(Delphi DLL) Sign String to create a CAdES-T Signature, using HTTP Proxy to Access Timestamp Server

This example will sign a string to create a CAdEST-T signature. It will use an HTTP proxy to access the timestamp server.

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, Http, BinData, Cert, JsonObject, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: HCkCrypt2;
cert: HCkCert;
success: Boolean;
attrs: HCkJsonObject;
strToSign: PWideChar;
bd: HCkBinData;
http: HCkHttp;

begin
crypt := CkCrypt2_Create();

cert := CkCert_Create();
CkCert_putSmartCardPin(cert,'123456');
success := CkCert_LoadFromSmartcard(cert,'');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

success := CkCrypt2_SetSigningCert(crypt,cert);

// Use SHA-256 rather than the default of SHA-1
CkCrypt2_putHashAlgorithm(crypt,'sha256');

// Create JSON that tells Chilkat what signing attributes to include:
attrs := CkJsonObject_Create();
CkJsonObject_UpdateBool(attrs,'contentType',True);
CkJsonObject_UpdateBool(attrs,'signingTime',True);
CkJsonObject_UpdateBool(attrs,'messageDigest',True);
CkJsonObject_UpdateBool(attrs,'signingCertificateV2',True);

// A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
// We must include the TSA's URL, as well as a few options to indicate what is desired.
// Except for the TSA URL, the options shown here are typically what you would need.
CkJsonObject_UpdateBool(attrs,'timestampToken.enabled',True);
CkJsonObject_UpdateString(attrs,'timestampToken.tsaUrl','https://freetsa.org/tsr');
CkJsonObject_UpdateBool(attrs,'timestampToken.addNonce',False);
CkJsonObject_UpdateBool(attrs,'timestampToken.requestTsaCert',True);
CkJsonObject_UpdateString(attrs,'timestampToken.hashAlg','sha256');

CkCrypt2_putSigningAttributes(crypt,CkJsonObject__emit(attrs));

strToSign := 'Hello World!';

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

// -------------------------------------------------------------------------
// The purpose of this example is to show how an HTTP object with custom
// settings can be used to access the Internet when signing.
// Access to the Internet is needed to communicate with the timestamp server.
http := CkHttp_Create();
// This can be a domain name, hostname, or IP address.
CkHttp_putProxyDomain(http,'172.16.16.56');
CkHttp_putProxyPort(http,808);
CkHttp_putProxyLogin(http,'myProxyLogin');
CkHttp_putProxyPassword(http,'myProxyPassword');
CkCrypt2_SetTsaHttpObj(crypt,http);
// -------------------------------------------------------------------------

// This creates the CAdES-T signature.  During the signature creation, it
// communicates with the TSA to get a timestampToken.
// The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
success := CkCrypt2_OpaqueSignBd(crypt,bd);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

// Get the signature in base64 format:
Memo1.Lines.Add(CkBinData__getEncoded(bd,'base64_mime'));

Memo1.Lines.Add('Success.');

CkCrypt2_Dispose(crypt);
CkCert_Dispose(cert);
CkJsonObject_Dispose(attrs);
CkBinData_Dispose(bd);
CkHttp_Dispose(http);

end;