vault

Simple password generator. Given a passphrase and the name of a service, returns a strong password for that service. You only need to remember your passphrase, which you do not give to anyone, and this program will give a different password for every service you use. The passphrase can be any text you like.

Given the same passphrase and service name, the program will generate the same result every time, so you can use it to 'look up' those impossible-to-remember passwords when you need them.

According to Dropbox's zxcvbn password strength measure, if your dictionary English password takes about a second to crack, those generated by vault take over a million times the age of the observable universe to crack by brute force.

Why?

I have a terrible memory and like keeping my stuff safe. Strong service-specific passwords are hard to remember, and many services have stupid restrictions on passwords. I want to remember one phrase and have a machine deal with making my passwords strong.

Installation

This program is written in JavaScript and is available as a Node program:

npm install -g vault

To enable tab-completion for bash, add this to your .bashrc scripts:

which vault > /dev/null && . "$( vault --initpath )"

Usage

The most basic usage involves passing your passphrase and the service name; when you pass the -p flag you will be prompted for your passphrase:

$ vault google -p
Passphrase: *********
2hk!W[L,2rWWI=~=l>,E

You can set the desired length using -l:

$ vault google -p -l 6
Passphrase: *********
Tc8k~8

You can control the character types present in the output, either to disable certain types or make sure they are present. For example, to get a password with no symbols in it:

$ vault google -p --symbol 0
Passphrase: *********
Bb4uFmAEUnTPJh23ecdQ

To get a password containing at least one dash and uppercase letter:

$ vault google -p --dash 1 --upper 1
Passphrase: *********
2-[w]thuTK8unIUVH"Lp

Available character classes include:

• lower: lowercase letters, a-z
• upper: uppercase letters, A-Z
• number: the digits 0-9
• space: the space character
• dash: dashes (-) and underscores (_)
• symbol: all other printable ASCII characters

Finally, some sites do not allow passwords containing strings of repeated characters beyond a certain length. For example, a site requiring passwords not to contain more than two of the same character in a row would reject the password ZOMG!!! because of the 3 ! characters. Vault lets you express this requirement using -r or --repeat; this option sets the maximum number of times the same character can appear in a row.

$ vault google -p -r 2

Using your private key

Instead of a simple passphrase, vault can use a value signed using your private key as its input. Use the --key or -k option:

$ vault twitter -k

Which key would you like to use?

1: james@tesla, AAAAB3NzaC1y...+XRS6wsfyB7D
2: james@tesla, AAAAB3NzaC1y...B4vwPOArAIKb

Enter a number (1-2): 1
\vXY"xP}m7;,./eI{cz<

If you only have one private key, that is used automatically. If you have several, a menu is displayed as above using snippets from the corresponding public keys. You will be prompted to unlock the selected key if necessary.

Note that all the prompts shown to you while using vault are printed to stderr and the generated password to stdout, so you can pipe vault to pbcopy and you'll just get the password in your clipboard, i.e.:

$ vault twitter -k | pbcopy

Which key would you like to use?
# etc.

Saving your settings

If you like, you can store your passphrase on disk; vault will save it in a file called .vault in your home directory.

The .vault file is encrypted with AES-256, using your username as the key by default. You can set your own key using the VAULT_KEY environment variable. You can also change the location of the file using the VAULT_PATH variable, for example you might set VAULT_PATH=Dropbox/.vault to sync it using Dropbox. If you do this, make sure any files containing the key are NOT also exposed to third-party services.

To save your passphrase, pass the --config or -c flag:

$ vault -c -p
Passphrase: *********
$ vault google
2hk!W[L,2rWWI=~=l>,E

You can also configure character class settings this way:

$ vault -c --upper 0
$ vault google -p
Passphrase: *********
=hk|,;,>=r'}k=p-u>1p

Both the passphrase and the character class settings can be overridden on a per-service basis:

$ vault -c twitter --upper 1 --symbol 0

$ vault twitter -p
Passphrase: *********
Z2juOG1Z31BX1A9ET8Cn

$ vault google -p
Passphrase: *********
=hk|,;,>=r'}k=p-u>1p

If you're using your private key instead of a passphrase, you can save your --key setting. The config file ends up storing the public key, not the private key or any value derived from it. Next time you run vault, the public key is used to find the corresponding private key from ssh-agent.

$ vault -c -k

Which key would you like to use?

1: james@tesla, AAAAB3NzaC1y...+XRS6wsfyB7D
2: james@tesla, AAAAB3NzaC1y...B4vwPOArAIKb

Enter a number (1-2): 1

$ vault twitter
\vXY"xP}m7;,./eI{cz<

If you'd like to get a plain-text copy of the encrypted settings file, or import a previously exported settings file, you can use the --export and --import flags. --export writes the contents of the .vault file to the given path, while --import reads the given file and stores it encrypted in your .vault file. This can be used, for example, to change the encryption key:

$ VAULT_KEY=oldkey vault --export settings.json
$ VAULT_KEY=newkey valut --import settings.json

Or, you can use it if Vault changes its encryption algorithm in the future. Just use your current installation to export the settings, upgrade, then import.

$ vault --export settings.json
$ npm install -g vault
$ vault --import settings.json

Deleting saved settings

You can delete any saved setting using the --delete, --delete-globals and --clear options. (--delete is aliased as lowercase -x and --clear as uppercase -X.) --delete removes settings for an individual service, --delete-globals removes your global settings and --clear deletes all saved settings.

$ vault --delete twitter
This will delete your "twitter" settings. Are you sure? (Y/n): Y

$ vault --delete-globals
This will delete your global settings. Are you sure? (Y/n): Y

$ vault --clear
This will delete ALL your settings. Are you sure? (Y/n): Y

How does it work?

vault takes your passphrase and a service name and generates a hash from them using PBKDF2. It then encodes the bits of this hash using a 94-character alphabet, subject to the given character constraints. This design means that each password is very hard to break by brute force, and ensures that the discovery of one service's password does not lead to other accounts being compromised. It also means you can tailor the output to the character set accepted by each service. The use of a deterministic hash function means we don't need to store your passwords since they can easily be regenerated; this means there's no storage to sync or keep secure.

License

(The MIT License)

Copyright (c) 2011-2013 James Coglan

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.