cfssh(1)

cfssh1

(somewhat) secure cfs shell

Usage

cfssh directory

Overview

cfssh uses cattach(1) to associate the encrypted directory (previously created with cmkdir(1)) with a randomly selected name. Once the correct passphrase is provided, cfssh invokes a new shell with the random directory in /crypt as its working directory. When the shell exits, the temporary attach name is deleted with cdetach(1). Since the generated names are somewhat obscure and are hidden from view with CFS's "." mechanism, casual attackers cannot easily exploit the attached cleartext even if they can spoof the UID of the user.

Releases

Unchanged in 3 releases since Debian 3.0 (Woody).

  1. 3.0–4.0

Bugs

The temporary names generated are not random in any cryptographically strong sense, so this command should really only be viewed as an example. A determined attacker could probably guess the generated name by exploiting the known properties of the way the ksh random function is seeded.

There's no hiding from an attacker who can compromise root on the client system while an attach is active.

Author

Matt Blaze; for information on cfs, email to [email protected].

From cfs 1.4.1-17 in Debian 4.0 (Etch). Parsed by carta from the page's man source.