Handle basic auth for OPDS

src/handlers/auth_handler.cr

@@ -3,23 +3,84 @@ require "../storage"
 require "../util"
 
 class AuthHandler < Kemal::Handler
+  # Some of the code is copied form kemalcr/kemal-basic-auth on GitHub
+
+  BASIC        = "Basic"
+  AUTH         = "Authorization"
+  AUTH_MESSAGE = "Could not verify your access level for that URL.\n" \
+                 "You have to login with proper credentials"
+  HEADER_LOGIN_REQUIRED = "Basic realm=\"Login Required\""
+
   def initialize(@storage : Storage)
   end
 
-  def call(env)
+  def require_basic_auth(env)
+    headers = HTTP::Headers.new
+    env.response.status_code = 401
+    env.response.headers["WWW-Authenticate"] = HEADER_LOGIN_REQUIRED
+    env.response.print AUTH_MESSAGE
+    call_next env
+  end
+
+  def validate_cookie_token(env)
+    cookie = env.request.cookies.find { |c| c.name == "token" }
+    !cookie.nil? && @storage.verify_token cookie.value
+  end
+
+  def validate_cookie_token_admin(env)
+    cookie = env.request.cookies.find { |c| c.name == "token" }
+    !cookie.nil? && @storage.verify_admin cookie.value
+  end
+
+  def validate_auth_header(env)
+    if env.request.headers[AUTH]?
+      if value = env.request.headers[AUTH]
+        if value.size > 0 && value.starts_with?(BASIC)
+          return !verify_user(value).nil?
+        end
+      end
+    end
+    false
+  end
+
+  def verify_user(value)
+    username, password = Base64.decode_string(value[BASIC.size + 1..-1])
+      .split(":")
+    @storage.verify_user username, password
+  end
+
+  def handle_opds_auth(env)
+    if validate_cookie_token(env) || validate_auth_header(env)
+      return call_next env
+    else
+      headers = HTTP::Headers.new
+      env.response.status_code = 401
+      env.response.headers["WWW-Authenticate"] = HEADER_LOGIN_REQUIRED
+      env.response.print AUTH_MESSAGE
+    end
+  end
+
+  def handle_auth(env)
     return call_next(env) if request_path_startswith env, ["/login", "/logout"]
 
-    cookie = env.request.cookies.find { |c| c.name == "token" }
-    if cookie.nil? || !@storage.verify_token cookie.value
+    unless validate_cookie_token env
       return redirect env, "/login"
     end
 
     if request_path_startswith env, ["/admin", "/api/admin", "/download"]
-      unless @storage.verify_admin cookie.value
+      unless validate_cookie_token_admin env
         env.response.status_code = 403
       end
     end
 
     call_next env
   end
+
+  def call(env)
+    if request_path_startswith env, ["/opds"]
+      handle_opds_auth env
+    else
+      handle_auth env
+    end
+  end
 end