SQL Server

Create P7M Using Pre-Installed Windows Certificate

See more Digital Signatures Examples

Demonstrates how to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M.

This example is for Windows only. It automatically searches and locates the desired certificate in the Current User or Local Machine certificate stores. (The certificate must have been pre-installed on the Windows machine, and it must have the private key available. The private key can be located on a USB Authentication Token / Smart Card. If so, then Chilkat *should* automatically use the private key located on the device.)

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
    DECLARE @iTmp0 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 assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @certSubjectCN nvarchar(4000)
    SELECT @certSubjectCN = 'Matt'

    DECLARE @cert int
    EXEC @hr = sp_OACreate 'Chilkat.Cert', @cert OUT

    -- Locate and load the certificate by the common name (subject CN).
    -- This searches the Windows registry-based Current User and Local Machine
    -- certificate stores for the certificate.  
    EXEC sp_OAMethod @cert, 'LoadByCommonName', @success OUT, @certSubjectCN
    IF @success <> 1
      BEGIN

        PRINT 'Failed to find certificate.'
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Make sure a private key is available.
    EXEC sp_OAMethod @cert, 'HasPrivateKey', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN

        PRINT 'This certificate does not have a private key located in the Windows protected store, or on a USB device.'
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Specify the cert (and implicitly the private key) to be used for signing.
    EXEC sp_OAMethod @crypt, 'SetSigningCert', @success OUT, @cert

    -- -----------------------------------------------------------------------------------------
    -- Also see Chilkat's online tool to examine a .p7m and generate code to duplicate the .p7m
    -- -----------------------------------------------------------------------------------------

    -- We can sign any type of file, creating a .p7m as output:
    DECLARE @inFile nvarchar(4000)
    SELECT @inFile = 'qa_data/pdf/fishing.pdf'
    DECLARE @outputFile nvarchar(4000)
    SELECT @outputFile = 'qa_output/fishing.pdf.p7m'
    EXEC sp_OAMethod @crypt, 'CreateP7M', @success OUT, @inFile, @outputFile
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @crypt, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Verify and restore the original file:
    EXEC sp_OAMethod @crypt, 'SetVerifyCert', @success OUT, @cert

    SELECT @inFile = @outputFile
    SELECT @outputFile = 'qa_output/restored.pdf'

    EXEC sp_OAMethod @crypt, 'VerifyP7M', @success OUT, @inFile, @outputFile
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @crypt, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END


    PRINT 'Success!'

    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @cert


END
GO