add request validation

lib/slanger/request_validation.rb

@@ -0,0 +1,25 @@
+module Slanger
+  class RequestValidation < Struct.new :body
+    def socket_id
+      validate_socket_id!(data["socket_id"])
+    end
+
+    def data
+      @data ||= JSON.parse(body.tap{ |s| s.force_encoding('utf-8')})
+    end
+
+    private
+
+    def validate_socket_id!(socket_id)
+      unless valid_socket_id?(socket_id)
+        raise Signature::AuthenticationError.new("Invalid socket_id: #{socket_id}")
+      end
+
+      socket_id
+    end
+
+    def valid_socket_id?(socket_id)
+      socket_id =~ /\A[\da-fA-F]{8}\-[\da-fA-F]{4}-[\da-fA-F]{4}-[\da-fA-F]{4}-[\da-fA-F]{12}\z/
+    end
+  end
+end

spec/unit/request_validation_spec.rb

@@ -0,0 +1,30 @@
+#encoding: utf-8
+require 'spec_helper'
+
+describe Slanger::RequestValidation do
+  describe '#socket_id' do
+    it 'validation' do
+      socket_id = "POST\n/apps/99759/events\nauth_key=840543d97de9803651b1&auth_timestamp=123&auth_version=1.0&body_md5=some_md5&dummy="
+
+      expect {validate(socket_id)      }.to     raise_error Signature::AuthenticationError
+      expect {validate("something 123")}.to     raise_error Signature::AuthenticationError
+      expect {validate("335e6070-96fc-4950-a94a-a9032d85ae26")                }.not_to raise_error Signature::AuthenticationError
+
+      expect {validate("335e6070-96fc-4950-a94a-a9032d85ae26 ")               }.to raise_error Signature::AuthenticationError
+      expect {validate(" 335e6070-96fc-4950-a94a-a9032d85ae26")               }.to raise_error Signature::AuthenticationError
+      expect {validate("hello\n35e6070-96fc-4950-a94a-a9032d85ae26\nhomakov") }.to raise_error Signature::AuthenticationError
+      expect {validate("35e6070-96fc-4950-a94a-a9032d85ae26")                 }.to raise_error Signature::AuthenticationError
+      expect {validate("335e6070-96fc-4950-a94aa9032d85ae26")                 }.to raise_error Signature::AuthenticationError
+    end
+  end
+
+  def validate(socket_id)
+    Slanger::RequestValidation.new(body(socket_id)).socket_id
+  end
+
+  def body(socket_id)
+    {socket_id: socket_id}.to_json
+  end
+
+end
+