Better handle basic authentication without a password

rails#43209 immediately rejects
the request if no password is passed, but there are legitimate
uses for accepting authentication without a password.

actionpack/CHANGELOG.md

@@ -1,3 +1,17 @@
+*   Fix `authenticate_with_http_basic` to allow for missing password.
+
+    Before Rails 7.0 it was possible to handle basic authentication with only a username.
+
+    ```ruby
+    authenticate_with_http_basic do |token, _|
+      ApiClient.authenticate(token)
+    end
+    ```
+
+    This ability is restored.
+
+    *Jean Boussier*
+
 *   Fix `content_security_policy` returning invalid directives.
 
     Directives such as `self`, `unsafe-eval` and few others were not

actionpack/lib/action_controller/metal/http_authentication.rb

@@ -74,6 +74,8 @@ module ClassMethods
           #
           # See ActionController::HttpAuthentication::Basic for example usage.
           def http_basic_authenticate_with(name:, password:, realm: nil, **options)
+            raise ArgumentError, "Expected name: to be a String, got #{name.class}" unless name.is_a?(String)
+            raise ArgumentError, "Expected password: to be a String, got #{password.class}" unless name.is_a?(String)
             before_action(options) { http_basic_authenticate_or_request_with name: name, password: password, realm: realm }
           end
         end
@@ -82,8 +84,8 @@ def http_basic_authenticate_or_request_with(name:, password:, realm: nil, messag
           authenticate_or_request_with_http_basic(realm, message) do |given_name, given_password|
             # This comparison uses & so that it doesn't short circuit and
             # uses `secure_compare` so that length information isn't leaked.
-            ActiveSupport::SecurityUtils.secure_compare(given_name, name) &
-              ActiveSupport::SecurityUtils.secure_compare(given_password, password)
+            ActiveSupport::SecurityUtils.secure_compare(given_name.to_s, name) &
+              ActiveSupport::SecurityUtils.secure_compare(given_password.to_s, password)
           end
         end
 
@@ -107,7 +109,7 @@ def authenticate(request, &login_procedure)
       end
 
       def has_basic_credentials?(request)
-        request.authorization.present? && (auth_scheme(request).downcase == "basic") && user_name_and_password(request).length == 2
+        request.authorization.present? && (auth_scheme(request).downcase == "basic")
       end
 
       def user_name_and_password(request)

actionpack/test/controller/http_basic_authentication_test.rb

@@ -31,6 +31,13 @@ def search
       render plain: "All inline"
     end
 
+    def no_password
+      username, password = authenticate_with_http_basic do |username, password|
+        [username, password]
+      end
+      render plain: "Hello #{username} (password: #{password.inspect})"
+    end
+
     private
       def authenticate
         authenticate_or_request_with_http_basic do |username, password|
@@ -112,11 +119,6 @@ def test_encode_credentials_has_no_newline
     assert_no_match(/\n/, result)
   end
 
-  test "has_basic_credentials? should fail with credentials without colon" do
-    @request.env["HTTP_AUTHORIZATION"] = "Basic #{::Base64.encode64("David Goliath")}"
-    assert_not ActionController::HttpAuthentication::Basic.has_basic_credentials?(@request)
-  end
-
   test "successful authentication with uppercase authorization scheme" do
     @request.env["HTTP_AUTHORIZATION"] = "BASIC #{::Base64.encode64("lifo:world")}"
     get :index
@@ -142,6 +144,21 @@ def test_encode_credentials_has_no_newline
     assert_equal 'Basic realm="SuperSecret"', @response.headers["WWW-Authenticate"]
   end
 
+  test "authentication request with a missing password" do
+    @request.env["HTTP_AUTHORIZATION"] = "Basic #{::Base64.encode64("David")}"
+    get :search
+
+    assert_response :unauthorized
+  end
+
+  test "authentication request with no required password" do
+    @request.env["HTTP_AUTHORIZATION"] = "Basic #{::Base64.encode64("George")}"
+    get :no_password
+
+    assert_response :success
+    assert_equal "Hello George (password: nil)", @response.body
+  end
+
   test "authentication request with valid credential" do
     @request.env["HTTP_AUTHORIZATION"] = encode_credentials("pretty", "please")
     get :display