php - 亚马逊MWS Scratchpad API

我试图让amazon mws scratchpad工作，但它一直给我一个信息：
我们计算的请求签名与您提供的签名不匹配。检查您的aws秘密访问密钥和签名方法。有关详细信息，请参阅服务文档。
我在这里寻找类似的话题，但没有什么真正有用的。所以，这里是代码：

$params = array(
    'AWSAccessKeyId'   => AWS_ACCESS_KEY_ID,
    'Action'           => "GetLowestOfferListingsForASIN",
    'SellerId'         => MERCHANT_ID,
    'SignatureMethod'  => "HmacSHA256",
    'SignatureVersion' => "2",
    'Timestamp'        => gmdate("Y-m-d\TH:i:s\Z", time()),
    'Version'          => "2011-10-01",
    'MarketplaceId'    => MARKETPLACE_ID,
    'ItemCondition'    => "new",
    'ASINList.ASIN.1'  => "B001T6OP32");

$url = array();

foreach($params as $key => $val){
    $val   = str_replace('%7E', '~', rawurlencode($val));
    $url[] = $key . '=' . $val;
}

$uri = implode('&', $url);

$string_to_sign  = 'POST';
$string_to_sign .= "\n";
$string_to_sign .= 'mws.amazonservices.co.uk' . "\n";
$string_to_sign .= '/Products/2011-10-01' . "\n";
$string_to_sign .= $uri;

$signature = hash_hmac("sha256", $string_to_sign, AWS_SECRET_ACCESS_KEY, TRUE);
$signature = base64_encode($signature);
$signature = urlencode($signature);
$signature = str_replace("%7E", "~", $signature);

$url  = 'https://mws.amazonservices.co.uk/';
$url .= 'Products/2011-10-01' . '?' . $uri . "&Signature=" . $signature;

我敢打赌，问题在于签名，当我用print $signature打印时，它总是包含%符号，当我与Amazon Scratchpad请求详细信息页比较时，SHA 256 HMAC字段-没有。
我有什么东西看不见吗？我正在检查秘密访问密钥中的空格，看起来不错。
多谢。

最佳答案

工作版本：

$param = array();
$param['AWSAccessKeyId']   = AWS_ACCESS_KEY_ID;
$param['Action']           = 'GetLowestOfferListingsForASIN';
$param['SellerId']         = MERCHANT_ID;
$param['SignatureMethod']  = 'HmacSHA256';
$param['SignatureVersion'] = '2';
$param['Timestamp']        = gmdate("Y-m-d\TH:i:s.\\0\\0\\0\\Z", time());
$param['Version']          = '2011-10-01';
$param['MarketplaceId']    = MARKETPLACE_ID;
$param['ItemCondition']    = 'new';
$param['ASINList.ASIN.1']  = << ITEM ASIN >>;

$url = array();
foreach ($param as $key => $val) {

    $key = str_replace("%7E", "~", rawurlencode($key));
    $val = str_replace("%7E", "~", rawurlencode($val));

    $url[] = "{$key}={$val}";
}

sort($url);

$arr   = implode('&', $url);

$sign  = 'GET' . "\n";
$sign .= 'mws.amazonservices.co.uk' . "\n";
$sign .= '/Products/2011-10-01' . "\n";
$sign .= $arr;

$signature = hash_hmac("sha256", $sign, AWS_SECRET_ACCESS_KEY, true);
$signature = urlencode(base64_encode($signature));

$link  = "https://mws.amazonservices.co.uk/Products/2011-10-01?";
$link .= $arr . "&Signature=" . $signature;

用curl和vualia加载$link！