Custom SSH key callback that serves key data from memory.
Used when key_data is set in SSH config, allowing keys to be
provided without writing them to disk (e.g. fetched from 1Password via op read).
Custom SSH key callback that serves key data from memory.
Used when key_data is set in SSH config, allowing keys to be
provided without writing them to disk (e.g. fetched from 1Password via op read).