| pmt-ehd(8) | pam_mount | pmt-ehd(8) |
pmt-ehd - create an encrypted disk image
pmt-ehd [-DFx] [-c fscipher] [-h digest] [-i cipher] [-k fscipher_keybits] [-t fstype] -f container_path -p fskey_path -s size_in_mb
Mandatory options that are absent are inquired interactively, and pmt-ehd will exit if stdin is not a terminal.
-D
Turn on debugging strings.
-F
Force operation that would otherwise ask for interactive confirmation. Multiple -F can be specified to apply more force.
-c cipher
The cipher to be used for the filesystem. This can take any value that cryptsetup(8) recognizes, usually in the form of "cipher-mode[-extras]". Recommended are aes-cbc-essiv:sha256 (this is the default) or blowfish-cbc-essiv:sha256.
-f path
Store the new disk image at path. If the file already exists, pmt-ehd will prompt before overwriting unless -F is given. If path refers to a symlink, pmt-ehd will act even more cautious.
-h digest
Digest used for fskey derivation from the password. This can take any value that OpenSSL recognizes. The default is sha1.
-i cipher
Cipher used for the filesystem key (not the encrypted filesystem itself). This can take any value that OpenSSL recognizes, usually in the form of "cipher-keysize-mode". Recommended is aes-256-cbc (this is the default).
-k keybits
The keysize for the cipher specified with -c. Some ciphers support multiple keysizes, AES for example is available with at least the keysizes 192 and 256. Example: -c aes-cbc-essiv:sha256 -k 192.
-p path
Store the filesystem key at path. The filesystem key is the ultimate key to open the encrypted filesystem, and the fs key itself is encrypted with your password.
-s size
The initial size of the encrypted filesystem, in megabytes. This option is ignored when the filesystem is created on a block device.
-t fstype
Filesystem to use for the encrypted filesystem. Defaults to xfs.
-u user
Give the container and fskey files to user (because the program is usually runs as root, and the files would otherwise retain root ownership).
-x
Do not initialize the container with random bytes. This may impact secrecy.
pmt-ehd can be used to create a new encrypted container, and replaces the previous mkehd script as well as any HOWTOs that explain how to do it manually. Without any arguments, pmt-ehd will interactively ask for all missing parameters. To create a container with a size of 256 MB, use:
pmt-ehd -f /home/user.key -p /home/user.enc -s 256