(SQL Server) Extract XML File from a .p7m (e.g. FATTURA ELETTRONICA, ITALY)

SQL Server example to extract the original file from a .p7m (Signed-Data PKCS7 Format) The .p7m contains the signed contents of the original file.

One use for this example is to extract the XML file from a Fattura Elettronica .p7m signature.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

    DECLARE @crypt int
    -- Use "Chilkat_9_5_0.Crypt2" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @outputFile nvarchar(4000)
    SELECT @outputFile = 'testData/xml/original.xml'
    DECLARE @inFile nvarchar(4000)
    SELECT @inFile = 'testData/p7m/fattura_signature.p7m'

    -- Verify the signature and extract the XML file.
    DECLARE @success int
    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
        RETURN
      END


    PRINT 'Success!'

    EXEC @hr = sp_OADestroy @crypt


END
GO