Lua Requires Chilkat v11.5.0+

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.

Lua

local chilkat = require("chilkat")

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

local pdf = chilkat.Pdf.new()

-- Load the PDF that will be digitally signed.
local success = pdf:load_file("qa_data/pdf/hello.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

-- Signing options are specified in a JSON object.
local json = chilkat.JsonObject.new()

-- 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:update_bool("ltvOcsp", true)

-- Specify the visual appearance of the signature on the PDF page.
json:update_int("page", 1)
json:update_string("appearance.y", "top")
json:update_string("appearance.x", "left")
json:update_string("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:update_string("appearance.text[0]", "Digitally signed by: cert_cn")
json:update_string("appearance.text[1]", "current_dt")
json:update_string("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.
local cert = chilkat.Cert.new()
success = cert:load_from_file("qa_data/certs/myCert.cer")
if not success then
    print(cert.last_error_text)
    return
end

-- 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.
local jsonArss = chilkat.JsonObject.new()

-- Required.  Indicates that the cloud signing provider is ARSS.
jsonArss:update_string("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:update_string("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:update_string("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:update_string("typeOtpAuth", "demoprod")

-- ARSS account username.
jsonArss:update_string("user", "YOUR_ARSS_USERNAME")

-- ARSS account password.
jsonArss:update_string("userPWD", "YOUR_ARSS_PASSWORD")

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

success = cert:set_cloud_signer(jsonArss)
if not success then
    print(cert.last_error_text)
    return
end

-- Associate the certificate with the PDF object.
-- All subsequent signing operations will use this certificate.
success = pdf:set_signing_cert(cert)
if not success then
    print(pdf.last_error_text)
    return
end

-- 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:sign_pdf(json, "qa_output/hello_ltv_signed.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

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