talisein/ppgen

Passphrase Generator (via console, C++14)

ppgen

Passphrase Generator

Requirements

C++14 compiler, acceptance of GPLv3+.

Uses meson and ninja to build.

Description

This simple command line program utilizes the EFF or Diceware wordlist to generate a passphrase with the number of words you desire. I use it to generate answers to security questions.

Why use THIS one?

A quick look through some of the many other generators shows they are not trivially inspectable. You want to trust the code of your passphrase generator! Even if you are not a skilled programmer, you can look at ppgen.cpp and see it is dead simple with no room for dirty tricks. Including the GPLv3 disclaimer, it is 64 lines. So you can plainly see:

• It seeds the random number generator from your system's random device.
• It uses a uniform distribution.
• I've GPG-signed all commits.

The only complexity caveat here is the use of the PCG-Random library. The PCG whitepaper convinces me that the C++14 standard library has too many shortcomings. This means that meson will download the PCG-Random library from github, and a meson wrap file from my dropbox. This is a tough compromise for a tool that is supposed to be easy to audit. My apologies.

Thanks to

The default wordlist was created by the Electronic Frontier Foundation (@EFForg), provided under the Creative Commons CC-BY 3.0 license. You can read their design criteria here, and you can read about how to use physical dice to generate your passphrases here.

The alternative wordlist comes from the classic Diceware, by Arnold Reinhold (@agreinhold). He has provided the wordlist under the Creative Commons CC-BY 3.0 license.

The random number generator used is the PCG-Random C++ library, by Melissa O'Neill (@imneme). While I am normally partial to pure STL implementations, Prof. O'Neill makes a compelling case that the C++14 RNG toolkit has too many shortcomings. This library is available under the Apache 2.0 license.

Building & Running

# mkdir build
# cd build
# meson ..
# ninja
# sudo ninja install # (Optional)
# ./ppgen
ppgen  Copyright © 2016 Andrew Potter
This program comes with ABSOLUTELY NO WARRANTY;
This is free software, and you are welcome to redistribute it
under certain conditions.

Using 6 words will give you 77.5489 bits of entropy.

Choose from one of these 10 passphrases:

untried umbilical detection spoken moonshine reps
storage immersion unshipped moaner empirical renewably
devotee prancing chewing climatic erasable backache
herself theology enlisted bobble skyward unlisted
harmful sabotage undefined knickers marlin case
tiger confider recluse populace relocate ecology
demeaning scooter naturist provider relieve nastiness
magnitude flounder scratch caddie plug earplugs
cornball unbridle depraved gerbil bundle engaging
freewill diaphragm guzzler amigo unbaked magnetize

# ./ppgen --diceware -n 10
ppgen  Copyright © 2016 Andrew Potter
This program comes with ABSOLUTELY NO WARRANTY;
This is free software, and you are welcome to redistribute it
under certain conditions.

Using 10 words will give you 129.248 bits of entropy.

Choose from one of these 10 passphrases:

disk flat slain puck cook menlo extra ue 42nd 7
due useful cecil tardy warty evil skim cock apex yap
chess mobil hoyt aiken errand fed carob jerry dull billy
cheek ghent cozy lane infra nymph pate krause red cruel
asset seat marks ruin hand wiley warmth patch aver 4th
almost oa align image bauer warm js madman cairo cider
stu basel dj rode 29th tonsil flout muslim tid usage
exact sara green label bacon yond ez march that alba
gain + cj muggy usage akin gc prom vo byrne
over ive buck preen hay vv cauchy sturm ghetto smug