Delphi ActiveX

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). 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
success: Integer;
cert: TChilkatCert;
bd: TChilkatBinData;
i: Integer;
rsa: TChilkatRsa;
sha256_base64: WideString;
rsaSig_base64: WideString;

begin
success := 0;

// Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
// this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

// Chilkat automatically detects and determines the way in which the HSM is used,
// which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

cert := TChilkatCert.Create(Self);

// Set the token/smartcard PIN prior to loading.
cert.SmartCardPin := '123456';

// Specify the certificate by its common name.
success := cert.LoadFromSmartcard('cn=chilkat-rsa-2048');
if (success = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Signing with the private key for this cert: ' + cert.SubjectCN);

// Create data to be hashed and signed.
bd := TChilkatBinData.Create(Self);

for i := 0 to 100 do
  begin
    bd.AppendEncoded('000102030405060708090A0B0C0D0E0F','hex');
  end;

rsa := TChilkatRsa.Create(Self);

// Use the certificate's private key for signing.
success := rsa.SetX509Cert(cert.ControlInterface,1);
if (success = 0) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

// We'll first compute the hash and then pass the encoded hash to be signed.
sha256_base64 := bd.GetHash('sha256','base64');
Memo1.Lines.Add('sha256 hash in base64 format: ' + sha256_base64);

// Pass in the base64 hash and return a base64 signature.
rsa.EncodingMode := 'base64';
rsaSig_base64 := rsa.SignHashENC(sha256_base64,'sha256');
if (success = 0) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('RSA signature as base64: ' + rsaSig_base64);
end;