RavenDB Auth in Ruby

get_warnings.rb

require 'restclient'
require 'digest/sha1'
require 'base64'
require 'securerandom'
require 'json'

class RavenCheck
	@server_url
	@api_key_name
	@api_key_secret

	def initialize(server_url, api_key_name, api_key_secret)
		throw 'Invalid ServerUrl' unless server_url =~ URI::regexp
		throw 'api_key_name empty' unless !api_key_name.to_s.empty?
		throw 'api_key_secret empty' unless !api_key_secret.to_s.empty?

		@server_url = server_url
		@api_key_name = api_key_name
		@api_key_secret = api_key_secret
	end

	def get_bearer_token
		request = get_auth_request_hash
		response = prepare_response(request['challenge'])
		public_key = create_rsa_key(request['modulus'], request['exponent'])

		data = "api key name=#{@api_key_name},challenge=#{request['challenge']},response=#{response}"
		response_data = "exponent=#{request['exponent']},modulus=#{request['modulus']},data=#{encrypt(public_key, data)}"
		get_auth_token(response_data)
	end

	def get_warnings
		res = RestClient.get("#{@server_url}/docs?id=Raven%2FAlerts", headers={ Authorization: "Bearer #{get_bearer_token}"})
		JSON.parse(res.body)
	end

	private

	def get_auth_request_hash
		res = RestClient.post("#{@server_url}/OAuth/API-Key", {}){|response,request,result| response }
		wwwauth_header = res.headers[:www_authenticate]
		wwwauth_header[7, wwwauth_header.length - 7] # Remove 'Raven '
			.split(',')
			.map{|str|
				idx = str.index '='
				[str[0, idx].strip.downcase, str[idx+1, str.length]]
			}
			.to_h
	end

	def get_auth_token (response_data)
		res = RestClient.post("#{@server_url}/OAuth/API-Key", response_data, headers={ grant_type: 'client_credentials'})
		res.body.to_s
	end

	def prepare_response (challenge)
		input = challenge + ";" + @api_key_secret
		Digest::SHA1.base64digest input 
	end

	def create_rsa_key (modulus_base64, exponent_base64)
		key = OpenSSL::PKey::RSA.new
		exponent = OpenSSL::BN.new(Base64.decode64(exponent_base64).unpack("H*").first, 16)
		modulus = OpenSSL::BN.new(Base64.decode64(modulus_base64).unpack("H*").first, 16)
		key.e = exponent
		key.n = modulus
		key
	end

	def encrypt(public_key, data)
		key = SecureRandom.random_bytes(32)
		iv = SecureRandom.random_bytes(16)

		key_and_iv_encrypted = public_key.public_encrypt(key + iv, OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)
		
		cipher = OpenSSL::Cipher::AES256.new(:CBC)
		cipher.encrypt
		cipher.key = key
		cipher.iv = iv
		encrypted = cipher.update(data) + cipher.final
		
		Base64.encode64 (key_and_iv_encrypted + encrypted)
	end
end

# RavenDB API-Key: name/abcdefg
check = RavenCheck.new('http://ravenserver:8080', 'name', 'abcdefg')
p check.get_warnings