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path: root/actions/recovery.go
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2026-04-14recovery: add O_NOFOLLOW|O_EXCL to prevent symlink-following in recovery ↵Karan Kurani
file creation WriteRecoveryInstructions() opens the recovery README with os.OpenFile using O_WRONLY|O_CREATE without O_NOFOLLOW. When fscrypt encrypt runs as root, this allows a local attacker to place a symlink at the recovery file path, causing root to write through the symlink and then fchown the target file to the attacker. Adding O_EXCL|O_NOFOLLOW aligns with the existing security pattern in filesystem.go:608 and filesystem.go:747.
2022-04-08Switch to google.golang.org/protobuf/protoEric Biggers
github.com/golang/protobuf/proto has been deprecated in favor of google.golang.org/protobuf/proto, so migrate to the non-deprecated one.
2022-02-23Make all new metadata files owned by user when neededEric Biggers
Since commit 4c7c6631cc5a ("Set owner of login protectors to correct user"), login protectors are made owned by the user when root creates one on a user's behalf. That's good, but the same isn't true of other files that get created at the same time: - The policy protecting the directory - The protector link file, if the policy is on a different filesystem - The recovery protector, if the policy is on a different filesystem - The recovery instructions file In preparation for setting all metadata files to mode 0600, start making all these files owned by the user in this scenario as well.
2021-10-05Adjust recovery passphrase generationEric Biggers
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
2020-05-09actions/protector: improve errorsEric Biggers
ErrProtectorName: Rename to ErrLoginProtectorName for clarity, and include the name and user. ErrMissingProtectorName: Include the correct protector source. ErrDuplicateName: Rename to ErrProtectorNameExists for clarity, and remove a level of wrapping by including the name directly. ErrDuplicateUID: Rename to ErrLoginProtectorExists for clarity, and remove a level of wrapping by including the user directly.
2020-01-28actions/recovery: revert protector if it can't be added to policyEric Biggers
Ensure that a failed AddRecoveryPassphrase() doesn't leave around an unneeded protector file.
2020-01-27actions/recovery: ensure recovery passphrase is really custom_passphraseEric Biggers
If the login protector was just created by the same 'fscrypt encrypt' command, then policy.Context.Config.Source will be pam_passphrase. This needs to be overridden to custom_passphrase when creating the protector for the recovery passphrase. This fixes the following error: fscrypt encrypt: login protectors do not need a name Resolves https://github.com/google/fscrypt/issues/187 Update https://github.com/google/fscrypt/issues/186
2020-01-22Automatically generate recovery passphrase when usefulEric Biggers
If a user re-installs their system (or otherwise loses the /.fscrypt directory on the root filesystem) they also lose access to any login passphrase-protected directories on other filesystems, unless additional protectors were manually added. This can be unexpected, as it may be expected that the old login passphrase would still work. We can't really fix this by storing a login protector on every filesystem because: - If a user were to have N login protectors, it would take them N times longer to log in, as every login protector would need to be unlocked. - If a user were to change their login passphrase while any external volumes were unmounted, login protectors would get out of sync. - It's preferable that an external volume isn't unlockable by itself using only a login passphrase, as login passphrases are often weak. Instead, generate a recovery passphrase when creating a login passphrase-protected directory on a non-root filesystem. The recovery passphrase is added as a custom_passphrase protector, thus giving the policy two protectors: one pam_passphrase and one custom_passphrase. Then this passphrase is written to a file in the new encrypted directory. Writing the passphrase to a file here is okay since it's encrypted, but it's obviously useless by itself; it's up to the user to store this passphrase somewhere else if they need it. Use a recovery passphrase instead of a "recovery code" that encodes the policy key directly because a passphrase is more user-friendly: it can safely be made much shorter than a key, and it works just like any other fscrypt protector. Also, it's not as critical to allow recovery when the .fscrypt directory on the *same* filesystem is deleted. Resolves https://github.com/google/fscrypt/issues/164