MD5 validator plugin

Entity bodies can sometimes be modified over the wire due to a faulty TCP transport or misbehaving proxy. If an HTTP response contains a Content-MD5 header, then a MD5 hash of the entity body of a response can be compared against the Content-MD5 header of the response to determine if the response was delivered intact. The Guzzle\Plugin\Md5\Md5ValidatorPlugin will throw an UnexpectedValueException if the calculated MD5 hash does not match the Content-MD5 header value:

use Guzzle\Http\Client;
use Guzzle\Plugin\Md5\Md5ValidatorPlugin;

$client = new Client('');

$md5Plugin = new Md5ValidatorPlugin();

// Add the md5 plugin to the client object

$request = $client->get('');

Calculating the MD5 hash of a large entity body or an entity body that was transferred using a Content-Encoding is an expensive operation. When working in high performance applications, you might consider skipping the MD5 hash validation for entity bodies bigger than a certain size or Content-Encoded entity bodies (see Guzzle\Plugin\Md5\Md5ValidatorPlugin for more information).