Owen Taylor, creator of GNOME Shell and the Pango library, who is part of the working group for the development of Fedora for workstations, has proposed a plan for default encryption of system partitions and user home directories in Fedora Workstation. The advantages of switching to default encryption include data protection in case of laptop theft, protection against attacks on unattended devices, and maintaining privacy and integrity out of the box without the need for unnecessary actions.
According to the draft plan prepared for encryption, it is planned to use Btrfs fscrypt. For system partitions, encryption keys are planned to be stored in the TPM module and used in conjunction with digital signatures applied for integrity verification of the bootloader, kernel, and initrd (i.e., at system boot, the user will not need to enter a password to decrypt the system partitions). For home directories, keys are planned to be generated based on the user's login and password (the connection to the encrypted home directory will occur during user login).
The implementation timeline for the initiative depends on the distribution's transition to the Unified Kernel Image (UKI), which combines a handler for loading the kernel from UEFI (UEFI boot stub), the Linux kernel image, and the memory-loaded initrd system environment into a single file. Without UKI support, the immutability of the initrd environment, where keys for decrypting the filesystem are determined, cannot be guaranteed (for example, an attacker can replace initrd and simulate a password prompt; to avoid this, a verified boot of the entire chain is required before mounting the filesystem).
În forma sa actuală, instalatorul Fedora are o opțiune pentru criptarea volumelor la nivel de bloc utilizând dm-crypt, folosind o frază de parolă separată, care nu este legată de contul utilizatorului. Această soluție prezintă probleme precum inadecvarea pentru criptarea separată în sistemele multi-utilizator, lipsa suportului pentru internaționalizare și accesibilitate, posibilitatea de a efectua atacuri prin înlocuirea bootloader-ului (bootloader-ul instalat de atacator poate pretinde că este bootloader-ul original și poate solicita parola de decriptare) și necesitatea suportului pentru framebuffer în initrd pentru a afișa cererea de parolă.
Sursa: opennet.ro
