Get Amazon Product Data using PHP + Amazon API

<?php
get_amazon_products('ASIN_ID');
get_amazon_products('ASIN_ID,ASIN_ID'); // Up to 10 asins
function get_amazon_products($asin){ 
    
    // Your AWS Access Key ID, as taken from the AWS Your Account page
    $aws_access_key_id = 'your-access-key-id';
    
    // Your AWS Secret Key corresponding to the above ID, as taken from the AWS Your Account page
    $aws_secret_key = 'your-secret-key';
    
    $aws_secret_code = 'your-secret-code';
    
    
    // The region you are interested in
    $endpoint = "webservices.amazon.com";
    
    $uri = "/onca/xml";
    
    $params = array(
        "Service" => "AWSECommerceService",
        "Operation" => "ItemLookup",
        "AWSAccessKeyId" => '' . $aws_access_key_id,
        "AssociateTag" => $aws_secret_code,
        "ItemId" => $asin,
        "IdType" => "ASIN",
        "ResponseGroup" => "ItemAttributes,Offers,OfferSummary,OfferFull,Images"
    );
    
    // 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
    $string_to_sign = "GET\n".$endpoint."\n".$uri."\n".$canonical_query_string;
    
    // Generate the signature required by the Product Advertising API
    $signature = base64_encode(hash_hmac("sha256", $string_to_sign, $aws_secret_key, true));
    
    // Generate the signed URL
    $request_url = 'http://'.$endpoint.$uri.'?'.$canonical_query_string.'&Signature='.rawurlencode($signature);
    
    $data =  file_get_contents($request_url);
    return $data;
}
?>