adworld [rev] babymips

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adworld [rev] babymips

简单的暴力题，直接上脚本：

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secret = [
    0x51, 0x7c, 0x6a, 0x7b, 0x67, 0x52, 0xFD, 0x16,
    0xA4, 0x89, 0xBD, 0x92, 0x80, 0x13, 0x41, 0x54,
    0xA0, 0x8D, 0x45, 0x18, 0x81, 0xDE, 0xFC, 0x95,
    0xF0, 0x16, 0x79, 0x1A, 0x15, 0x5B, 0x75, 0x1F
]

flag = []
# qctf{ReA11y_4_B@89_mlp5_4_XmAn_}
for i in range(32):
    if i < 5:
        flag.append(secret[i] ^ (32 - i))
    else:
        if i & 1 == 1:
            flag.append((((secret[i] << 2) | (secret[i] >> 6)) ^ (32 - i)) & 0xff)
        else:
            for j in range(1, 127):
                tmp = j
                tmp ^= 32 - i
                tmp &= 0xff
                tmp = (4 * tmp) | (tmp >> 6)
                tmp &= 0xff
                if tmp == secret[i]:
                    flag.append(j)
                    break

print(len(secret))
print(len(flag))
print(''.join(list(map(chr, flag))))