[PHP] mcrypt

[Purushotham Komaravolu]

        Hello, 
          I am getting some odd errors trying to get an encrypt/decrypt process to 
      work. Looking at the manual examples and some other literature, I have tried 
      the two approaches listed below. For each, I get a sometimes-works, 
      sometimes fails result. The manual entry has a string of user notes with 
      problem like mine, but I still have problems. 



      Server API Apache 



      mcrypt 
            mcrypt support enabled 
            version 2.4.x 
            Supported ciphers twofish rijndael-128 rijndael-192 rijndael-256 
      saferplus rc2 xtea serpent safer-sk64 safer-sk128 cast-256 loki97 gost 
      threeway cast-128 des tripledes enigma arcfour panama wake 
            Supported modes ofb cfb nofb cbc ecb stream 


      --] 



      The first attempt used the following code: 


      --> 
      <?php 
          $key = "this is a secret key"; 
          $input = "Let us meet at 9 o'clock at the secret place."; 


          $td = mcrypt_module_open ('tripledes', '', 'ecb', ''); 
          $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size ($td), MCRYPT_RAND); 
          mcrypt_generic_init ($td, $key, $iv); 
          $encrypted_data = mcrypt_generic ($td, $input); 
          $decrypted_data = mdecrypt_generic ($td, $encrypted_data); 
          mcrypt_generic_end ($td); 


        echo "key: 
      $key<br>input:$input<br>encrypted:$encrypted_data<br>decrypted:$decrypted_da 
      ta"; 
      ?> 
      --] 


      This resulted, at first, in "key: this is a secret key 
      input:Let us meet at 9 o'clock at the secret place. 
      encrypted:\ºþêTÏ'áz(v¹FýaõFËU³æç SäÇÚÖzßù5Qì<±_T-:Í 
      decrypted:Let us meet at 9 o'clock at the secret place." 


      BUT after I refreshed/reloaded a couple of times, I got this: "Warning: 
      mcrypt_generic_init: Memory allocation error in 
      /home/pndrdrm001/www/administrator/crypt.php on line 64 


      Warning: 1 is not a valid MCrypt resource in 
      /home/pndrdrm001/www/administrator/crypt.php on line 65 


      Warning: 1 is not a valid MCrypt resource in 
      /home/pndrdrm001/www/administrator/crypt.php on line 66 


      Warning: 1 is not a valid MCrypt resource in 
      /home/pndrdrm001/www/administrator/crypt.php on line 67 
      key: this is a secret key 
      input:Let us meet at 9 o'clock at the secret place. 
      encrypted: 
      decrypted: " 


      There were no changes to the code. 



      The second try used the following: 


      In file 1, the functions: 
      --> 
      <?php 


       function my_encrypt($sString) 
       { 
        GLOBAL $sCryptoKey; 


        $iIV = mcrypt_create_iv (mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, 
      MCRYPT_MODE_ECB), MCRYPT_RAND); 


        $sEncrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $sCryptoKey, $sString, 
      MCRYPT_MODE_ECB, $iIV); 


        return($sEncrypted); 
       } // End function my_encrypt 


       function my_decrypt($sString) 
       { 
        GLOBAL $sCryptoKey; 


        $iIV = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, 
      MCRYPT_MODE_ECB), MCRYPT_RAND); 


        $sDecrypted = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $sCryptoKey, $sString, 
      MCRYPT_MODE_ECB, $iIV); 


        return(trim($sDecrypted)); 


       } // End function my_decrypt 
      ?> 
      --] 
      and in file 2, the main page: 
      --> 
      <?php 
        include "cryption.php"; 
        $sCryptoKey = "key"; 
        $input = "test"; 
        $encrypted = my_encrypt($input); 
        $decrypted = my_decrypt($encrypted); 


        echo "key: 
      $sCryptoKey<br>input:$input<br>encrypted:$encrypted<br>decrypted:$decrypted" 
      ; 



      ?> 
      --] 


      This resulted in "key: key 
      input:test 
      encrypted: &foUÝø§ª~RM¡°Kz à¼O¼¿rw"x@nÉ 
      decrypted:test " the first time, but then I got "Fatal error: generic_init 
      failed in /home/pndrdrm001/www/administrator/cryption.php on line 9" on the 
      second refresh. 



      Is there a missing call to free resources, or something? What can be done? 


      Thanks! 
      Regards,

      Puru