recover filevault external disk password from keychain

[al404]

I encrypted my external backup disk, and saved password into keychain
I forgot about that till today, i need to update firmware to WD external disk, since 10.12.4 they don't connect on startup

wen i attached the USB disk to an other mac, since i recommended that is the only device connected on update, it asked me for password

unfortunately I don't remember if I stored out of the keychain, I'm not sure how to look for it inside keychain

if is not possible to recover can i change the password? if i right click i can only see decode option

 

[Weaselboy]

Open Keychain and search for whatever the disk is named and you will see the entry like in my screenshot (Backup). Double click that and enter your Keychain password and it will allow you to see the encrypted disk's password.

If you cannot find it in Keychain, or you cannot remember it, there is no way to change the password or recover it.

 

[al404]

Thanks! I found it