[原创] 第三题石像病毒-CTF对抗-看雪-安全社区|安全招聘|kanxue.com

[原创] 第三题石像病毒

2022-5-13 20:44 5587

[原创] 第三题石像病毒

Emtanling

2022-5-13 20:44

5587

异常处理，ida跟进调试，md5计算出key（调试可以得到），进行aes加密(aes改了一点)，百度一个aes加密修改一下。

aes.h 中修改的部分

//S盒
unsigned char S[256] = {
0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01,
  0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76, 0xCA, 0x82, 0xC9, 0x7D,
  0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4,
  0x72, 0xC0, 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC,
  0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15, 0x04, 0xC7,
  0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2,
  0xEB, 0x27, 0xB2, 0x75, 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E,
  0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
  0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB,
  0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF, 0xD0, 0xEF, 0xAA, 0xFB,
  0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C,
  0x9F, 0xA8, 0x51, 0x0A, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5,
  0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2, 0xCD, 0x0C,
  0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D,
  0x64, 0x5D, 0x19, 0x73, 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A,
  0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
  0xE0, 0x32, 0x3A, 0xA3, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3,
  0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79, 0xE7, 0xC8, 0x37, 0x6D,
  0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A,
  0xAE, 0x08, 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6,
  0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A, 0x70, 0x3E,
  0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9,
  0x86, 0xC1, 0x1D, 0x9E, 0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9,
  0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
  0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99,
  0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
};
 
//逆S盒
unsigned char inv_S[256] = {
    0x52, 0x9, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0x71, 0x9e, 0x81, 0xf3, 
    0xd7, 0xfb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44,
    0xc4, 0xde, 0xe9, 0xcb, 0x54,0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 
    0x95, 0xb, 0x42, 0xfa, 0xc3, 0x4e, 0x8, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 
    0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 
    0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, 0x6c, 0x70, 0x48, 0x50, 
    0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, 0x90, 0xd8, 
    0xab,0x0, 0x8c, 0xbc, 0xd3, 0xa, 0xf7, 0xe4, 0x58, 0x5, 0xb8, 0xb3, 0x45, 0x6, 0xd0, 
    0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0xf, 0x2, 0xc1, 0xaf, 0xbd, 0x3, 0x1, 0x13, 0x8a, 0x6b,
    0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4,
    0xe6, 0x73, 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 
    0x1c, 0x75, 0xdf, 0x6e, 0x47, 0xf1, 0x1a, 0xa3, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 
    0x62, 0xe, 0xaa, 0x18, 0xbe, 0x1b, 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 
    0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x7, 
    0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 
    0x19, 0xb5, 0x4a, 0xd, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, 0xa0, 0xe0, 
    0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, 
    0x17, 0x2b, 0x4, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0xc, 0x7d
};
 
//逆行移位
int invShiftRows(uint8_t(*state)[4]) {
    uint32_t block[4] = { 0 };
    for (int i = 0; i < 4; ++i) {
        LOAD32H(block[i], state[i]);
        block[i] = ROF32(block[i], 8 * i);
        STORE32H(block[i], state[i]);
    }
 
    return 0;
}

main.cpp

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <cstdint>
#include "aes.h"
int main() {
    const uint8_t key[16] = { 0x2F, 0x65, 0xB1, 0xFF, 0x31, 0xED, 0x86, 0xD0, 0x9A, 0x28,0x5C, 0x0F, 0x40, 0x48, 0x05, 0x9D };
    uint8_t plain[48] = { 0 };
    uint8_t ct[32] = { 0x57, 0x7C, 0xF5, 0x6D, 0x56, 0x96, 0x77, 0x45, 0xB0, 0xBD,0xA1, 0xC7, 0x89, 0xA5, 0xAB, 0xDC, 0xF2, 0xF4, 0x4B, 0xFE,0xBE, 0xF5, 0xF5, 0x5C, 0x4D, 0x30, 0x42, 0x0F, 0x2B, 0x3B,
  0xE6, 0xCB };      
    ct[16] = 0xf4;
    ct[17] = 0xf2;
    aesDecrypt(key, 16, ct, plain, 32);
    return 0;
}
// plain = 0x0019fe6c "flag{db5c6a8dfec4d0ec5569899640}"