Diceware Passphrase Generator

Bash script to create passphrases from any diceware list.

Description

This script can generate (pseudo-)random passphrases from diceware lists like this one using the Bash variable SRANDOM. It can also be used to simulate rolling five dices simultaneously for a set amount of times to get random results to be used with diceware lists.

Note that from a cryptographic point of view, it's always better to use actual dice instead of a script to generate random numbers.

Settings

Two variables can be set in diceware.conf (has to be in the same folder as the script):

Default word list

defaultdwfile The standard word list to be used. This can be a link to an online file or a local file. Has to be a text file with a list of either 1296 or 7776 words (i.e rolling four resp. five 6-sided dice simultaneously).

If this is set to a link to an online resource, the script will check for updated versions on each run and download an updated version automatically. If checking for updates is not wanted after the first download, the variable can be changed to use the local file the script has previously downloaded.

Default is this excellent and carefully curated German word list by dys2p (created after the excellent example of this English list by the EFF).

List format has to be as follows (see here for examples in various languages):

1111 word1
1112 word2
...
6665 word1295
6666 word1296

or

11111 word1
11112 word2
...
66665 word7775
66666 word7776

Default passphrase length

defaultlength Amount of words constituting the passphrase / times the dice are thrown together.

Usage

./diceware.sh [passphrase length] [options]
	or
./diceware.sh [options] [passhrase length]

Possible command arguments:

• any number without a flag: passphrase length
• -f [word list file]: set a custom word list file to use for this run
• -n: only simulate dice rolls without using a word list.
• -h: show help

Default mode

If run without any arguments, the script will generate a six-word passphrase from the word list set in the configuration file diceware.conf. If another default passphrase length is set in the configuration file, it will generate a passphrase containing as many words as the number there.

Custom passphrase length

./diceware.sh [passphrase length]

If a number is passed with the command before, after or without another argument, this number overrides the default passphrase length set in diceware.conf. The script will generate a passphrase containing as many words as the number passed with the command.

Example:

./diceware.sh 8

Output:

word1 word2 word3 word4 word5 word6 word7 word8
word1-word2-word3-word4-word5-word6-word7-word8
--
Dice roll results: 11111 22222 33333 444444 55555 66666 12345 23456

Custom word list file

./diceware.sh -f [word list file]

If the path to a word list file is passed after the flag -f, this file is used instead of the default word list set in diceware.conf.

Unlike diceware.conf this can only be a local file, not a link to an online resource. It has to contain 1296 or 7776 words with their corresponding numbers from 1111 to 6666 resp. 11111 to 66666 (see settings for more information on the required format).

Examples:

./diceware.sh -f /homer/user/diceware/diceware-7776.txt

This will generate a passphrase from the words in the file /homer/user/diceware/diceware-7776.txt. The passphrase will consist of as many words as set in the configuration file. It will consist of 6 words if nothing is set there.

This option can be used in combination with a custom passphrase length:

./diceware.sh 8 -f /homer/user/diceware/diceware-7776.txt

This will generate an 8-word passphrase from the words in the file /homer/user/diceware/diceware-7776.txt

This is also possible:

./diceware.sh -f /homer/user/diceware/diceware-7776.txt 8

This is not possible:

./diceware.sh -f 8 /homer/user/diceware/diceware-7776.txt

Default settings will be used instead.

Only numbers mode

./diceware.sh -n

If the flag -n is used, random rolls of five dice will be simulated and the results will be printed to screen. No word list will be used and no passphrase will be generated.

Examples:

./diceware.sh -n

This will print blocks of five randomly generated digits between 1 and 6 to the screen. By default the output will be as many blocks as the value of defaultlength in diceware.conf. If nothing is set there, it will be six 5-digit blocks.

This option can be used in combination with a custom passphrase length:

./diceware.sh 8 -n

This will output 8 randomly generated 5-digit blocks consisting of numbers between 1 and 6.

This is also possible:

./diceware.sh -n 8

Requirements

• bash > 5.1
• curl