(SQL Server) Unzip an AES Encrypted Text File directly into a String Variable

A common need is to unzip from an AES encrypted Zip archive directly into a string variable, such that the unencrypted file never resides on disk, even temporarily. This example shows how to do it.

Note: This example requires Chilkat v11.0.0 or greater.

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

    -- This example opens a WinZip-compatible AES encrypted
    -- .zip that contains a single file: hamlet.xml.

    -- It decrypts and unzips hamlet.xml directly into a string
    -- variable.
    EXEC sp_OAMethod @zip, 'SetPassword', NULL, 'secret'
    EXEC sp_OAMethod @zip, 'OpenZip', @success OUT, 'qa_data/hamlet.zip'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @zip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        RETURN
      END

    DECLARE @entry int
    EXEC @hr = sp_OACreate 'Chilkat.ZipEntry', @entry OUT

    EXEC sp_OAMethod @zip, 'EntryOf', @success OUT, 'hamlet.xml', @entry
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @zip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        EXEC @hr = sp_OADestroy @entry
        RETURN
      END

    -- lineEndingBehavior:
    -- 0 = leave unchanged.
    -- 1 = convert all to bare LF's
    -- 2 = convert all to CRLF's
    DECLARE @lineEndingBehavior int
    SELECT @lineEndingBehavior = 0
    DECLARE @srcCharset nvarchar(4000)
    SELECT @srcCharset = 'utf-8'
    DECLARE @xmlText nvarchar(4000)
    EXEC sp_OAMethod @entry, 'UnzipToString', @xmlText OUT, @lineEndingBehavior, @srcCharset

    PRINT @xmlText

    EXEC @hr = sp_OADestroy @zip
    EXEC @hr = sp_OADestroy @entry


END
GO