Tcl 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.

Tcl

load ./chilkat.dll

set success 0

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

set pdf [new_CkPdf]

#  Load the PDF that will be digitally signed.
set success [CkPdf_LoadFile $pdf "qa_data/pdf/hello.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    exit
}

#  Signing options are specified in a JSON object.
set json [new_CkJsonObject]

#  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.
CkJsonObject_UpdateBool $json "ltvOcsp" 1

#  Specify the visual appearance of the signature on the PDF page.
CkJsonObject_UpdateInt $json "page" 1
CkJsonObject_UpdateString $json "appearance.y" "top"
CkJsonObject_UpdateString $json "appearance.x" "left"
CkJsonObject_UpdateString $json "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.
CkJsonObject_UpdateString $json "appearance.text[0]" "Digitally signed by: cert_cn"
CkJsonObject_UpdateString $json "appearance.text[1]" "current_dt"
CkJsonObject_UpdateString $json "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.
set cert [new_CkCert]

set success [CkCert_LoadFromFile $cert "qa_data/certs/myCert.cer"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    exit
}

#  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.
set jsonArss [new_CkJsonObject]

#  Required.  Indicates that the cloud signing provider is ARSS.
CkJsonObject_UpdateString $jsonArss "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.
CkJsonObject_UpdateString $jsonArss "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.
CkJsonObject_UpdateString $jsonArss "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.
CkJsonObject_UpdateString $jsonArss "typeOtpAuth" "demoprod"

#  ARSS account username.
CkJsonObject_UpdateString $jsonArss "user" "YOUR_ARSS_USERNAME"

#  ARSS account password.
CkJsonObject_UpdateString $jsonArss "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.
CkJsonObject_UpdateString $jsonArss "endpoint" "https://app1.firma-remota.it/ArubaSignerService/webresources/signerservice"

set success [CkCert_SetCloudSigner $cert $jsonArss]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    delete_CkJsonObject $jsonArss
    exit
}

#  Associate the certificate with the PDF object.
#  All subsequent signing operations will use this certificate.
set success [CkPdf_SetSigningCert $pdf $cert]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    delete_CkJsonObject $jsonArss
    exit
}

#  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.
set success [CkPdf_SignPdf $pdf $json "qa_output/hello_ltv_signed.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkCert $cert
    delete_CkJsonObject $jsonArss
    exit
}

puts "The PDF has been successfully cryptographically signed with long-term validation."

delete_CkPdf $pdf
delete_CkJsonObject $json
delete_CkCert $cert
delete_CkJsonObject $jsonArss