Delphi ActiveX

URL Signing for Google Maps API

See more Encryption Examples

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
sig: WideString;

begin
// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

crypt := TChilkatCrypt2.Create(Self);

// 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';

// Set the hash algorithm to sha-1
crypt.HashAlgorithm := 'sha-1';
crypt.MacAlgorithm := 'hmac';

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

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

// The result should be KrU1TzVQM7Ur0i8i7K3huiw3MsA=
Memo1.Lines.Add(sig);
end;