南京邮电大学CTF密码学之MD5-golang与php代码实现

题目内容：这里有一段丢失的md5密文 e9032???da???08????911513?0???a2 要求你还原出他并且加上nctf{}提交 已知线索 明文为： TASC?O3RJMV?WDJKX?ZM 题目来源：安恒杯

简单的MD5密码碰撞，通过对比密文e9032 与加密后的数据 定位相关信息

解题代码如下

GO语言版

package main

import (
	"crypto/md5"
	"io"
	"encoding/hex"
	"strings"
	"fmt"
)

var Enable = []rune{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','1','2','3','4','5','6','7','8','9',' ', '!', '"', '#', '$', '%', '&', '\'', '(', ')', '*', '+', ',', '-', '.', '/', ':', ';', '<', '=', '>', '?', '@','[', '\\', ']', '^', '_', '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '|', '}', '~'}

func main() {
	var(
		rune1 rune
		rune2 rune
		rune3 rune
	)

	for i:=0; i< len(Enable);i++  {
		rune1 = Enable[i]
		for j:=0; j< len(Enable);j++  {
			rune2 = Enable[j]
			for k:=0; k< len(Enable);k++  {
				rune3 = Enable[k]
				strToDecode := "TASC"+string(rune1)+"O3RJMV"+string(rune2)+"WDJKX"+string(rune3)+"ZM"
				str := md5.New()
				io.WriteString(str, strToDecode)
				hexStr := str.Sum(nil)
				code := hex.EncodeToString(hexStr)
				result := "e9032"
				com01 := strings.Contains(code,result)
				if com01 == true {
					fmt.Println(strToDecode,code)
				}
			}
		}
	}
}

PHP版

<?php
	$list = array(
        'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','1','2','3','4','5','6','7','8','9',' ', '!', '"', '#', '$', '%', '&', '\'', '(', ')', '*', '+', ',', '-', '.', '/', ':', ';', '<', '=', '>', '?', '@','[', '\\', ']', '^', '_', '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '|', '}', '~'
	);

	for ($i=0;$i<count($list);$i++){
		$str1 = $list[$i];
        for ($j=0;$j<count($list);$j++){
            $str2 = $list[$j];
            for ($k=0;$k<count($list);$k++){
                $str3 = $list[$k];
                $str = "TASC".$str1."O3RJMV".$str2."WDJKX".$str3."ZM";
				$md5 = md5($str);
				if(strstr($md5,"e9032")){
					echo $str."---".$md5."\n";
				}
            }
        }
	}