(Delphi DLL) RSA Sign using Base64 Private Key

Signs a string using a non-encrypted RSA private key in base64 encoding. Returns the RSA signature as a base64 string.

Note: This example requires Chilkat v11.0.0 or greater.

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, StringBuilder, PrivateKey, Rsa, BinData;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
privKey: HCkPrivateKey;
sbPem: HCkStringBuilder;
rsa: HCkRsa;
bd: HCkBinData;
strOriginal: PWideChar;

begin
success := False;

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

privKey := CkPrivateKey_Create();

sbPem := CkStringBuilder_Create();
CkStringBuilder_AppendLine(sbPem,'-----BEGIN RSA PRIVATE KEY-----',True);
CkStringBuilder_AppendLine(sbPem,'MIIC .... j5A==',True);
CkStringBuilder_AppendLine(sbPem,'-----END RSA PRIVATE KEY-----',True);

success := CkPrivateKey_LoadPem(privKey,CkStringBuilder__getAsString(sbPem));
if (success = False) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

rsa := CkRsa_Create();

success := CkRsa_UsePrivateKey(rsa,privKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

bd := CkBinData_Create();
CkBinData_AppendString(bd,'12345678','utf-8');

success := CkRsa_SignRawBd(rsa,bd);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// Get the base64 RSA signature.
Memo1.Lines.Add(CkBinData__getEncoded(bd,'base64'));

success := CkRsa_VerifyRawBd(rsa,bd);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

strOriginal := CkBinData__getString(bd,'utf-8');
Memo1.Lines.Add(strOriginal);

CkPrivateKey_Dispose(privKey);
CkStringBuilder_Dispose(sbPem);
CkRsa_Dispose(rsa);
CkBinData_Dispose(bd);

end;