Command Line decryption of aes-256-gcm no-longer working after OpenSSL updated

Question

Late last year (2022) I encrypted a file using OpenSSL using terminal on my Mac with a very simple openssl enc command and was able to decrypt using this command:

openssl enc -d -aes-256-gcm -in filename.lock  -out filename.unlock

Fast forward to now (early 2024), it appears that when openssl updated I now receive an error message of "AEAD ciphers are not supported".

After much research, I believe I understand why I'm getting this message, but not sure what to do.

Is there a way to downgrade back to an older version of openssl? I would really like access back to this file. Thank you in advance for your help!

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Update: Something I found in the comments of another post on Stack Overflow may be a similar situation. The user said they were:

"I am using OpenSSL version of OpenSSL 1.1.1c and by using LibreSSL I am able encrypt and decrypt"

Answer 1

I ended up solving the issue by finding an old machine running MacOS version 11.6.4 at work which had an older version of LibreSSL. That machine let me run the decrypt command like I did previously on my machine - problem solved and I will not be using aes-256-gcm for this in the future.

Thank you to everyone for your ideas. I knew walking down the path of downgrading was going to be a nightmare most likely and could break something else.

This is by far an area I'm a novice in so thank you Cpt.Whale and Gordon Davisson for offering helpful guidance.