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

  $modes = mcrypt_list_modes ();

	foreach(mcrypt_list_algorithms() as $cipher)
	{
    $cipher_name = mcrypt_get_cipher_name($cipher);

  	echo "<b>$cipher_name ($cipher)</b>";

  	echo " (self test: ";
  	echo (mcrypt_module_self_test($cipher)) ? 'OK' : 'Error';
  	echo ")<hr>\n";

    if ($cipher_name)
    {
 			$mode_list = mcrypt_list_modes();

 			while(list(,$mode) = each($mode_list))
 			{
  			$iv_size = @mcrypt_get_iv_size ($cipher, $mode);
  			$iv = @mcrypt_create_iv ($iv_size,MCRYPT_RAND);

				$td = @mcrypt_module_open ($cipher, "", $mode, "");

				echo "mcrypt_module_open ($cipher, \"\", $mode, \"\") - ";
			  if (!$td){
			    echo "failed";
			  }else{
  		    echo "ok";
          if (@mcrypt_generic_init($td, $key, $iv) != -1)
      	  {
            $c_t = mcrypt_generic ($td, $input);
            @mcrypt_generic_init ($td, $key, $iv);
            $p_t = mdecrypt_generic ($td, $c_t);
        	}

	        echo "(mdecrypt|mcrypt)_generic)$mode): ";
  	      if (strncmp ($p_t, $input, strlen($input)) == 0)
            echo "ok";
    	    else
            echo "error";

					echo "\n";
				}
        echo "\n\n";
      }
		}
	}
?>


(gdb) run -f new.php
Starting program: /export/work/php-4.1.1/./php -f new.php
<pre>
<b>Twofish (twofish)</b> (self test: OK)<hr>
mcrypt_module_open (twofish, "", ofb, "") - ok
Program received signal SIGSEGV, Segmentation fault.
0x40017c34 in ofb_LTX__mcrypt (buf=0x0, plaintext=0x83ce5ec, len=45, blocksize=16, akey=0x0, 
    func=0x425eea30 <twofish_LTX__mcrypt_encrypt>, func2=0x425ef59c <twofish_LTX__mcrypt_decrypt>) at ofb.c:114
114                     memmove(buf->enc_s_register, buf->s_register, blocksize);
(gdb) bt
#0  0x40017c34 in ofb_LTX__mcrypt (buf=0x0, plaintext=0x83ce5ec, len=45, blocksize=16, akey=0x0, 
    func=0x425eea30 <twofish_LTX__mcrypt_encrypt>, func2=0x425ef59c <twofish_LTX__mcrypt_decrypt>) at ofb.c:114
#1  0x4023d47d in mcrypt_enc_get_algorithms_name () at mcrypt_modules.c:367
#2  0x4023c741 in mcrypt_generic (td=0x83cc2c0, plaintext=0x83ce5ec, len=45) at mcrypt.c:165
#3  0x0814c185 in zif_mcrypt_generic (ht=2, return_value=0x83cc264, this_ptr=0x0, return_value_used=1) at mcrypt.c:566
#4  0x081aae6a in execute (op_array=0x83c1e8c) at ./zend_execute.c:1590
#5  0x080e5239 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at zend.c:814
#6  0x080801c1 in php_execute_script (primary_file=0xbffff7f0) at main.c:1307
#7  0x0807a8cc in main (argc=3, argv=0xbffff864) at cgi_main.c:738
#8  0x404f19cb in __libc_start_main (main=0x8079f34 <main>, argc=3, argv=0xbffff864, init=0x8076e1c <_init>, 
    fini=0x82310d0 <_fini>, rtld_fini=0x4000aea0 <_dl_fini>, stack_end=0xbffff85c) at ../sysdeps/generic/libc-start.c:92