MrMick - Decoding Base64 files!!

Hi there,

MrMick very kindly answered a question of mine a few day ago and provided me with a routine to encode a file into base64.  I've used this routine and it works fine but would now like the ability in my app to decode these files as well.

Has anyone got a VB sub that will do this?

Thanks

Pete
LVL 2
peterwestAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

clifABBCommented:
Most encryption routines will decrypt if the encrypted object is run through the encryption again.
0
clifABBCommented:
Make a backup of the file first!
0
peterwestAuthor Commented:
I don't think Base64 will decrypt the file by running it through again!!!  I've already tried that and it didn't work.
0
The Ultimate Tool Kit for Technolgy Solution Provi

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy for valuable how-to assets including sample agreements, checklists, flowcharts, and more!

sbmcCommented:
Base64 encoding works in chunks of three bytes converted to four bytes. Decoding works by grabbing 4 byte chunks and converting these 4 bytes into 3 bytes as follows:
   1. grab 4 bytes
   2. convert to binary ie 32 bits
   3. remove 1st 2 bits of every byte
   4. divide the resulting 24 bits into 3 8bit chunks
   5. convert each 8 bit string into a byte
   6. repeat 1-6 for each group of 4 byte strings in your file

0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
peterwestAuthor Commented:
Thanks,

I've already got the necessary routine to decode Base64 but it is useful to understand how it works - maybe i'll even write my own routine as the one i'm using at the moment is a little convoluted and inefficient (or at least it would appear so).

Pete

0
peterwestAuthor Commented:
Thanks,

I've already got the necessary routine to decode Base64 but it is useful to understand how it works - maybe i'll even write my own routine as the one i'm using at the moment is a little convoluted and inefficient (or at least it would appear so).

Pete

0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic Classic

From novice to tech pro — start learning today.