From fa22e04e65ffa79c6527170bb68369fb20ee026d Mon Sep 17 00:00:00 2001
From: dsainty <dsainty@redhat.com>
Date: Tue, 11 Jun 2024 16:35:22 +1000
Subject: [PATCH] v0.4 -- change to attempt use of Auth::DefaultAuthenticator
 Instead of User, code comments

---
 plugin.rb | 75 +++++++++++++++++++++++++++++--------------------------
 1 file changed, 39 insertions(+), 36 deletions(-)

diff --git a/plugin.rb b/plugin.rb
index f562a4a..e7b1a2d 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -4,54 +4,57 @@
 
 # name: discourse-md5_authentication
 # about: A plugin to authenticate users with MD5 passwords from legacy systems
-# version: 0.3
+# version: 0.4
 # authors: saint
 # url: https://gitea.federated.computer/saint/discourse-md5_authentication.git
 
+# This block of code is executed after the Discourse application is initialized.
 after_initialize do
-  Rails.logger.error("MD5 Authentication Plugin: Initialized")
-  class ::User
+  # Reopening the Auth::DefaultAuthenticator class to add custom authentication logic.
+  class ::Auth::DefaultAuthenticator
+    # Define a module to encapsulate the MD5 authentication logic.
     module LegacyMd5Authentication
-      def self.included(base)
-        base.singleton_class.prepend(ClassMethods)
+      # This method is called when the module is prepended to the class.
+      # It creates an alias for the existing authenticate method to preserve it.
+      def self.prepended(base)
+        base.singleton_class.class_eval do
+          alias_method :old_authenticate, :authenticate
+        end
       end
 
-      module ClassMethods
-        def authenticate(login, password)
-          Rails.logger.error("LegacyMd5Authentication: Trying to authenticate user with login #{login}")
+      # Override the authenticate method to add custom MD5 password logic.
+      def authenticate(email_or_username, password)
+        # Log an attempt to authenticate.
+        Rails.logger.info("MD5 Auth: Attempting to authenticate #{email_or_username}")
 
-          user = nil
-          
-          if login.include?('@')
-            # Assume it's an email address
-            user_email = UserEmail.find_by(email: login.downcase.strip)
-            user = user_email ? User.find(user_email.user_id) : nil
-          else
-            # Assume it's a username
-            user = User.find_by(username: login.downcase.strip)
-          end
+        # Find the user by their username or email.
+        user = User.find_by_username_or_email(email_or_username.downcase.strip)
 
-          if user
-            Rails.logger.error("LegacyMd5Authentication: User found: #{user.username}")
-            if user.custom_fields['md5_password'] && user.custom_fields['md5_password'] == Digest::MD5.hexdigest(password)
-              Rails.logger.error("LegacyMd5Authentication: MD5 password match for user: #{user.username}")
-              user.update!(password: password)
-              user.custom_fields['md5_password'] = nil
-              user.save_custom_fields
-              return user
-            else
-              Rails.logger.error("LegacyMd5Authentication: MD5 password did not match for user: #{user.username}")
-            end
-          else
-            Rails.logger.error("LegacyMd5Authentication: No user found with login #{login}")
-          end
-
-          super(login, password)
+        # Log if a user is found.
+        if user
+          Rails.logger.info("MD5 Auth: User found - #{user.username}")
         end
+
+        # Check if the user's custom field contains an MD5 password and if it matches the provided password.
+        if user && user.custom_fields['md5_password'] && user.custom_fields['md5_password'] == Digest::MD5.hexdigest(password)
+          Rails.logger.info("MD5 Auth: MD5 password match for user #{user.username}")
+          
+          # Update the user's password to the new format and clear the MD5 password field.
+          user.update!(password: password)
+          user.custom_fields['md5_password'] = nil
+          user.save_custom_fields
+
+          # Return an authentication result indicating success.
+          return Auth::Result.new(user)
+        end
+
+        # If MD5 authentication fails, fall back to the original authentication method.
+        Rails.logger.info("MD5 Auth: Falling back to default authentication for #{email_or_username}")
+        old_authenticate(email_or_username, password)
       end
     end
 
-    include LegacyMd5Authentication
+    # Prepend the module to the DefaultAuthenticator class.
+    prepend LegacyMd5Authentication
   end
 end
-