I hope this is the correct category for my question.

I'm trying to decrypt my messages without involving the Joplin App (for a project I'm doing). When using openssl_decrypt (in PHP) I get this message "Setting of IV length for AEAD mode failed"

What am I missing to get the IV length correct? (I'm base64 decoding it before usage, as it looks base64 encoded)

Do any of you have experience with this?

Kim Andersen

@kimdk welcome to the forum.

I am not knowledgeable about Joplin encryption but I have seen the below information linked in other posts. Thought I'd mention it just in case it helps.

This thread makes reference to Joplin using the Stanford Javascript Crypto Library and also links to code on GitHub.

This page gives further information on Joplin E2EE.

Hi dpoulton
Thanks for your answer.

I saw those posts, but I can't figure out why I can’t make it work.

From this git hub (dot) com/laurent22/joplin/issues/3937 (sorry for the bad link - I'm not allowed to use links) I infer that PHP is not a preferable way for decoding Joplin messages.

Then I tried in plain bash using OpenSSL, and using the "aes-128-ccm" cipher, I am getting another error saying "AEAD ciphers not supported". Using "aes-128-cbc" I get a "bad magic number" error.

Some things I definitely miss in my understanding