I tried the following

sudo cryptsetup luksChangekey /dev/nvme0n1p3 < new passphrase >

It then asks for the Sudo password, then asks for the old passphrase, but then it prints this error message

Failed to open key file.

what went wrong ?

Edit: turns out using GNOME Disks is way more straightforward… 😅, thank you all

    • 乇ㄥ乇¢ㄒ尺ㄖ@infosec.pubOPEnglish
      2·
      30 days ago

      It asks for the sudo password, then it prints

      No usable token is available.

      Then it asks : Enter passphrase for /dev/nvme0n1p3:

      After entering my old passphrase it prints:

      Key slot 0 unlocked
Command Successful.
      • booooop [any]@hexbear.netEnglish
        2·
        30 days ago

        Alright so no permission issue, what if you run the changekey command in a separate bash subprocess? sudo bash -c '($your-changekey-command-here)'

        • 乇ㄥ乇¢ㄒ尺ㄖ@infosec.pubOPEnglish
          2·
          30 days ago

          Is it like the same first “cryptsetup luksChangekey…” But inside parentheses ? Im sure I’m getting the syntax wrong… It prints

          bash: line 1: -luksChangekey: command not found