SQL Server

Sign PDF in the Cloud using AWS KMS

See more Signing in the Cloud Examples

Demonstrates how to sign a PDF using the AWS Key Management Service. The signing of the hash happens in the Cloud on AWS KMS. 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 AWS KMS
    -- 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 private key AWS KMS:
    -- (image:https://example-code.com/images/aws_kms.jpg/endImage)

    -- To sign using AWS KMS, 
    -- add the following lines of code to specify your AWS authentication credentials,
    -- and the ID of the KMS private key.
    DECLARE @jsonAwsKms int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jsonAwsKms OUT

    -- Set the "service" equal to "aws_kms" to tell Chilkat to use AWS KMS for signing.
    EXEC sp_OAMethod @jsonAwsKms, 'UpdateString', @success OUT, 'service', 'aws_kms'
    EXEC sp_OAMethod @jsonAwsKms, 'UpdateString', @success OUT, 'access_key', 'ACCESS_KEY'
    EXEC sp_OAMethod @jsonAwsKms, 'UpdateString', @success OUT, 'secret_key', 'SECRET_KEY'
    -- Make sure to specify the correct region for your case.
    EXEC sp_OAMethod @jsonAwsKms, 'UpdateString', @success OUT, 'region', 'us-west-2'
    -- In the above screenshot, our key ID is "187012e8-008f-4fc7-b100-5efe6146dff2".  You will use your key ID.
    EXEC sp_OAMethod @jsonAwsKms, 'UpdateString', @success OUT, 'key_id', '187012e8-008f-4fc7-b100-5efe6146dff2'

    EXEC sp_OAMethod @cert, 'SetCloudSigner', @success OUT, @jsonAwsKms

    -- Tell the pdf object to use the certificate for signing (and for AWS KMS 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 @jsonAwsKms
        RETURN
      END

    -- Chilkat will build the signed PDF locally, but will (internally) use AWS KMS
    -- 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 @jsonAwsKms
        RETURN
      END


    PRINT 'PDF Cloud Signing using AWS KMS Successful.'

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


END
GO