SQL Server

Sign PDF with Long-Term Validation (LTV Enabled)

See more PDF Signatures Examples

This example demonstrates how to a sign a PDF with long-term validation (LTV) enabled.

Note: This example requires Chilkat v9.5.0.85 or greater.

SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

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

    DECLARE @pdf int
    EXEC @hr = sp_OACreate 'Chilkat.Pdf', @pdf OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- Load a PDF to be signed.
    -- The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    EXEC sp_OAMethod @pdf, 'LoadFile', @success OUT, 'qa_data/pdf/hello.pdf'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        RETURN
      END

    -- Options for signing are specified in JSON.
    DECLARE @json int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT

    -- In most cases, the signingCertificateV2 and signingTime attributes are required.
    EXEC sp_OAMethod @json, 'UpdateInt', @success OUT, 'signingCertificateV2', 1
    EXEC sp_OAMethod @json, 'UpdateInt', @success OUT, 'signingTime', 1

    -- Add the "ltvOcsp" instruction to the JSON passed to SignPdf.
    -- This is what causes Chilkat to create an LTV-enabled signature.
    -- 
    -- If we are signing a PDF that already has signatures, then the existing signatures
    -- are automatically verified, and Chilkat will do OCSP certificate status checking (if possible) 
    -- for those certs in existing signatures (including certs in the certificate chains) 
    -- that do not yet have a valid OCSP response in the DSS (Document Security Store).
    -- Chilkat will add the OCSP responses to the /OCSPs in the Document Security Store (/DSS).
    -- Also, and certificates from existing signatures not yet in the DSS are added to the /Certs 
    -- in the DSS.
    -- 
    -- Also, the "ltvOcsp" causes Chilkat to add the pdfRevocationInfoArchival authenticated attribute
    -- to the CMS signature.  The pdfRevocationInfoArchival attribute (1.2.840.113583.1.1.8)
    -- contains OCSP responses and the CRL for the issuer of the signing certificate.
    -- Therefore, Chilkat will send an OCSP request to the signing certificate's OCSP URl (if one exists)
    -- and will download the CRL from the issuer certificate's CRL Distribution Point (if one exists).
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'ltvOcsp', 1

    -- -----------------------------------------------------------------------------------
    -- Note: If Chilkat produces a signed PDF, but the signature is not LTV-enabled,
    -- the cause might be related to a failure to download CRL's or OCSP requests.
    -- See Possible Solution for Failure to Produce LTV-enabled PDF Signature
    -- -----------------------------------------------------------------------------------
    -- You can add the following to UncommonOptions to get detailed information about the CRL and OCSP requests
    -- You shouldn't set the following logging options unless there is a need, because it adds a large amount of information to the LastErrorText.
    EXEC sp_OASetProperty @pdf, 'UncommonOptions', 'LOG_OCSP_HTTP,LOG_CRL_HTTP'

    -- Define the appearance of the signature.
    EXEC sp_OAMethod @json, 'UpdateInt', @success OUT, 'page', 1
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'appearance.y', 'top'
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'appearance.x', 'left'
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'appearance.fontScale', '10.0'
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'appearance.text[0]', 'Digitally signed by: cert_cn'
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'appearance.text[1]', 'current_dt'
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'appearance.text[2]', 'This is an LTV-enabled signature.'

    -- Load the signing certificate. (Use your own certificate.)
    DECLARE @cert int
    EXEC @hr = sp_OACreate 'Chilkat.Cert', @cert OUT

    EXEC sp_OAMethod @cert, 'LoadPfxFile', @success OUT, 'qa_data/pfx/myPdfSigningCert.pfx', 'pfxPassword'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @cert, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Tell the pdf object to use the certificate for signing.
    EXEC sp_OAMethod @pdf, 'SetSigningCert', @success OUT, @cert
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    EXEC sp_OAMethod @pdf, 'SignPdf', @success OUT, @json, 'qa_output/hello_ltv_signed.pdf'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END


    PRINT 'The PDF has been successfully cryptographically signed with long-term validation.'

    -- If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
    -- as shown here:
    -- (image:https://example-code.com/images/ltv_signature.jpg/endImage)

    EXEC @hr = sp_OADestroy @pdf
    EXEC @hr = sp_OADestroy @json
    EXEC @hr = sp_OADestroy @cert


END
GO