Alfred 3 workflow for computing file checksums.
1) Install alfred-file-checksums workflow.
2) All further updates are handled automatically.
Select a file or multiple files in finder and invoke the alfred file actions, by default the ⌃⌘\ shortcut.
Choose the appropriate digest algorithm in displayed menu. Be aware, that a digest computation takes its time on large files, so be patient! By default, computed digests will be shown. This could be overridden by pressing the ⌘ key, which forces to put computed digests to clipboard.
Then, by default, the computed digests from selected files will be shown.