Sliced Software

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pwgen: Secure Password Generator

pwgen is a simple command line utility for generating secure passwords. I know what you're thinking, 'like I need another random String generator'. Well, pwgen does generate random Strings, yes, but pwgen can also generate passwords based on dictionary words. If you pass a dictionary file to pwgen, it will randomly choose a word from the list and manipulate it into a strong, memorable password.

It was pretty fun writing this little utility when it simply generated passwords but last night I came across a java port of getopt which led me to release my utility for all to use. I have to say that getopt is really excellent and if you are ever writing a command line utility that can be run with different options, I highly suggest it. In fact, I have been meaning to update some utilities I wrote for work and I may go back and incorporate getopt now.

The dictionary word manipulation is pretty interesting. I have a method that accepts a list of dictionary words, a minimum password length, a maximum password length and the maximum amount of characters to be replaced with random numbers. I randomly choose a dictionary word, say 'diversity'. Then I check to see if it is less than the maximum, if not, I randomly remove letters until it is the maximum password length. Then I choose a random number between 1 and the maximum amount of characters to be replaced with random numbers passed to the method, say 3. The number that gets picked may be 2, for example. Then I randomly select a character from the String and replace it with a random number from 0 to 9, two times (because 2 was picked). In this particular example, the generated string was 'd9ver1ity'. Perfectly secure, and not that hard to remember.

There are a lot of options for pwgen and running it with no flags or with -h will give you the whole list. Oh, also, I have bundled the source with the download and am releasing it under the BSD license. I also have a syntax highlighted version here.

Enjoy and may all of your passwords be nice and strong!