Merge pull request #87 from spreemo/add-decrypt-table

add decrypt table (the reverse of encrypt table)

gemfiles/activerecord_3_1.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ../
   specs:
-    crypt_keeper (0.18.4)
+    crypt_keeper (0.19.0)
       activerecord (>= 3.1, < 4.3)
       activesupport (>= 3.1, < 4.3)
       aes (~> 0.5.0)

gemfiles/activerecord_3_2.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ../
   specs:
-    crypt_keeper (0.18.4)
+    crypt_keeper (0.19.0)
       activerecord (>= 3.1, < 4.3)
       activesupport (>= 3.1, < 4.3)
       aes (~> 0.5.0)

gemfiles/activerecord_4_0.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ../
   specs:
-    crypt_keeper (0.18.4)
+    crypt_keeper (0.19.0)
       activerecord (>= 3.1, < 4.3)
       activesupport (>= 3.1, < 4.3)
       aes (~> 0.5.0)

gemfiles/activerecord_4_1.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ../
   specs:
-    crypt_keeper (0.18.4)
+    crypt_keeper (0.19.0)
       activerecord (>= 3.1, < 4.3)
       activesupport (>= 3.1, < 4.3)
       aes (~> 0.5.0)

gemfiles/activerecord_4_2.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ../
   specs:
-    crypt_keeper (0.18.4)
+    crypt_keeper (0.19.0)
       activerecord (>= 3.1, < 4.3)
       activesupport (>= 3.1, < 4.3)
       aes (~> 0.5.0)

lib/crypt_keeper/model.rb

@@ -98,6 +98,22 @@ def encrypt_table!
         end
       end
 
+      # Public: Decrypt a table (reverse of encrypt_table!)
+      def decrypt_table!
+        enc       = encryptor_klass.new(crypt_keeper_options)
+        tmp_table = Class.new(ActiveRecord::Base).tap { |c| c.table_name = self.table_name }
+
+        transaction do
+          tmp_table.find_each do |r|
+            crypt_keeper_fields.each do |field|
+              r.send("#{field}=", enc.decrypt(r[field])) if r[field].present?
+            end
+
+            r.save!
+          end
+        end
+      end
+
       private
 
       # Private: The encryptor class

spec/model_spec.rb

@@ -124,6 +124,21 @@ module CryptKeeper
       end
     end
 
+    context "Table Decryption (Reverse of Initial Table Encryption)" do
+      subject { create_encrypted_model :storage, key: 'tool', salt: 'salt', encryptor: :aes_new }
+      let!(:storage_entries) { 5.times.map { |i| "testing#{i}" } }
+
+      before do
+        subject.delete_all
+        storage_entries.each { |entry| subject.create! storage: entry}
+      end
+
+      it "decrypts the table" do
+        subject.decrypt_table!
+        expect( create_model.first(5).map(&:storage) ).to eq( storage_entries )
+      end
+    end
+
     context "Missing Attributes" do
       subject { create_encrypted_model :storage, key: 'tool', salt: 'salt', encryptor: :aes_new, encoding: 'utf-8' }