From d192d170f09d8c2f1e3e3c3bff4ea0d50f142d55 Mon Sep 17 00:00:00 2001
From: fitblip <fitblip@gmail.com>
Date: Mon, 5 Mar 2018 00:40:34 -0800
Subject: [PATCH] Add in arguments for supporting base64 serialization and
 domain name extraction

---
 lib/easy_ssl.ex        | 51 +++++++++++++++++++++++++++++++++++++-----
 mix.exs                |  2 +-
 test/easy_ssl_test.exs | 24 ++++++++++++++++++++
 3 files changed, 71 insertions(+), 6 deletions(-)

diff --git a/lib/easy_ssl.ex b/lib/easy_ssl.ex
index 0584a78..75a5f92 100644
--- a/lib/easy_ssl.ex
+++ b/lib/easy_ssl.ex
@@ -58,15 +58,56 @@ defmodule EasySSL do
         }
       }
   """
-  def parse_der(certificate_der) when is_binary(certificate_der) do
+  def parse_der(certificate_der, opts \\ [all_domains: false, serialize: false]) when is_binary(certificate_der) do
     cert = :public_key.pkix_decode_cert(certificate_der, :otp) |> get_field(:tbsCertificate)
 
-    %{}
+    serialized_certificate = %{}
       |> Map.put(:fingerprint, certificate_der |> fingerprint_cert)
       |> Map.put(:serial_number, cert |> get_field(:serialNumber) |> Integer.to_string(16))
       |> Map.put(:subject, cert |> parse_subject)
       |> Map.put(:extensions, cert |> parse_extensions)
       |> Map.merge(parse_expiry(cert))
+
+    Enum.reduce(opts, serialized_certificate, fn {option, flag}, serialized_certificate ->
+      case option do
+        :all_domains when flag == true ->
+          serialized_certificate
+            |> Map.put(:all_domains, get_all_domain_names(cert, serialized_certificate))
+
+        :serialize when flag == true ->
+          serialized_certificate
+            |> Map.put(:as_der, Base.encode64(certificate_der))
+        _ -> serialized_certificate
+      end
+    end)
+  end
+
+  def get_all_domain_names(cert, serialized_cert) do
+    domain_names = MapSet.new()
+
+    domain_names = case serialized_cert[:subject][:CN] do
+      nil -> domain_names
+      _ -> MapSet.put(domain_names, serialized_cert[:subject][:CN])
+    end
+
+    extensions = cert |> get_field(:extensions)
+
+    extensions
+      |> Enum.reduce(domain_names, fn extension, domain_names ->
+          case extension do
+            {:Extension, {2, 5, 29, 17}, _critical, san_entries} ->
+              san_entries
+                |> Enum.reduce(domain_names, fn entry, names ->
+                  case entry do
+                    {:dNSName, dns_name} -> MapSet.put(names, dns_name |> to_string)
+                    _ -> names
+                  end
+                end)
+            :asn1_NOVALUE -> domain_names
+            _ -> domain_names
+          end
+        end)
+      |> MapSet.to_list
   end
 
   @doc """
@@ -104,7 +145,7 @@ defmodule EasySSL do
       }
 """
   def parse_pem(cert_charlist) when is_list(cert_charlist) do parse_pem(cert_charlist |> to_string) end
-  def parse_pem(cert_pem) do
+  def parse_pem(cert_pem, opts \\ [all_domains: false, return_base64: false]) do
     cert_regex = ~r/^\-{5}BEGIN\sCERTIFICATE\-{5}\n(?<certificate>[^\-]+)\-{5}END\sCERTIFICATE\-{5}/
     match = Regex.named_captures(cert_regex, cert_pem)
 
@@ -115,7 +156,7 @@ defmodule EasySSL do
     match["certificate"]
       |> String.replace("\n", "")
       |> Base.decode64!
-      |> parse_der
+      |> parse_der(opts)
   end
 
   defp get_field(record, field) do
@@ -284,7 +325,7 @@ defmodule EasySSL do
 
                     # Basically ignore those
                     {:directoryName, _sequence} -> san_list
-                    {:otherName, other_name} -> san_list
+                    {:otherName, _sequence} -> san_list
 
                     _ ->
                       raise("Unhandled SAN entry type #{inspect entry}")
diff --git a/mix.exs b/mix.exs
index 99634b2..1532c48 100644
--- a/mix.exs
+++ b/mix.exs
@@ -5,7 +5,7 @@ defmodule EasySSL.MixProject do
     [
       app: :easy_ssl,
       name: "EasySSL",
-      version: "1.0.2",
+      version: "1.0.3",
       elixir: "~> 1.6",
       description: "SSL/X509 parsing for humans.",
       deps: deps(),
diff --git a/test/easy_ssl_test.exs b/test/easy_ssl_test.exs
index 8bbfaee..5785d8c 100644
--- a/test/easy_ssl_test.exs
+++ b/test/easy_ssl_test.exs
@@ -57,4 +57,28 @@ defmodule EasySSLTest do
     assert_has_normal_atom_keys(cert)
   end
 
+  test "parses and adds all domains to the top level leaf node" do
+    cert_bytes = File.read!(@der_cert_dir <> "twitter.com.der")
+
+    serialized_cert = cert_bytes
+      |> EasySSL.parse_der()
+    refute Enum.member?(Map.keys(serialized_cert), :as_der)
+    refute Enum.member?(Map.keys(serialized_cert), :all_domains)
+
+    serialized_cert = cert_bytes
+      |> EasySSL.parse_der(all_domains: true)
+    refute Enum.member?(Map.keys(serialized_cert), :as_der)
+    assert Enum.member?(Map.keys(serialized_cert), :all_domains)
+
+    serialized_cert = cert_bytes
+      |> EasySSL.parse_der(serialize: true)
+    assert Enum.member?(Map.keys(serialized_cert), :as_der)
+    refute Enum.member?(Map.keys(serialized_cert), :all_domains)
+
+    serialized_cert = cert_bytes
+      |> EasySSL.parse_der(serialize: true, all_domains: true)
+    assert Enum.member?(Map.keys(serialized_cert), :as_der)
+    assert Enum.member?(Map.keys(serialized_cert), :all_domains)
+  end
+
 end