uoftctf2025 WP

clev1L Lv3
  2025-01-14 15:48:04 2025-01-14 15:48:04 Created   2025-02-23 12:29:57 2025-02-23 12:29:57 Updated  2.3k Words  14 Mins  

Highly Optimized

取余

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ops = [0x0000000000000000, 0x00CFFB289AF4B1D1, 0x0000000000000000, 0x0000000000000083, 0x0000000000000002,
       0x0000000000000001, 0x0000000000000000, 0x0000000000000083, 0x0000000000000003, 0x0000000000000004,
       0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x00955F7E7A2ABC09, 0x0000000000000000,
       0x0000000000000082, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000082,
       0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000,
       0x0171D0EEF6E34564, 0x0000000000000000, 0x0000000000000092, 0x0000000000000002, 0x0000000000000001,
       0x0000000000000000, 0x0000000000000092, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009,
       0x0000000000000005, 0x0000000000000000, 0x01C8C0106F982D2C, 0x0000000000000000, 0x0000000000000078,
       0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000078, 0x0000000000000003,
       0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x01A3DF010DB43D50,
       0x0000000000000000, 0x0000000000000079, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000,
       0x0000000000000079, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005,
       0x0000000000000000, 0x0070D52B655429D4, 0x0000000000000000, 0x00000000000000A0, 0x0000000000000002,
       0x0000000000000001, 0x0000000000000000, 0x00000000000000A0, 0x0000000000000003, 0x0000000000000004,
       0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x0086BA083DB4A00E, 0x0000000000000000,
       0x000000000000008F, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x000000000000008F,
       0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000,
       0x01EE6D244821E17E, 0x0000000000000000, 0x0000000000000093, 0x0000000000000002, 0x0000000000000001,
       0x0000000000000000, 0x0000000000000093, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009,
       0x0000000000000005, 0x0000000000000000, 0x021F3E25788406B2, 0x0000000000000000, 0x000000000000008A,
       0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x000000000000008A, 0x0000000000000003,
       0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x013C0021E70D77B4,
       0x0000000000000000, 0x00000000000000A3, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000,
       0x00000000000000A3, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005,
       0x0000000000000000, 0x027EDD2385F658C6, 0x0000000000000000, 0x00000000000000AA, 0x0000000000000002,
       0x0000000000000001, 0x0000000000000000, 0x00000000000000AA, 0x0000000000000003, 0x0000000000000004,
       0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x00A07DA21EF9E1B4, 0x0000000000000000,
       0x0000000000000034, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000034,
       0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000,
       0x00D00E8519E9CC06, 0x0000000000000000, 0x0000000000000041, 0x0000000000000002, 0x0000000000000001,
       0x0000000000000000, 0x0000000000000041, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009,
       0x0000000000000005, 0x0000000000000000, 0x00D6DFC3F1E11375, 0x0000000000000000, 0x0000000000000078,
       0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000078, 0x0000000000000003,
       0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x00EFAA53300DA663,
       0x0000000000000000, 0x000000000000008D, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000,
       0x000000000000008D, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005,
       0x0000000000000000, 0x007568123DB27DB8, 0x0000000000000000, 0x0000000000000089, 0x0000000000000002,
       0x0000000000000001, 0x0000000000000000, 0x0000000000000089, 0x0000000000000003, 0x0000000000000004,
       0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x00F174602422164A, 0x0000000000000000,
       0x0000000000000087, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000087,
       0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000,
       0x009B991D46E343EE, 0x0000000000000000, 0x0000000000000075, 0x0000000000000002, 0x0000000000000001,
       0x0000000000000000, 0x0000000000000075, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009,
       0x0000000000000005, 0x0000000000000000, 0x0016C43FB0F9B780, 0x0000000000000000, 0x0000000000000044,
       0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000044, 0x0000000000000003,
       0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x010C7B1796D09C04,
       0x0000000000000000, 0x0000000000000044, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000,
       0x0000000000000044, 0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005,
       0x0000000000000000, 0x005F5CFCF58C8717, 0x0000000000000000, 0x000000000000007A, 0x0000000000000002,
       0x0000000000000001, 0x0000000000000000, 0x000000000000007A, 0x0000000000000003, 0x0000000000000004,
       0x0000000000000009, 0x0000000000000005, 0x0000000000000000, 0x00D715FDA1220CE0, 0x0000000000000000,
       0x0000000000000093, 0x0000000000000002, 0x0000000000000001, 0x0000000000000000, 0x0000000000000093,
       0x0000000000000003, 0x0000000000000004, 0x0000000000000009, 0x0000000000000005, 0x0000000000000006]
for i in range(len(ops)):
    if ops[i]>0xff:
        print(chr(ops[i]%ops[i+2]),end="")

Py_FlagChecker

断在python310.dll的marshal.loads函数就能dump出pyc

pycdas看到flag

Encrypted Flag

爆破时间戳，这时间戳在2034年，我从2025年爆到了1970年，蒙蔽了

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#include<stdio.h>
#include<stdlib.h>
int main(){
  int v4 = 64;
  int v6,v9,i;
  unsigned int v7;
  char v10;
  int v5;
  int tar[4]={0xa8, 0xf9, 0xdd, 0x73};
  int idx[4];
  for(int v5=0;v5<0xffffffff;v5+=1){
    srand(v5);
    if(v5%0x100000==0){
      printf("0x%x\n",v5);
    }
    v6 = 0;
  v7 = rand();
  char buf[256]={0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
  do
  {
    for ( i = v7&0xff; ; i = (i + 1)&0xff )
    {
      v9 = i;
      if ( buf[i] == -1 )
        break;
    }
    idx[v6]=v9;
    if(idx[v6]!=tar[v6]){
      break;
    }
    v7>>=8;
    v6+=1;
    buf[v9]=1;
  }while ( v6 != 4 );
  if(idx[0]==tar[0]&&idx[1]==tar[1]&&idx[2]==tar[2]&&idx[3]==tar[3]){
    printf("find:0x%x\n",v5);
  }
  }
}
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from z3 import *
from tqdm import tqdm
key1 = [0x57, 0x2D, 0xAF, 0x32, 0x00, 0x00, 0x00, 0x00, 0x4A, 0x0A,
        0x27, 0x7E, 0x00, 0x00, 0x00, 0x00, 0x23, 0x58, 0xDA, 0x47,
        0x23, 0x58, 0xDA, 0x47, 0x69, 0x52, 0xFD, 0x39, 0x69, 0x52,
        0xFD, 0x39, 0xAE, 0xE4, 0xDE, 0x3A, 0x8D, 0xBC, 0x04, 0x7D,
        0xE4, 0xEE, 0xF9, 0x44, 0x8D, 0xBC, 0x04, 0x7D, 0x70, 0x19,
        0x59, 0xFA, 0xFD, 0xA5, 0x5D, 0x87, 0x19, 0x4B, 0xA4, 0xC3,
        0x94, 0xF7, 0xA0, 0xBE, 0x81, 0x97, 0xF1, 0xE7, 0x7C, 0x32,
        0xAC, 0x60, 0x65, 0x79, 0x08, 0xA3, 0xF1, 0x8E, 0xA8, 0x1D,
        0xC7, 0x97, 0x6E, 0x31, 0xBB, 0xA5, 0xC2, 0x51, 0xDE, 0xDC,
        0xCA, 0xF2, 0x2F, 0x52, 0x62, 0xEF, 0x68, 0x2C, 0x7E, 0x4B,
        0xD3, 0x89, 0xBC, 0x1A, 0x0D, 0x55, 0x76, 0xE8, 0x22, 0x07,
        0x14, 0x07, 0x97, 0x07, 0xC1, 0xC0, 0x44, 0x8E, 0x7D, 0xDA,
        0x49, 0xDB, 0x0B, 0x32, 0x6B, 0xDC, 0x1F, 0x35, 0x5D, 0xCB,
        0x85, 0xED, 0x19, 0x45, 0xF8, 0x37, 0x50, 0x9E, 0xF3, 0x05,
        0x3B, 0x42, 0xEC, 0x30, 0xC4, 0x23, 0x2E, 0x73, 0xDD, 0x66,
        0xD6, 0x44, 0x8D, 0xF8, 0x25, 0x41, 0xB6, 0xBA, 0xC9, 0x71,
        0xC4, 0xC6, 0x24, 0x0B, 0x19, 0xA0, 0xF2, 0x4F, 0x94, 0x58,
        0xD7, 0x0E, 0x22, 0xE2, 0x1E, 0x7F, 0x75, 0x93, 0x08, 0xE2,
        0xFD, 0xFE, 0x0E, 0xBF, 0xFF, 0x17, 0x1F, 0x59, 0x6F, 0xAF,
        0x13, 0xA0, 0x66, 0xAD, 0x85, 0x2F, 0x2B, 0x68, 0x9C, 0x3B,
        0x5F, 0xB1, 0xBA, 0x14, 0x23, 0x9F, 0xC3, 0xCC, 0x53, 0x4B,
        0x8B, 0xD7, 0x35, 0x54, 0xA4, 0x28, 0xC2, 0x1E, 0x32, 0x33,
        0x19, 0x96, 0xDD, 0x7A, 0xAB, 0xDE, 0x5B, 0x0B, 0x0F, 0x44,
        0x94, 0xEC, 0xF5, 0x04, 0x34, 0x9E, 0xC4, 0xC5, 0x30, 0xB3,
        0x20, 0x6D, 0x82, 0x7B, 0x83, 0xA1, 0x92, 0x43, 0x1B, 0x7C,
        0xB2, 0xB4, 0xB7, 0x37, 0x0D, 0x26]
test = [ord(i) for i in "1234567890abcdef"]
buf = [0x75, 0x93, 0x08, 0xE2, 0xFD, 0xFE, 0x0E, 0xBF, 0xFF, 0x17,
       0x1F, 0x59, 0x6F, 0xAF, 0x13, 0xA0, 0x66, 0xAD, 0x85, 0x2F,
       0x2B, 0x68, 0x9C, 0x3B, 0x5F, 0xB1, 0xBA, 0x14, 0x23, 0x9F,
       0xC3, 0xCC, 0x53, 0x4B, 0x8B, 0xD7, 0x35, 0x54, 0xA4, 0x28,
       0xC2, 0x1E, 0x32, 0x33, 0x19, 0x96, 0xDD, 0x7A, 0xAB, 0xDE,
       0x5B, 0x0B, 0x0F, 0x44, 0x94, 0xEC, 0xF5, 0x04, 0x34, 0x9E,
       0xC4, 0xC5, 0x30, 0xB3, 0x20, 0x6D, 0x82, 0x7B, 0x83, 0xA1,
       0x92, 0x43, 0x1B, 0x7C, 0xB2, 0xB4, 0xB7, 0x37, 0x0D, 0x26,
       0x07, 0x47, 0x8F, 0xAC, 0x3F, 0xC1, 0xCF, 0x3C, 0xD9, 0x12,
       0x67, 0x69, 0x9B, 0x25, 0x09, 0x74, 0xA3, 0xB0, 0xBB, 0x42,
       0x3E, 0x4F, 0x18, 0xD0, 0x05, 0x7D, 0x29, 0x2D, 0x55, 0x7F,
       0x81, 0x71, 0x5A, 0x0A, 0x4C, 0x03, 0x76, 0x27, 0x57, 0x1C,
       0x63, 0x6B, 0x73, 0x1A, 0x77, 0x87, 0x5D, 0x97, 0x61, 0x11,
       0x21, 0x99, 0x58, 0x9D, 0x0C, 0xA2, 0x8C, 0x38, 0xA7, 0x6C,
       0xA6, 0xC0, 0x56, 0xC7, 0x46, 0x51, 0x49, 0xB6, 0x1D, 0xC8,
       0x48, 0xC9, 0x2E, 0x3D, 0x52, 0x80, 0x41, 0x50, 0x40, 0x70,
       0x8E, 0x64, 0x45, 0x86, 0xCA, 0x16, 0xAE, 0xB5, 0x00, 0x7E,
       0x2C, 0xB8, 0xB9, 0xBD, 0xBE, 0x8A, 0xCB, 0xD1, 0xD2, 0xD3,
       0x62, 0x6E, 0x78, 0x79, 0x89, 0x84, 0x36, 0xD5, 0xDA, 0xCE,
       0xA8, 0xDB, 0xDC, 0x3A, 0x39, 0xDF, 0x9A, 0xE0, 0xE1, 0xE3,
       0x2A, 0xE5, 0xE6, 0x72, 0x31, 0xE7, 0x06, 0x5C, 0x88, 0x6A,
       0xAA, 0xE9, 0x90, 0xEB, 0x4E, 0xEE, 0xEF, 0xCD, 0xF0, 0x24,
       0x4A, 0x02, 0x4D, 0xEA, 0xF1, 0xF3, 0x15, 0xA9, 0x95, 0xF4,
       0x65, 0xC6, 0x5E, 0xA5, 0x8D, 0xD8, 0xE8, 0xED, 0xF2, 0x10,
       0xF6, 0xD6, 0x22, 0xD4, 0x91, 0xF7, 0xF8, 0xF9, 0xFA, 0x01,
       0xE4, 0x60, 0xFB, 0xBC, 0xFC, 0x98]
byte1 = [0x00, 0x03, 0x06, 0x05, 0x0C, 0x0F, 0x0A, 0x09, 0x18, 0x1B,
         0x1E, 0x1D, 0x14, 0x17, 0x12, 0x11, 0x30, 0x33, 0x36, 0x35,
         0x3C, 0x3F, 0x3A, 0x39, 0x28, 0x2B, 0x2E, 0x2D, 0x24, 0x27,
         0x22, 0x21, 0x60, 0x63, 0x66, 0x65, 0x6C, 0x6F, 0x6A, 0x69,
         0x78, 0x7B, 0x7E, 0x7D, 0x74, 0x77, 0x72, 0x71, 0x50, 0x53,
         0x56, 0x55, 0x5C, 0x5F, 0x5A, 0x59, 0x48, 0x4B, 0x4E, 0x4D,
         0x44, 0x47, 0x42, 0x41, 0xC0, 0xC3, 0xC6, 0xC5, 0xCC, 0xCF,
         0xCA, 0xC9, 0xD8, 0xDB, 0xDE, 0xDD, 0xD4, 0xD7, 0xD2, 0xD1,
         0xF0, 0xF3, 0xF6, 0xF5, 0xFC, 0xFF, 0xFA, 0xF9, 0xE8, 0xEB,
         0xEE, 0xED, 0xE4, 0xE7, 0xE2, 0xE1, 0xA0, 0xA3, 0xA6, 0xA5,
         0xAC, 0xAF, 0xAA, 0xA9, 0xB8, 0xBB, 0xBE, 0xBD, 0xB4, 0xB7,
         0xB2, 0xB1, 0x90, 0x93, 0x96, 0x95, 0x9C, 0x9F, 0x9A, 0x99,
         0x88, 0x8B, 0x8E, 0x8D, 0x84, 0x87, 0x82, 0x81, 0x9B, 0x98,
         0x9D, 0x9E, 0x97, 0x94, 0x91, 0x92, 0x83, 0x80, 0x85, 0x86,
         0x8F, 0x8C, 0x89, 0x8A, 0xAB, 0xA8, 0xAD, 0xAE, 0xA7, 0xA4,
         0xA1, 0xA2, 0xB3, 0xB0, 0xB5, 0xB6, 0xBF, 0xBC, 0xB9, 0xBA,
         0xFB, 0xF8, 0xFD, 0xFE, 0xF7, 0xF4, 0xF1, 0xF2, 0xE3, 0xE0,
         0xE5, 0xE6, 0xEF, 0xEC, 0xE9, 0xEA, 0xCB, 0xC8, 0xCD, 0xCE,
         0xC7, 0xC4, 0xC1, 0xC2, 0xD3, 0xD0, 0xD5, 0xD6, 0xDF, 0xDC,
         0xD9, 0xDA, 0x5B, 0x58, 0x5D, 0x5E, 0x57, 0x54, 0x51, 0x52,
         0x43, 0x40, 0x45, 0x46, 0x4F, 0x4C, 0x49, 0x4A, 0x6B, 0x68,
         0x6D, 0x6E, 0x67, 0x64, 0x61, 0x62, 0x73, 0x70, 0x75, 0x76,
         0x7F, 0x7C, 0x79, 0x7A, 0x3B, 0x38, 0x3D, 0x3E, 0x37, 0x34,
         0x31, 0x32, 0x23, 0x20, 0x25, 0x26, 0x2F, 0x2C, 0x29, 0x2A,
         0x0B, 0x08, 0x0D, 0x0E, 0x07, 0x04, 0x01, 0x02, 0x13, 0x10,
         0x15, 0x16, 0x1F, 0x1C, 0x19, 0x1A]
byte2 = [0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E, 0x10, 0x12,
         0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E, 0x20, 0x22, 0x24, 0x26,
         0x28, 0x2A, 0x2C, 0x2E, 0x30, 0x32, 0x34, 0x36, 0x38, 0x3A,
         0x3C, 0x3E, 0x40, 0x42, 0x44, 0x46, 0x48, 0x4A, 0x4C, 0x4E,
         0x50, 0x52, 0x54, 0x56, 0x58, 0x5A, 0x5C, 0x5E, 0x60, 0x62,
         0x64, 0x66, 0x68, 0x6A, 0x6C, 0x6E, 0x70, 0x72, 0x74, 0x76,
         0x78, 0x7A, 0x7C, 0x7E, 0x80, 0x82, 0x84, 0x86, 0x88, 0x8A,
         0x8C, 0x8E, 0x90, 0x92, 0x94, 0x96, 0x98, 0x9A, 0x9C, 0x9E,
         0xA0, 0xA2, 0xA4, 0xA6, 0xA8, 0xAA, 0xAC, 0xAE, 0xB0, 0xB2,
         0xB4, 0xB6, 0xB8, 0xBA, 0xBC, 0xBE, 0xC0, 0xC2, 0xC4, 0xC6,
         0xC8, 0xCA, 0xCC, 0xCE, 0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA,
         0xDC, 0xDE, 0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE,
         0xF0, 0xF2, 0xF4, 0xF6, 0xF8, 0xFA, 0xFC, 0xFE, 0x1B, 0x19,
         0x1F, 0x1D, 0x13, 0x11, 0x17, 0x15, 0x0B, 0x09, 0x0F, 0x0D,
         0x03, 0x01, 0x07, 0x05, 0x3B, 0x39, 0x3F, 0x3D, 0x33, 0x31,
         0x37, 0x35, 0x2B, 0x29, 0x2F, 0x2D, 0x23, 0x21, 0x27, 0x25,
         0x5B, 0x59, 0x5F, 0x5D, 0x53, 0x51, 0x57, 0x55, 0x4B, 0x49,
         0x4F, 0x4D, 0x43, 0x41, 0x47, 0x45, 0x7B, 0x79, 0x7F, 0x7D,
         0x73, 0x71, 0x77, 0x75, 0x6B, 0x69, 0x6F, 0x6D, 0x63, 0x61,
         0x67, 0x65, 0x9B, 0x99, 0x9F, 0x9D, 0x93, 0x91, 0x97, 0x95,
         0x8B, 0x89, 0x8F, 0x8D, 0x83, 0x81, 0x87, 0x85, 0xBB, 0xB9,
         0xBF, 0xBD, 0xB3, 0xB1, 0xB7, 0xB5, 0xAB, 0xA9, 0xAF, 0xAD,
         0xA3, 0xA1, 0xA7, 0xA5, 0xDB, 0xD9, 0xDF, 0xDD, 0xD3, 0xD1,
         0xD7, 0xD5, 0xCB, 0xC9, 0xCF, 0xCD, 0xC3, 0xC1, 0xC7, 0xC5,
         0xFB, 0xF9, 0xFF, 0xFD, 0xF3, 0xF1, 0xF7, 0xF5, 0xEB, 0xE9,
         0xEF, 0xED, 0xE3, 0xE1, 0xE7, 0xE5]
for i in range(len(test)):
    test[i] ^= key1[i]

get1 = [0xE8, 0x2A, 0x34, 0xBE, 0x63, 0x3B, 0x87, 0xA3, 0xD1, 0x01,
        0xDA, 0x6B, 0x74, 0x8C, 0xA2, 0x11]
get2 = [0xE8, 0x3B, 0xDA, 0x11, 0x63, 0x01, 0xA2, 0xBE, 0xD1, 0x8C,
        0x34, 0xA3, 0x74, 0x2A, 0x87, 0x6B]
for k in range(1, 10):
    ntest = [0] * 16
    for i in range(len(test)):
        ntest[get2.index(get1[i])] = buf[test[i]]
    test = ntest
    ntest = [0] * 16
    for i in range(0, len(test), 4):
        temp = test[i:i + 4]
        ntest[i] = byte1[temp[1]] ^ byte2[temp[0]] ^ temp[3] ^ temp[2]
        ntest[i + 1] = byte1[temp[2]] ^ byte2[temp[1]] ^ temp[3] ^ temp[0]
        ntest[i + 2] = byte1[temp[3]] ^ byte2[temp[2]] ^ temp[1] ^ temp[0]
        ntest[i + 3] = byte1[temp[0]] ^ byte2[temp[3]] ^ temp[2] ^ temp[1]
    test = ntest


    for i in range(len(test)):
        test[i] ^= key1[16 * k + i]

ntest = [0] * 16
for i in range(len(test)):
    ntest[get2.index(get1[i])] = buf[test[i]]
test = ntest

for i in range(len(test)):
    test[i] ^= key1[16 * 10 + i]


'''解密'''
def sol(tar):
    temp = [BitVec('%d' % i, 8) for i in range(4)]
    x = Solver()
    byte1Arr = Array('byte1', BitVecSort(8), BitVecSort(8))
    byte2Arr = Array('byte2', BitVecSort(8), BitVecSort(8))

    # 设置 byte1 和 byte2 数组的值
    for i in range(256):
        x.add(byte1Arr[i] == BitVecVal(byte1[i], 8))  # 用你的值替换 byte1_values
        x.add(byte2Arr[i] == BitVecVal(byte2[i], 8))  # 用你的值替换 byte2_values

    # 定义目标数组

    # 计算 ntest 的每一项，使用条件表达式
    ntest = [0] * 4

    ntest[0] = Select(byte1Arr, temp[1]) ^ Select(byte2Arr, temp[0]) ^ temp[3] ^ temp[2]
    ntest[1] = Select(byte1Arr, temp[2]) ^ Select(byte2Arr, temp[1]) ^ temp[3] ^ temp[0]
    ntest[2] = Select(byte1Arr, temp[3]) ^ Select(byte2Arr, temp[2]) ^ temp[1] ^ temp[0]
    ntest[3] = Select(byte1Arr, temp[0]) ^ Select(byte2Arr, temp[3]) ^ temp[2] ^ temp[1]

    for i in range(4):
        x.add(ntest[i] == tar[i])
    ans = []
    if x.check() == sat:
        model = x.model()
        for i in range(4):
            ans.append(model[temp[i]].as_long().real)
    return ans


tests=list(bytes.fromhex('''96 14 91 D5 1A B3 31 F3 89 A5 A1 55 3D 74 4E C9 E6 05 86 7F 71 3F 44 10 E6 50 DE 1A 49 20 35 AA'''))
for _ in range(0,len(tests),16):
    test=tests[_:_+16]
    for i in range(len(test)):
        test[i] ^= key1[16 * 10 + i]
    ntest = [0] * 16
    for i in range(len(test)):
        ntest[i] = test[get2.index(get1[i])]
        ntest[i] = buf.index(ntest[i])
    test = ntest

    for k in range(9, 0, -1):
        for i in range(len(test)):
            test[i] ^= key1[16 * k + i]
        for i in range(0,16,4):
            ans=sol(test[i:i+4])
            test[i:i+4]=ans

        ntest = [0] * 16
        for i in range(len(test)):
            ntest[i] = test[get2.index(get1[i])]
            ntest[i] = buf.index(ntest[i])
        test = ntest

    for i in range(len(test)):
        test[i] ^= key1[i]

    print("".join(map(chr,test)),end="")
  • Title: uoftctf2025 WP
  • Author: clev1L
  • Created at : 2025-01-14 15:48:04
  • Updated at : 2025-02-23 12:29:57
  • Link: https://github.com/clev1l/2025/01/14/uoftctf2025-WP/
  • License: This work is licensed under CC BY-NC-SA 4.0.
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uoftctf2025 WP
  1. Highly Optimized
  2. Py_FlagChecker
  3. Encrypted Flag