Just to recap for anyone following. One of the problems that Glenn found was a timing issue with Visual FoxPro that required doevents and autoyield in Visual FoxPro to fix (the FLL was doing what it was supposed to be doing). The other two problems Glenn ran into were caused by a critical bug in the AES C++ code... note to self I have to be careful to play nice with Visual FoxPro when moving stuff around in memory. Anyways... the problems have been fixed and a new FLL is available for download.

New FLL and example use code can be found at:
http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,06a3d44e-c3aa-4f0d-9937-06441c59e840.aspx

I did a few other things besides fixing the bugs...

1. Simplified the encryption/decryption functions. Now there is just a Encrypt() and Decrypt() function. This will be the last time I change the function signatures in such a way as to make it non-backward compatible... I figured now was the time to make the change before this thing started to be heavily used.

2. Added a new encryption algorithm TEA - known for being secure and also super fast.

3. Started debugging the direct file encryption/decryption functions -- EncryptFile()/DecryptFile()

So anyways, this FLL appears to be stable and useful. An increase in use will soon ferret out anything that has been missed. I will continue to address issues and add functionality to this in a very timely manner. Thanks again Glenn for the repro code and helping me make this FLL better.

>I started my testing and may have found a problem??? I sent a email to you with the test code for VFP8.0. Maybe I fouled something.
>
>Glenn
>
>>Your welcome Glenn. Feedback is always appreciated. Most of the base algorithms are derived from established code, but should you find any bugs or have a feature/enhancement suggestion, please feel free to leave a comment on my blog. I monitor the comments there closely, and make it a point to respond in a timely manner (not only to the comment, but also with new versions fixing problems in any of the projects). Keep me posted on how it worked out for you.
>>
>>>Thanks Craig, I will give it a "go". We will be encrypting strings to and from table fields. This sounds like a match made in heaven!
>>>
>>>Will you be needing "Beta" feedback?
>>>
>>>Glenn
>>>
>>>>Hi Glenn,
>>>>
>>>>I've been working on an FLL that you might find useful in your endeavours. It's freely available on my blog and includes AES and Blowfish encryption functions, as well as the following hash functions: SHA1, SHA256, SHA384, SHA512, MD5, RIPEMD128, and RIPEMD160. Here's the permalink to the blog entry detailing the AES functions, there is a download link for the FLL in that entry as well:
>>>>
>>>>http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,5f4231f7-abc5-4649-a74d-6779f0bce659.aspx
>>>>
>>>>I'll be adding more to this as I go along, it's a pretty good start for now. I will be working in more features that will allow Visual FoxPro developers to use seemlessly in a variety of ways... in other words, more good stuff to come. Hopefully the simple aesencrypt and aesdecrypt functions will suit your needs, if you have data that is non-string... then you will need to convert it using Transform(), Filetostr(), or Strtofile() - or something similar.
>>>>
>>>>>Does anyone have any GOOD experience with a third party tool for doing AES strong encryption on table fields?
>>>>>
>>>>>Thanks
>>>>>
>>>>>Glenn