Helper Colletion

A bunch of useful functions and constants

Usage

const {auth,crypto,util,encoding,http_consts} = require('@scode/helper-collection');

// auth is a express middleware that uses a knex database conenction to authorize users
const authentication = auth(knex);

// add cookieParser to allow session management via cookies
app.use(cookieParser());
app.use(authentication.handler);

to create the necessary users table, add the following to your migrations

function up(knex) {
  await knex.schema.createTable ('users', (table) => {
    table.increments ('id');
    table.string ('name');
    table.string ('email');
    table.string ('password');
    table.string ('salt');
    table.boolean ('deleted')
      .default (false);
  });
}

// additionally it offers functions like create_user
const salt = crypto.create_salt();
const hash = crypto.hash_sha512('1234', salt);
authentication.create_user('test', 'test@example.com', hash, salt);

// helper functions include a bunch of different quick functions

// util
const json = util.try_parse_json('}!!invalid json') // returns null instead of throwing an error
const n = util.truncate_decimal(23.45678, 2); // n = 23.45

// crypto
const rand_hex = crypto.random_hex(16); // outputs 16 byte random hex
const rand_salt = crypto.create_salt(); // same as random_hex, but with fixed length of 32 bytes
const random_string = crypto.random_string(16) // output 16 character long random string
const hash = crypto.hash_sha512(random_string, random_hex); // returns sha 512 hex
const check = crypto.checksum('foo'); // returns a sha 256 hex
const argon = crypto.argon_hash(random_string); // returns an argon hash
const is_argon_valid = crypto.argon_verify(argon, random_hex); // returns false because a different input was used

// encoding
const hex = encoding.to_hex('abc'); // convert any encoding to hex, default is utf-8
const b64 = encoding.to_b64(hex, 'hex'); // convert any encoding to base64, default is utf-8
const utf8 = encoding.to_utf8(hex, 'hex'); // convert any encoding to utf-8, no default

// jwt like object signing
const signed = crypto.sign_object({foo: 'bar'}, 'secret');
const dec = crypto.decode_signed(signed); // decode a signed object without verifying the signature
const ver = crypto.verify_signature(signed, 'secret', 10000); // verifies the signature and returns the contents. the timeout is in milliseconds and optional, timing will be ignored if omitted.

// http consts contain useful constants like response codes

http_consts.status_ok // easier to understand than '200'

Breaking Changes

v2.0

• functions.random_string is now synchronous
• functions.random_hex
  • is now synchronous
  • uses length for the actual string length instead of the contained bytes
• functions.create_salt is now synchronous

v3.0

• functions.hash has been removed
  • replaced by hash_sha512 (different hash algorithm)
• all functions are now only accessible via their module
• new module structure:
  • crypto:
    • checksum
    • create_salt
    • decode_signed
    • get_signature_info
    • hash_sha512
    • random_hex
    • random_string
    • sign_object
    • verify_signature
  • util
    • try_parse_json
    • truncate_decimal
  • encoding
    • to_b64
    • to_hex
    • to_utf8
  • auth {...}
  • http_consts {...}

Deprecations

v2.4

• functions.hash has been deprecated since it was using pbkdf2
  • replaced by hash_sha512