In PHP md5 () function bypassing

Simple methods to bypass PHP md5 () function, as the study notes that the article simply record it.

example

Link example: http://ctf5.shiyanbar.com/web/houtai/ffifdyop.php

The main code segment:

1     $password=$_POST['password'];
2     $sql = "SELECT * FROM admin WHERE username = 'admin' and password = '".md5($password,true)."'";
3     $result=mysqli_query($link,$sql);
4         if(mysqli_num_rows($result)>0){
5             echo 'flag is :'.$flag;
6         }
7         else{
8             echo '密码错误!';
9         }

PHP md5 () function

Quote from https://www.w3school.com.cn/php/func_string_md5.asp

MD5 () function MD5 hash calculated string.

md5 () function uses the RSA Data Security, including the MD5 message digest algorithm.

From RFC 1321 explains - MD5 message digest algorithm: MD5 message digest algorithm arbitrary length information as an input value, and converted it into a 128-bit "fingerprint" or "message digest" value to represent the input value, and is converted value as a result. MD5 algorithm primarily for digital signature applications designed; digital signature in this application, large files will be encrypted (by encryption process here is in a cryptographic system: a public key [such as the RSA] in set the private key and completed) in a secure manner before compression.

To calculate the MD5 hash of the file, use the md5_file () function.

Syntax: md5 (string, raw)

String : encrypted string required

RAW : optional parameter TRUE or FALSE. FALSE (the default, 32-character hexadecimal number); TRUE (binary format of the original character 16 )

Workaround

Using MD5 () function of the encrypted string reaches sql injection, destruction sql statement structure.

Common string: ffifdyop

In the above examples, the Enter ffifdyop, sql statement structure becomes:

SELECT * FROM admin WHERE pass = ''or'6<trash>'

So as to achieve the effect of bypassing MD5 () function

Thus the simple end of the study notes.

In PHP md5 () function bypassing

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