Encryp and decrypt methods according to flow. PKCS5 + PBE + AES

lib/mifiel/crypto.rb

@@ -1,25 +1,34 @@
+require_relative '../core_extensions.rb'
+CoreExtensions.load
+
 module Mifiel
   module Crypto
     autoload :PBE, 'mifiel/crypto/pbe'
     autoload :Response, 'mifiel/crypto/response'
     autoload :AES, 'mifiel/crypto/aes'
     autoload :ECIES, 'mifiel/crypto/ecies'
     autoload :PKCS5, 'mifiel/crypto/pkcs5'
-  end
-end
 
-class String
-  def bth
-    unpack('H*').first
-  end
-
-  def htb
-    Array(self).pack('H*')
-  end
+    def self.decrypt(asn1, pass)
+      pkcs5 = Mifiel::Crypto::PKCS5.parse(asn1.force_binary)
+      params = pkcs5.values
+      params[:data] = params[:cipher_text]
+      params[:key] =
+        Mifiel::Crypto::PBE.derive_key({ password: pass }.merge(params.slice(:salt, :iterations, :key_size)))
+      Mifiel::Crypto::AES.decrypt(params.slice(:key, :data, :iv, :cipher))
+    end
 
-  def force_binary
-    return htb if match?(/^[0-9A-F]+$/i)
-    return self if bth.match?(/^[0-9A-F]+$/i)
-    raise ArgumentError, 'Invalid encoding, hex or binary'
+    def self.encrypt(document, password)
+      params = {
+        salt: Mifiel::Crypto::PBE.random_salt,
+        iterations: Mifiel::Crypto::PBE::ITERATIONS,
+        password: password
+      }
+      params[:key] = Mifiel::Crypto::PBE.derive_key(params)
+      params[:iv] = Mifiel::Crypto::AES.random_iv
+      params[:data] = document
+      params[:cipher_text] = Mifiel::Crypto::AES.encrypt(params.slice(:key, :iv, :data))
+      Mifiel::Crypto::PKCS5.new(params.slice(:salt, :iv, :iterations, :cipher_text))
+    end
   end
 end

spec/mifiel/crypto_spec.rb

@@ -0,0 +1,20 @@
+describe Mifiel::Crypto do
+  pkcs5_fixture = JSON.parse(File.read('spec/fixtures/pkcs5.json'), symbolize_names: true)
+  describe '#Crypto' do
+    pkcs5_fixture[:valid].each do |v|
+      describe "ASN1: #{v[:asn1]}" do
+        it 'Should decrypt message' do
+          decrypted = Mifiel::Crypto.decrypt(v[:asn1], v[:password])
+          expect(decrypted).to eq(pkcs5_fixture[:plain_text])
+        end
+      end
+      it "Should encrypt a document, password: #{v[:password]}" do
+        pdf = File.read('spec/fixtures/example.pdf')
+        encrypted = Mifiel::Crypto.encrypt(pdf, v[:password])
+        encrypted_parsed = Mifiel::Crypto::PKCS5.parse(encrypted.to_der)
+        expect(encrypted).to be_a Mifiel::Crypto::PKCS5
+        expect(encrypted == encrypted_parsed).to be true
+      end
+    end
+  end
+end