HMAC SHA1 for Amazon S3

Demonstrates the HMAC SHA1 computation required by the Amazon S3 web service.

Download Chilkat Crypt ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATCRYPT2Lib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
strToSign: String;
crypt: TChilkatCrypt2;
success: Integer;
AWSAccessKeyId: String;
AWSSecretAccessKey: String;
signature: String;

begin
//  This example uses sample data from:
//  http://docs.amazonwebservices.com/AmazonS3/2006-03-01/RESTAuthentication.html
strToSign := 'GET' + #10 + #10 + #10 + 'Tue, 27 Mar 2007 19:36:42 +0000' + #10 + '/johnsmith/photos/puppy.jpg';

crypt := TChilkatCrypt2.Create(Self);

success := crypt.UnlockComponent('Anything for 30-day trial.');
if (success <> 1) then
  begin
    //  Unlock Failed.
    ShowMessage(crypt.LastErrorText);
    Exit;
  end;

//  We want SHA1 for the HMAC hash algorithm:
crypt.HashAlgorithm := 'sha1';

AWSAccessKeyId := '0PN5J17HBGZHT7JJ3X82';
AWSSecretAccessKey := 'uV3F3YluFJax1cknvbcGwgjvx4QpvB+leU8dUj2o';

//  Set the HMAC secret key:
crypt.SetHmacKeyString(AWSSecretAccessKey);

//  By setting the charset = "utf-8", the string will be converted
//  to utf-8 (internal to the Chilkat component) prior to signing:
crypt.Charset := 'utf-8';

//  Indicate that Base64 output is desired:
crypt.EncodingMode := 'base64';

signature := crypt.HmacStringENC(strToSign);
Memo1.Lines.Add(crypt.LastErrorText);

//  Display the signature as part of the HTTP Authorization header:
Memo1.Lines.Add('Authorization: AWS ' + AWSAccessKeyId
     + ':' + signature);

Memo1.Lines.Add('Expected:      AWS 0PN5J17HBGZHT7JJ3X82:xXjDGYUmKxnwqr5KXNPGldn5LbA=');
end;