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.


Turn on debugging strings.


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).


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


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