(PureBasic) A3 Certificate Sign PDF to pdf.p7s

Demonstrates how to use an A3/A4 certificate on a smartcard or hardware token to convert a PDF into a .p7s file that contains the PDF within a PKCS7 signature (the .p7s format).

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCrypt2.pb"
IncludeFile "CkCert.pb"

Procedure ChilkatExample()

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

    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

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

    ; If the smartcard or token requires a PIN, we can set it here to avoid the dialog...
    CkCert::setCkSmartCardPin(cert, "000000")

    success.i = CkCert::ckLoadFromSmartcard(cert,"")
    If success <> 1
        Debug CkCert::ckLastErrorText(cert)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Tell the crypt component to use this cert.
    success = CkCrypt2::ckSetSigningCert(crypt,cert)
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; The CadesEnabled property applies to all methods that create PKCS7 signatures. 
    ; To create a CAdES-BES signature, set this property equal to true. 
    CkCrypt2::setCkCadesEnabled(crypt, 1)

    CkCrypt2::setCkHashAlgorithm(crypt, "sha256")

    ; We can sign any type of file, creating a .p7s as output.
    ; The .p7s contains the signature and also embeds the data of the file that is signed.
    inFile.s = "qa_data/pdf/sample.pdf"
    p7sFile.s = "qa_output/sample.pdf.p7s"

    ; Create the CAdES-BES attached signature, which contains the original data.
    ; Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
    ; is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
    ; is NOT contained within the signature.  We want the data to be contained in the signature, therefore
    ; we call CreateP7M even though we are naming our output file .p7s.
    success = CkCrypt2::ckCreateP7M(crypt,inFile,p7sFile)
    If success = 0
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Verify the .p7s file and extract the original file from the .p7s. 
    extractedToFilePath.s = "qa_output/sample.pdf"
    success = CkCrypt2::ckVerifyP7M(crypt,p7sFile,extractedToFilePath)
    If success = 0
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    Debug "Success!"


    CkCrypt2::ckDispose(crypt)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure