How can I decode a Laravel encrypted String in VB.Net

I can't seem to find a valid answer to this issue...

I am encrypting a password in Laravel using the built in Crypt::encrypt() helper function and passing in a simple string value (let's say 'abcde' for the purpose of this example) I don't want to install any 3rd party libraries in Laravel if I can help it. I also have my Laravel APP_KEY which is a string value starting with Base64:, but I'm not sure where this comes into it.

This generates me an encrypted string to which I pass down to a VB.Net application. I cannot workout how to simply decode the encrypted string in my application to pluck out the raw password of 'abcde'.

I have tried many examples that I can find online, but I keep getting errors about "Not a valid key" or "Not a valid Base64 string", etc.

Does someone have an example of a code snippet that will decode a Laravel encrypted string in .Net?

The best I can get to is breaking the encrypted string down into iv, value and mac, but I can't seem to get any further.

Any help would be appreciated.

via Chebli Mohamed