Yes. LUKS/dm-crypt/cryptsetup is available for Fedora, and AES 256 is supported.
But, if you are asking if the Fedora Installation GUI will allow you to do this, I do not know. It may default to AES-XTS with 256 bit keys--but I don't know.
However, this really isn't a distribution specific problem. LUKS, dm-crypt, cryptsetup, and kernel mods are a kernel level problem, and applies to each distribution.
ArchLinux generally has good info on technologies such as this.
https://wiki.archlinux.org/index.php/Dm-crypt/Device_encryption
Search for this line on that page:
# cryptsetup -v --cipher aes-xts-plain64 --key-size 512 --hash sha512 --iter-time 5000 --use-random luksFormat <device>
Other Relevant Questions to Ask:
- How to Configure/Install LUKS after installation.
- How to encrypt Linux mount points after installation.
- How to encrypt Linux swap partitions.
- How to load dm-crypt kernel mods, to decrypt drive at boot.
- How to configure Grub and/or SysLinux to mount encrypted partitions at boot.
- How to configure crypttab and fstab to mount partitions at boot.
- How to configure Linux to mount LUKS partitions, EncFS or ecryptFS at login.