I'm not sure how this passed the GitHub checks.
filesystem: store mountpoint in link files as a fallback
Make remove-protector-from-policy work even if the protector cannot be loaded (for example, due to having been deleted already). Fixes https://github.com/google/fscrypt/issues/258 Fixes https://github.com/google/fscrypt/issues/272
Currently, linked protectors use filesystem link files of the form "UUID=<uuid>". These links get broken if the filesystem's UUID changes, e.g. due to the filesystem being re-created even if the ".fscrypt" directory is backed up and restored. To prevent links from being broken (in most cases), start storing the mountpoint path in the link files too, in the form "UUID=<uuid>\nPATH=<path>\n". When following a link, try the UUID first, and if it doesn't work try the PATH. While it's possible that the path changed too, for login protectors (the usual use case of linked protectors) this won't be an issue as the path will always be "/". An alternative solution would be to fall back to scanning all filesystems for the needed protector descriptor. I decided not to do that, since relying on a global scan doesn't seem to be a good design. It wouldn't scale to large numbers of filesystems, it could cross security boundaries, and it would make it possible for adding a new filesystem to break fscrypt on existing filesystems. And if a global scan was an acceptable way to find protectors during normal use, then there would be no need for link files in the first place. Note: this change is backwards compatible (i.e., fscrypt will continue to recognize old link files) but not forwards-compatible (i.e., previous versions of fscrypt won't recognize new link files). Fixes https://github.com/google/fscrypt/issues/311
Forbid 'fscrypt setup' on filesystems that aren't expected to support encryption (other than the root filesystem), and skip looking for fscrypt metadata directories on such filesystems. This has two benefits. First, it avoids the printing of annoying warnings like: pam_fscrypt[75038]: stat /run/user/0/.fscrypt: permission denied pam_fscrypt[75038]: stat /run/user/0/.fscrypt/policies: permission denied pam_fscrypt[75038]: stat /run/user/0/.fscrypt/protectors: permission denied pam_fscrypt[75038]: stat /sys/firmware/efi/efivars/.fscrypt: invalid argument pam_fscrypt[75038]: stat /sys/firmware/efi/efivars/.fscrypt/policies: invalid argument pam_fscrypt[75038]: stat /sys/firmware/efi/efivars/.fscrypt/protectors: invalid argument pam_fscrypt[75038]: stat /sys/fs/pstore/.fscrypt: permission denied pam_fscrypt[75038]: stat /sys/fs/pstore/.fscrypt/policies: permission denied pam_fscrypt[75038]: stat /sys/fs/pstore/.fscrypt/protectors: permission denied Second, it avoids long delays or side effects on some filesystems. To do this, introduce an allowlist of filesystem types that fscrypt will recognize. I wanted to avoid doing this, since this list will need to be updated in the future, but I don't see a better solution.
When the root user creates a login protector for a non-root user, make sure to chown() the protector file to make it owned by the user. Without this, the protector cannot be updated by the user, which causes it to get out of sync if the user changes their login passphrase. Fixes https://github.com/google/fscrypt/issues/319
Fixes #123
As per the feedback at https://github.com/google/fscrypt/issues/115 where users didn't understand that the recovery passphrase is important, restore the original behavior where recovery passphrase generation happens automatically without a prompt. This applies to the case where 'fscrypt encrypt' is using a login protector on a non-root filesystem. However, leave the --no-recovery option so that the recovery passphrase can still be disabled if the user really wants to. Also, clarify the information provided about the recovery passphrase. Update https://github.com/google/fscrypt/issues/115
These confuse the latest version of shellcheck into thinking that functions which take no arguments actually take arguments, which triggers a bunch of warnings like "Use func "$@" if function's $1 should mean script's $1", which causes 'make lint' to fail. These checks aren't too useful, so just remove them.