Amazon MWS：将有效的PHP解决方案转换为c＃时提供的计算签名不匹配

如何解决Amazon MWS：将有效的PHP解决方案转换为c＃时提供的计算签名不匹配

我共同编写了一个可行的解决方案，用于使用PHP从Internet上通过示例将账单上载到Amazon，并上载发票（我检查了，效果很好）。在尝试用C＃代码重写它时，我总是得到以下答案：

<?xml version="1.0"?>
<ErrorResponse xmlns="http://mws.amazonaws.com/doc/2009-01-01/">
    <Error>
        <Type>Sender</Type>
        <Code>SignatureDoesNotMatch</Code>
        <Message>The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details.</Message>
    </Error>
    <RequestID>bc0409f1-881a-468e-9435-4c5b0a7c78b4</RequestID>
</ErrorResponse>

PHP代码如下：

<?php
    $fileName                        = "Invoice12345656.pdf";
    $file                            = fopen($fileName,"r");
    $pdf_feed                        = '@'. fread($file,filesize($fileName));
    $hash                            = base64_encode(md5($pdf_feed,true));
    $param                           = array();
    $param['AWSAccessKeyId']         = '*******************'; 
    $param['Action']                 = 'SubmitFeed';
    $param['SellerId']               = '********************';
    $param['FeedType']               = '_UPLOAD_VAT_INVOICE_';
    $param['FeedOptions']            = 'metadata:OrderId=123-4567890-2949968;metadata:InvoiceNumber=20173723;metadata:documenttype=Invoice';
    $param['SignatureMethod']        = 'HmacSHA256';
    $param['SignatureVersion']       = '2';
    $param['ContentMD5Value']        = $hash;
    $param['Timestamp']              = gmdate("Y-m-d\TH:i:s.\\0\\0\\0\\Z",time());
    $param['Version']                = '2009-01-01';
    $param['MarketplaceIdList.Id.1'] = 'A1PA6795UKMFR9';
    $param['PurgeAndReplace']        = 'false'; 
    $secret                          = '*****************************************';
    $url                             = array();

    foreach ($param as $key => $val) {
        $key    = urlencode($key);
        $val    = urlencode($val);
        $url[]  = "{$key}={$val}";
    }

    fclose($file);
    sort($url);

    $arr            = implode('&',$url);
    $sign           = 'POST' . "\n";
    $sign          .= 'mws.amazonservices.de' . "\n";
    $sign          .= '/Feeds/'.$param['Version'].'' . "\n";
    $sign          .= $arr;
    $signature      = hash_hmac("sha256",$sign,$secret,true);
    $httpHeader     =   array();
    $httpHeader[]   =   'Content-Type: multipart/form-data';
    $httpHeader[]   =   'Content-MD5: ' . $hash;
    $signature      = urlencode(base64_encode($signature));
    $link           = "https://mws.amazonservices.de/Feeds/".$param['Version']."?" . $arr . "&Signature=" . $signature;
    $ch             = curl_init($link);

    curl_setopt($ch,CURLOPT_HTTPHEADER,$httpHeader);
    curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
    curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);
    curl_setopt($ch,CURLOPT_POST,1);
    curl_setopt($ch,CURLOPT_POSTFIELDS,$pdf_feed);
    curl_exec($ch);
    curl_getinfo($ch);
    curl_close($ch);

这就是我不幸的尝试在c＃中的样子：

    public static void Main()
    {
        var httpClient = new HttpClient();
        var requestMessage = new HttpRequestMessage();

        var pdfStream = File.OpenRead("../../Invoice12345656.pdf");
        var pdfMD5Hash = MD5.Create().ComputeHash(pdfStream);
        var pdfMD5HashString = Convert.ToBase64String(pdfMD5Hash);

        var query = new Dictionary<string,string>()
        {
            { "AWSAccessKeyId","*******************" },{ "Action","SubmitFeed" },{ "SellerId",{ "FeedType","_UPLOAD_VAT_INVOICE_" },{ "FeedOptions","metadata:DocumentType=Invoice;metadata:InvoiceNumber=20177311;metadata:OrderId=123-4567890-8041110" },{ "SignatureMethod","HmacSHA256" },{ "SignatureVersion","2" },{ "ContentMD5Value",pdfMD5HashString },{ "Timestamp",DateTime.UtcNow.ToString("yyyy-MM-dd\\THH:mm:ss.000\\Z",CultureInfo.InvariantCulture) },{ "Version","2009-01-01" },{ "MarketplaceIdList.Id.1","A1PA6795UKMFR9" },{ "PurgeAndReplace","false" },};

        var queryString = string.Join("&",query.Select(x => $"{x.Key}={WebUtility.UrlEncode(x.Value)}"));
        var textToSign = $"POST{Environment.NewLine}mws.amazonservices.de{Environment.NewLine}/Feeds/2009-01-01{Environment.NewLine}{queryString}";
        var textToSignBytes = Encoding.Default.GetBytes(textToSign);
        var hmacSHA256 = new HMACSHA256(Convert.FromBase64String("*******************"));
        var signature = WebUtility.UrlEncode(Convert.ToBase64String(hmacSHA256.ComputeHash(textToSignBytes)));

        var formDataContent = new MultipartFormDataContent();
        formDataContent.Headers.ContentType = new MediaTypeHeaderValue("multipart/form-data");
        formDataContent.Headers.Add("Content-MD5",pdfMD5HashString);
        formDataContent.Add(new StringContent("@" + Convert.ToBase64String(File.ReadAllBytes("../../Invoice12345656.pdf"))));

        requestMessage.RequestUri = new Uri($"https://mws.amazonservices.de/Feeds/2009-01-01?{queryString}&Signature={signature}");
        requestMessage.Method = HttpMethod.Post;
        requestMessage.Content = formDataContent;

        var response = httpClient.SendAsync(requestMessage).Result;

        Console.WriteLine(response.Content.ReadAsStringAsync().Result);
    }

任何想法为什么会发生这种情况。

感谢您的帮助。 预先感谢。