C#

Sign PDF using ARSS (Aruba Remote Signing Service)

See more Signing in the Cloud Examples

Demonstrates how to digitally sign a PDF using the Aruba Remote Signing Service (ARSS). The example loads a local PDF and certificate, configures the ARSS cloud signer credentials, specifies the OTP authentication type with typeOtpAuth, and creates an LTV-enabled signed PDF where the private key remains protected on the Aruba signing server.

C#

bool success = false;

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

Chilkat.Pdf pdf = new Chilkat.Pdf();

//  Load the PDF that will be digitally signed.
success = pdf.LoadFile("qa_data/pdf/hello.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  Signing options are specified in a JSON object.
Chilkat.JsonObject json = new Chilkat.JsonObject();

//  Enable LTV (Long-Term Validation).
//  When ltvOcsp is true, OCSP validation information is embedded in the PDF
//  so that signature validation can continue to succeed in the future,
//  even if the original OCSP responder is no longer available.
json.UpdateBool("ltvOcsp",true);

//  Specify the visual appearance of the signature on the PDF page.
json.UpdateInt("page",1);
json.UpdateString("appearance.y","top");
json.UpdateString("appearance.x","left");
json.UpdateString("appearance.fontScale","10.0");

//  Text lines displayed in the visible signature appearance.
//  Special values such as "cert_cn" and "current_dt" are replaced
//  with the certificate common name and current date/time.
json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn");
json.UpdateString("appearance.text[1]","current_dt");
json.UpdateString("appearance.text[2]","This is an LTV-enabled signature.");

//  Load the signing certificate.
//  
//  The private key is NOT stored locally.  Instead, the private key is
//  stored and protected on the Aruba Remote Signing Service (ARSS).
//  
//  Even though the signing operation will occur remotely, Chilkat still
//  needs the corresponding public certificate locally so that it can
//  construct the CMS/PAdES signature and embed the certificate chain
//  in the signed PDF.
Chilkat.Cert cert = new Chilkat.Cert();
success = cert.LoadFromFile("qa_data/certs/myCert.cer");
if (success == false) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

//  Configure Aruba Remote Signing Service (ARSS) credentials.
//  
//  When SetCloudSigner is called, Chilkat is instructed to perform
//  cryptographic signing operations through the ARSS web service.
//  The PDF is assembled locally, but the actual RSA signature operation
//  is performed remotely using the private key held by Aruba.
Chilkat.JsonObject jsonArss = new Chilkat.JsonObject();

//  Required.  Indicates that the cloud signing provider is ARSS.
jsonArss.UpdateString("service","ARSS");

//  The ARSS certificate identifier (for example, "AS0").
//  This identifies which remote certificate/private key pair should be used.
//  The remote certificate should correspond to the certificate loaded above.
jsonArss.UpdateString("certID","YOUR_ARSS_CERT_ID");

//  OTP password associated with the Aruba remote-signing account.
//  Depending on the ARSS configuration, an OTP may be required to
//  authorize each signing operation.
jsonArss.UpdateString("otpPwd","YOUR_OTP_PWD");

//  Specifies the OTP authentication environment.
//  
//  Common values are:
//    "demoprod" - Demo/Test environment
//    "prod"     - Production environment
//  
//  This value is sent to the ARSS service and determines how the OTP
//  authentication is validated.  The correct value depends on the type
//  of Aruba account and environment that has been provisioned.
//  
//  If signing fails with an authentication-related error, verify that
//  the typeOtpAuth value matches the environment associated with the
//  ARSS account credentials being used.
jsonArss.UpdateString("typeOtpAuth","demoprod");

//  ARSS account username.
jsonArss.UpdateString("user","YOUR_ARSS_USERNAME");

//  ARSS account password.
jsonArss.UpdateString("userPWD","YOUR_ARSS_PASSWORD");

//  Beginning with Chilkat v11.5.0, the ARSS endpoint can be explicitly
//  specified.  This allows the application to target a particular
//  Aruba signing service endpoint when required.
jsonArss.UpdateString("endpoint","https://app1.firma-remota.it/ArubaSignerService/webresources/signerservice");

success = cert.SetCloudSigner(jsonArss);
if (success == false) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

//  Associate the certificate with the PDF object.
//  All subsequent signing operations will use this certificate.
success = pdf.SetSigningCert(cert);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  Create the signed PDF.
//  
//  Chilkat performs all PDF processing locally.  When the time comes
//  to generate the cryptographic signature value, Chilkat sends the
//  hash to ARSS, which signs it using the remote private key and returns
//  the signature.  The private key never leaves the Aruba service.
success = pdf.SignPdf(json,"qa_output/hello_ltv_signed.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("The PDF has been successfully cryptographically signed with long-term validation.");