base64_decode

add a note User Contributed Notes

gabor dot barta at freemail dot hu
08-Jan-2005 10:09


Hi,



I just would like to add a comment, i was strugging with it for some time. So i opened a POP3 mailbox fopen, and listed the emails with attachments. I copied the base64 encoded text to a file and saved it. Then i tried to decode this file to a jpeg picture, and it just didnt work... Then i realized that there were some spaces in the text file....



Hope it will help anyone.



Bobi

paul at ijsfontein dot nl
10-Jun-2004 09:04


The user notes posted here helped me a lot in writing the PHP code to upload uuencoded files to a server using $_POST. Hardest thing to figure out was why the files came out scrambled and corrupted. After comparing the original file with the file reconstructed by the uudecode script, I found out that a simple "stripcslashes" on the posted data will do the trick.



So, to upload any kind of uuencoded file using a POST:

1. send the raw file data to the PHP script

2. $uuencoded_data = stripcslashes($_POST['filedata']);

3. strip the marker lines from $uuencoded_data (first line, last line and second last line of the data. Each line is seperated by a LF (chr(10)) character.)

4. $decoded_data = uudecode($stripped_uuencoded_data); (this function can be found in the user notes here).

5. Use the script provided in one of the user notes on this page to write the decoded data to a binary file.



That should do the trick!

tobias at silverxnet dot de
24-Dec-2003 04:16


I was wondering how to decode attached images within mails. Basically they are mostly JPEG files, so it was obviously to write a function that decodes JPEG images.


I guess the plainest way to do so was the following:





<?php


function base64_to_jpeg( $inputfile, $outputfile ) {


  /* read data (binary) */


  $ifp = fopen( $inputfile, "rb" );


  $imageData = fread( $ifp, filesize( $inputfile ) );


  fclose( $ifp );


  /* encode & write data (binary) */


  $ifp = fopen( $outputfile, "wb" );


  fwrite( $ifp, base64_decode( $imageData ) );


  fclose( $ifp );


  /* return output filename */


  return( $outputfile );


}


?>





This function decodes the given inputfile (a filename!) and saves it to the given outputfile (a filename as well) and then returns the output filename for further usage (e.g. redirect, imagejpeg() and so on).


I thought that might be helpful.

dharwood at synopsistechnologies dot com
06-Dec-2003 03:34


Encode/DEcode PAGE.



Here is a page that will accept plain text password and return an encoded password.  It will also do the opposite.  It will allow you to enter an encoded password and generate the plain text password... (just in case you forgot your password.)



<?php 



if (isset($_POST['text_pass'])){

    $but=$_POST['button'];

    process_form();

}else{

    print_form();

}



function process_form(){



  switch ($_POST['button']){

    case "Get Encoded": 



        $text_pass = $_REQUEST['text_pass'];

        echo "<html>\n";

        echo "<head>\n";

        echo "<title>Password Encoding</title>\n";

        echo "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=iso-8859-1\">\n";

        echo "</head>\n";

        echo "<body>\n";

        echo "<table border=\"0\" cellspacing=\"0\" cellpadding=\"4\" width=\"100%\">\n";

        echo "<div align=\"center\">\n";

        echo "<h3 align=center>Password Encoding Page</h3>\n";

        echo "<table align=\"center\" border=\"0\">\n";

        echo "<tr>\n";

        echo "<td ><b>You Entered:  </b></td>\n";

        echo "<td>$text_pass</td>\n";

        echo "</tr>\n";

        $test = base64_encode(serialize($text_pass));

        echo "<tr>\n";

        echo "<td ><b>Your encoded password (base 64) is:  </b></td>\n";

        echo "<td>$test</td>\n";

        echo "</tr>\n";

        $untest = unserialize(base64_decode($test));

        echo "<tr>\n";

        echo "<td ><b>To double test, your UNencoded password (base 64) is:  </b></td>\n";

        echo "<td>$untest</td>\n";

        echo "</tr>\n";

        echo "</table>\n";

        break;

    case "Get UNEncoded":

        $text_pass = $_REQUEST['text_pass'];

        echo "<html>\n";

        echo "<head>\n";

        echo "<title>Password Encoding</title>\n";

        echo "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=iso-8859-1\">\n";

        echo "</head>\n";

        echo "<body>\n";

        echo "<table border=\"0\" cellspacing=\"0\" cellpadding=\"4\" width=\"100%\">\n";

        echo "<div align=\"center\">\n";

        echo "<h3 align=center>Password Encoding Page</h3>\n";

    

        echo "<table align=\"center\" border=\"0\">\n";

        echo "<tr>\n";

        echo "<td ><b>You Entered:  </b></td>\n";

        echo "<td>$text_pass</td>\n";

        echo "</tr>\n";

        $untest = unserialize(base64_decode($text_pass));

        echo "<tr>\n";

        echo "<td ><b>Your UNencoded password (base 64) is:  </b></td>\n";

        echo "<td>$untest</td>\n";

        echo "</tr>\n";

        echo "</table>\n";

    

    default:

    

        break;

  }

}



function print_form(){

    echo "<html>\n";

    echo "<head>\n";

    echo "<title>Password Encoding</title>\n";

    echo "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=iso-8859-1\">\n";

    echo "</head>\n";

    echo "<body>\n";

    echo "<table border=\"0\" cellspacing=\"0\" width=\"100%\">\n";

    echo "<div align=\"center\">\n";

    echo "<h3 align=center>Password Encoding Page</h3>\n";

    echo "<tr>\n";

    echo "<form action=\"$_SERVER[PHP_SELF]\" method=\"post\">\n";

    echo "<table align=\"center\" border=\"0\">\n";

    echo "<tr>\n";

    echo "<td align=\"right\"><b>Password to Encode/Decode:</b></td>\n";

    echo "<td align=\"right\">";

    echo "  <input type=\"text\" name=\"text_pass\" size=\"30\" >\n";

    echo "</td>\n";

    echo "</tr>\n";

    echo "</tr>\n";

    echo "<tr>\n";

    echo "<tr>\n";

    echo "&nbsp;\n";

    echo "</tr>\n";

    echo "<td >";

    echo "<input type=\"submit\" name=\"button\" value=\"Get Encoded\"><br>\n";

    echo "</td>";

    echo "<td >";

    echo "<input type=\"submit\" name=\"button\" value=\"Get UNEncoded\"><br>\n";

    echo "</td>";

    echo "</tr>\n";

    echo "</table>\n";

    echo "</form>\n";

    echo "<tr>\n";

    echo "</table>\n";

    echo "</body>\n";

    echo "</html>\n";

}

?>

dhirendrak at yahoo dot com
07-Aug-2003 04:19


Heading : Your customizable encode 


and decode function.





A customizable encoded and decode


Function which can encode and decode


the data. You need to pass variable to 


the encode function to encrypt and 


whenever you want you can get the 


data by using decode function.





Cracking / hacking of encoded value


is impossible, until user know the 


actual coding. 





<?php


function encoded($ses) 


{    


  $sesencoded = $ses;


  $num = mt_rand(3,9);


  for($i=1;$i<=$num;$i++) 


  {


     $sesencoded = 


     base64_encode($sesencoded);


  }


  $alpha_array = 


  array('Y','D','U','R','P',


  'S','B','M','A','T','H');


  $sesencoded = 


  $sesencoded."+".$alpha_array[$num];


  $sesencoded =


  base64_encode($sesencoded);


  return $sesencoded;


}//end of encoded function





function decoded($str)


{


   $alpha_array = 


   array('Y','D','U','R','P', 


   'S','B','M','A','T','H');


   $decoded = 


    base64_decode($str);


   list($decoded,$letter) = 


   split("\+",$decoded);


   for($i=0;$i<count($alpha_array);$i++)


   {


   if($alpha_array[$i] == $letter)


   break;


   }


   for($j=1;$j<=$i;$j++) 


   {


      $decoded = 


       base64_decode($decoded);


   }


   return $decoded;


}//end of decoded function


?>





http://members.lycos.co.uk/dhirendrak

Klaus Fehrenbacher
17-Apr-2003 07:05


this script can correct the bug





<?php


$enc = chunk_split(preg_replace('!\015\012|\015|\012!','',$enc));


$enc = base64_decode($enc);


?>

nsayer at kfu dot com
22-Mar-2002 05:15


I used to do uudecode as a C module, but I've discovered a really fast way to do it in PHP. Here it is:





<?php


function uudecode($encode) {


  $b64chars="ABCDEFGHIJKLMNOPQRSTUVWXYZ\


abcdefghijklmnopqrstuvwxyz0123456789+/";





  $encode = preg_replace("/^./m","",$encode);


  $encode = preg_replace("/\n/m","",$encode);


  for($i=0; $i<strlen($encode); $i++) {


    if ($encode[$i] == '`')


      $encode[$i] = ' ';


    $encode[$i] = $b64chars[ord($encode[$i])-32];


  }





  while(strlen($encode) % 4)


    $encode .= "=";





  return base64_decode($encode);


}


?>





This is the PHP equivalent to perl's unpack("u",___). That is, you need to strip the 'begin' and 'end' lines from the typical uuencoded file.

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base64_decode

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