Client initialization parameters (#2)

* Adds crypto module

* Adds new authentication module & params

* Add parameters implementation

* Add parameters usage to readme

* Fix and improve readme. Remove test.

Author: davideluque

Gemfile.lock

@@ -2,11 +2,13 @@ PATH
   remote: .
   specs:
     nemid (0.1.0)
+      openssl (~> 2.2, >= 2.2.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
     diff-lcs (1.4.4)
+    openssl (2.2.0)
     rake (12.3.3)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)

README.md

@@ -20,7 +20,23 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+This gem implements one main module:
+
+- `Authentication`: the purpose of this module is to generate client initialization 
+parameters and response handling.
+
+### Authentication::Parameters
+
+Generate client initialization parameters
+
+```ruby
+nemid = NemID::Authentication::Parameters.new(
+  'path/to/your/voces/certificate',
+  'your_voces_certificate_password',
+)
+
+nemid.client_initialization_parameters # ruby hash with signed parameters
+```
 
 ## Development
 

lib/nemid.rb

@@ -1,4 +1,6 @@
 require "nemid/version"
+require "nemid/authentication"
+require "nemid/crypto"
 
 module NemID
   class Error < StandardError; end

lib/nemid/authentication.rb

@@ -0,0 +1,6 @@
+require_relative "authentication/params"
+
+module NemID
+  module Authentication
+  end
+end

lib/nemid/authentication/params.rb

@@ -0,0 +1,52 @@
+require 'date'
+
+module NemID
+  module Authentication
+    class Params
+      def initialize(certificate, pass)
+        @nemid_crypto = NemID::Crypto.new(certificate, pass)
+      end
+  
+      def client_initialization_parameters
+        params = unsigned_params
+        normalized_unsigned_params = normalize(unsigned_params)
+        
+        params.merge({
+          "DIGEST_SIGNATURE": digest_signature(normalized_unsigned_params),
+          "PARAMS_DIGEST": params_digest(normalized_unsigned_params),
+        })
+      end
+  
+      private
+      def digest_signature(normalized_unsigned_params)
+        @nemid_crypto.base64_encoded_rsa_signature(normalized_unsigned_params)
+      end
+  
+      def normalize(params)
+        params = params.transform_keys(&:upcase)
+        
+        str = String.new
+        
+        params.keys.sort.each { |k| str += "#{k.to_s}#{params[k]}" }
+  
+        return str
+      end
+  
+      def params_digest(normalized_unsigned_params)
+        @nemid_crypto.base64_encoded_digest_representation(normalized_unsigned_params)
+      end
+  
+      def sp_cert
+        @nemid_crypto.base64_encoded_der_representation
+      end
+  
+      def unsigned_params
+        {
+          "CLIENTFLOW": "OCESLOGIN2",
+          "SP_CERT": sp_cert,
+          "TIMESTAMP": DateTime.now.new_offset(0).strftime('%F %T%z'),
+        }
+      end
+    end
+  end
+end

lib/nemid/crypto.rb

@@ -0,0 +1,46 @@
+require 'base64'
+require 'openssl'
+
+module NemID
+ class Crypto
+  
+  def initialize(certificate, pass)
+    certificate = read_file(certificate)
+    @pkcs12 = read_pkcs12(certificate, pass)
+    @rsa_instance = rsa_keypair(@pkcs12, pass)
+  end
+
+  def base64_encoded_der_representation
+    Base64.strict_encode64(@pkcs12.certificate.to_der)
+  end
+
+  def base64_encoded_digest_representation(data)
+    Base64.strict_encode64(digest(data))
+  end
+
+  def base64_encoded_rsa_signature(data)
+    Base64.strict_encode64(sign(data))
+  end
+
+  private
+  def digest(data)
+    OpenSSL::Digest::SHA256.new.digest(data)
+  end
+
+  def read_file(certificate)
+    File.read(certificate)
+  end
+
+  def read_pkcs12(certificate, pass)
+    OpenSSL::PKCS12::new(certificate, pass)
+  end
+
+  def rsa_keypair(pkcs12, passphrase)
+    OpenSSL::PKey::RSA.new(pkcs12.key, passphrase)
+  end
+
+  def sign(data)
+    @rsa_instance.sign(OpenSSL::Digest::SHA256.new, data)
+  end
+ end
+end

nemid.gemspec

@@ -12,6 +12,8 @@ Gem::Specification.new do |spec|
   spec.license       = "MIT"
   spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
 
+  spec.add_dependency 'openssl', '~> 2.2', '>= 2.2.0'
+
   spec.metadata["allowed_push_host"] = "http://rubygems.org"
 
   spec.metadata["homepage_uri"] = spec.homepage

spec/nemid_spec.rb

@@ -2,8 +2,4 @@
   it "has a version number" do
     expect(NemID::VERSION).not_to be nil
   end
-
-  it "does something useful" do
-    expect(false).to eq(true)
-  end
 end