title: mcrypt_decrypt PHP proper usage
body: <p>I think my PHP intall might have problems. When I try to do this I get</p>
  <blockquote>
  <p>Warning: mcrypt_decrypt() [function.mcrypt-decrypt]: Module initialization failed</p>
  </blockquote>
  <p>I am writing a small snippet of code that will decrypt the following string encrypted with AES-128 using mode ECB.</p>
  <blockquote>
  <p>Key (encoded in base64): aXJhbmRvbXNlY3VyZWtleQ==</p>
  <p>Encrypted string&gt; (encoded in base64): 3l6xiNdgRG+PkBw5M0lawvJ/fmuTZPRhEcbtqAmOpDI=</p>
  </blockquote>
  <p>I keep getting module errors.</p>
  <p>This is what I have tried:</p>
  <pre><code>&lt;?PHP
  $retval = mcrypt_decrypt( &quot;AES-128&quot;,
      base64_decode( &quot;aXJhbmRvbXNlY3VyZWtleQ==&quot;), 
      base64_decode( &quot;3l6xiNdgRG+PkBw5M0lawvJ/fmuTZPRhEcbtqAmOpDI&quot;) ,
      &quot;ECB&quot;);
  
  echo $retval;
  ?&gt; 
  </code></pre>
  <p>here is my relevant phpinfo.   I dont see AES-128  . Maybe thats the problem.</p>
  <pre><code>    mcrypt
      mcrypt support  enabled
      Version     2.5.8
      Api No  20021217
      Supported ciphers   cast-128 gost rijndael-128 twofish arcfour      cast-256           loki97      rijndael-192 saferplus wake blowfish-compat des rijndael-256 serpent xtea blowfish enigma rc2 tripledes
      Supported modes     cbc cfb ctr ecb ncfb nofb ofb stream 
  </code></pre>