Crypto Butter

Spread some crypto butter all over your project and scramble it into omelette-y
goodness ready to pour into the storage container of your choice. Also good for
squeezing into web inter-tubes for long-distance crypto flows. Act now, and get
all this, plus a limited time compression/decompression add-on for only six
monthly payments of $0.00.

Huh?

- convert between Uint8Array and base64 or hex using base64-js
- inflate & deflate your data using pako
- encrypt & decrypt with AES-256 CBC HMAC using a key of your choice
- sign & verify macs with SHA-512 signatures
- get random bytes
- PBKDF2 your PW using your own salt to get a SHA-256 hash

Why?

This just mashes some functions from Node's Crypto Lib with some string and
compression functions to make a little package of crypto goodies that can help
you get going with some random good times using a more basic interface.

Install

npm install crypto-butter

Usage

$3

size = how many bytes of randomness you want back as an int

returns = size * randome bytes

$3

password = a string that's, you know, not easy to guess ;)

salt = another string that's different than your password

returns = a promise that resolves to a key

$3

data = stuff you want to make a signature from

key = a key generated from pbkdf()

returns = a promise that resolves to a sha-512 hmac digest of your data smushed
together with your key

$3

data = the stuff

key = made with pbkdf()

mac = hmac made from data and signature

length = size of data in bytes

returns = a resolved promise

$3

data = stuff to make hash

returns = a promise that resolves to an sha-512 hmac digest

$3

data = Uint8Array of stuff you want to encrypt

key = a key generated from pbkdf()

returns = an object containing iv, data, and mac as Uint8Arrays formatted as:

``javascript
{
iv,
data,
mac
}
`

$3

data = ciphertext to be decrypted as Uint8Array

key = key generated by pbkdf()

iv = created from encrypt function as Uint8Array

mac = created from encrypt function as Uint8Array

returns = decrypted data as Uint8Array

$3

data = a Uint8Array of stuff

returns = the equivalent base64 representation of that stuff

$3

data = a base64-encoded string

returns = the equivalent Uint8Array representation of that string

$3

data = a Uint8Array of stuff

returns = a hex string representation of that stuff

$3

data = a hex-encoded string

returns = a Uint8Array representation of that string

$3

data = a string of data you want to compress

returns = a Uint8Array of compressed data

$3

data = a Uint8Array of compressed data

returns = a plain string of data

$3

data = a UTF-8 encoded string

returns = an equivalent base64-encoded string

$3

data = a base64-encoded string

returns = an equivalent UTF-8 encoded string

$3

data = data that is MACed

key = the key used to MACify the data

mac = the original mac to compare

calculatedMac = a newly calculated mac from the data to verify the data didn't
change compared to the original mac

length = length of mac in bytes

returns = true, or it throws an error in your face

$3

data = Uint8Array of data to pack

iv = iv created from encrypt function

mac = mac created from encrypt function

returns = a string of base64-encoded data separated by . formatted as
iv.data.mac

$3

data = a string created using pack() formatted as iv.data.mac

returns = an object containing the decoded iv, data, and mac each as Uint8Arrays
formatted as:

`javascript
{
iv,
data,
mac
}
``

Licesnse

MIT

Acknowledgements

I'm using base64-js for encoding
stuff and pako for compression stuff. The rest
of the crypto parts are from the
NodeJS Crypto module.