SQL Server

Sign PDF in the Cloud using Azure Key Vault

See more Signing in the Cloud Examples

Demonstrates how to sign a PDF using Azure Key Vault. The signing of the hash happens in the Cloud on Azure Key Vault. Everything else involving the updating the PDF to add the signature happens locally within Chilkat.

Note: This example requires Chilkat v9.5.0.96 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.
    EXEC sp_OAMethod @pdf, 'LoadFile', @success OUT, 'qa_data/pdf/helloWorld.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

    -- Optionally create an LTV-enabled signature
    EXEC sp_OAMethod @json, 'UpdateBool', @success OUT, 'ltvOcsp', 1

    -- 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 certificate used for signing.  The certificate's private key is stored in 
    -- the Azure Key Vault.
    -- However, we still need the certificate locally (without private key).
    DECLARE @cert int
    EXEC @hr = sp_OACreate 'Chilkat.Cert', @cert OUT

    EXEC sp_OAMethod @cert, 'LoadFromFile', @success OUT, 'qa_data/certs/myCert.cer'
    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

    -- Here's a screenshot of our certificate with private key on Azure Key Vault:
    -- (image:https://example-code.com/images/azure_key_vault.jpg/endImage)

    -- To sign using the Azure Key Vault, 
    -- add the following lines of code to specify your authentication credentials,
    -- and the name of the certificate w/ private key on the Azure server to be used.
    DECLARE @jsonAzure int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jsonAzure OUT

    -- Set the "service" equal to "azure_keyvault" to tell Chilkat to use Azure Key Vault for signing.
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'service', 'azure_keyvault'
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'client_id', 'APP_ID'
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'client_secret', 'APP_PASSWORD'
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'tenant_id', 'TENANT_ID'
    -- In the above screenshot, our vault name is "kvchilkat".  You will use your vault name.
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'vault_name', 'VAULT_NAME'
    -- In the above screenshot, our cert name is "ChilkatTest1".  You will use your cert name.
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'cert_name', 'CERT_NAME'
    -- In the above screenshot, our cert version is "63b94a23389546ecbc8eb6208a1bef37".  You will use your cert version.
    EXEC sp_OAMethod @jsonAzure, 'UpdateString', @success OUT, 'cert_version', 'CERT_VERSION'
    EXEC sp_OAMethod @cert, 'SetCloudSigner', @success OUT, @jsonAzure

    -- Tell the pdf object to use the certificate for signing (and for Azure Key Vault to do the actual signing of the hash).
    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
        EXEC @hr = sp_OADestroy @jsonAzure
        RETURN
      END

    -- Chilkat will build the signed PDF locally, but will (internally) use Azure Key Vault
    -- to do the RSA (or EC) sign hash operation.
    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
        EXEC @hr = sp_OADestroy @jsonAzure
        RETURN
      END


    PRINT 'PDF Cloud Signing using Azure Key Vault Successful.'

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


END
GO