c# - 使用来自 .NET 命令行应用程序的签名 Google Maps API 地理编码请求

Question

所以我正在编写一个应用程序来在导入记录时缓存地理编码数据。当我使用未签名的请求时，它工作正常，但是当我尝试使用我公司的 clientid 和签名时，我似乎无法弄清楚出了什么问题。我总是收到 403 Forbidden。

这是我的 URL 构建器:

    private const string _googleUri = "http://maps.googleapis.com/maps/api/geocode/xml?address=";
    private const string _googleClientId = "XXXXXXXX";
    private const string _googleSignature = "XXXXXXXXXXXXXXXXXXXXXXXX";

//RESOLVED
    private static String GetGeocodeUri(string address)
    {
        ASCIIEncoding encoding = new ASCIIEncoding();
        string url = String.Format("{0}{1}&client={2}&sensor=false"
                                   , _googleUri
                                   , HttpUtility.UrlEncode(address)
                                   , _googleClientId);

        // converting key to bytes will throw an exception, need to replace '-' and '_' characters first.
        string usablePrivateKey = _googleSignature.Replace("-", "+").Replace("_", "/");
        byte[] privateKeyBytes = Convert.FromBase64String(usablePrivateKey);

        Uri uri = new Uri(url);
        byte[] encodedPathAndQueryBytes = encoding.GetBytes( uri.LocalPath + uri.Query );

        // compute the hash
        HMACSHA1 algorithm = new HMACSHA1(privateKeyBytes);
        byte[] hash = algorithm.ComputeHash(encodedPathAndQueryBytes);

        // convert the bytes to string and make url-safe by replacing '+' and '/' characters
        string signature = Convert.ToBase64String(hash).Replace("+", "-").Replace("/", "_");

        // Add the signature to the existing URI.
        return uri.Scheme + "://" + uri.Host + uri.LocalPath + uri.Query + "&signature=" + signature;

    } 

程序如下:

public static AddressClass GetResponseAddress(string address)
    {
        AddressClass GoogleAddress = new AddressClass();
        XmlDocument doc = new XmlDocument();
        String myUri = GetGeocodeUri(address);

        try
        {
            doc.Load(myUri);
            XmlNode root = doc.DocumentElement;
            if (root.SelectSingleNode("/GeocodeResponse/status").InnerText == "OK")
            {
                GoogleAddress.Latitude = Double.Parse(root.SelectSingleNode("/GeocodeResponse/result/geometry/location/lat").InnerText);
                GoogleAddress.Longitude = Double.Parse(root.SelectSingleNode("/GeocodeResponse/result/geometry/location/lat").InnerText);

            }
         }
         catch (Exception ex)
         {
            Console.WriteLine("Exception <" + ex.Message + ">");

         }           

        return GoogleAddress;
    }

现在，我对它不起作用的最初 react 是 Google 一定缺少引荐域，因为它们必须注册。所以我尝试使用 HttpWebRequest 并将 referer 设置为我的域，但仍然没有成功。

//Not needed, Just an alternate method
public static AddressClass GetResponseAddress(string address)
    {
        AddressClass GoogleAddress = new AddressClass();
        WebClient client = new WebClient();
        XmlDocument doc = new XmlDocument();
        Uri myUri = new Uri(GetGeocodeUri(address));
        HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(myUri);
        myRequest.Referer = "http://www.myDomain.com/";

        //I've even tried pretending to be Chrome
        //myRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.75 Safari/535.7";

        try
        {
            doc.Load(myRequest.GetResponse().GetResponseStream());
            XmlNode root = doc.DocumentElement;
            if (root.SelectSingleNode("/GeocodeResponse/status").InnerText == "OK")
            {
                GoogleAddress.Latitude = Double.Parse(root.SelectSingleNode("/GeocodeResponse/result/geometry/location/lat").InnerText);
                GoogleAddress.Longitude = Double.Parse(root.SelectSingleNode("/GeocodeResponse/result/geometry/location/lat").InnerText);
            }
         }
         catch (Exception ex)
         {
              Console.WriteLine("Exception <" + ex.Message + ">");

         }

        return GoogleAddress;
    }

如有任何帮助，我们将不胜感激。

Answer 1

const String gmeClientID = "gme-myClientId";
const String key = "myGoogleKey";

var urlRequest = String.Format("/maps/api/geocode/json?latlng={0},{1}&sensor=false&client={2}",Latitude,Longitude,gmeClientID);

HMACSHA1 myhmacsha1 = new HMACSHA1();
myhmacsha1.Key = Convert.FromBase64String(key); 
var hash = myhmacsha1.ComputeHash(Encoding.ASCII.GetBytes(urlRequest));

var url = String.Format("http://maps.googleapis.com{0}&signature={1}", urlRequest, Convert.ToBase64String(hash).Replace("+", "-").Replace("/", "_"));

var request = (HttpWebRequest)HttpWebRequest.Create(url);