(C#) URL Signing for Google Maps API

Demonstrates how to sign a URL for the Google Maps API.

Download: Chilkat .NET Assemblies

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

//  Any string argument automatically begins the 30-day trial.
bool success;
success = crypt.UnlockComponent("Anything for 30-day trial.");
if (success != true) {
    textBox1.Text += crypt.LastErrorText + "\r\n";
    return;
}

//  The output will be modified Base64.
//  Modified Base64 for URLs replaces the '+' and '/' characters
//  of standard Base64 with '-' and '_' respectively, so that these
//  Base64 signatures no longer need to be URL-encoded.
crypt.EncodingMode = "modBase64";

//  NOTE: At the time of this writing, the "modBase64" encoding mode is
//  available in the pre-release build only.  Send email to
//  support@chilkatsoft.com if you need a pre-release.  This feature will be
//  included in the next official release.

//  Set the hash algorithm to sha-1
crypt.HashAlgorithm = "sha-1";

string sig;

//  Set the HMAC key (this is the private key provided by Google)
crypt.SetHmacKeyEncoded("vNIXE0xscrmjlyV-12Nj_BvUPaw=","modBase64");

//  Compute the URL signature
sig = crypt.HmacStringENC("/maps/api/geocode/json?address=New+York&sensor=false&client=clientID");

//  The result should be KrU1TzVQM7Ur0i8i7K3huiw3MsA=
textBox1.Text += sig + "\r\n";