(SQL Server) ClickBank Decrypt Instant Notification

Demonstrates how to decrypt a ClickBank instant notification. See Instant Notification Service for more information and alternative code snippets.

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
    DECLARE @sTmp0 nvarchar(4000)
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- secret key from your ClickBank account
    DECLARE @secretKey nvarchar(4000)
    SELECT @secretKey = 'MY_SECRET_KEY'

    DECLARE @jsonStr nvarchar(4000)
    SELECT @jsonStr = '{"notification":"BASE64_NOTIFICATION","iv":"BASE64_IV"}'

    DECLARE @json int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.JsonObject', @json OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int
    EXEC sp_OAMethod @json, 'Load', @success OUT, @jsonStr

    -- Get the encrypted notification (binary) and IV from the JSON.
    DECLARE @bdNotif int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.BinData', @bdNotif OUT

    DECLARE @bdIv int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.BinData', @bdIv OUT

    EXEC sp_OAMethod @json, 'StringOf', @sTmp0 OUT, 'notification'
    EXEC sp_OAMethod @bdNotif, 'AppendEncoded', @success OUT, @sTmp0, 'base64'
    EXEC sp_OAMethod @json, 'StringOf', @sTmp0 OUT, 'iv'
    EXEC sp_OAMethod @bdIv, 'AppendEncoded', @success OUT, @sTmp0, 'base64'

    -- Get an SHA1 digest (as a hex string) of the secret key.
    -- A SHA1 digest is 20 bytes.  Therefore the hex string is 40 chars.
    -- Treat each us-ascii char as a binary byte of the secret key.
    -- 256-bit AES needs a 256-bit key, which is 32-bytes.  Therefore
    -- use the 1st 32 us-ascii chars of the hex SHA1 as the AES secret key.

    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.Crypt2', @crypt OUT

    -- Because we're using the hex string as the actual AES key, it matters whether the hex is uppercase or lowercase.
    -- We want lowercase.
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex_lower'
    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'sha1'
    DECLARE @hexSha1 nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'HashStringENC', @hexSha1 OUT, @secretKey

    PRINT @hexSha1

    -- Treat the hex string as binary data for the AES key..
    DECLARE @bdKey int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.BinData', @bdKey OUT

    EXEC sp_OAMethod @bdKey, 'AppendString', @success OUT, @hexSha1, 'us-ascii'
    EXEC sp_OAMethod @bdKey, 'RemoveChunk', @success OUT, 32, 8

    EXEC sp_OASetProperty @crypt, 'KeyLength', 256
    EXEC sp_OASetProperty @crypt, 'CryptAlgorithm', 'aes'
    EXEC sp_OASetProperty @crypt, 'CipherMode', 'cbc'

    -- We can use any encoding because were just getting the binary bytes in an encoding, and then setting from the same encoding.
    -- We'll just use base64..
    EXEC sp_OAMethod @bdIv, 'GetEncoded', @sTmp0 OUT, 'base64'
    EXEC sp_OAMethod @crypt, 'SetEncodedIV', NULL, @sTmp0, 'base64'
    EXEC sp_OAMethod @bdKey, 'GetEncoded', @sTmp0 OUT, 'base64'
    EXEC sp_OAMethod @crypt, 'SetEncodedKey', NULL, @sTmp0, 'base64'

    EXEC sp_OAMethod @crypt, 'DecryptBd', @success OUT, @bdNotif

    EXEC sp_OAMethod @bdNotif, 'GetString', @sTmp0 OUT, 'utf-8'
    PRINT 'Decrypted: ' + @sTmp0

    EXEC @hr = sp_OADestroy @json
    EXEC @hr = sp_OADestroy @bdNotif
    EXEC @hr = sp_OADestroy @bdIv
    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @bdKey


END
GO