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

getRandomBytes(size)

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

returns = size * randome bytes

pbkdf(password, salt)

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

sign(data, key)

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

verify(data, key, mac, length)

data = the stuff

key = made with pbkdf()

mac = hmac made from data and signature

length = size of data in bytes

returns = a resolved promise

hash(data)

data = stuff to make hash

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

encrypt_AES_CBC_HMAC(data, key)

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:

{
  iv,
  data,
  mac
}

decrypt_AES_CBC_HMAC(data, key, iv, mac)

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

base64FromBytes(data)

data = a Uint8Array of stuff

returns = the equivalent base64 representation of that stuff

base64ToBytes(data)

data = a base64-encoded string

returns = the equivalent Uint8Array representation of that string

hexFromBytes(data)

data = a Uint8Array of stuff

returns = a hex string representation of that stuff

hexToBytes(data)

data = a hex-encoded string

returns = a Uint8Array representation of that string

compress(data)

data = a string of data you want to compress

returns = a Uint8Array of compressed data

decompress(data)

data = a Uint8Array of compressed data

returns = a plain string of data

encodeBase64(data)

data = a UTF-8 encoded string

returns = an equivalent base64-encoded string

decodeBase64(data)

data = a base64-encoded string

returns = an equivalent UTF-8 encoded string

verifyMac(data, key, mac, calculatedMac, length)

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

pack(data, iv, mac)

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

unpack(data)

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:

{
  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.