* Added the XChaCha20-Poly1305 encryption cipher. For new filesystems, this will be the default, but you're still able to create a filesystem with the previous default of AES-256-GCM
by saying "no" to the "use default settings?" question when creating the file system. Also, old filesystems will not be automatically converted and will keep using AES-256-GCM.
XChaCha20-Poly1305 is significantly slower than AES-256-GCM on modern CPUs, but it is more secure for large filesystems (>64GB).
For AES-256-GCM, it is recommended to encrypt at most 2^32 blocks, which at the CryFS default block size of 16KB would be 64GB. The more the filesystem grows above that, the
more likely it gets that a nonce gets reused and the two corresponding blocks become decryptable by an adversary. Other blocks would not be affected, but an adversary being
able to access those two blocks (i.e. 64KB of the stored data) is bad enough. See Section 8.3 in https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf
XChaCha20-Poly1305 does not suffer from this constraint and stays secure even if the filesystem gets very large.
* Add a --create-missing-basedir and --create-missing-mountpoint flag to create the base directory and mount directory respectively, if they don't exist, skipping the confirmation prompt.
* Fixed determining the user's homedir: If $HOME and the /etc/passwd entry for the current user contradict each other, now $HOME takes preference over /etc/passwd.
* When trying to migrate a file system from CryFS 0.9.3 or older, show an error message suggesting to first open it with 0.9.10 because we can't load that anymore.
* Use boost::stacktrace instead of libbacktrace to build stack traces. This fixes a segfault issue with platforms using libexecinfo and is generally more portable.
* File system nodes (files, directories, symlinks) store a parent pointer to the directory that contains them. This information can be used in later versions to resolve some synchronization conflicts.
* Allow mounting using system mount tool and /etc/fstab (e.g. mount -t fuse.cryfs basedir mountdir)
* CryFS tells the operating system to lock the encryption key to memory, i.e. not swap it to the disk (note: this is best-effort and cannot be guaranteed. Hibernation, for example, will still write the encryption key to the disk).
* Allow building with -DCRYFS_UPDATE_CHECKS=off, which will create an executable with disabled update checks (the alternative to disable them in the environment also still works).
* Ciphertext blocks are split into subdirectories (before, all were on top level) to reduce number of files per directory. Some unix tools don't work well with directories with too many entries.
* Renaming a file to an existing file (i.e. overwriting an existing file) didn't free the allocated memory for the overwritten file
* Renaming a file to an existing file could hurt an invariant in the directory layout (directory entries have to be sorted) and doing so could cause files to seemingly disappear.
* The generated .deb packages work for any Ubuntu/Debian based distribution, but will not install the package source for automatic updates if it's an unsupported operating system.
* Report file system usage statistics to the operating system (e.g. amount of space used). This information can be queried using the 'df' tool on linux. See https://github.com/cryfs/cryfs/commit/68acc27e88ff5209ca55ddb4e91f5a449d77fb54
* Use stronger scrypt parameters when generating the config file key from the user password. This makes it a bit more secure, but also takes a bit longer to load a file system. See https://github.com/cryfs/cryfs/commit/7f1493ab9210319cab008e71d4ee8f4d7d920f39
* Fix a bug where deleting a non-empty directory could leave some blocks over. See https://github.com/cryfs/cryfs/commit/df041ac84511e4560c4f099cd8cc089d08e05737
* Remove --extpass parameter, because that encourages tool writers to do bad things like storing a password in a file and using --extpass="cat filename".
The password can now be passed in to stdin without problems, so tools should use that.
* Works with zuluMount GUI, https://mhogomchungu.github.io/zuluCrypt/
* Fix a bug that prevented deleting symlinks, see https://github.com/cryfs/cryfs/issues/2
* Gracefully accept modifications to the file access times instead of failing, although they're not stored yet (they will be stored in 0.9.0). This should fix https://github.com/cryfs/cryfs/issues/4
* Config File Encryption: Configuration files are encrypted with two ciphers. The user specifies a password, which is then used with the scrypt KDF to generate the two encryption keys.
- Inner level: Encrypts the config data using the user specified cipher.
- Outer level: Encrypts the name of the inner cipher and the inner level ciphertext using aes-256-gcm.
The config file is padded to hide the size of the configuration data (including the name of the cipher used).
* No external config file needed: If the configuration file is not specified as command line parameter, it will be put into the base directory. This way, the filesystem can be mounted with the password only, without specifying a config file on command line.
* Better error messages when base directory is not existing, not readable or not writeable.
* Allow --cipher=xxx to specify cipher on command line. If cryfs is creating a new filesystem, it will use this cipher. If it is opening an existing filesystem, it will check whether this is the cipher used by it.
