hashids

Hashids lets you obfuscate numerical identifiers via reversible mapping.


License
MIT

Documentation

Hashids

Build status Module Version Hex Docs Total Download License Last Updated

Hashids lets you obfuscate numerical identifiers via reversible mapping.

This is a port of Hashids from JavaScript.

Installation

Add Hashids as a dependency to your Mix project:

defp deps do
  [
    {:hashids, "~> 2.0"}
  ]
end

Usage

Hashids encodes a list of integers into a string (technically, iodata). Some of the encoding parameters can be customized.

s = Hashids.new([
  salt: "123",  # using a custom salt helps producing unique cipher text
  min_len: 2,   # minimum length of the cipher text (1 by default)
])

cipher1 = Hashids.encode(s, 129)
#=> "pE6"

cipher2 = Hashids.encode(s, [1,2,3,4])
#=> "4bSwImsd"

# decode() always returns a list of numbers

Hashids.decode(s, cipher1)
#=> {:ok, [129]}

Hashids.decode!(s, cipher2)
#=> [1, 2, 3, 4]

It is also possible to customize the character set used for the cipher text by providing a custom alphabet. It has to be at least 16 characters long.

defmodule MyAccessToken do
  @cyrillic_alphabet "123456789абвгґдеєжзиіїйклмнопрстуфцчшщьюяАБВГҐДЕЄЖЗИІЇЙКЛМНОПРСТУФЦЧШЩЬЮЯ"
  @coder Hashids.new(alphabet: @cyrillic_alphabet)

  def encode(token_ids) do
    Hashids.encode(@coder, token_ids)
  end

  def decode(data) do
    Hashids.decode(@coder, data)
  end
end

data = MyAccessToken.encode([1234, 786, 21, 0])
#=> "ЦфюєИНаЛ1И"

MyAccessToken.decode(data)
#=> {:ok, [1234, 786, 21, 0]}

Migrating from 1.0

See the changelog.

Copyright and License

Copyright (c) 2014 Alexei Sholik

This software is licensed under the MIT license.