From 229ebf1380cdd8576e0566a00d2ae6add1838c4e Mon Sep 17 00:00:00 2001
From: Mark Moser <mark.moser@perficient.com>
Date: Fri, 26 Aug 2016 16:03:55 -0500
Subject: [PATCH] start encoding candidate emails - completes #57

---
 app/models/candidate.rb                       |  2 +
 app/services/crypt_serializer.rb              | 46 +++++++++++++++++++
 .../20160826200610_encode_candidate_emails.rb | 26 +++++++++++
 db/schema.rb                                  |  2 +-
 test/fixtures/candidates.yml                  | 16 +++----
 test/models/candidate_test.rb                 | 14 ++++++
 test/services/crypt_serializer_test.rb        | 26 +++++++++++
 7 files changed, 123 insertions(+), 9 deletions(-)
 create mode 100644 app/services/crypt_serializer.rb
 create mode 100644 db/migrate/20160826200610_encode_candidate_emails.rb
 create mode 100644 test/services/crypt_serializer_test.rb

diff --git a/app/models/candidate.rb b/app/models/candidate.rb
index 8af27fa..b54bea3 100644
--- a/app/models/candidate.rb
+++ b/app/models/candidate.rb
@@ -4,6 +4,8 @@ class Candidate < ApplicationRecord
   has_many :answers
   belongs_to :recruiter, class_name: "User"
 
+  serialize :email, CryptSerializer
+
   before_validation(:generate_test_hash, on: :create)
 
   validates_presence_of :recruiter_id
diff --git a/app/services/crypt_serializer.rb b/app/services/crypt_serializer.rb
new file mode 100644
index 0000000..bf39363
--- /dev/null
+++ b/app/services/crypt_serializer.rb
@@ -0,0 +1,46 @@
+require 'openssl'
+require 'base64'
+
+class CryptSerializer
+  attr_reader :cipher
+
+  class << self
+    # pulling from DB - return plain value
+    def load value
+      new.decrypt value
+    end
+
+    # saving to DB - return encrypted value
+    def dump value
+      new.encrypt value
+    end
+  end
+
+  def initialize
+    @cipher = OpenSSL::Cipher::AES.new(128, :CBC)
+  end
+
+  def encrypt(value)
+    unless value.is_a?(String)
+      raise "Attribute was supposed to be a `String`, but was instead a `#{value.class}`"
+    end
+
+    return value if value.nil?
+
+    cipher.encrypt
+    parts = [cipher.random_key, cipher.random_iv, cipher.update(value) + cipher.final]
+
+    Base64.urlsafe_encode64 Marshal.dump(parts)
+  end
+
+  def decrypt(value)
+    return value if value.nil?
+
+    parts = Marshal.load Base64.urlsafe_decode64(value)
+    cipher.decrypt
+    cipher.key = parts[0]
+    cipher.iv = parts[1]
+
+    cipher.update(parts[2]) + cipher.final
+  end
+end
diff --git a/db/migrate/20160826200610_encode_candidate_emails.rb b/db/migrate/20160826200610_encode_candidate_emails.rb
new file mode 100644
index 0000000..6872e22
--- /dev/null
+++ b/db/migrate/20160826200610_encode_candidate_emails.rb
@@ -0,0 +1,26 @@
+class EncodeCandidateEmails < ActiveRecord::Migration[5.0]
+  def change
+    sql = "select id, email from candidates;"
+    candidates = ActiveRecord::Base.connection.execute(sql).to_h
+
+    candidates.each do |id, email|
+      sql = if base64?(email)
+              # going down - decrypt
+              "UPDATE candidates set email = '#{CryptSerializer.load email}' WHERE id = #{id};"
+            else
+              # going up - encrypt emails
+              "UPDATE candidates set email = '#{CryptSerializer.dump email}' WHERE id = #{id};"
+            end
+      ActiveRecord::Base.connection.execute(sql)
+    end
+  end
+
+  private
+
+    def base64? string
+      Base64.urlsafe_decode64 string
+      true
+    rescue ArgumentError
+      false
+    end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 2964332..ac3eb57 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160824183159) do
+ActiveRecord::Schema.define(version: 20160826200610) do
 
   create_table "answers", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
     t.integer  "candidate_id"
diff --git a/test/fixtures/candidates.yml b/test/fixtures/candidates.yml
index 0e1aa25..c55d18f 100644
--- a/test/fixtures/candidates.yml
+++ b/test/fixtures/candidates.yml
@@ -2,7 +2,7 @@
 
 roy: # Roy should have started, and is ready for a reminder
   name: Roy Cruz
-  email: roy.cruz@mailinator.com
+  email: <%= CryptSerializer.dump 'roy.cruz@mailinator.com' %>
   experience: 0-3
   recruiter: recruiter
   quiz: fed
@@ -12,7 +12,7 @@ roy: # Roy should have started, and is ready for a reminder
 
 gillian: # Gillian has not begun the test
   name: Gillian Anderson
-  email: gillian.anderson@mailinator.com
+  email: <%= CryptSerializer.dump 'gillian.anderson@mailinator.com' %>
   experience: 4-6
   recruiter: recruiter
   quiz: fed
@@ -22,7 +22,7 @@ gillian: # Gillian has not begun the test
 
 martha: # Martha has not begun the test
   name: Martha Watts
-  email: martha.watts@mailinator.com
+  email: <%= CryptSerializer.dump 'martha.watts@mailinator.com' %>
   experience: 4-6
   recruiter: recruiter
   quiz: fed
@@ -32,7 +32,7 @@ martha: # Martha has not begun the test
 
 dawn: # Dawn has completed, and been reminded, but not submitted the test
   name: Dawn Hopkins
-  email: dawn.hopkins@mailinator.com
+  email: <%= CryptSerializer.dump 'dawn.hopkins@mailinator.com' %>
   experience: 0-2
   recruiter: recruiter
   quiz: fed
@@ -42,7 +42,7 @@ dawn: # Dawn has completed, and been reminded, but not submitted the test
 
 peggy: # Peggy has completed, and been reminded, but not submitted the test
   name: Peggy Blisters
-  email: peggy.blisters@mailinator.com
+  email: <%= CryptSerializer.dump 'peggy.blisters@mailinator.com' %>
   experience: 0-2
   recruiter: recruiter
   quiz: fed
@@ -52,7 +52,7 @@ peggy: # Peggy has completed, and been reminded, but not submitted the test
 
 richard: # Richard has completed AND submitted the test
   name: Richard Burns
-  email: richard.burns@mailinator.com
+  email: <%= CryptSerializer.dump 'richard.burns@mailinator.com' %>
   experience: 15+
   recruiter: recruiter
   quiz: fed
@@ -62,10 +62,10 @@ richard: # Richard has completed AND submitted the test
 
 juan: # Juan has chosen "finish later" for live coders
   name: Juan Campbell
-  email: juan.campbell@mailinator.com
+  email: <%= CryptSerializer.dump 'juan.campbell@mailinator.com' %>
   experience: 15+
   recruiter: recruiter
   quiz: fed
   completed: false
   reminded: true
-  test_hash: qKQo0l4dyol
+  test_hash: <%= CryptSerializer.dump 'qKQo0l4dyol
diff --git a/test/models/candidate_test.rb b/test/models/candidate_test.rb
index 112f8ef..5707062 100644
--- a/test/models/candidate_test.rb
+++ b/test/models/candidate_test.rb
@@ -9,4 +9,18 @@ class CandidateTest < ActiveSupport::TestCase
 
     assert candidate.test_hash.present?
   end
+
+  test "should encrypt emails" do
+    email = 'test@mailinator.com'
+    candidate = Candidate.create(name: 'new name',
+                                 email: email,
+                                 experience: '0-3',
+                                 recruiter_id: users(:recruiter).id,
+                                 quiz_id: quizzes(:fed).id)
+
+    sql = "select email from candidates where id = #{candidate.id};"
+    enc_email = ActiveRecord::Base.connection.execute(sql).first.first
+
+    refute_equal email, enc_email
+  end
 end
diff --git a/test/services/crypt_serializer_test.rb b/test/services/crypt_serializer_test.rb
new file mode 100644
index 0000000..c649076
--- /dev/null
+++ b/test/services/crypt_serializer_test.rb
@@ -0,0 +1,26 @@
+require 'test_helper'
+
+class CryptSerializerTest < ActiveSupport::TestCase
+  test "should generate marshaled array" do
+    string = "some string to encrypt"
+    encrypted = CryptSerializer.dump string
+    ar = Marshal.load(Base64.urlsafe_decode64(encrypted))
+
+    assert_instance_of Array, ar
+    assert_equal 3, ar.count
+  end
+
+  test "should encrypt and dencrypt" do
+    string = "test@string.email"
+    encrypted = CryptSerializer.dump string
+    decrypted = CryptSerializer.load encrypted
+
+    assert_equal string, decrypted
+  end
+
+  test "must raise RuntimeError" do
+    assert_raises RuntimeError do
+      CryptSerializer.dump nil
+    end
+  end
+end