1: <?php
 2: namespace Sotr\Crypto;
 3: 
 4: use Psr\Http\Message\RequestInterface;
 5: 
 6: interface RequestSignerInterface
 7: {
 8:     /**
 9:      * Returns a signed copy of the
10:      * provided request using the given
11:      * API key, secret and, optionally, the
12:      * customer's ID.
13:      *
14:      * Exchanges which don't require the
15:      * customer's ID for signing might pass
16:      * null as this parameter.
17:      *
18:      * @param   Psr\Http\Message\RequestInterface   $request
19:      * @param   string                              $key
20:      * @param   string                              $secret
21:      * @param   string                              $secret
22:      * @param   int                                 $customerId
23:      * @return  Psr\Http\Message\RequestInterface
24:      */
25:     public function sign(RequestInterface $request, $key, $secret, $customerId = null);
26: }
27: