hello everyone
im working on my masters thesis project, i need a help on how to convert md5 password into binary andthen generate a randomly number, then calculate there exclusive OR, i mean that suppose i have attechd the code in this msg. but the PROBLEM here is that it not showing the correct result, it is always showing TRUE value in \$calculate variable.

``````<?php
// function for converting md5 user password into binary
function binary_convert(\$md5_1){

for(\$i = 0; \$i < \$length_of_text_to_convert_to_binary; \$i++)
{

{
case '0':
break;

case '1':
break;

case '2':
break;

case '3':
break;

case '4':
break;

case '5':
break;

case '6':
break;

case '7':
break;

case '8':
break;

case '9':
break;

case 'a':
break;

case 'b':
break;

case 'c':
break;

case 'd':
break;

case 'e':
break;

case 'f':
break;
}
}

}

\$md5_1=md5(\$_POST['user_pass']); //encrypted md5 user password,which is coming from user form
\$random_num = rand(0,100); //randomly generated number between 0-100
\$converted_md5_binary = binary_convert(\$md5_1); //calling function here, to convert MD5 user password into binary
\$converted_random_num =decbin(\$random_num); //converted random number into binary
\$calculate=\$converted_random_num^\$converted_md5_binary ;

?>
``````

## All 11 Replies

You may be bound by the maximum value for an integer on your system for the xor (I think!).

then how can i solve that ??

Maybe:

``````\$xor1 = gmp_init(md5('test'), 16);
\$xor2 = gmp_init(decbin(rand(0, 100)), 2);
\$xor3 = gmp_xor(\$xor1, \$xor2);

echo gmp_strval(\$xor3);
``````

?

gmp may need to be installed.

IMHO, the hashed user_pass is not necessarily be the subject of un-needed iteration.

if

``````\$md5_1=md5(\$_POST['user_pass']);
``````

is equal to 'password', then the hashed password is now equal to

``````\$md5_1 = '5f4dcc3b5aa765d61d8327deb882cf99';
``````

and this

``````print_r(str_split(\$md5_1));
``````

will deliver \$md5_1 as an array.

``````Array ( [0] => 5 [1] => f [2] => 4 [3] => d [4] => c [5] => c [6] => 3 [7] => b [8] => 5 [9] => a [10] => a [11] => 7 [12] => 6 [13] => 5 [14] => d [15] => 6 [16] => 1 [17] => d [18] => 8 [19] => 3 [20] => 2 [21] => 7 [22] => d [23] => e [24] => b [25] => 8 [26] => 8 [27] => 2 [28] => c [29] => f [30] => 9 [31] => 9 )
``````

just apply minor manipulation to convert those items into whatever format you want and you should be done.

Hint: Look for the array functions here. That should help you in the conversion to binary and I am sure it is a lot faster than what you have using switch statement.

This is what I meant by without iteration on conversion. I used foreach loop to prove successful conversion..

``````<?php

\$pass = '5f4dcc3b5aa765d61d8327deb882cf99';

print_r(str_split(\$pass));

\$replacements = array(

'0'=> "0000", '1' => "0001", '2' => "0010", '3' => "0011", '4' => "0100", '5' => "0101", '6'=> "0110", '7' => "0111",
'8'=> "1000",'9' => "1001", 'a' => "1010", 'b' => "1011", 'c' => "1100", 'd' => "1101", 'e' => "1110", 'f' => "1111" );

\$x = (str_replace(array_keys(\$replacements), \$replacements, \$pass));

echo '<br/> this is the converted md5 password : '. \$x .'<br/>';

/*
* we can further split the converted md5 password as proof
*/
echo 'below are the split converted md5 as proof <br/>';

\$x_array = (str_split(\$x,4));

foreach(\$x_array as \$value){

echo \$value.'<br/>';

}
``````

the rest is all up to you. Good luck on your Master thesis.

You can use

``````base_convert(\$hex,16,2)
``````

So maybe avoid using "checking" arrays

how to insall gmp, im using xampp

Fatal error: Call to undefined function gmp_init() in C:\xampp\htdocs\test\test.1.php on line 14
its giving this error

sir,veedeoo
thanku, but my problme is still there,can u please give me any simple expamle of that, to get XOR of md5 and randmly numbr

Check if in your system there is the php_gmp.dll file, then edit php.ini and append:

``````extension=php_gmp.dll
``````

Otherwise, if you cannot find the dll file, you can use Math_BigInteger, you can install it by using pear or composer:

``````pear install Math_BigInteger
composer require pear/math_biginteger
``````

In both cases you need to install the pear client or the composer client:

There's also BC Math which sometimes is shipped with the PHP core installation, but it depends a lot on the PHP version in use, I'm not sure about Windows situation. All these libraries treats the numbers as strings, which gives you the ability to not be limited by the CPU architecture. Math_BigInteger, when available, will use GMP or BC_Math to speed up the execution.

Example:

``````<?php

\$a = new Math_BigInteger(rand(0,100), 10);
\$b = new Math_BigInteger(md5('test'), 16);

echo \$a->bitwise_xor(\$b);
``````

By the way, I'm not sure this example is what you need, I'm just replicating my first example ^_^'

edit

I was forgetting, Math_BigInteger is also available on GitHub:

Just donwload library and include it in your script. This does not require for you to install pear or composer... bye!

commented: great post! +15
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