[BUGFIX] Make username_attribute a mandatory placeholder in users_filter (#1449)

* [BUGFIX] Make username_attribute a mandatory placeholder in users_filter

Not including the `username_attribute` in the `users_filter` will cause issues with the LDAP session refresh and will result in session resets when the refresh interval has expired.

This change makes said attribute mandatory for the `users_filter`.

* Update version referenced in docs for fix

config.template.yml

@@ -133,7 +133,7 @@ authentication_backend:
     # The users filter used in search queries to find the user profile based on input filled in login form.
     # Various placeholders are available to represent the user input and back reference other options of the configuration:
     # - {input} is a placeholder replaced by what the user inputs in the login form. 
-    # - {username_attribute} is a placeholder replaced by what is configured in `username_attribute`.
+    # - {username_attribute} is a mandatory placeholder replaced by what is configured in `username_attribute`.
     # - {mail_attribute} is a placeholder replaced by what is configured in `mail_attribute`.
     # - DON'T USE - {0} is an alias for {input} supported for backward compatibility but it will be deprecated in later versions, so please don't use it.
     #

docs/configuration/authentication/ldap.md

@@ -78,7 +78,7 @@ authentication_backend:
     # The users filter used in search queries to find the user profile based on input filled in login form.
     # Various placeholders are available to represent the user input and back reference other options of the configuration:
     # - {input} is a placeholder replaced by what the user inputs in the login form. 
-    # - {username_attribute} is a placeholder replaced by what is configured in `username_attribute`.
+    # - {username_attribute} is a mandatory placeholder replaced by what is configured in `username_attribute`.
     # - {mail_attribute} is a placeholder replaced by what is configured in `mail_attribute`.
     # - DON'T USE - {0} is an alias for {input} supported for backward compatibility but it will be deprecated in later versions, so please don't use it.
     #
@@ -185,6 +185,11 @@ In order to avoid such problems, we highly recommended you follow https://www.ie
 `sAMAccountName` for Active Directory and `uid` for other implementations as the attribute holding the
 unique identifier for your users.
 
+As of versions > `4.24.0` the `users_filter` must include the `username_attribute` placeholder, not including this will
+result in Authelia throwing an error.
+In versions <= `4.24.0` not including the `username_attribute` placeholder will cause issues with the session refresh
+and will result in session resets when the refresh interval has expired, default of 5 minutes. 
+
 ## Loading a password from a secret instead of inside the configuration
 
 Password can also be defined using a [secret](../secrets.md).

internal/configuration/validator/authentication.go

@@ -137,7 +137,12 @@ func validateLdapAuthenticationBackend(configuration *schema.LDAPAuthenticationB
 		validator.Push(errors.New("Please provide a users filter with `users_filter` attribute"))
 	} else {
 		if !strings.HasPrefix(configuration.UsersFilter, "(") || !strings.HasSuffix(configuration.UsersFilter, ")") {
-			validator.Push(errors.New("The users filter should contain enclosing parenthesis. For instance uid={input} should be (uid={input})"))
+			validator.Push(errors.New("The users filter should contain enclosing parenthesis. For instance {username_attribute}={input} should be ({username_attribute}={input})"))
+		}
+
+		if !strings.Contains(configuration.UsersFilter, "{username_attribute}") {
+			validator.Push(errors.New("Unable to detect {username_attribute} placeholder in users_filter, your configuration is broken. " +
+				"Please review configuration options listed at https://docs.authelia.com/configuration/authentication/ldap.html"))
 		}
 
 		// This test helps the user know that users_filter is broken after the breaking change induced by this commit.

internal/configuration/validator/authentication_test.go

@@ -165,7 +165,7 @@ func (suite *LdapAuthenticationBackendSuite) SetupTest() {
 	suite.configuration.Ldap.Password = "password"
 	suite.configuration.Ldap.BaseDN = "base_dn"
 	suite.configuration.Ldap.UsernameAttribute = "uid"
-	suite.configuration.Ldap.UsersFilter = "(uid={input})"
+	suite.configuration.Ldap.UsersFilter = "({username_attribute}={input})"
 	suite.configuration.Ldap.GroupsFilter = "(cn={input})"
 }
 
@@ -267,10 +267,10 @@ func (suite *LdapAuthenticationBackendSuite) TestShouldSetDefaultRefreshInterval
 }
 
 func (suite *LdapAuthenticationBackendSuite) TestShouldRaiseWhenUsersFilterDoesNotContainEnclosingParenthesis() {
-	suite.configuration.Ldap.UsersFilter = "uid={input}"
+	suite.configuration.Ldap.UsersFilter = "{username_attribute}={input}"
 	ValidateAuthenticationBackend(&suite.configuration, suite.validator)
 	require.Len(suite.T(), suite.validator.Errors(), 1)
-	assert.EqualError(suite.T(), suite.validator.Errors()[0], "The users filter should contain enclosing parenthesis. For instance uid={input} should be (uid={input})")
+	assert.EqualError(suite.T(), suite.validator.Errors()[0], "The users filter should contain enclosing parenthesis. For instance {username_attribute}={input} should be ({username_attribute}={input})")
 }
 
 func (suite *LdapAuthenticationBackendSuite) TestShouldRaiseWhenGroupsFilterDoesNotContainEnclosingParenthesis() {
@@ -280,8 +280,15 @@ func (suite *LdapAuthenticationBackendSuite) TestShouldRaiseWhenGroupsFilterDoes
 	assert.EqualError(suite.T(), suite.validator.Errors()[0], "The groups filter should contain enclosing parenthesis. For instance cn={input} should be (cn={input})")
 }
 
+func (suite *LdapAuthenticationBackendSuite) TestShouldRaiseWhenUsersFilterDoesNotContainUsernameAttribute() {
+	suite.configuration.Ldap.UsersFilter = "(&({mail_attribute}={input})(objectClass=person))"
+	ValidateAuthenticationBackend(&suite.configuration, suite.validator)
+	require.Len(suite.T(), suite.validator.Errors(), 1)
+	assert.EqualError(suite.T(), suite.validator.Errors()[0], "Unable to detect {username_attribute} placeholder in users_filter, your configuration is broken. Please review configuration options listed at https://docs.authelia.com/configuration/authentication/ldap.html")
+}
+
 func (suite *LdapAuthenticationBackendSuite) TestShouldHelpDetectNoInputPlaceholder() {
-	suite.configuration.Ldap.UsersFilter = "(objectClass=person)"
+	suite.configuration.Ldap.UsersFilter = "(&({username_attribute}={mail_attribute})(objectClass=person))"
 	ValidateAuthenticationBackend(&suite.configuration, suite.validator)
 	require.Len(suite.T(), suite.validator.Errors(), 1)
 	assert.EqualError(suite.T(), suite.validator.Errors()[0], "Unable to detect {input} placeholder in users_filter, your configuration might be broken. Please review configuration options listed at https://docs.authelia.com/configuration/authentication/ldap.html")
@@ -308,79 +315,3 @@ func (suite *LdapAuthenticationBackendSuite) TestShouldAdaptLDAPURL() {
 func TestLdapAuthenticationBackend(t *testing.T) {
 	suite.Run(t, new(LdapAuthenticationBackendSuite))
 }
-
-type ActiveDirectoryAuthenticationBackendSuite struct {
-	suite.Suite
-	configuration schema.AuthenticationBackendConfiguration
-	validator     *schema.StructValidator
-}
-
-func (suite *ActiveDirectoryAuthenticationBackendSuite) SetupTest() {
-	suite.validator = schema.NewStructValidator()
-	suite.configuration = schema.AuthenticationBackendConfiguration{}
-	suite.configuration.Ldap = &schema.LDAPAuthenticationBackendConfiguration{}
-	suite.configuration.Ldap.Implementation = schema.LDAPImplementationActiveDirectory
-	suite.configuration.Ldap.URL = "ldap://ldap"
-	suite.configuration.Ldap.User = "user"
-	suite.configuration.Ldap.Password = "password"
-	suite.configuration.Ldap.BaseDN = "base_dn"
-}
-
-func (suite *ActiveDirectoryAuthenticationBackendSuite) TestShouldSetActiveDirectoryDefaults() {
-	ValidateAuthenticationBackend(&suite.configuration, suite.validator)
-
-	assert.Len(suite.T(), suite.validator.Errors(), 0)
-
-	assert.Equal(suite.T(),
-		suite.configuration.Ldap.UsersFilter,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.UsersFilter)
-	assert.Equal(suite.T(),
-		suite.configuration.Ldap.UsernameAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.UsernameAttribute)
-	assert.Equal(suite.T(),
-		suite.configuration.Ldap.DisplayNameAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.DisplayNameAttribute)
-	assert.Equal(suite.T(),
-		suite.configuration.Ldap.MailAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.MailAttribute)
-	assert.Equal(suite.T(),
-		suite.configuration.Ldap.GroupsFilter,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.GroupsFilter)
-	assert.Equal(suite.T(),
-		suite.configuration.Ldap.GroupNameAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.GroupNameAttribute)
-}
-
-func (suite *ActiveDirectoryAuthenticationBackendSuite) TestShouldOnlySetDefaultsIfNotManuallyConfigured() {
-	suite.configuration.Ldap.UsersFilter = "(&({username_attribute}={input})(objectCategory=person)(objectClass=user)(!userAccountControl:1.2.840.113556.1.4.803:=2))"
-	suite.configuration.Ldap.UsernameAttribute = "cn"
-	suite.configuration.Ldap.MailAttribute = "userPrincipalName"
-	suite.configuration.Ldap.DisplayNameAttribute = "name"
-	suite.configuration.Ldap.GroupsFilter = "(&(member={dn})(objectClass=group)(objectCategory=group))"
-	suite.configuration.Ldap.GroupNameAttribute = "distinguishedName"
-
-	ValidateAuthenticationBackend(&suite.configuration, suite.validator)
-
-	assert.NotEqual(suite.T(),
-		suite.configuration.Ldap.UsersFilter,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.UsersFilter)
-	assert.NotEqual(suite.T(),
-		suite.configuration.Ldap.UsernameAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.UsernameAttribute)
-	assert.NotEqual(suite.T(),
-		suite.configuration.Ldap.DisplayNameAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.DisplayNameAttribute)
-	assert.NotEqual(suite.T(),
-		suite.configuration.Ldap.MailAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.MailAttribute)
-	assert.NotEqual(suite.T(),
-		suite.configuration.Ldap.GroupsFilter,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.GroupsFilter)
-	assert.NotEqual(suite.T(),
-		suite.configuration.Ldap.GroupNameAttribute,
-		schema.DefaultLDAPAuthenticationBackendImplementationActiveDirectoryConfiguration.GroupNameAttribute)
-}
-
-func TestActiveDirectoryAuthenticationBackend(t *testing.T) {
-	suite.Run(t, new(ActiveDirectoryAuthenticationBackendSuite))
-}