blog/dispass_passwords.org

#+TITLE: Using DisPass to manage your passwords
#+DATE: 2016-02-14
#+COLESLAW_TAGS: dispass
#+OPTIONS: num:nil

*tl;dr*: If you don’t care about any of the back story and just want
to know how to use DisPass to manage passwords, skip to [[Managing
passwords]] for instant gratification.

* Introduction

  DisPass is a project that was started, and is still maintained, by a
  [[https://babab.nl][friend]] and former colleague of mine. I've been using it for quite
  some time. It helps me feel safe online, knowing that all my
  accounts have different and strong passwords.

  DisPass uses algorithms to make reproducible passphrases. Making it
  a kind-of functional password manager, just like Haskell is a
  functional programming language and Guix is a functional package
  manager. Given the same input DisPass will always produce the same
  output. This means that the generated passphrases are never stored
  anywhere and cannot be discovered by crackers[fn:1] and the like.

  The input for DisPass consists of a label, algorithm, length,
  possibly a sequence number (depending on the algorithm used) and
  finally a password. All but the label and password have some default
  value, but can also be specified through command-line switches.

* The Labelfile

  Being a functional anything usually means that whatever you're using
  doesn't maintain any state. This can be true for DisPass, but isn't
  necessarily so. It can be a challenge to remember the size,
  algorithm and sequence number for a large number of labels, so there
  is the labelfile.

  The labelfile is normally located in either
  ~$XDG_CONFIG_HOME/dispass/labels~ or ~$HOME/.dispass/labels~, but
  can also be specified on the command-line. It contains the metadata
  for the labels, and the labels themselves. This lets you run
  something like:

  : dispass generate foobar

  And it'll know the size, algorithm and sequence number for the label
  “foobar”, assuming you’ve saved it to the labelfile. The labelfile
  is unencrypted, but this information is useless as long as nobody
  knows the password(s) you use to generate the passphrases.

* Setting up

  DisPass is easy to install if you have either Archlinux or pip
  installed. Windows is a bit more problematic and I don’t even know
  how to get started on a Mac personally, but there is no reason it
  can’t work. It doesn’t have many dependencies, so you don’t need to
  install anything else first.

  The latest release is quite old, but a new release should be coming
  soon. There haven’t been too many developments since version
  0.3.0-dev because it basically does what it needs to do, and the
  user base is currently very small, so bugs might not be encountered
  too quickly. Don’t think that it’s an abandoned project, if you look
  at it’s [[https://github.com/babab/DisPass][github]] page you’ll see that it’s seen a bit of development
  again as of late.

  In the case of Archlinux I’ve provided packages in the AUR for both
  [[https://aur.archlinux.org/packages/python2-dispass/][python2-dispass]] version 0.2.0 and [[https://aur.archlinux.org/packages/python2-dispass-git/][python2-dispass-git]]. Installing
  either of these like any regular old aur package will get you set
  up. Incidentally, if you’re using Archlinux on x86_64 and have the
  testing package repository enabled, you could also use [[https://ryuslash.org/packages/][my package
  repository]], though no guarantees that it’ll ever work are given
  there.

  For a general pip installation it should be as easy as running:

  : sudo pip install dispass

* UIs

  Seeing as how my friend would like it to be generally useful, and
  he’s a VIM user, there is both a GUI and CLI interface. Since I’m an
  Emacs user I’ve created an Emacs and a Conkeror interface for it as
  well.

** CLI

   The CLI is what gets the most attention and gets developed the
   most. I will be working with this in the [[Managing passwords]]
   section.

** GUI

   There is a basic GUI included with dispass, it can be started with
   either the ~gdispass~ or the ~dispass gui~ commands. It requires
   tkinter to be installed. It doesn't do everything the CLI does, but
   there are plans to improve it and use a different gui library (such
   as Qt). In some situations it can copy the generated passphrases
   directly to the clipboard, but this is only true on GNU/Linux, not
   on Windows.

** Emacs

   I wrote an Emacs interface when I started using DisPass. It tries
   to copy the generated passwords directly to the clipboard, instead
   of needing the user to copy it manually as the CLI does. It can
   also insert generated passphrases into a buffer, such as the
   minibuffer.

   It's available on [[https://github.com/ryuslash/dispass.el][github]].

** Conkeror

   I also wrote a Conkeror interface some time later, because I didn't
   want to keep copying and pasting the passphrases through one of the
   other interfaces (usually Emacs). It inserts the generated
   passphrases into the focused input.

   It's also available on [[https://github.com/ryuslash/cdispass][github]].

** Wishlist

   As I mentioned, the idea is to expand the GUI and use a different
   gui library for it, to make it look a little better. The
   functionality should also be extended to do everything the CLI
   does.

   A Firefox extension is also still on the list of desirable
   interfaces. I'm not sure how plausible it is with the new
   WebExtension plugin api, I haven't looked into it yet. I don't
   think chrom(e|ium) allows developers to call external programs,
   which is an obstacle, but I haven't looked at this either.

* Managing passwords

  Now for the real fun. Generating passphrases is simple. Use the
  ~generate~ command:

  : dispass generate foobar

  If no entry exists in the labelfile for ~foobar~, it uses the
  defaults, which at the time of writing are a length of 30, and the
  algorithm ~dispass1~. This algorithm doesn't use a sequence
  number. It can generate more than one passphrase at a time.

  The generated passphrases are presented in an ncurses screen so they
  aren't kept in your terminal emulator's scrollback history, at least
  in some cases. You can use the ~-o~ switch to do away with the
  ncurses screen and just output a line for each generated
  passphrase. Together with something like awk this can be used to
  directly send some command the passphrase it needs. For example, if
  the program ~foo~ needs a password from stdin, you could use:

  : dispass generate -o foobar | awk '{ print $2 }' | foo

  You can specify a different length, algorithm and sequence number by
  using command line switches. For example, I normally prefer the
  ~dispass2~ algorithm since it adds a sequence number. For some crazy
  reason the place I use the passphrase limits it to a length of 16
  characters and I've had to change my password twice, so I use a
  sequence number of 3. I could use:

  : dispass generate -l 16 -a dispass2 -s 3 foobar

  It would be difficult to remember all this, so I personally would
  add it to the labelfile. To do this I can use the ~add~
  command. Basically this is:

  : dispass add foobar

  This creates an entry in the label file with the same default values
  as the generate command: a length of 30 and using the ~dispass1~
  algorithm. To use the values we used before we can instead do:

  : dispass add foobar:16:dispass2:3

  This way we can add multiple entries with different values at once:

  : dispass add foo:16 bar::dispass2:2

  This would add the ~foo~ label with a length of 16, using the
  default algorithm and the label ~bar~ with the default length, using
  the ~dispass2~ algorithm and the sequence number 2. As you can see
  you can omit any trailing parameters and leave any parameters in
  between empty to use their default values.

  If you added it before I showed you the extended add syntax you can
  use ~update~ to change an existing entry in the labelfile:

  : dispass update foobar 13:dispass2:3

  Unlike the ~add~ command, the ~update~ command only updates one
  label at a time.

  Now, the place I use my password was cracked by crackers[fn:1], my
  password was stolen. That's no biggie. I use the ~list~ command to
  check what my sequence number is:

  : dispass list

  Then I can update my labelfile and use a new sequence number:

  : dispass update foobar ::4

  I could also use the convenient ~increment~ command:

  : dispass increment foobar

  Everytime the sequence number is changed the input changes and so
  does the passphrase. So a simple call to the ~increment~ command
  will completely change your passphrase. This is nice, because
  otherwise I'd have to change either the label or the password used
  to generate the passphrase.

  Actually, I just quit the job where I used my ~foobar~ label. I
  still use many other labels and don't want my list to get too big. I
  also don't want to delete the label in case I ever need to get back
  in there, so I just disable it:

  : dispass disable foobar

  This keeps it in the labelfile, but commands such as ~list~ don't
  show it anymore. But then they really need me back, and since I'm
  now a freelance worker I can accommodate them, so I enable my label
  again:

  : dispass enable foobar

  But now the place where I use the ~foobar~ label has gone out of
  business (I mean, come on, using a maximum password length of 16 and
  getting cracked by crackers all the time, are you really surprised?)
  and their site has been taken offline. Now I really have no reason
  to keep this label around, so I remove it:

  : dispass remove foobar

* Cons

  Yes, this is an excellent project and I'm not just saying that
  because a friend of mine wrote it. There are some things that it
  just isn't suited for.

  When sharing a single account with someone else (don't do this!),
  you can't expect the other party to use the same label and password
  to generate the passphrase, if they're even tech-savvy enough to use
  DisPass just like you. It also increases the amount of information
  you need to remember to use DisPass. There are better programs to
  store pre-generated passwords.

  Due to the way the current algorithms are implemented there is a
  limit to the length of the passphrases and that limit isn't entirely
  consistent. This is only a problem when you need passphrases of more
  than 100 characters, and I haven't had that problem yet.

* Footnotes

[fn:1] I refuse to use the term hackers, because to me that means
  something completely [[http://www.catb.org/jargon/html/C/cracker.html][different]], and I hope to you as well.