simple working ruby-encryption to elixir-decryption (DO NOT USE a zero IV for real)

elixir_decrypt.exs

defmodule Decrypt do
  @iv String.duplicate("0", 16)

  def unpad(data) do
    to_remove = :binary.last(data)
    :binary.part(data, 0, byte_size(data) - to_remove)
  end


  def decrypt(data, key) do
    IO.puts "WOrking to decrypt #{data} using #{key}"
    padded = :crypto.block_decrypt(:aes_cbc256, key, @iv, :base64.decode(data))
    unpad(padded)
  end
end

ruby_encrypt.rb

#!/usr/bin/env ruby

require "openssl"
require 'digest/sha2'
require 'base64'

alg = "AES-256-CBC"
key = ARGV[0]
iv = "0" * 16
key64 = [key].pack('m')
raise 'Key Error' if(key.nil? or iv.size != 16)
aes = OpenSSL::Cipher::Cipher.new(alg)
aes.encrypt
aes.key = key
aes.iv = iv
cipher = ""
cipher << aes.update(ARGV[1])
cipher << aes.final
cipher64 = [cipher].pack('m')
puts cipher64

Oh, and yes, for sure typically random IV and base64 encoding it makes total sense, that's approx what ruby does, but for decrypting obviously random doesn't work, and in either case it's good to be able to control it... I'm considering making it a SHA1 of something already unique about the data so I can avoid shipping around the IV also and just have a convention, but we'll see....

Oh and yes, I was aware it wasn't really a zero iv, it was just meant to be simple and the same in both languages, not necessarily have any special properties.