PureBasic 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.

PureBasic

IncludeFile "CkCert.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkPdf.pb"

Procedure ChilkatExample()

    success.i = 0

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

    pdf.i = CkPdf::ckCreate()
    If pdf.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  Load the PDF that will be digitally signed.
    success = CkPdf::ckLoadFile(pdf,"qa_data/pdf/hello.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        ProcedureReturn
    EndIf

    ;  Signing options are specified in a JSON object.
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  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::ckUpdateBool(json,"ltvOcsp",1)

    ;  Specify the visual appearance of the signature on the PDF page.
    CkJsonObject::ckUpdateInt(json,"page",1)
    CkJsonObject::ckUpdateString(json,"appearance.y","top")
    CkJsonObject::ckUpdateString(json,"appearance.x","left")
    CkJsonObject::ckUpdateString(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::ckUpdateString(json,"appearance.text[0]","Digitally signed by: cert_cn")
    CkJsonObject::ckUpdateString(json,"appearance.text[1]","current_dt")
    CkJsonObject::ckUpdateString(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.
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadFromFile(cert,"qa_data/certs/myCert.cer")
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ;  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.
    jsonArss.i = CkJsonObject::ckCreate()
    If jsonArss.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  Required.  Indicates that the cloud signing provider is ARSS.
    CkJsonObject::ckUpdateString(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::ckUpdateString(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::ckUpdateString(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::ckUpdateString(jsonArss,"typeOtpAuth","demoprod")

    ;  ARSS account username.
    CkJsonObject::ckUpdateString(jsonArss,"user","YOUR_ARSS_USERNAME")

    ;  ARSS account password.
    CkJsonObject::ckUpdateString(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::ckUpdateString(jsonArss,"endpoint","https://app1.firma-remota.it/ArubaSignerService/webresources/signerservice")

    success = CkCert::ckSetCloudSigner(cert,jsonArss)
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        CkJsonObject::ckDispose(jsonArss)
        ProcedureReturn
    EndIf

    ;  Associate the certificate with the PDF object.
    ;  All subsequent signing operations will use this certificate.
    success = CkPdf::ckSetSigningCert(pdf,cert)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        CkJsonObject::ckDispose(jsonArss)
        ProcedureReturn
    EndIf

    ;  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 = CkPdf::ckSignPdf(pdf,json,"qa_output/hello_ltv_signed.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf)
        CkPdf::ckDispose(pdf)
        CkJsonObject::ckDispose(json)
        CkCert::ckDispose(cert)
        CkJsonObject::ckDispose(jsonArss)
        ProcedureReturn
    EndIf

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


    CkPdf::ckDispose(pdf)
    CkJsonObject::ckDispose(json)
    CkCert::ckDispose(cert)
    CkJsonObject::ckDispose(jsonArss)


    ProcedureReturn
EndProcedure