[REVERSE]我出的题大家觉得BT，毕竟大家都在F5伪代码

// 对输入进行异或0x42的操作for(int i = 0; i < len; i++) {    output[i] = input[i] ^ 0x42;}

// 对字符进行处理for(int i = 0; i < len; i++) {    char c = input[i];    // 处理小写字母a-z    if(c >= 'a' && c <= 'z') {        int x = ((c - 0x5E) * 0x13C) >> 0xD;        x *= 0x1A;            c = (c - x + 3);    }    // 处理大写字母A-Z     else if(c >= 'A' && c <= 'Z') {        int x = ((c - 0x3E) * 0x13C) >> 0xD;        x *= 0x1A;        c = (c - x + 3);    }    output[i] = c;}

// 将处理后的字符转为16进制字符串const char hex[] = "0123456789abcdef";for(int i = 0; i < len; i++) {    char c = input[i];    output[i*2] = hex[(c >> 4) & 0xF];    output[i*2+1] = hex[c & 0xF];}

import base64def hex_to_bytes(hex_str):    """将十六进制字符串转换为字节"""    return bytes.fromhex(hex_str)def create_reverse_substitution_table():    """创建反向替换表"""    substitution_table = {        'a': 'q', 'b': 'w', 'c': 'e', 'd': 'r', 'e': 't',        'f': 'y', 'g': 'u', 'h': 'i', 'i': 'o', 'j': 'p',        'k': 'a', 'l': 's', 'm': 'd', 'n': 'f', 'o': 'g',        'p': 'h', 'q': 'j', 'r': 'k', 's': 'l', 't': 'z',        'u': 'x', 'v': 'c', 'w': 'v', 'x': 'b', 'y': 'n',        'z': 'm', '@': '#', '{': '<', '}': '>', '_': '-',        '1': '7', '2': '8', '3': '9', '4': '0', '0': '6'    }    # 创建反向映射    return {v: k for k, v in substitution_table.items()}def reverse_substitution(encrypted_text, reverse_table):    """反向替换解密"""    result = []    for char in encrypted_text:        char = chr(char)        if char in reverse_table:            result.append(reverse_table[char])        else:            result.append(char)    return ''.join(result)def caesar_decrypt(text, shift=3):    """凯撒密码解密"""    result = []    for char in text:        if char.isalpha():            # 确定字符范围（大写或小写）            ascii_offset = ord('A') if char.isupper() else ord('a')            # 解密并确保在字母范围内            decrypted = chr((ord(char) - ascii_offset - shift) % 26 + ascii_offset)            result.append(decrypted)        else:            result.append(char)    return ''.join(result)def xor_decrypt(data, key=0x42):    """异或解密"""    return bytes([b ^ key for b in data])def decrypt_flag(encrypted_hex):    """完整的解密过程"""    # 1. 转换十六进制为字节    encrypted_bytes = hex_to_bytes(encrypted_hex)    print(f"[+] 十六进制解码后: {encrypted_bytes}")    # 2. 替换表解密    reverse_table = create_reverse_substitution_table()    substitution_decrypted = reverse_substitution(encrypted_bytes, reverse_table)    print(f"[+] 替换表解密后: {substitution_decrypted}")    # 3. 凯撒密码解密    caesar_decrypted = caesar_decrypt(substitution_decrypted)    print(f"[+] 凯撒解密后: {caesar_decrypted}")    # 4. Base64解码    base64_decrypted = base64.b64decode(caesar_decrypted)    print(f"[+] Base64解码后: {base64_decrypted}")    # 5. 异或解密    final_result = xor_decrypt(base64_decrypted)    print(f"[+] 异或解密后: {final_result.decode()}")    return final_result.decode()def main():    # 加密后的十六进制字符串    encrypted_hex = "4d4630644d576637447350634d576c654f4536494a71376d796a45384b55704d4b5444494657383d"    print("=== Flag 解密过程 ===")    flag = decrypt_flag(encrypted_hex)    print("n[*] 最终 Flag:", flag)if __name__ == "__main__":    main()