(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.

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;

...

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

begin
//  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 <> True) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

rsa := CkRsa_Create();

success := CkRsa_ImportPrivateKeyObj(rsa,privKey);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

CkRsa_putEncodingMode(rsa,'base64');
strSigned := CkRsa__openSslSignStringENC(rsa,'12345678');
Memo1.Lines.Add(strSigned);

strOriginal := CkRsa__openSslVerifyStringENC(rsa,strSigned);
Memo1.Lines.Add(strOriginal);

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

end;