"AWSECommerceService", "Operation" => "ItemSearch", "AWSAccessKeyId" => "your-access-key", "AssociateTag" => "your-associate-tag", "SearchIndex" => "Electronics", "Keywords" => "best mobile phones", "Sort" => "salesrank", "ResponseGroup" => "Images,ItemAttributes,Offers", "ItemPage" => 1 ); // Set current timestamp if not set if (!isset($params["Timestamp"])) { $params["Timestamp"] = gmdate('Y-m-d\TH:i:s\Z'); } // Sort the parameters by key ksort($params); $pairs = array(); foreach ($params as $key => $value) { array_push($pairs, rawurlencode($key)."=".rawurlencode($value)); } // Generate the canonical query $canonical_query_string = join("&", $pairs); // Generate the string to be signed $string_to_sign = "GET\n".$host."\n".$uri."\n".$canonical_query_string; // Generate the signature required by the Product Advertising API $signature = base64_encode(hash_hmac("sha256", $string_to_sign, $secret_key, true)); // Generate the signed URL $request_url = 'http://'.$host.$uri.'?'.$canonical_query_string.'&Signature='.rawurlencode($signature); $response = file_get_contents($request_url); $parsed_xml = simplexml_load_string($response); echo ""; ?>