Amazon Product API with PHP

Question

Hi All,

I'm trying to integrate Amazon Product API into my website and came across several posts that helped me construct the URL. Only problem is when I execute the code below I get the following error. Am I doing something wrong?

Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error. More information about this error may be available in the server error log.

$AWS_ACCESS_KEY_ID = "[myaccesskeyhere]";
$AWS_SECRET_ACCESS_KEY = "[mysecretkeyhere]";

$base_url = "http://ecs.amazonaws.com/onca/xml?";
$url_params = array('Operation'=>"ItemSearch",'Service'=>"AWSECommerceService",
 'AWSAccessKeyId'=>$AWS_ACCESS_KEY_ID,'AssociateTag'=>"yourtag-10",
 'Version'=>"2006-09-11",'Availability'=>"Available",'Condition'=>"All",
 'ItemPage'=>"1",'ResponseGroup'=>"Images,ItemAttributes,EditorialReview",
 'Keywords'=>"Amazon");

// Add the Timestamp
$url_params['Timestamp'] = gmdate("Y-m-d\TH:i:s.\\0\\0\\0\\Z", time());

// Sort the URL parameters
$url_parts = array();
foreach(array_keys($url_params) as $key)
    $url_parts[] = $key."=".$url_params[$key];
sort($url_parts);

// Construct the string to sign
$string_to_sign = "GET\necs.amazonaws.com\n/onca/xml\n".implode("&",$url_parts);
$string_to_sign = str_replace('+','%20',$string_to_sign);
$string_to_sign = str_replace(':','%3A',$string_to_sign);
$string_to_sign = str_replace(';',urlencode(';'),$string_to_sign);

// Sign the request
$signature = hash_hmac("sha256",$string_to_sign,$AWS_SECRET_ACCESS_KEY,TRUE);

// Base64 encode the signature and make it URL safe
$signature = base64_encode($signature);
$signature = str_replace('+','%2B',$signature);
$signature = str_replace('=','%3D',$signature);

$url_string = implode("&",$url_parts);
$url = $base_url.$url_string."&Signature=".$signature;
print $url;

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 15);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);

$xml_response = curl_exec($ch);
echo $xml_response;

EDIT

THE ABOVE CODE NOW WORKS...I WAS MISSING A "?" after the BASE URL

Answer 1

$AWS_ACCESS_KEY_ID = "[myaccesskeyhere]";
$AWS_SECRET_ACCESS_KEY = "[mysecretkeyhere]";

$base_url = "http://ecs.amazonaws.com/onca/xml?";
$url_params = array('Operation'=>"ItemSearch",'Service'=>"AWSECommerceService",
 'AWSAccessKeyId'=>$AWS_ACCESS_KEY_ID,'AssociateTag'=>"yourtag-10",
 'Version'=>"2006-09-11",'Availability'=>"Available",'Condition'=>"All",
 'ItemPage'=>"1",'ResponseGroup'=>"Images,ItemAttributes,EditorialReview",
 'Keywords'=>"Amazon");

// Add the Timestamp
$url_params['Timestamp'] = gmdate("Y-m-d\TH:i:s.\\0\\0\\0\\Z", time());

// Sort the URL parameters
$url_parts = array();
foreach(array_keys($url_params) as $key)
    $url_parts[] = $key."=".$url_params[$key];
sort($url_parts);

// Construct the string to sign
$string_to_sign = "GET\necs.amazonaws.com\n/onca/xml\n".implode("&",$url_parts);
$string_to_sign = str_replace('+','%20',$string_to_sign);
$string_to_sign = str_replace(':','%3A',$string_to_sign);
$string_to_sign = str_replace(';',urlencode(';'),$string_to_sign);

// Sign the request
$signature = hash_hmac("sha256",$string_to_sign,$AWS_SECRET_ACCESS_KEY,TRUE);

// Base64 encode the signature and make it URL safe
$signature = base64_encode($signature);
$signature = str_replace('+','%2B',$signature);
$signature = str_replace('=','%3D',$signature);

$url_string = implode("&",$url_parts);
$url = $base_url.$url_string."&Signature=".$signature;
print $url;

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 15);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);

$xml_response = curl_exec($ch);
echo $xml_response;

For anyone that was wondering. You can then navigate the xml_response using simplexml!

Hope this helps someone out there :)