Altpass

A Ruby gem and command-line utility for generating passwords derived from hand-alternating, visually unambiguous, alphanumeric characters.

Example

nXH3ix9w

General Characteristics

alternates hands (currently only supports QWERTY keyboard layout)
always starts with a lower-case character (left-hand first for odd-length passwords; right if even)
always ends with a left-hand character (so that the right-hand can finalize the hand alternation by hitting Enter/Return)
all characters are alphanumeric; there are no symbols (so the passwords highlight when double-clicked)
all characters are visually unambigous (some fonts make it difficult/impossible to distinguish zero and capital 'o', or one and lowercase 'L', and uppercase i, etc. so such characters are purposely not used)

The "memorizable" pattern

the "memorizable" pattern is: lower, UPPER, UPPER, number, lower, lower, number, lower
this pattern repeats for longer passwords

At a glance, a password such as nXH3ix9w looks incredibly difficult to memorize, but practicing it 5-10 times usually does the trick, particularly after first taking note of the pattern.

Options

make passwords of any length (:length => [0-9]+)
use the memorizable pattern or not (:memorizable => true|false)
show the sample sets and number of permutations (:permutations => [vvv]) (more v's increase verbosity)

Defaults

:length => 8
:memorizable => true

Examples of Gem Usage

Return a default password:

Altpass.generate
 => "uGL4ox7f"

Return an odd-length password, not using the memorizable pattern:

Altpass.generate(:length => 15, :memorizable => false)
 => "cH5L3jwyw9XPw8V"

Return an even-length password, not using the memorizable pattern:

Altpass.generate(:length => 16, :memorizable => false)
 => "uV7AhspqySkBUwhs"

Return the number of permutations:

Altpass.permutations(:length => 16, :memorizable => false)
 => 2869959681148181529600

Print the sample sets and permutation calculation of a default password, and return the number of permutations:

Altpass.permutations(:length => 8, :memorizable => true, :permutations => 'vvv')
sample sets:
["y", "u", "i", "o", "p", "h", "j", "k", "n", "m"]
["Q", "W", "E", "R", "T", "A", "S", "D", "F", "G", "Z", "X", "C", "V", "B"]
["Y", "U", "P", "H", "J", "K", "L", "N", "M"]
["2", "3", "4", "5"]
["y", "u", "i", "o", "p", "h", "j", "k", "n", "m"]
["q", "w", "e", "r", "t", "a", "s", "d", "f", "g", "z", "x", "c", "v"]
["7", "8", "9"]
["q", "w", "e", "r", "t", "a", "s", "d", "f", "g", "z", "x", "c", "v"]
10 * 15 * 9 * 4 * 10 * 14 * 3 * 14 permutations
 => 31752000

Installation

Add this line to your application's Gemfile:

gem 'altpass'

And then execute:

$ bundle

Or install it yourself:

$ gem install altpass

The Command-Line Utility

The command-line utility, altpass.rb, is built into the gem.

Example

$ altpass.rb 
nF7zHTNrjtYRmxod

Options

Usage: altpass.rb [options]
    -c                               Create default configuration file /Users/abatko/.altpass.yaml
    -l, --length [INTEGER>0]         Password length
    -m, --memorizable [true|false]   Use the memorizable pattern or not
    -p, --permutations [vvv]         Show permutation size; verbosity increases with v's
    -s, --switches                   Show password switches
    -h, --help                       Show this message

Configuration

Program defaults

The program itself comes with the following defaults:

options[:length] = 8
options[:memorizable] = true
options[:permutations] = false
options[:switches] = false

File override

Overrides program defaults.

cat ~/.altpass.yaml 
:length: 16
:memorizable: false

Command-line override

Command-line options override everything mentioned above. See Command-line Options above.

Examples of Command-Line Usage

These examples assume the above mentioned Configuration section is in effect.

$ altpass.rb 
nF7zHTNrjtYRmxod

$ altpass.rb -p
oDKfhfYznFN3j4Nv
2,869,959,681,148,181,529,600 permutations

$ altpass.rb --length 8 --memorizable true
kSU5yx9e

$ altpass.rb -l8 -mt -pvvv -s
jXJ3oc7z
sample sets:
["y", "u", "i", "o", "p", "h", "j", "k", "n", "m"]
["Q", "W", "E", "R", "T", "A", "S", "D", "F", "G", "Z", "X", "C", "V", "B"]
["Y", "U", "P", "H", "J", "K", "L", "N", "M"]
["2", "3", "4", "5"]
["y", "u", "i", "o", "p", "h", "j", "k", "n", "m"]
["q", "w", "e", "r", "t", "a", "s", "d", "f", "g", "z", "x", "c", "v"]
["7", "8", "9"]
["q", "w", "e", "r", "t", "a", "s", "d", "f", "g", "z", "x", "c", "v"]
10 * 15 * 9 * 4 * 10 * 14 * 3 * 14 permutations
31,752,000 permutations
--length 8 --memorizable true

Create a configuration file

Use the convenience of the -c switch to create a default configuration file:

$ altpass.rb -c
Created configuration file /Users/abatko/.altpass.yaml

$ altpass.rb 
yZH3jw9r

Note that once a configuration file exists, the -c option changes to show its content:

$ altpass.rb -h
Usage: altpass.rb [options]
    -c                               Show default configuration file /Users/abatko/.altpass.yaml
    ...                              ...
    ...                              ...
    ...                              ...

$ altpass.rb -c
Your altpass configuration file is /Users/abatko/.altpass.yaml
:length: 8
:memorizable: true
:permutations: false
:switches: false

Let's remove the configuration file, and create another one with custom settings:

$ rm ~/.altpass.yaml
remove /Users/abatko/.altpass.yaml? y

$ altpass.rb -c -l20 -mf
Created configuration file /Users/abatko/.altpass.yaml

$ altpass.rb -c 
Your altpass configuration file is /Users/abatko/.altpass.yaml
:length: 20
:memorizable: false
:permutations: false
:switches: false

$ altpass.rb 
mgYzNWjdy2JEMZ9emDy5

Recommended configuration and usage

If you create accounts frequently, and like to have unique passwords that are as long as the service you are signing up for allows, then consider this default: length 20, non-memoriable.

Create your configuration file as follows:

$ altpass.rb -c -l20 -mf

and simply override it at the command-line on a per-need basis (for instance, when the service has a shorter maximum):

$ altpass.rb -l16

Note that some services don't specify a maximum, yet they actually have one. In such cases, you may create your account with a password that will ultimately not let you log in, and you will have to use their "forgot/reset password" feature (consider also contacting that service and asking them to post the password length limit on their sign-up page).

Contributing

Fork it
Create your feature branch (git checkout -b my_new_feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my_new_feature)
Create new Pull Request