(Delphi DLL) RSASSA-PSS Algorithm with SHA256 Hashing

RSA encrypt a SHA256 hash with OAEP padding.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
privkey: HCkPrivateKey;
success: Boolean;
rsa: HCkRsa;
sigStr: PWideChar;

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

privkey := CkPrivateKey_Create();

// Load the private key object from a PEM file.
// (To load from a PEM string, call LoadPem instead.)
success := CkPrivateKey_LoadPemFile(privkey,'somePath/myPrivateKey.pem');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privkey));
    Exit;
  end;

rsa := CkRsa_Create();
// Use RSA-PSS by setting OaepPadding = True
CkRsa_putOaepPadding(rsa,True);
// Use SHA256
CkRsa_putOaepHash(rsa,'SHA-256');

CkRsa_ImportPrivateKeyObj(rsa,privkey);

// Generate a base64 signature.
CkRsa_putEncodingMode(rsa,'base64');

sigStr := CkRsa__signStringENC(rsa,'String to be signed','SHA-256');
if (CkRsa_getLastMethodSuccess(rsa) <> True) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

Memo1.Lines.Add('Signature: ' + sigStr);

CkPrivateKey_Dispose(privkey);
CkRsa_Dispose(rsa);

end;