[idx(0x4C)] = (data[idx(0x4C)] - 113) & 0xFF
    data[idx(0x65)] = (data[idx(0x65)] + 67) & 0xFF
    data[idx(0x5C)] = (data[idx(0x5C)] - 46) & 0xFF
    data[idx(0x4F)] = (data[idx(0x4F)] + 116) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] + 107) & 0xFF
    data[idx(0x72)] = (data[idx(0x72)] + 51) & 0xFF

    data[idx(0x55)] = (data[idx(0x55)] + 37) & 0xFF
    data[idx(0x6B)] = (data[idx(0x6B)] - 115) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] ^ 0xF2) & 0xFF
    data[idx(0x66)] = (data[idx(0x66)] ^ 0x56) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] - 53) & 0xFF
    data[idx(0x6F)] = (data[idx(0x6F)] + 16) & 0xFF
    data[idx(0x7D)] = (data[idx(0x7D)] + 119) & 0xFF
    data[idx(0x71)] = (data[idx(0x71)] + 7) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] - 25) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] ^ 0x6C) & 0xFF
    data[idx(0x63)] = (data[idx(0x63)] - 125) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] ^ 0xFD) & 0xFF
    data[idx(0x6C)] = (data[idx(0x6C)] ^ 0x4A) & 0xFF
    data[idx(0x7C)] = (data[idx(0x7C)] ^ 0x4C) & 0xFF
    data[idx(0x6A)] = (data[idx(0x6A)] - 28) & 0xFF

    data[idx(flag_index )] = (data[idx(flag_index )] + 108) & 0xFF

    data[idx(0x68)] = (data[idx(0x68)] + 52) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] + 75) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] + 118) & 0xFF
    data[idx(0x48)] = (data[idx(0x48)] + 119) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] + 6) & 0xFF
    data[idx(0x6B)] = (data[idx(0x6B)] ^ 0xD6) & 0xFF
    data[idx(0x49)] = (data[idx(0x49)] - 83) & 0xFF
    data[idx(0x77)] = (data[idx(0x77)] ^ 0x2F) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] + 9) & 0xFF
    data[idx(0x72)] = (data[idx(0x72)] - 90) & 0xFF
    data[idx(0x7B)] = (data[idx(0x7B)] ^ 0xFA) & 0xFF
    data[idx(0x67)] = (data[idx(0x67)] + 38) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] ^ 0x87) & 0xFF
    data[idx(0x72)] = (data[idx(0x72)] + 52) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] - 67) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] + 120) & 0xFF
    data[idx(0x77)] = (data[idx(0x77)] - 4) & 0xFF
    data[idx(0x71)] = (data[idx(0x71)] ^ 0xBE) & 0xFF
    data[idx(0x68)] = (data[idx(0x68)] ^ 0xED) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] ^ 0x82) & 0xFF
    data[idx(0x4D)] = (data[idx(0x4D)] + 74) & 0xFF
    data[idx(0x7C)] = (data[idx(0x7C)] + 44) & 0xFF
    data[idx(0x45)] = (data[idx(0x45)] ^ 0x2D) & 0xFF
    data[idx(0x4F)] = (data[idx(0x4F)] + 12) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] ^ 0x22) & 0xFF
    data[idx(0x54)] = (data[idx(0x54)] + 98) & 0xFF
    data[idx(0x7E)] = (data[idx(0x7E)] - 121) & 0xFF
    data[idx(0x6B)] = (data[idx(0x6B)] ^ 0x8E) & 0xFF
    data[idx(0x49)] = (data[idx(0x49)] + 64) & 0xFF
    data[idx(0x67)] = (data[idx(0x67)] ^ 0x5C) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] - 32) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] + 86) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] + 127) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] - 115) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] ^ 0xD3) & 0xFF
    data[idx(0x4F)] = (data[idx(0x4F)] + 96) & 0xFF
    data[idx(0x47)] = (data[idx(0x47)] - 94) & 0xFF
    data[idx(0x73)] = (data[idx(0x73)] + 67) & 0xFF
    data[idx(0x63)] = (data[idx(0x63)] + 47) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] + 105) & 0xFF
    data[idx(0x5B)] = (data[idx(0x5B)] - 11) & 0xFF
    data[idx(0x7C)] = (data[idx(0x7C)] - 49) & 0xFF
    data[idx(0x6A)] = (data[idx(0x6A)] ^ 0x21) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] - 53) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] - 83) & 0xFF
    data[idx(0x47)] = (data[idx(0x47)] + 49) & 0xFF
    data[idx(0x63)] = (data[idx(0x63)] - 96) & 0xFF
    data[idx(0x68)] = (data[idx(0x68)] + 30) & 0xFF
    data[idx(0x6D)] = (data[idx(0x6D)] ^ 0xE4) & 0xFF
    data[idx(0x48)] = (data[idx(0x48)] - 44) & 0xFF

    data[idx(0x6E)] = (data[idx(0x6E)] - 58) & 0xFF
    data[idx(0x4E)] = (data[idx(0x4E)] ^ 0x5) & 0xFF

    data[idx(0x72)] = (data[idx(0x72)] + 11) & 0xFF          
    data[idx(0x54)] = (data[idx(0x54)] - 18) & 0xFF
    data[idx(0x63)] = (data[idx(0x63)] ^ 0x7E) & 0xFF
    data[idx(0x4B)] = (data[idx(0x4B)] ^ 0x22) & 0xFF
    data[idx(0x7E)] = (data[idx(0x7E)] - 116) & 0xFF
    data[idx(0x46)] = (data[idx(0x46)] - 69) & 0xFF
    data[idx(0x61)] = (data[idx(0x61)] ^ 0xDC) & 0xFF
    data[idx(0x4F)] = (data[idx(0x4F)] + 69) & 0xFF
    data[idx(0x67)] = (data[idx(0x67)] ^ 0xB0) & 0xFF
    data[idx(0x65)] = (data[idx(0x65)] + 45) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] + 46) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] - 19) & 0xFF
    data[idx(0x45)] = (data[idx(0x45)] ^ 0xC3) & 0xFF
    data[idx(0x43)] = (data[idx(0x43)] - 33) & 0xFF
    data[idx(0x5B)] = (data[idx(0x5B)] ^ 0x7A) & 0xFF
    data[idx(0x56)] = (data[idx(0x56)] - 92) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] - 117) & 0xFF
    data[idx(0x68)] = (data[idx(0x68)] ^ 0x57) & 0xFF
    data[idx(0x7A)] = (data[idx(0x7A)] - 11) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] + 44) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] - 125) & 0xFF
    data[idx(0x6F)] = (data[idx(0x6F)] + 80) & 0xFF
    data[idx(0x4C)] = (data[idx(0x4C)] - 73) & 0xFF

    data[idx(flag_index )] = (data[idx(flag_index )] - 25) & 0xFF

    data[idx(0x7A)] = (data[idx(0x7A)] + 105) & 0xFF
    data[idx(0x6F)] = (data[idx(0x6F)] + 88) & 0xFF
    data[idx(0x4C)] = (data[idx(0x4C)] + 27) & 0xFF
    data[idx(0x48)] = (data[idx(0x48)] - 55) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] + 107) & 0xFF
    data[idx(0x5D)] = (data[idx(0x5D)] + 30) & 0xFF
    data[idx(0x74)] = (data[idx(0x74)] - 57) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] + 94) & 0xFF
    data[idx(0x7B)] = (data[idx(0x7B)] + 52) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] - 14) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] - 109) & 0xFF
    data[idx(0x42)] = (data[idx(0x42)] ^ 0x42) & 0xFF
    data[idx(0x66)] = (data[idx(0x66)] - 61) & 0xFF
    data[idx(0x46)] = (data[idx(0x46)] - 32) & 0xFF
    data[idx(0x69)] = (data[idx(0x69)] + 49) & 0xFF
    data[idx(0x46)] = (data[idx(0x46)] + 99) & 0xFF

    data[idx(0x62)] = (data[idx(0x62)] ^ 0xD1) & 0xFF
    data[idx(0x46)] = (data[idx(0x46)] ^ 0xEC) & 0xFF
    data[idx(0x66)] = (data[idx(0x66)] + 66) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] ^ 0xB2) & 0xFF
    data[idx(0x4F)] = (data[idx(0x4F)] ^ 0x5E) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] + 11) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] - 78) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] - 41) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] - 118) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] ^ 0x61) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] ^ 0x73) & 0xFF
    data[idx(0x56)] = (data[idx(0x56)] + 89) & 0xFF
    data[idx(0x5C)] = (data[idx(0x5C)] + 64) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] + 100) & 0xFF
    data[idx(0x5A)] = (data[idx(0x5A)] - 123) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] + 17) & 0xFF
    data[idx(0x4A)] = (data[idx(0x4A)] - 58) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] - 79) & 0xFF
    data[idx(0x5F)] = (data[idx(0x5F)] ^ 0x29) & 0xFF
    data[idx(0x6C)] = (data[idx(0x6C)] + 92) & 0xFF
    data[idx(0x6E)] = (data[idx(0x6E)] ^ 0x32) & 0xFF
    data[idx(0x5B)] = (data[idx(0x5B)] - 111) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] - 55) & 0xFF
    data[idx(0x7D)] = (data[idx(0x7D)] + 48) & 0xFF
    data[idx(0x62)] = (data[idx(0x62)] ^ 0x0A) & 0xFF
    data[idx(0x4E)] = (data[idx(0x4E)] + 119) & 0xFF
    data[idx(0x60)] = (data[idx(0x60)] ^ 0xAA) & 0xFF
    data[idx(0x75)] = (data[idx(0x75)] + 71) & 0xFF
    data[idx(0x44)] = (data[idx(0x44)] + 127) & 0xFF
    data[idx(0x6D)] = (data[idx(0x6D)] + 44) & 0xFF
    data[idx(0x76)] = (data[idx(0x76)] ^ 0xE0) & 0xFF
    data[idx(0x41)] = (data[idx(0x41)] - 71) & 0xFF
    data[idx(0x5E)] = (data[idx(0x5E)] ^ 0x03) & 0xFF
    data[idx(0x69)] = (data[idx(0x69)] - 52) & 0xFF
    data[idx(0x5C)] = (data[idx(0x5C)] ^ 0x82) & 0xFF
    data[idx(0x4A)] = (data[idx(0x4A)] - 103) & 0xFF
    data[idx(0x48)] = (data[idx(0x48)] - 95) & 0xFF
    data[idx(0x64)] = (data[idx(0x64)] + 93) & 0xFF
    data[idx(0x55)] = (data[idx(0x55)] + 30) & 0xFF
    data[idx(0x70)] = (data[idx(0x70)] ^ 0x4F) & 0xFF
    data[idx(0x4D)] = (data[idx(0x4D)] + 120) & 0xFF


    return bytes(data)

if __name__ == "__main__":
    flag = decrypt(data)
    print("Recovered flag:", flag.decode(errors="ignore"))
##Recovered flag: DASCTF{5ac3b28711aac86da0c6f4f489b05e96}kή%_"