feat: allow multiple auth sources per user (#500,#477) (#612)

* feat: allow multiple auth sources per user (#500,#477)

* only override isAdmin flag if it is provided by the authentication source

docs/documentation/rest-api/swagger.yaml

@@ -443,6 +443,18 @@ definitions:
                 maxLength: 64
                 minLength: 32
                 type: string
+            AuthSources:
+                description: The source of the user. This field is optional.
+                example:
+                    - db
+                items:
+                    enum:
+                        - db
+                        - ldap
+                        - oauth
+                    type: string
+                readOnly: true
+                type: array
             Department:
                 description: The department of the user. This field is optional.
                 example: Software Development
@@ -503,19 +515,6 @@ definitions:
                 description: The phone number of the user. This field is optional.
                 example: "+1234546789"
                 type: string
-            ProviderName:
-                description: The name of the authentication provider. This field is read-only.
-                example: ""
-                readOnly: true
-                type: string
-            Source:
-                description: The source of the user. This field is optional.
-                enum:
-                    - db
-                    - ldap
-                    - oauth
-                example: db
-                type: string
         required:
             - Identifier
         type: object

docs/documentation/usage/authentication.md

@@ -0,0 +1,152 @@
+WireGuard Portal supports multiple authentication mechanisms to manage user access. This includes
+
+ - Local user accounts
+ - LDAP authentication
+ - OAuth2 and OIDC authentication
+ - Passkey authentication (WebAuthn)
+
+Users can have two roles which limit their permissions in WireGuard Portal:
+
+- **User**: Can manage their own account and peers.
+- **Admin**: Can manage all users and peers, including the ability to manage WireGuard interfaces.
+
+In general, each user is identified by a _unique identifier_. If the same user identifier exists across multiple authentication sources, WireGuard Portal automatically merges those accounts into a single user record.
+When a user is associated with multiple authentication sources, their information in WireGuard Portal is updated based on the most recently logged-in source. For more details, see [User Synchronization](./user-sync.md) documentation.
+
+## Password Authentication
+
+WireGuard Portal supports username and password authentication for both local and LDAP-backed accounts.
+Local users are stored in the database, while LDAP users are authenticated against an external LDAP server.
+
+On initial startup, WireGuard Portal automatically creates a local admin account with the password `wgportal-default`.
+> :warning: This password must be changed immediately after the first login.
+
+The minimum password length for all local users can be configured in the [`auth`](../configuration/overview.md#auth)
+section of the configuration file. The default value is **16** characters, see [`min_password_length`](../configuration/overview.md#min_password_length).
+The minimum password length is also enforced for the default admin user.
+
+
+## Passkey (WebAuthn) Authentication
+
+Besides the standard authentication mechanisms, WireGuard Portal supports Passkey authentication.
+This feature is enabled by default and can be configured in the [`webauthn`](../configuration/overview.md#webauthn-passkeys) section of the configuration file.
+
+Users can register multiple Passkeys to their account. These Passkeys can be used to log in to the web UI as long as the user is not locked.
+> :warning: Passkey authentication does not disable password authentication. The password can still be used to log in (e.g., as a fallback).
+
+To register a Passkey, open the settings page *(1)* in the web UI and click on the "Register Passkey" *(2)* button.
+
+![Passkey UI](../../assets/images/passkey_setup.png)
+
+
+## OAuth2 and OIDC Authentication
+
+WireGuard Portal supports OAuth2 and OIDC authentication. You can use any OAuth2 or OIDC provider that supports the authorization code flow,
+such as Google, GitHub, or Keycloak.
+
+For OAuth2 or OIDC to work, you need to configure the [`external_url`](../configuration/overview.md#external_url) property in the [`web`](../configuration/overview.md#web) section of the configuration file.
+If you are planning to expose the portal to the internet, make sure that the `external_url` is configured to use HTTPS.
+
+To add OIDC or OAuth2 authentication to WireGuard Portal, create a Client-ID and Client-Secret in your OAuth2 provider and
+configure a new authentication provider in the [`auth`](../configuration/overview.md#auth) section of the configuration file.
+Make sure that each configured provider has a unique `provider_name` property set. Samples can be seen [here](../configuration/examples.md).
+
+#### Limiting Login to Specific Domains
+
+You can limit the login to specific domains by setting the `allowed_domains` property for OAuth2 or OIDC providers.
+This property is a comma-separated list of domains that are allowed to log in. The user's email address is checked against this list.
+For example, if you want to allow only users with an email address ending in `outlook.com` to log in, set the property as follows:
+
+```yaml
+auth:
+  oidc:
+    - provider_name: "oidc1"
+      # ... other settings
+      allowed_domains:
+        - "outlook.com"
+```
+
+#### Limit Login to Existing Users
+
+You can limit the login to existing users only by setting the `registration_enabled` property to `false` for OAuth2 or OIDC providers.
+If registration is enabled, new users will be created in the database when they log in for the first time.
+
+#### Admin Mapping
+
+You can map users to admin roles based on their attributes in the OAuth2 or OIDC provider. To do this, set the `admin_mapping` property for the provider.
+Administrative access can either be mapped by a specific attribute or by group membership.
+
+**Attribute specific mapping** can be achieved by setting the `admin_value_regex` and the `is_admin` property.
+The `admin_value_regex` property is a regular expression that is matched against the value of the `is_admin` attribute.
+The user is granted admin access if the regex matches the attribute value.
+
+Example:
+```yaml
+auth:
+  oidc:
+    - provider_name: "oidc1"
+      # ... other settings
+      field_map:
+        is_admin: "wg_admin_prop"
+      admin_mapping:
+        admin_value_regex: "^true$"
+```
+The example above will grant admin access to users with the `wg_admin_prop` attribute set to `true`.
+
+**Group membership mapping** can be achieved by setting the `admin_group_regex` and `user_groups` property.
+The `admin_group_regex` property is a regular expression that is matched against the group names of the user.
+The user is granted admin access if the regex matches any of the group names.
+
+Example:
+```yaml
+auth:
+  oidc:
+    - provider_name: "oidc1"
+      # ... other settings
+      field_map:
+        user_groups: "groups"
+      admin_mapping:
+        admin_group_regex: "^the-admin-group$"
+```
+The example above will grant admin access to users who are members of the `the-admin-group` group.
+
+
+## LDAP Authentication
+
+WireGuard Portal supports LDAP authentication. You can use any LDAP server that supports the LDAP protocol, such as Active Directory or OpenLDAP.
+Multiple LDAP servers can be configured in the [`auth`](../configuration/overview.md#auth) section of the configuration file.
+WireGuard Portal remembers the authentication provider of the user and therefore avoids conflicts between multiple LDAP providers.
+
+To configure LDAP authentication, create a new [`ldap`](../configuration/overview.md#ldap) authentication provider in the [`auth`](../configuration/overview.md#auth) section of the configuration file.
+
+### Limiting Login to Specific Users
+
+You can limit the login to specific users by setting the `login_filter` property for LDAP provider. This filter uses the LDAP search filter syntax.
+The username can be inserted into the query by placing the `{{login_identifier}}` placeholder in the filter. This placeholder will then be replaced with the username entered by the user during login.
+
+For example, if you want to allow only users with the `objectClass` attribute set to `organizationalPerson` to log in, set the property as follows:
+
+```yaml
+auth:
+  ldap:
+    - provider_name: "ldap1"
+      # ... other settings
+      login_filter: "(&(objectClass=organizationalPerson)(uid={{login_identifier}}))"
+```
+
+The `login_filter` should always be designed to return at most one user.
+
+### Limit Login to Existing Users
+
+You can limit the login to existing users only by setting the `registration_enabled` property to `false` for LDAP providers.
+If registration is enabled, new users will be created in the database when they log in for the first time.
+
+### Admin Mapping
+
+You can map users to admin roles based on their group membership in the LDAP server. To do this, set the `admin_group` and `memberof` property for the provider.
+The `admin_group` property defines the distinguished name of the group that is allowed to log in as admin.
+All groups that are listed in the `memberof` attribute of the user will be checked against this group. If one of the groups matches, the user is granted admin access.
+
+
+## User Synchronization
+

docs/documentation/usage/general.md

@@ -14,7 +14,7 @@ WireGuard Interfaces can be categorized into three types:
 ## Accessing the Web UI
 
 The web UI should be accessed via the URL specified in the `external_url` property of the configuration file.
-By default, WireGuard Portal listens on port `8888` for HTTP connections. Check the [Security](security.md) section for more information on securing the web UI.
+By default, WireGuard Portal listens on port `8888` for HTTP connections. Check the [Security](security.md) or [Authentication](authentication.md) sections for more information on securing the web UI.
 
 So the default URL to access the web UI is:
 

docs/documentation/usage/ldap.md

@@ -1,37 +0,0 @@
-WireGuard Portal lets you hook up any LDAP server such as Active Directory or OpenLDAP for both authentication and user sync. 
-You can even register multiple LDAP servers side-by-side. When someone logs in via LDAP, their specific provider is remembered, 
-so there's no risk of cross-provider conflicts. Details on the log-in process can be found in the [Security](security.md#ldap-authentication) documentation.
-
-If you enable LDAP synchronization, all users within the LDAP directory will be created automatically in the WireGuard Portal database if they do not exist.
-If a user is disabled or deleted in LDAP, the user will be disabled in WireGuard Portal as well. 
-The synchronization process can be fine-tuned by multiple parameters, which are described below.
-
-## LDAP Synchronization
-
-WireGuard Portal can automatically synchronize users from LDAP to the database. 
-To enable this feature, set the `sync_interval` property in the LDAP provider configuration to a value greater than "0".
-The value is a string representing a duration, such as "15m" for 15 minutes or "1h" for 1 hour (check the [exact format definition](https://pkg.go.dev/time#ParseDuration) for details).
-The synchronization process will run in the background and synchronize users from LDAP to the database at the specified interval.
-Also make sure that the `sync_filter` property is a well-formed LDAP filter, or synchronization will fail.
-
-### Limiting Synchronization to Specific Users
-
-Use the `sync_filter` property in your LDAP provider block to restrict which users get synchronized. 
-It accepts any valid LDAP search filter, only entries matching that filter will be pulled into the portal's database. 
-
-For example, to import only users with a `mail` attribute:
-```yaml
-auth:
-  ldap:
-    - id: ldap
-      # ... other settings
-      sync_filter: (mail=*)
-```
-
-### Disable Missing Users
-
-If you set the `disable_missing` property to `true`, any user that is not found in LDAP during synchronization will be disabled in WireGuard Portal.
-All peers associated with that user will also be disabled.
-
-If you want a user and its peers to be automatically re-enabled once they are found in LDAP again, set the `auto_re_enable` property to `true`.
-This will only re-enable the user if they where disabled by the synchronization process. Manually disabled users will not be re-enabled.

docs/documentation/usage/security.md

@@ -1,153 +1,12 @@
 This section describes the security features available to administrators for hardening WireGuard Portal and protecting its data.
 
-## Authentication
+## Database Encryption
 
-WireGuard Portal supports multiple authentication methods, including:
+WireGuard Portal supports multiple database backends. To reduce the risk of data exposure, sensitive information stored in the database can be encrypted.
-
+To enable encryption, set the [`encryption_passphrase`](../configuration/overview.md#database) in the database configuration section.
-- Local user accounts
-- LDAP authentication
-- OAuth and OIDC authentication
-- Passkey authentication (WebAuthn)
-
-Users can have two roles which limit their permissions in WireGuard Portal:
-
-- **User**: Can manage their own account and peers.
-- **Admin**: Can manage all users and peers, including the ability to manage WireGuard interfaces.
-
-### Password Security
-
-WireGuard Portal supports username and password authentication for both local and LDAP-backed accounts.
-Local users are stored in the database, while LDAP users are authenticated against an external LDAP server.
-
-On initial startup, WireGuard Portal automatically creates a local admin account with the password `wgportal-default`.
-> :warning: This password must be changed immediately after the first login.
-
-The minimum password length for all local users can be configured in the [`auth`](../configuration/overview.md#auth) 
-section of the configuration file. The default value is **16** characters, see [`min_password_length`](../configuration/overview.md#min_password_length).
-The minimum password length is also enforced for the default admin user.
-
-
-### Passkey (WebAuthn) Authentication
-
-Besides the standard authentication mechanisms, WireGuard Portal supports Passkey authentication.
-This feature is enabled by default and can be configured in the [`webauthn`](../configuration/overview.md#webauthn-passkeys) section of the configuration file.
-
-Users can register multiple Passkeys to their account. These Passkeys can be used to log in to the web UI as long as the user is not locked.
-> :warning: Passkey authentication does not disable password authentication. The password can still be used to log in (e.g., as a fallback).
-
-To register a Passkey, open the settings page *(1)* in the web UI and click on the "Register Passkey" *(2)* button.
-
-![Passkey UI](../../assets/images/passkey_setup.png)
-
-
-### OAuth and OIDC Authentication
-
-WireGuard Portal supports OAuth and OIDC authentication. You can use any OAuth or OIDC provider that supports the authorization code flow, 
-such as Google, GitHub, or Keycloak.
-
-For OAuth or OIDC to work, you need to configure the [`external_url`](../configuration/overview.md#external_url) property in the [`web`](../configuration/overview.md#web) section of the configuration file.
-If you are planning to expose the portal to the internet, make sure that the `external_url` is configured to use HTTPS.
-
-To add OIDC or OAuth authentication to WireGuard Portal, create a Client-ID and Client-Secret in your OAuth provider and 
-configure a new authentication provider in the [`auth`](../configuration/overview.md#auth) section of the configuration file.
-Make sure that each configured provider has a unique `provider_name` property set. Samples can be seen [here](../configuration/examples.md).
-
-#### Limiting Login to Specific Domains
-
-You can limit the login to specific domains by setting the `allowed_domains` property for OAuth or OIDC providers.
-This property is a comma-separated list of domains that are allowed to log in. The user's email address is checked against this list.
-For example, if you want to allow only users with an email address ending in `outlook.com` to log in, set the property as follows:
-
-```yaml
-auth:
-  oidc:
-    - provider_name: "oidc1"
-      # ... other settings
-      allowed_domains:
-        - "outlook.com"
-```
-
-#### Limit Login to Existing Users
-
-You can limit the login to existing users only by setting the `registration_enabled` property to `false` for OAuth or OIDC providers.
-If registration is enabled, new users will be created in the database when they log in for the first time.
-
-#### Admin Mapping
-
-You can map users to admin roles based on their attributes in the OAuth or OIDC provider. To do this, set the `admin_mapping` property for the provider.
-Administrative access can either be mapped by a specific attribute or by group membership.
-
-**Attribute specific mapping** can be achieved by setting the `admin_value_regex` and the `is_admin` property.
-The `admin_value_regex` property is a regular expression that is matched against the value of the `is_admin` attribute.
-The user is granted admin access if the regex matches the attribute value.
-
-Example:
-```yaml
-auth:
-  oidc:
-    - provider_name: "oidc1"
-      # ... other settings
-      field_map:
-        is_admin: "wg_admin_prop"
-      admin_mapping:
-        admin_value_regex: "^true$"
-```
-The example above will grant admin access to users with the `wg_admin_prop` attribute set to `true`.
-
-**Group membership mapping** can be achieved by setting the `admin_group_regex` and `user_groups` property.
-The `admin_group_regex` property is a regular expression that is matched against the group names of the user.
-The user is granted admin access if the regex matches any of the group names.
-
-Example:
-```yaml
-auth:
-  oidc:
-    - provider_name: "oidc1"
-      # ... other settings
-      field_map:
-        user_groups: "groups"
-      admin_mapping:
-        admin_group_regex: "^the-admin-group$"
-```
-The example above will grant admin access to users who are members of the `the-admin-group` group.
-
-
-### LDAP Authentication
-
-WireGuard Portal supports LDAP authentication. You can use any LDAP server that supports the LDAP protocol, such as Active Directory or OpenLDAP.
-Multiple LDAP servers can be configured in the [`auth`](../configuration/overview.md#auth) section of the configuration file. 
-WireGuard Portal remembers the authentication provider of the user and therefore avoids conflicts between multiple LDAP providers.
-
-To configure LDAP authentication, create a new [`ldap`](../configuration/overview.md#ldap) authentication provider in the [`auth`](../configuration/overview.md#auth) section of the configuration file.
-
-#### Limiting Login to Specific Users
-
-You can limit the login to specific users by setting the `login_filter` property for LDAP provider. This filter uses the LDAP search filter syntax.
-The username can be inserted into the query by placing the `{{login_identifier}}` placeholder in the filter. This placeholder will then be replaced with the username entered by the user during login.
-
-For example, if you want to allow only users with the `objectClass` attribute set to `organizationalPerson` to log in, set the property as follows:
-
-```yaml
-auth:
-  ldap:
-    - provider_name: "ldap1"
-      # ... other settings
-      login_filter: "(&(objectClass=organizationalPerson)(uid={{login_identifier}}))"
-```
-
-The `login_filter` should always be designed to return at most one user.
-
-#### Limit Login to Existing Users
-
-You can limit the login to existing users only by setting the `registration_enabled` property to `false` for LDAP providers.
-If registration is enabled, new users will be created in the database when they log in for the first time.
-
-#### Admin Mapping
-
-You can map users to admin roles based on their group membership in the LDAP server. To do this, set the `admin_group` and `memberof` property for the provider.
-The `admin_group` property defines the distinguished name of the group that is allowed to log in as admin. 
-All groups that are listed in the `memberof` attribute of the user will be checked against this group. If one of the groups matches, the user is granted admin access.
 
+> :warning: Important: Once encryption is enabled, it cannot be disabled, and the passphrase cannot be changed! 
+> Only new or updated records will be encrypted; existing data remains in plaintext until it’s next modified.
 
 ## UI and API Access
 
@@ -158,3 +17,8 @@ It is recommended to use HTTPS for all communication with the portal to prevent
 
 Event though, WireGuard Portal supports HTTPS out of the box, it is recommended to use a reverse proxy like Nginx or Traefik to handle SSL termination and other security features.
 A detailed explanation is available in the [Reverse Proxy](../getting-started/reverse-proxy.md) section.
+
+### Secure Authentication
+To prevent unauthorized access, WireGuard Portal supports integrating with secure authentication providers such as LDAP, OAuth2, or Passkeys, see [Authentication](./authentication.md) for more details.
+When possible, use centralized authentication and enforce multi-factor authentication (MFA) at the provider level for enhanced account security.
+For local accounts, administrators should enforce strong password requirements.

docs/documentation/usage/user-sync.md

@@ -0,0 +1,46 @@
+For all external authentication providers (LDAP, OIDC, OAuth2), WireGuard Portal can automatically create a local user record upon the user's first successful login.
+This behavior is controlled by the `registration_enabled` setting in each authentication provider's configuration.
+
+User information from external authentication sources is merged into the corresponding local WireGuard Portal user record whenever the user logs in.
+Additionally, WireGuard Portal supports periodic synchronization of user data from an LDAP directory.
+
+To prevent overwriting local changes, WireGuard Portal allows you to set a per-user flag that disables synchronization of external attributes.
+When this flag is set, the user in WireGuard Portal will not be updated automatically during log-ins or LDAP synchronization.
+
+### LDAP Synchronization
+
+WireGuard Portal lets you hook up any LDAP server such as Active Directory or OpenLDAP for both authentication and user sync.
+You can even register multiple LDAP servers side-by-side. Details on the log-in process can be found in the [LDAP Authentication](./authentication.md#ldap-authentication) section.
+
+If you enable LDAP synchronization, all users within the LDAP directory will be created automatically in the WireGuard Portal database if they do not exist.
+If a user is disabled or deleted in LDAP, the user will be disabled in WireGuard Portal as well.
+The synchronization process can be fine-tuned by multiple parameters, which are described below.
+
+#### Synchronization Parameters
+
+To enable the LDAP sycnhronization this feature, set the `sync_interval` property in the LDAP provider configuration to a value greater than "0".
+The value is a string representing a duration, such as "15m" for 15 minutes or "1h" for 1 hour (check the [exact format definition](https://pkg.go.dev/time#ParseDuration) for details).
+The synchronization process will run in the background and synchronize users from LDAP to the database at the specified interval.
+Also make sure that the `sync_filter` property is a well-formed LDAP filter, or synchronization will fail.
+
+##### Limiting Synchronization to Specific Users
+
+Use the `sync_filter` property in your LDAP provider block to restrict which users get synchronized.
+It accepts any valid LDAP search filter, only entries matching that filter will be pulled into the portal's database.
+
+For example, to import only users with a `mail` attribute:
+```yaml
+auth:
+  ldap:
+    - id: ldap
+      # ... other settings
+      sync_filter: (mail=*)
+```
+
+##### Disable Missing Users
+
+If you set the `disable_missing` property to `true`, any user that is not found in LDAP during synchronization will be disabled in WireGuard Portal.
+All peers associated with that user will also be disabled.
+
+If you want a user and its peers to be automatically re-enabled once they are found in LDAP again, set the `auto_re_enable` property to `true`.
+This will only re-enable the user if they were disabled by the synchronization process. Manually disabled users will not be re-enabled.

docs/documentation/usage/webhooks.md

@@ -69,15 +69,14 @@ All payload models are encoded as JSON objects. Fields with empty values might b
 #### User Payload (entity: `user`)
 
 | JSON Field     | Type          | Description                       |
-|----------------|-------------|-----------------------------------|
+|----------------|---------------|-----------------------------------|
 | CreatedBy      | string        | Creator identifier                |
 | UpdatedBy      | string        | Last updater identifier           |
 | CreatedAt      | time.Time     | Time of creation                  |
 | UpdatedAt      | time.Time     | Time of last update               |
 | Identifier     | string        | Unique user identifier            |
 | Email          | string        | User email                        |
-| Source         | string      | Authentication source             |
+| AuthSources    | []AuthSource  | Authentication sources            |
-| ProviderName   | string      | Name of auth provider             |
 | IsAdmin        | bool          | Whether user has admin privileges |
 | Firstname      | string        | User's first name (optional)      |
 | Lastname       | string        | User's last name (optional)       |
@@ -89,6 +88,13 @@ All payload models are encoded as JSON objects. Fields with empty values might b
 | Locked         | *time.Time    | When user account was locked      |
 | LockedReason   | string        | Reason for being locked           |
 
+`AuthSource`:
+
+| JSON Field   | Type          | Description                                         |
+|--------------|---------------|-----------------------------------------------------|
+| Source       | string        | The authentication source (e.g. LDAP, OAuth, or DB) |
+| ProviderName | string        | The identifier of the authentication provider       |
+
 
 #### Peer Payload (entity: `peer`)
 

frontend/src/components/UserEditModal.vue

@@ -42,7 +42,7 @@ const passwordWeak = computed(() => {
 })
 
 const formValid = computed(() => {
-  if (formData.value.Source !== 'db') {
+  if (!formData.value.AuthSources.some(s => s === 'db')) {
     return true // nothing to validate
   }
   if (props.userId !== '#NEW#' && passwordWeak.value) {
@@ -70,7 +70,7 @@ watch(() => props.visible, async (newValue, oldValue) => {
         } else { // fill existing userdata
           formData.value.Identifier = selectedUser.value.Identifier
           formData.value.Email = selectedUser.value.Email
-          formData.value.Source = selectedUser.value.Source
+          formData.value.AuthSources = selectedUser.value.AuthSources
           formData.value.IsAdmin = selectedUser.value.IsAdmin
           formData.value.Firstname = selectedUser.value.Firstname
           formData.value.Lastname = selectedUser.value.Lastname
@@ -80,6 +80,7 @@ watch(() => props.visible, async (newValue, oldValue) => {
           formData.value.Password = ""
           formData.value.Disabled = selectedUser.value.Disabled
           formData.value.Locked = selectedUser.value.Locked
+          formData.value.PersistLocalChanges = selectedUser.value.PersistLocalChanges
         }
       }
     }
@@ -133,7 +134,7 @@ async function del() {
 <template>
   <Modal :title="title" :visible="visible" @close="close">
     <template #default>
-      <fieldset v-if="formData.Source==='db'">
+      <fieldset>
         <legend class="mt-4">{{ $t('modals.user-edit.header-general') }}</legend>
         <div v-if="props.userId==='#NEW#'" class="form-group">
           <label class="form-label mt-4">{{ $t('modals.user-edit.identifier.label') }}</label>
@@ -141,16 +142,22 @@ async function del() {
         </div>
         <div class="form-group">
           <label class="form-label mt-4">{{ $t('modals.user-edit.source.label') }}</label>
-          <input v-model="formData.Source" class="form-control" disabled="disabled" :placeholder="$t('modals.user-edit.source.placeholder')" type="text">
+          <input v-model="formData.AuthSources" class="form-control" disabled="disabled" :placeholder="$t('modals.user-edit.source.placeholder')" type="text">
         </div>
-        <div v-if="formData.Source==='db'" class="form-group">
+        <div class="form-group" v-if="formData.AuthSources.some(s => s ==='db')">
           <label class="form-label mt-4">{{ $t('modals.user-edit.password.label') }}</label>
           <input v-model="formData.Password" aria-describedby="passwordHelp" class="form-control" :class="{ 'is-invalid': passwordWeak,  'is-valid': formData.Password !== '' && !passwordWeak }" :placeholder="$t('modals.user-edit.password.placeholder')" type="password">
           <div class="invalid-feedback">{{ $t('modals.user-edit.password.too-weak') }}</div>
           <small v-if="props.userId!=='#NEW#'" id="passwordHelp" class="form-text text-muted">{{ $t('modals.user-edit.password.description') }}</small>
         </div>
       </fieldset>
-      <fieldset v-if="formData.Source==='db'">
+      <fieldset v-if="formData.AuthSources.some(s => s !=='db') && !formData.PersistLocalChanges">
+        <legend class="mt-4">{{ $t('modals.user-edit.header-personal') }}</legend>
+        <div class="alert alert-warning mt-3">
+          {{ $t('modals.user-edit.sync-warning') }}
+        </div>
+      </fieldset>
+      <fieldset v-if="!formData.AuthSources.some(s => s !=='db') || formData.PersistLocalChanges">
         <legend class="mt-4">{{ $t('modals.user-edit.header-personal') }}</legend>
         <div class="form-group">
           <label class="form-label mt-4">{{ $t('modals.user-edit.email.label') }}</label>
@@ -194,10 +201,14 @@ async function del() {
           <input v-model="formData.Locked" class="form-check-input" type="checkbox">
           <label class="form-check-label" >{{ $t('modals.user-edit.locked.label') }}</label>
         </div>
-        <div class="form-check form-switch" v-if="formData.Source==='db'">
+        <div class="form-check form-switch" v-if="!formData.AuthSources.some(s => s !=='db') || formData.PersistLocalChanges">
           <input v-model="formData.IsAdmin" checked="" class="form-check-input" type="checkbox">
           <label class="form-check-label">{{ $t('modals.user-edit.admin.label') }}</label>
         </div>
+        <div class="form-check form-switch" v-if="formData.AuthSources.some(s => s !=='db')">
+          <input v-model="formData.PersistLocalChanges" class="form-check-input" type="checkbox">
+          <label class="form-check-label" >{{ $t('modals.user-edit.persist-local-changes.label') }}</label>
+        </div>
       </fieldset>
 
     </template>

frontend/src/helpers/models.js

@@ -137,7 +137,7 @@ export function freshUser() {
     Identifier: "",
 
     Email: "",
-    Source: "db",
+    AuthSources: ["db"],
     IsAdmin: false,
 
     Firstname: "",
@@ -155,6 +155,8 @@ export function freshUser() {
 
     ApiEnabled: false,
 
+    PersistLocalChanges: false,
+
     PeerCount: 0,
 
     // Internal values

frontend/src/lang/translations/de.json

@@ -147,7 +147,7 @@
       "email": "E-Mail",
       "firstname": "Vorname",
       "lastname": "Nachname",
-      "source": "Quelle",
+      "sources": "Quellen",
       "peers": "Peers",
       "admin": "Admin"
     },
@@ -378,7 +378,11 @@
       },
       "admin": {
         "label": "Ist Administrator"
-      }
+      },
+      "persist-local-changes": {
+        "label": "Lokale Änderungen speichern"
+      },
+      "sync-warning": "Um diesen synchronisierten Benutzer zu bearbeiten, aktivieren Sie die lokale Änderungsspeicherung. Andernfalls werden Ihre Änderungen bei der nächsten Synchronisierung überschrieben."
     },
     "interface-view": {
       "headline": "Konfiguration für Schnittstelle:"

frontend/src/lang/translations/en.json

@@ -147,7 +147,7 @@
       "email": "E-Mail",
       "firstname": "Firstname",
       "lastname": "Lastname",
-      "source": "Source",
+      "sources": "Sources",
       "peers": "Peers",
       "admin": "Admin"
     },
@@ -378,7 +378,11 @@
       },
       "admin": {
         "label": "Is Admin"
-      }
+      },
+      "persist-local-changes": {
+        "label": "Persist local changes"
+      },
+      "sync-warning": "To modify this synchronized user, enable local change persistence. Otherwise, your changes will be overwritten during the next synchronization."
     },
     "interface-view": {
       "headline": "Config for Interface:"

frontend/src/lang/translations/es.json

@@ -162,7 +162,7 @@
       "email": "Correo electrónico",
       "firstname": "Nombre",
       "lastname": "Apellido",
-      "source": "Origen",
+      "sources": "Origen",
       "peers": "Peers",
       "admin": "Administrador"
     },

frontend/src/lang/translations/fr.json

@@ -137,7 +137,7 @@
       "email": "E-mail",
       "firstname": "Prénom",
       "lastname": "Nom",
-      "source": "Source",
+      "sources": "Sources",
       "peers": "Pairs",
       "admin": "Admin"
     },

frontend/src/lang/translations/ko.json

@@ -136,7 +136,7 @@
         "email": "이메일",
         "firstname": "이름",
         "lastname": "성",
-        "source": "소스",
+        "sources": "소스",
         "peers": "피어",
         "admin": "관리자"
       },

frontend/src/lang/translations/pt.json

@@ -137,7 +137,7 @@
       "email": "E-Mail",
       "firstname": "Primeiro Nome",
       "lastname": "Último Nome",
-      "source": "Fonte",
+      "sources": "Fonte",
       "peers": "Peers",
       "admin": "Administrador"
     },

frontend/src/lang/translations/ru.json

@@ -143,7 +143,7 @@
       "email": "Электронная почта",
       "firstname": "Имя",
       "lastname": "Фамилия",
-      "source": "Источник",
+      "sources": "Источник",
       "peers": "Пиры",
       "admin": "Админ"
     },

frontend/src/lang/translations/uk.json

@@ -135,7 +135,7 @@
       "email": "E-Mail",
       "firstname": "Ім'я",
       "lastname": "Прізвище",
-      "source": "Джерело",
+      "sources": "Джерело",
       "peers": "Піри",
       "admin": "Адміністратор"
     },

frontend/src/lang/translations/vi.json

@@ -134,7 +134,7 @@
       "email": "E-Mail",
       "firstname": "Tên",
       "lastname": "Họ",
-      "source": "Nguồn",
+      "sources": "Nguồn",
       "peers": "Peers",
       "admin": "Quản trị viên"
     },

frontend/src/lang/translations/zh.json

@@ -134,7 +134,7 @@
         "email": "电子邮件",
         "firstname": "名",
         "lastname": "姓",
-        "source": "来源",
+        "sources": "来源",
         "peers": "节点",
         "admin": "管理员"
       },

frontend/src/views/UserView.vue

@@ -131,7 +131,7 @@ onMounted(() => {
           <th scope="col">{{ $t('users.table-heading.email') }}</th>
           <th scope="col">{{ $t('users.table-heading.firstname') }}</th>
           <th scope="col">{{ $t('users.table-heading.lastname') }}</th>
-          <th class="text-center" scope="col">{{ $t('users.table-heading.source') }}</th>
+          <th class="text-center" scope="col">{{ $t('users.table-heading.sources') }}</th>
           <th class="text-center" scope="col">{{ $t('users.table-heading.peers') }}</th>
           <th class="text-center" scope="col">{{ $t('users.table-heading.admin') }}</th>
           <th scope="col"></th><!-- Actions -->
@@ -150,7 +150,7 @@ onMounted(() => {
           <td>{{user.Email}}</td>
           <td>{{user.Firstname}}</td>
           <td>{{user.Lastname}}</td>
-          <td class="text-center"><span class="badge rounded-pill bg-light">{{user.Source}}</span></td>
+          <td><span class="badge bg-light me-1" v-for="src in user.AuthSources" :key="src">{{src}}</span></td>
           <td class="text-center">{{user.PeerCount}}</td>
           <td class="text-center">
             <span v-if="user.IsAdmin" class="text-danger" :title="$t('users.admin')"><i class="fa fa-check-circle"></i></span>

internal/adapters/database.go

@@ -23,9 +23,6 @@ import (
 	"github.com/h44z/wg-portal/internal/domain"
 )
 
-// SchemaVersion describes the current database schema version. It must be incremented if a manual migration is needed.
-var SchemaVersion uint64 = 2
-
 // SysStat stores the current database schema version and the timestamp when it was applied.
 type SysStat struct {
 	MigratedAt    time.Time `gorm:"column:migrated_at"`
@@ -225,6 +222,8 @@ func (r *SqlRepo) preCheck() error {
 func (r *SqlRepo) migrate() error {
 	slog.Debug("running migration: sys-stat", "result", r.db.AutoMigrate(&SysStat{}))
 	slog.Debug("running migration: user", "result", r.db.AutoMigrate(&domain.User{}))
+	slog.Debug("running migration: user authentications", "result",
+		r.db.AutoMigrate(&domain.UserAuthentication{}))
 	slog.Debug("running migration: user webauthn credentials", "result",
 		r.db.AutoMigrate(&domain.UserWebauthnCredential{}))
 	slog.Debug("running migration: interface", "result", r.db.AutoMigrate(&domain.Interface{}))
@@ -238,35 +237,84 @@ func (r *SqlRepo) migrate() error {
 
 	// Migration: 0 --> 1
 	if existingSysStat.SchemaVersion == 0 {
+		const schemaVersion = 1
 		sysStat := SysStat{
 			MigratedAt:    time.Now(),
-			SchemaVersion: SchemaVersion,
+			SchemaVersion: schemaVersion,
 		}
 		if err := r.db.Create(&sysStat).Error; err != nil {
-			return fmt.Errorf("failed to write sysstat entry for schema version %d: %w", SchemaVersion, err)
+			return fmt.Errorf("failed to write sysstat entry for schema version %d: %w", schemaVersion, err)
 		}
-		slog.Debug("sys-stat entry written", "schema_version", SchemaVersion)
+		slog.Debug("sys-stat entry written", "schema_version", schemaVersion)
+		existingSysStat = sysStat // ensure that follow-up checks test against the latest version
 	}
 
 	// Migration: 1 --> 2
 	if existingSysStat.SchemaVersion == 1 {
+		const schemaVersion = 2
 		// Preserve existing behavior for installations that had default-peer-creation enabled.
 		if r.cfg.Core.CreateDefaultPeer {
 			err := r.db.Model(&domain.Interface{}).
 				Where("type = ?", domain.InterfaceTypeServer).
 				Update("create_default_peer", true).Error
 			if err != nil {
-				return fmt.Errorf("failed to migrate interface flags for schema version %d: %w", SchemaVersion, err)
+				return fmt.Errorf("failed to migrate interface flags for schema version %d: %w", schemaVersion, err)
 			}
-			slog.Debug("migrated interface create_default_peer flags", "schema_version", SchemaVersion)
+			slog.Debug("migrated interface create_default_peer flags", "schema_version", schemaVersion)
 		}
 		sysStat := SysStat{
 			MigratedAt:    time.Now(),
-			SchemaVersion: SchemaVersion,
+			SchemaVersion: schemaVersion,
 		}
 		if err := r.db.Create(&sysStat).Error; err != nil {
-			return fmt.Errorf("failed to write sysstat entry for schema version %d: %w", SchemaVersion, err)
+			return fmt.Errorf("failed to write sysstat entry for schema version %d: %w", schemaVersion, err)
 		}
+		existingSysStat = sysStat // ensure that follow-up checks test against the latest version
+	}
+
+	// Migration: 2 --> 3
+	if existingSysStat.SchemaVersion == 2 {
+		const schemaVersion = 3
+		// Migration to multi-auth
+		err := r.db.Transaction(func(tx *gorm.DB) error {
+			var users []domain.User
+			if err := tx.Find(&users).Error; err != nil {
+				return err
+			}
+
+			now := time.Now()
+			for _, user := range users {
+				auth := domain.UserAuthentication{
+					BaseModel: domain.BaseModel{
+						CreatedBy: domain.CtxSystemDBMigrator,
+						UpdatedBy: domain.CtxSystemDBMigrator,
+						CreatedAt: now,
+						UpdatedAt: now,
+					},
+					UserIdentifier: user.Identifier,
+					Source:         user.Source,
+					ProviderName:   user.ProviderName,
+				}
+				if err := tx.Create(&auth).Error; err != nil {
+					return err
+				}
+			}
+
+			slog.Debug("migrated users to multi-auth model", "schema_version", schemaVersion)
+
+			return nil
+		})
+		if err != nil {
+			return fmt.Errorf("failed to migrate to multi-auth: %w", err)
+		}
+		sysStat := SysStat{
+			MigratedAt:    time.Now(),
+			SchemaVersion: schemaVersion,
+		}
+		if err := r.db.Create(&sysStat).Error; err != nil {
+			return fmt.Errorf("failed to write sysstat entry for schema version %d: %w", schemaVersion, err)
+		}
+		existingSysStat = sysStat // ensure that follow-up checks test against the latest version
 	}
 
 	return nil
@@ -776,7 +824,7 @@ func (r *SqlRepo) GetUsedIpsPerSubnet(ctx context.Context, subnets []domain.Cidr
 func (r *SqlRepo) GetUser(ctx context.Context, id domain.UserIdentifier) (*domain.User, error) {
 	var user domain.User
 
-	err := r.db.WithContext(ctx).Preload("WebAuthnCredentialList").First(&user, id).Error
+	err := r.db.WithContext(ctx).Preload("WebAuthnCredentialList").Preload("Authentications").First(&user, id).Error
 
 	if err != nil && errors.Is(err, gorm.ErrRecordNotFound) {
 		return nil, domain.ErrNotFound
@@ -794,7 +842,8 @@ func (r *SqlRepo) GetUser(ctx context.Context, id domain.UserIdentifier) (*domai
 func (r *SqlRepo) GetUserByEmail(ctx context.Context, email string) (*domain.User, error) {
 	var users []domain.User
 
-	err := r.db.WithContext(ctx).Where("email = ?", email).Preload("WebAuthnCredentialList").Find(&users).Error
+	err := r.db.WithContext(ctx).Where("email = ?",
+		email).Preload("WebAuthnCredentialList").Preload("Authentications").Find(&users).Error
 	if err != nil && errors.Is(err, gorm.ErrRecordNotFound) {
 		return nil, domain.ErrNotFound
 	}
@@ -834,7 +883,7 @@ func (r *SqlRepo) GetUserByWebAuthnCredential(ctx context.Context, credentialIdB
 func (r *SqlRepo) GetAllUsers(ctx context.Context) ([]domain.User, error) {
 	var users []domain.User
 
-	err := r.db.WithContext(ctx).Preload("WebAuthnCredentialList").Find(&users).Error
+	err := r.db.WithContext(ctx).Preload("WebAuthnCredentialList").Preload("Authentications").Find(&users).Error
 	if err != nil {
 		return nil, err
 	}
@@ -854,6 +903,7 @@ func (r *SqlRepo) FindUsers(ctx context.Context, search string) ([]domain.User,
 		Or("lastname LIKE ?", searchValue).
 		Or("email LIKE ?", searchValue).
 		Preload("WebAuthnCredentialList").
+		Preload("Authentications").
 		Find(&users).Error
 	if err != nil {
 		return nil, err
@@ -913,7 +963,17 @@ func (r *SqlRepo) getOrCreateUser(ui *domain.ContextUserInfo, tx *gorm.DB, id do
 ) {
 	var user domain.User
 
-	// userDefaults will be applied to newly created user records
+	result := tx.Model(&user).Preload("WebAuthnCredentialList").Preload("Authentications").Find(&user, id)
+	if result.Error != nil {
+		if !errors.Is(result.Error, gorm.ErrRecordNotFound) {
+			return nil, result.Error
+		}
+	}
+	if result.Error == nil && result.RowsAffected > 0 {
+		return &user, nil
+	}
+
+	// create a new user record if no user record exists yet
 	userDefaults := domain.User{
 		BaseModel: domain.BaseModel{
 			CreatedBy: ui.UserId(),
@@ -922,16 +982,15 @@ func (r *SqlRepo) getOrCreateUser(ui *domain.ContextUserInfo, tx *gorm.DB, id do
 			UpdatedAt: time.Now(),
 		},
 		Identifier: id,
-		Source:     domain.UserSourceDatabase,
 		IsAdmin:    false,
 	}
 
-	err := tx.Attrs(userDefaults).FirstOrCreate(&user, id).Error
+	err := tx.Create(&userDefaults).Error
 	if err != nil {
 		return nil, err
 	}
 
-	return &user, nil
+	return &userDefaults, nil
 }
 
 func (r *SqlRepo) upsertUser(ui *domain.ContextUserInfo, tx *gorm.DB, user *domain.User) error {
@@ -948,6 +1007,11 @@ func (r *SqlRepo) upsertUser(ui *domain.ContextUserInfo, tx *gorm.DB, user *doma
 		return fmt.Errorf("failed to update users webauthn credentials: %w", err)
 	}
 
+	err = tx.Session(&gorm.Session{FullSaveAssociations: true}).Unscoped().Model(user).Association("Authentications").Unscoped().Replace(user.Authentications)
+	if err != nil {
+		return fmt.Errorf("failed to update users authentications: %w", err)
+	}
+
 	return nil
 }
 

internal/app/api/core/assets/doc/v0_swagger.json

@@ -2676,6 +2676,12 @@
                 "ApiTokenCreated": {
                     "type": "string"
                 },
+                "AuthSources": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
                 "Department": {
                     "type": "string"
                 },
@@ -2719,14 +2725,11 @@
                 "PeerCount": {
                     "type": "integer"
                 },
+                "PersistLocalChanges": {
+                    "type": "boolean"
+                },
                 "Phone": {
                     "type": "string"
-                },
-                "ProviderName": {
-                    "type": "string"
-                },
-                "Source": {
-                    "type": "string"
                 }
             }
         },

internal/app/api/core/assets/doc/v0_swagger.yaml

@@ -431,6 +431,10 @@ definitions:
         type: string
       ApiTokenCreated:
         type: string
+      AuthSources:
+        items:
+          type: string
+        type: array
       Department:
         type: string
       Disabled:
@@ -461,12 +465,10 @@ definitions:
         type: string
       PeerCount:
         type: integer
+      PersistLocalChanges:
+        type: boolean
       Phone:
         type: string
-      ProviderName:
-        type: string
-      Source:
-        type: string
     type: object
   model.WebAuthnCredentialRequest:
     properties:

internal/app/api/core/assets/doc/v1_swagger.json

@@ -2132,6 +2132,22 @@
                     "minLength": 32,
                     "example": ""
                 },
+                "AuthSources": {
+                    "description": "The source of the user. This field is optional.",
+                    "type": "array",
+                    "items": {
+                        "type": "string",
+                        "enum": [
+                            "db",
+                            "ldap",
+                            "oauth"
+                        ]
+                    },
+                    "readOnly": true,
+                    "example": [
+                        "db"
+                    ]
+                },
                 "Department": {
                     "description": "The department of the user. This field is optional.",
                     "type": "string",
@@ -2205,22 +2221,6 @@
                     "description": "The phone number of the user. This field is optional.",
                     "type": "string",
                     "example": "+1234546789"
-                },
-                "ProviderName": {
-                    "description": "The name of the authentication provider. This field is read-only.",
-                    "type": "string",
-                    "readOnly": true,
-                    "example": ""
-                },
-                "Source": {
-                    "description": "The source of the user. This field is optional.",
-                    "type": "string",
-                    "enum": [
-                        "db",
-                        "ldap",
-                        "oauth"
-                    ],
-                    "example": "db"
                 }
             }
         },

internal/app/api/core/assets/doc/v1_swagger.yaml

@@ -490,6 +490,18 @@ definitions:
         maxLength: 64
         minLength: 32
         type: string
+      AuthSources:
+        description: The source of the user. This field is optional.
+        example:
+        - db
+        items:
+          enum:
+          - db
+          - ldap
+          - oauth
+          type: string
+        readOnly: true
+        type: array
       Department:
         description: The department of the user. This field is optional.
         example: Software Development
@@ -552,19 +564,6 @@ definitions:
         description: The phone number of the user. This field is optional.
         example: "+1234546789"
         type: string
-      ProviderName:
-        description: The name of the authentication provider. This field is read-only.
-        example: ""
-        readOnly: true
-        type: string
-      Source:
-        description: The source of the user. This field is optional.
-        enum:
-        - db
-        - ldap
-        - oauth
-        example: db
-        type: string
     required:
     - Identifier
     type: object

internal/app/api/v0/backend/user_service.go

@@ -3,6 +3,7 @@ package backend
 import (
 	"context"
 	"fmt"
+	"slices"
 	"strings"
 
 	"github.com/h44z/wg-portal/internal/config"
@@ -95,8 +96,10 @@ func (u UserService) ChangePassword(
 	}
 
 	// ensure that the user uses the database backend; otherwise we can't change the password
-	if user.Source != domain.UserSourceDatabase {
+	if !slices.ContainsFunc(user.Authentications, func(authentication domain.UserAuthentication) bool {
-		return nil, fmt.Errorf("user source %s does not support password changes", user.Source)
+		return authentication.Source == domain.UserSourceDatabase
+	}) {
+		return nil, fmt.Errorf("user has no linked authentication source that does support password changes")
 	}
 
 	// validate old password

internal/app/api/v0/model/models_user.go

@@ -3,14 +3,14 @@ package model
 import (
 	"time"
 
+	"github.com/h44z/wg-portal/internal"
 	"github.com/h44z/wg-portal/internal/domain"
 )
 
 type User struct {
 	Identifier  string   `json:"Identifier"`
 	Email       string   `json:"Email"`
-	Source       string `json:"Source"`
+	AuthSources []string `json:"AuthSources"`
-	ProviderName string `json:"ProviderName"`
 	IsAdmin     bool     `json:"IsAdmin"`
 
 	Firstname  string `json:"Firstname"`
@@ -29,6 +29,8 @@ type User struct {
 	ApiTokenCreated *time.Time `json:"ApiTokenCreated,omitempty"`
 	ApiEnabled      bool       `json:"ApiEnabled"`
 
+	PersistLocalChanges bool `json:"PersistLocalChanges"`
+
 	// Calculated
 
 	PeerCount int `json:"PeerCount"`
@@ -38,8 +40,9 @@ func NewUser(src *domain.User, exposeCreds bool) *User {
 	u := &User{
 		Identifier: string(src.Identifier),
 		Email:      src.Email,
-		Source:          string(src.Source),
+		AuthSources: internal.Map(src.Authentications, func(authentication domain.UserAuthentication) string {
-		ProviderName:    src.ProviderName,
+			return string(authentication.Source)
+		}),
 		IsAdmin:             src.IsAdmin,
 		Firstname:           src.Firstname,
 		Lastname:            src.Lastname,
@@ -54,6 +57,7 @@ func NewUser(src *domain.User, exposeCreds bool) *User {
 		ApiToken:            "", // by default, do not expose API token
 		ApiTokenCreated:     src.ApiTokenCreated,
 		ApiEnabled:          src.IsApiEnabled(),
+		PersistLocalChanges: src.PersistLocalChanges,
 
 		PeerCount: src.LinkedPeerCount,
 	}
@@ -79,8 +83,6 @@ func NewDomainUser(src *User) *domain.User {
 	res := &domain.User{
 		Identifier:          domain.UserIdentifier(src.Identifier),
 		Email:               src.Email,
-		Source:          domain.UserSource(src.Source),
-		ProviderName:    src.ProviderName,
 		IsAdmin:             src.IsAdmin,
 		Firstname:           src.Firstname,
 		Lastname:            src.Lastname,
@@ -93,6 +95,7 @@ func NewDomainUser(src *User) *domain.User {
 		Locked:              nil, // set below
 		LockedReason:        src.LockedReason,
 		LinkedPeerCount:     src.PeerCount,
+		PersistLocalChanges: src.PersistLocalChanges,
 	}
 
 	if src.Disabled {

internal/app/api/v1/models/models_user.go

@@ -3,6 +3,7 @@ package models
 import (
 	"time"
 
+	"github.com/h44z/wg-portal/internal"
 	"github.com/h44z/wg-portal/internal/domain"
 )
 
@@ -13,9 +14,7 @@ type User struct {
 	// The email address of the user. This field is optional.
 	Email string `json:"Email" binding:"omitempty,email" example:"test@test.com"`
 	// The source of the user. This field is optional.
-	Source string `json:"Source" binding:"oneof=db ldap oauth" example:"db"`
+	AuthSources []string `json:"AuthSources" readonly:"true" binding:"oneof=db ldap oauth" example:"db"`
-	// The name of the authentication provider. This field is read-only.
-	ProviderName string `json:"ProviderName,omitempty" readonly:"true" example:""`
 	// If this field is set, the user is an admin.
 	IsAdmin bool `json:"IsAdmin" example:"false"`
 
@@ -54,8 +53,9 @@ func NewUser(src *domain.User, exposeCredentials bool) *User {
 	u := &User{
 		Identifier: string(src.Identifier),
 		Email:      src.Email,
-		Source:         string(src.Source),
+		AuthSources: internal.Map(src.Authentications, func(authentication domain.UserAuthentication) string {
-		ProviderName:   src.ProviderName,
+			return string(authentication.Source)
+		}),
 		IsAdmin:        src.IsAdmin,
 		Firstname:      src.Firstname,
 		Lastname:       src.Lastname,
@@ -93,8 +93,6 @@ func NewDomainUser(src *User) *domain.User {
 	res := &domain.User{
 		Identifier:     domain.UserIdentifier(src.Identifier),
 		Email:          src.Email,
-		Source:         domain.UserSource(src.Source),
-		ProviderName:   src.ProviderName,
 		IsAdmin:        src.IsAdmin,
 		Firstname:      src.Firstname,
 		Lastname:       src.Lastname,

internal/app/app.go

@@ -129,8 +129,6 @@ func (a *App) createDefaultUser(ctx context.Context) error {
 		},
 		Identifier:      adminUserId,
 		Email:           "admin@wgportal.local",
-		Source:          domain.UserSourceDatabase,
-		ProviderName:    "",
 		IsAdmin:         true,
 		Firstname:       "WireGuard Portal",
 		Lastname:        "Admin",

internal/app/auth/auth.go

@@ -29,8 +29,8 @@ type UserManager interface {
 	GetUser(context.Context, domain.UserIdentifier) (*domain.User, error)
 	// RegisterUser creates a new user in the database.
 	RegisterUser(ctx context.Context, user *domain.User) error
-	// UpdateUser updates an existing user in the database.
+	// UpdateUserInternal updates an existing user in the database.
-	UpdateUser(ctx context.Context, user *domain.User) (*domain.User, error)
+	UpdateUserInternal(ctx context.Context, user *domain.User) (*domain.User, error)
 }
 
 type EventBus interface {
@@ -232,7 +232,7 @@ func (a *Authenticator) setupExternalAuthProviders(
 	}
 	for i := range ldap { // LDAP
 		providerCfg := &ldap[i]
-		providerId := strings.ToLower(providerCfg.URL)
+		providerId := strings.ToLower(providerCfg.ProviderName)
 
 		if _, exists := a.ldapAuthenticators[providerId]; exists {
 			// this is an unrecoverable error, we cannot register the same provider twice
@@ -354,21 +354,45 @@ func (a *Authenticator) passwordAuthentication(
 	var ldapProvider AuthenticatorLdap
 
 	var userInDatabase = false
-	var userSource domain.UserSource
 	existingUser, err := a.users.GetUser(ctx, identifier)
 	if err == nil {
 		userInDatabase = true
-		userSource = existingUser.Source
 	}
 	if userInDatabase && (existingUser.IsLocked() || existingUser.IsDisabled()) {
 		return nil, errors.New("user is locked")
 	}
 
-	if !userInDatabase || userSource == domain.UserSourceLdap {
+	authOK := false
-		// search user in ldap if registration is enabled
+	if userInDatabase {
+		// User is already in db, search for authentication sources which support password authentication and
+		// validate the password.
+		for _, authentication := range existingUser.Authentications {
+			if authentication.Source == domain.UserSourceDatabase {
+				err := existingUser.CheckPassword(password)
+				if err == nil {
+					authOK = true
+					break
+				}
+			}
+
+			if authentication.Source == domain.UserSourceLdap {
+				ldapProvider, ok := a.ldapAuthenticators[strings.ToLower(authentication.ProviderName)]
+				if !ok {
+					continue // ldap provider not found, skip further checks
+				}
+				err := ldapProvider.PlaintextAuthentication(identifier, password)
+				if err == nil {
+					authOK = true
+					break
+				}
+			}
+		}
+	} else {
+		// User is not yet in the db, check ldap providers which have registration enabled.
+		// If the user is found, check the password - on success, sync it to the db.
 		for _, ldapAuth := range a.ldapAuthenticators {
-			if !userInDatabase && !ldapAuth.RegistrationEnabled() {
+			if !ldapAuth.RegistrationEnabled() {
-				continue
+				continue // ldap provider does not support registration, skip further checks
 			}
 
 			rawUserInfo, err := ldapAuth.GetUserInfo(context.Background(), identifier)
@@ -379,56 +403,40 @@ func (a *Authenticator) passwordAuthentication(
 				}
 				continue // user not found / other ldap error
 			}
+
+			// user found, check if the password is correct
+			err = ldapAuth.PlaintextAuthentication(identifier, password)
+			if err != nil {
+				continue // password is incorrect, skip further checks
+			}
+
+			// create a new user in the db
 			ldapUserInfo, err = ldapAuth.ParseUserInfo(rawUserInfo)
 			if err != nil {
 				slog.Error("failed to parse ldap user info",
 					"source", ldapAuth.GetName(), "identifier", identifier, "error", err)
 				continue
 			}
+			user, err := a.processUserInfo(ctx, ldapUserInfo, domain.UserSourceLdap, ldapProvider.GetName(), true)
+			if err != nil {
+				return nil, fmt.Errorf("unable to process user information: %w", err)
+			}
 
-			// ldap user found
+			existingUser = user
-			userSource = domain.UserSourceLdap
+			slog.Debug("created new LDAP user in db",
-			ldapProvider = ldapAuth
+				"identifier", user.Identifier, "provider", ldapProvider.GetName())
 
+			authOK = true
 			break
 		}
 	}
 
-	if userSource == "" {
+	if !authOK {
-		slog.Warn("no user source found for user",
+		return nil, errors.New("failed to authenticate user")
-			"identifier", identifier, "ldapProviderCount", len(a.ldapAuthenticators), "inDb", userInDatabase)
-		return nil, errors.New("user not found")
 	}
 
-	if userSource == domain.UserSourceLdap && ldapProvider == nil {
-		slog.Warn("no ldap provider found for user",
-			"identifier", identifier, "ldapProviderCount", len(a.ldapAuthenticators), "inDb", userInDatabase)
-		return nil, errors.New("ldap provider not found")
-	}
-
-	switch userSource {
-	case domain.UserSourceDatabase:
-		err = existingUser.CheckPassword(password)
-	case domain.UserSourceLdap:
-		err = ldapProvider.PlaintextAuthentication(identifier, password)
-	default:
-		err = errors.New("no authentication backend available")
-	}
-	if err != nil {
-		return nil, fmt.Errorf("failed to authenticate: %w", err)
-	}
-
-	if !userInDatabase {
-		user, err := a.processUserInfo(ctx, ldapUserInfo, domain.UserSourceLdap, ldapProvider.GetName(),
-			ldapProvider.RegistrationEnabled())
-		if err != nil {
-			return nil, fmt.Errorf("unable to process user information: %w", err)
-		}
-		return user, nil
-	} else {
 	return existingUser, nil
 }
-}
 
 // endregion password authentication
 
@@ -590,17 +598,34 @@ func (a *Authenticator) registerNewUser(
 	source domain.UserSource,
 	provider string,
 ) (*domain.User, error) {
+	ctxUserInfo := domain.GetUserInfo(ctx)
+	now := time.Now()
+
 	// convert user info to domain.User
 	user := &domain.User{
 		Identifier: userInfo.Identifier,
 		Email:      userInfo.Email,
-		Source:       source,
+		IsAdmin:    false,
-		ProviderName: provider,
-		IsAdmin:      userInfo.IsAdmin,
 		Firstname:  userInfo.Firstname,
 		Lastname:   userInfo.Lastname,
 		Phone:      userInfo.Phone,
 		Department: userInfo.Department,
+		Authentications: []domain.UserAuthentication{
+			{
+				BaseModel: domain.BaseModel{
+					CreatedBy: ctxUserInfo.UserId(),
+					UpdatedBy: ctxUserInfo.UserId(),
+					CreatedAt: now,
+					UpdatedAt: now,
+				},
+				UserIdentifier: userInfo.Identifier,
+				Source:         source,
+				ProviderName:   provider,
+			},
+		},
+	}
+	if userInfo.AdminInfoAvailable && userInfo.IsAdmin {
+		user.IsAdmin = true
 	}
 
 	err := a.users.RegisterUser(ctx, user)
@@ -610,6 +635,7 @@ func (a *Authenticator) registerNewUser(
 
 	slog.Debug("registered user from external authentication provider",
 		"user", user.Identifier,
+		"adminInfoAvailable", userInfo.AdminInfoAvailable,
 		"isAdmin", user.IsAdmin,
 		"provider", source)
 
@@ -643,6 +669,39 @@ func (a *Authenticator) updateExternalUser(
 		return nil // user is locked or disabled, do not update
 	}
 
+	// Update authentication sources
+	foundAuthSource := false
+	for _, auth := range existingUser.Authentications {
+		if auth.Source == source && auth.ProviderName == provider {
+			foundAuthSource = true
+			break
+		}
+	}
+	if !foundAuthSource {
+		ctxUserInfo := domain.GetUserInfo(ctx)
+		now := time.Now()
+		existingUser.Authentications = append(existingUser.Authentications, domain.UserAuthentication{
+			BaseModel: domain.BaseModel{
+				CreatedBy: ctxUserInfo.UserId(),
+				UpdatedBy: ctxUserInfo.UserId(),
+				CreatedAt: now,
+				UpdatedAt: now,
+			},
+			UserIdentifier: existingUser.Identifier,
+			Source:         source,
+			ProviderName:   provider,
+		})
+	}
+
+	if existingUser.PersistLocalChanges {
+		if !foundAuthSource {
+			// Even if local changes are persisted, we need to save the new authentication source
+			_, err := a.users.UpdateUserInternal(ctx, existingUser)
+			return err
+		}
+		return nil
+	}
+
 	isChanged := false
 	if existingUser.Email != userInfo.Email {
 		existingUser.Email = userInfo.Email
@@ -664,32 +723,23 @@ func (a *Authenticator) updateExternalUser(
 		existingUser.Department = userInfo.Department
 		isChanged = true
 	}
-	if existingUser.IsAdmin != userInfo.IsAdmin {
+	if userInfo.AdminInfoAvailable && existingUser.IsAdmin != userInfo.IsAdmin {
 		existingUser.IsAdmin = userInfo.IsAdmin
 		isChanged = true
 	}
-	if existingUser.Source != source {
-		existingUser.Source = source
-		isChanged = true
-	}
-	if existingUser.ProviderName != provider {
-		existingUser.ProviderName = provider
-		isChanged = true
-	}
 
-	if !isChanged {
+	if isChanged || !foundAuthSource {
-		return nil // nothing to update
+		_, err := a.users.UpdateUserInternal(ctx, existingUser)
-	}
-
-	_, err := a.users.UpdateUser(ctx, existingUser)
 		if err != nil {
 			return fmt.Errorf("failed to update user: %w", err)
 		}
 
 		slog.Debug("updated user with data from external authentication provider",
 			"user", existingUser.Identifier,
+			"adminInfoAvailable", userInfo.AdminInfoAvailable,
 			"isAdmin", existingUser.IsAdmin,
 			"provider", source)
+	}
 
 	return nil
 }

internal/app/auth/auth_ldap.go

@@ -127,10 +127,17 @@ func (l LdapAuthenticator) GetUserInfo(_ context.Context, userId domain.UserIden
 
 // ParseUserInfo parses the user information from the LDAP server into a domain.AuthenticatorUserInfo struct.
 func (l LdapAuthenticator) ParseUserInfo(raw map[string]any) (*domain.AuthenticatorUserInfo, error) {
-	isAdmin, err := internal.LdapIsMemberOf(raw[l.cfg.FieldMap.GroupMembership].([][]byte), l.cfg.ParsedAdminGroupDN)
+	isAdmin := false
+	adminInfoAvailable := false
+	if l.cfg.FieldMap.GroupMembership != "" {
+		adminInfoAvailable = true
+		var err error
+		isAdmin, err = internal.LdapIsMemberOf(raw[l.cfg.FieldMap.GroupMembership].([][]byte), l.cfg.ParsedAdminGroupDN)
 		if err != nil {
 			return nil, fmt.Errorf("failed to check admin group: %w", err)
 		}
+	}
+
 	userInfo := &domain.AuthenticatorUserInfo{
 		Identifier:         domain.UserIdentifier(internal.MapDefaultString(raw, l.cfg.FieldMap.UserIdentifier, "")),
 		Email:              internal.MapDefaultString(raw, l.cfg.FieldMap.Email, ""),
@@ -139,6 +146,7 @@ func (l LdapAuthenticator) ParseUserInfo(raw map[string]any) (*domain.Authentica
 		Phone:              internal.MapDefaultString(raw, l.cfg.FieldMap.Phone, ""),
 		Department:         internal.MapDefaultString(raw, l.cfg.FieldMap.Department, ""),
 		IsAdmin:            isAdmin,
+		AdminInfoAvailable: adminInfoAvailable,
 	}
 
 	return userInfo, nil

internal/app/auth/oauth_common.go

@@ -15,9 +15,11 @@ func parseOauthUserInfo(
 	raw map[string]any,
 ) (*domain.AuthenticatorUserInfo, error) {
 	var isAdmin bool
+	var adminInfoAvailable bool
 
 	// first try to match the is_admin field against the given regex
 	if mapping.IsAdmin != "" {
+		adminInfoAvailable = true
 		re := adminMapping.GetAdminValueRegex()
 		if re.MatchString(strings.TrimSpace(internal.MapDefaultString(raw, mapping.IsAdmin, ""))) {
 			isAdmin = true
@@ -26,6 +28,7 @@ func parseOauthUserInfo(
 
 	// next try to parse the user's groups
 	if !isAdmin && mapping.UserGroups != "" && adminMapping.AdminGroupRegex != "" {
+		adminInfoAvailable = true
 		userGroups := internal.MapDefaultStringSlice(raw, mapping.UserGroups, nil)
 		re := adminMapping.GetAdminGroupRegex()
 		for _, group := range userGroups {
@@ -44,6 +47,7 @@ func parseOauthUserInfo(
 		Phone:              internal.MapDefaultString(raw, mapping.Phone, ""),
 		Department:         internal.MapDefaultString(raw, mapping.Department, ""),
 		IsAdmin:            isAdmin,
+		AdminInfoAvailable: adminInfoAvailable,
 	}
 
 	return userInfo, nil

internal/app/auth/webauthn.go

@@ -23,8 +23,8 @@ type WebAuthnUserManager interface {
 	GetUser(context.Context, domain.UserIdentifier) (*domain.User, error)
 	// GetUserByWebAuthnCredential returns a user by its WebAuthn ID.
 	GetUserByWebAuthnCredential(ctx context.Context, credentialIdBase64 string) (*domain.User, error)
-	// UpdateUser updates an existing user in the database.
+	// UpdateUserInternal updates an existing user in the database.
-	UpdateUser(ctx context.Context, user *domain.User) (*domain.User, error)
+	UpdateUserInternal(ctx context.Context, user *domain.User) (*domain.User, error)
 }
 
 type WebAuthnAuthenticator struct {
@@ -89,7 +89,7 @@ func (a *WebAuthnAuthenticator) StartWebAuthnRegistration(ctx context.Context, u
 
 	if user.WebAuthnId == "" {
 		user.GenerateWebAuthnId()
-		user, err = a.users.UpdateUser(ctx, user)
+		user, err = a.users.UpdateUserInternal(ctx, user)
 		if err != nil {
 			return nil, nil, fmt.Errorf("failed to store webauthn id to user: %w", err)
 		}
@@ -150,7 +150,7 @@ func (a *WebAuthnAuthenticator) FinishWebAuthnRegistration(
 		return nil, err
 	}
 
-	user, err = a.users.UpdateUser(ctx, user)
+	user, err = a.users.UpdateUserInternal(ctx, user)
 	if err != nil {
 		return nil, err
 	}
@@ -181,7 +181,7 @@ func (a *WebAuthnAuthenticator) RemoveCredential(
 	}
 
 	user.RemoveCredential(credentialIdBase64)
-	user, err = a.users.UpdateUser(ctx, user)
+	user, err = a.users.UpdateUserInternal(ctx, user)
 	if err != nil {
 		return nil, err
 	}
@@ -205,7 +205,7 @@ func (a *WebAuthnAuthenticator) UpdateCredential(
 		return nil, err
 	}
 
-	user, err = a.users.UpdateUser(ctx, user)
+	user, err = a.users.UpdateUserInternal(ctx, user)
 	if err != nil {
 		return nil, err
 	}

internal/app/migrate_v1.go

@@ -144,8 +144,6 @@ func migrateV1Users(oldDb, newDb *gorm.DB) error {
 			},
 			Identifier:      domain.UserIdentifier(oldUser.Email),
 			Email:           oldUser.Email,
-			Source:          domain.UserSource(oldUser.Source),
-			ProviderName:    "",
 			IsAdmin:         oldUser.IsAdmin,
 			Firstname:       oldUser.Firstname,
 			Lastname:        oldUser.Lastname,
@@ -159,11 +157,25 @@ func migrateV1Users(oldDb, newDb *gorm.DB) error {
 			LockedReason:    "",
 			LinkedPeerCount: 0,
 		}
-
 		if err := newDb.Create(&newUser).Error; err != nil {
 			return fmt.Errorf("failed to migrate user %s: %w", oldUser.Email, err)
 		}
 
+		authentication := domain.UserAuthentication{
+			BaseModel: domain.BaseModel{
+				CreatedBy: domain.CtxSystemV1Migrator,
+				UpdatedBy: domain.CtxSystemV1Migrator,
+				CreatedAt: oldUser.CreatedAt,
+				UpdatedAt: oldUser.UpdatedAt,
+			},
+			UserIdentifier: domain.UserIdentifier(oldUser.Email),
+			Source:         domain.UserSource(oldUser.Source),
+			ProviderName:   "", // unknown
+		}
+		if err := newDb.Create(&authentication).Error; err != nil {
+			return fmt.Errorf("failed to migrate user-authentication %s: %w", oldUser.Email, err)
+		}
+
 		slog.Debug("user migrated successfully", "identifier", newUser.Identifier)
 	}
 
@@ -346,8 +358,6 @@ func migrateV1Peers(oldDb, newDb *gorm.DB) error {
 				},
 				Identifier:   domain.UserIdentifier(oldPeer.Email),
 				Email:        oldPeer.Email,
-				Source:       domain.UserSourceDatabase,
-				ProviderName: "",
 				IsAdmin:      false,
 				Locked:       &now,
 				LockedReason: domain.DisabledReasonMigrationDummy,
@@ -358,6 +368,21 @@ func migrateV1Peers(oldDb, newDb *gorm.DB) error {
 				return fmt.Errorf("failed to migrate dummy user %s: %w", oldPeer.Email, err)
 			}
 
+			authentication := domain.UserAuthentication{
+				BaseModel: domain.BaseModel{
+					CreatedBy: domain.CtxSystemV1Migrator,
+					UpdatedBy: domain.CtxSystemV1Migrator,
+					CreatedAt: now,
+					UpdatedAt: now,
+				},
+				UserIdentifier: domain.UserIdentifier(oldPeer.Email),
+				Source:         domain.UserSourceDatabase,
+				ProviderName:   "", // unknown
+			}
+			if err := newDb.Create(&authentication).Error; err != nil {
+				return fmt.Errorf("failed to migrate dummy user-authentication %s: %w", oldPeer.Email, err)
+			}
+
 			slog.Debug("dummy user migrated successfully", "identifier", user.Identifier)
 		}
 		newPeer := domain.Peer{

internal/app/users/ldap_helper.go

@@ -2,6 +2,7 @@ package users
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 	"time"
 
@@ -25,6 +26,8 @@ func convertRawLdapUser(
 		return nil, fmt.Errorf("failed to check admin group: %w", err)
 	}
 
+	uid := domain.UserIdentifier(internal.MapDefaultString(rawUser, fields.UserIdentifier, ""))
+
 	return &domain.User{
 		BaseModel: domain.BaseModel{
 			CreatedBy: domain.CtxSystemLdapSyncer,
@@ -32,11 +35,16 @@ func convertRawLdapUser(
 			CreatedAt: now,
 			UpdatedAt: now,
 		},
-		Identifier:   domain.UserIdentifier(internal.MapDefaultString(rawUser, fields.UserIdentifier, "")),
+		Identifier: uid,
 		Email:      strings.ToLower(internal.MapDefaultString(rawUser, fields.Email, "")),
+		IsAdmin:    isAdmin,
+		Authentications: []domain.UserAuthentication{
+			{
+				UserIdentifier: uid,
 				Source:         domain.UserSourceLdap,
 				ProviderName:   providerName,
-		IsAdmin:      isAdmin,
+			},
+		},
 		Firstname:  internal.MapDefaultString(rawUser, fields.Firstname, ""),
 		Lastname:   internal.MapDefaultString(rawUser, fields.Lastname, ""),
 		Phone:      internal.MapDefaultString(rawUser, fields.Phone, ""),
@@ -72,7 +80,9 @@ func userChangedInLdap(dbUser, ldapUser *domain.User) bool {
 		return true
 	}
 
-	if dbUser.ProviderName != ldapUser.ProviderName {
+	if !slices.ContainsFunc(dbUser.Authentications, func(authentication domain.UserAuthentication) bool {
+		return authentication.Source == ldapUser.Authentications[0].Source
+	}) {
 		return true
 	}
 

internal/app/users/ldap_sync.go

@@ -0,0 +1,239 @@
+package users
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"time"
+
+	"github.com/go-ldap/ldap/v3"
+
+	"github.com/h44z/wg-portal/internal"
+	"github.com/h44z/wg-portal/internal/app"
+	"github.com/h44z/wg-portal/internal/config"
+	"github.com/h44z/wg-portal/internal/domain"
+)
+
+func (m Manager) runLdapSynchronizationService(ctx context.Context) {
+	ctx = domain.SetUserInfo(ctx, domain.LdapSyncContextUserInfo()) // switch to service context for LDAP sync
+
+	for _, ldapCfg := range m.cfg.Auth.Ldap { // LDAP Auth providers
+		go func(cfg config.LdapProvider) {
+			syncInterval := cfg.SyncInterval
+			if syncInterval == 0 {
+				slog.Debug("sync disabled for LDAP server", "provider", cfg.ProviderName)
+				return
+			}
+
+			// perform initial sync
+			err := m.synchronizeLdapUsers(ctx, &cfg)
+			if err != nil {
+				slog.Error("failed to synchronize LDAP users", "provider", cfg.ProviderName, "error", err)
+			} else {
+				slog.Debug("initial LDAP user sync completed", "provider", cfg.ProviderName)
+			}
+
+			// start periodic sync
+			running := true
+			for running {
+				select {
+				case <-ctx.Done():
+					running = false
+					continue
+				case <-time.After(syncInterval):
+					// select blocks until one of the cases evaluate to true
+				}
+
+				err := m.synchronizeLdapUsers(ctx, &cfg)
+				if err != nil {
+					slog.Error("failed to synchronize LDAP users", "provider", cfg.ProviderName, "error", err)
+				}
+			}
+		}(ldapCfg)
+	}
+}
+
+func (m Manager) synchronizeLdapUsers(ctx context.Context, provider *config.LdapProvider) error {
+	slog.Debug("starting to synchronize users", "provider", provider.ProviderName)
+
+	dn, err := ldap.ParseDN(provider.AdminGroupDN)
+	if err != nil {
+		return fmt.Errorf("failed to parse admin group DN: %w", err)
+	}
+	provider.ParsedAdminGroupDN = dn
+
+	conn, err := internal.LdapConnect(provider)
+	if err != nil {
+		return fmt.Errorf("failed to setup LDAP connection: %w", err)
+	}
+	defer internal.LdapDisconnect(conn)
+
+	rawUsers, err := internal.LdapFindAllUsers(conn, provider.BaseDN, provider.SyncFilter, &provider.FieldMap)
+	if err != nil {
+		return err
+	}
+
+	slog.Debug("fetched raw ldap users", "count", len(rawUsers), "provider", provider.ProviderName)
+
+	// Update existing LDAP users
+	err = m.updateLdapUsers(ctx, provider, rawUsers, &provider.FieldMap, provider.ParsedAdminGroupDN)
+	if err != nil {
+		return err
+	}
+
+	// Disable missing LDAP users
+	if provider.DisableMissing {
+		err = m.disableMissingLdapUsers(ctx, provider.ProviderName, rawUsers, &provider.FieldMap)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (m Manager) updateLdapUsers(
+	ctx context.Context,
+	provider *config.LdapProvider,
+	rawUsers []internal.RawLdapUser,
+	fields *config.LdapFields,
+	adminGroupDN *ldap.DN,
+) error {
+	for _, rawUser := range rawUsers {
+		user, err := convertRawLdapUser(provider.ProviderName, rawUser, fields, adminGroupDN)
+		if err != nil && !errors.Is(err, domain.ErrNotFound) {
+			return fmt.Errorf("failed to convert LDAP data for %v: %w", rawUser["dn"], err)
+		}
+
+		if provider.SyncLogUserInfo {
+			slog.Debug("ldap user data",
+				"raw-user", rawUser, "user", user.Identifier,
+				"is-admin", user.IsAdmin, "provider", provider.ProviderName)
+		}
+
+		existingUser, err := m.users.GetUser(ctx, user.Identifier)
+		if err != nil && !errors.Is(err, domain.ErrNotFound) {
+			return fmt.Errorf("find error for user id %s: %w", user.Identifier, err)
+		}
+
+		tctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+		tctx = domain.SetUserInfo(tctx, domain.SystemAdminContextUserInfo())
+
+		if existingUser == nil {
+			// create new user
+			slog.Debug("creating new user from provider", "user", user.Identifier, "provider", provider.ProviderName)
+
+			_, err := m.create(tctx, user)
+			if err != nil {
+				cancel()
+				return fmt.Errorf("create error for user id %s: %w", user.Identifier, err)
+			}
+		} else {
+			// update existing user
+			if provider.AutoReEnable && existingUser.DisabledReason == domain.DisabledReasonLdapMissing {
+				user.Disabled = nil
+				user.DisabledReason = ""
+			} else {
+				user.Disabled = existingUser.Disabled
+				user.DisabledReason = existingUser.DisabledReason
+			}
+
+			if existingUser.PersistLocalChanges {
+				cancel()
+				continue // skip synchronization for this user
+			}
+
+			if userChangedInLdap(existingUser, user) {
+				syncedUser, err := m.users.GetUser(ctx, user.Identifier)
+				if err != nil && !errors.Is(err, domain.ErrNotFound) {
+					cancel()
+					return fmt.Errorf("find error for user id %s: %w", user.Identifier, err)
+				}
+				syncedUser.UpdatedAt = time.Now()
+				syncedUser.UpdatedBy = domain.CtxSystemLdapSyncer
+				syncedUser.MergeAuthSources(user.Authentications...)
+				syncedUser.Email = user.Email
+				syncedUser.Firstname = user.Firstname
+				syncedUser.Lastname = user.Lastname
+				syncedUser.Phone = user.Phone
+				syncedUser.Department = user.Department
+				syncedUser.IsAdmin = user.IsAdmin
+				syncedUser.Disabled = user.Disabled
+				syncedUser.DisabledReason = user.DisabledReason
+
+				_, err = m.update(tctx, existingUser, syncedUser, false)
+				if err != nil {
+					cancel()
+					return fmt.Errorf("update error for user id %s: %w", user.Identifier, err)
+				}
+			}
+		}
+
+		cancel()
+	}
+
+	return nil
+}
+
+func (m Manager) disableMissingLdapUsers(
+	ctx context.Context,
+	providerName string,
+	rawUsers []internal.RawLdapUser,
+	fields *config.LdapFields,
+) error {
+	allUsers, err := m.users.GetAllUsers(ctx)
+	if err != nil {
+		return err
+	}
+	for _, user := range allUsers {
+		userHasAuthSource := false
+		for _, auth := range user.Authentications {
+			if auth.Source == domain.UserSourceLdap && auth.ProviderName == providerName {
+				userHasAuthSource = true
+				break
+			}
+		}
+		if !userHasAuthSource {
+			continue // ignore non ldap users
+		}
+		if user.IsDisabled() {
+			continue // ignore deactivated
+		}
+		if user.PersistLocalChanges {
+			continue // skip sync for this user
+		}
+
+		existsInLDAP := false
+		for _, rawUser := range rawUsers {
+			userId := domain.UserIdentifier(internal.MapDefaultString(rawUser, fields.UserIdentifier, ""))
+			if user.Identifier == userId {
+				existsInLDAP = true
+				break
+			}
+		}
+
+		if existsInLDAP {
+			continue
+		}
+
+		slog.Debug("user is missing in ldap provider, disabling", "user", user.Identifier, "provider", providerName)
+
+		now := time.Now()
+		user.Disabled = &now
+		user.DisabledReason = domain.DisabledReasonLdapMissing
+
+		err := m.users.SaveUser(ctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
+			u.Disabled = user.Disabled
+			u.DisabledReason = user.DisabledReason
+			return u, nil
+		})
+		if err != nil {
+			return fmt.Errorf("disable error for user id %s: %w", user.Identifier, err)
+		}
+
+		m.bus.Publish(app.TopicUserDisabled, user)
+	}
+
+	return nil
+}

internal/app/users/user_manager.go

@@ -4,15 +4,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log/slog"
 	"math"
 	"sync"
 	"time"
 
-	"github.com/go-ldap/ldap/v3"
 	"github.com/google/uuid"
 
-	"github.com/h44z/wg-portal/internal"
 	"github.com/h44z/wg-portal/internal/app"
 	"github.com/h44z/wg-portal/internal/config"
 	"github.com/h44z/wg-portal/internal/domain"
@@ -79,7 +76,7 @@ func (m Manager) RegisterUser(ctx context.Context, user *domain.User) error {
 		return err
 	}
 
-	createdUser, err := m.CreateUser(ctx, user)
+	createdUser, err := m.create(ctx, user)
 	if err != nil {
 		return err
 	}
@@ -101,20 +98,11 @@ func (m Manager) GetUser(ctx context.Context, id domain.UserIdentifier) (*domain
 		return nil, err
 	}
 
-	user, err := m.users.GetUser(ctx, id)
+	return m.getUser(ctx, id)
-	if err != nil {
-		return nil, fmt.Errorf("unable to load user %s: %w", id, err)
-	}
-	peers, _ := m.peers.GetUserPeers(ctx, id) // ignore error, list will be empty in error case
-
-	user.LinkedPeerCount = len(peers)
-
-	return user, nil
 }
 
 // GetUserByEmail returns the user with the given email address.
 func (m Manager) GetUserByEmail(ctx context.Context, email string) (*domain.User, error) {
-
 	user, err := m.users.GetUserByEmail(ctx, email)
 	if err != nil {
 		return nil, fmt.Errorf("unable to load user for email %s: %w", email, err)
@@ -124,16 +112,11 @@ func (m Manager) GetUserByEmail(ctx context.Context, email string) (*domain.User
 		return nil, err
 	}
 
-	peers, _ := m.peers.GetUserPeers(ctx, user.Identifier) // ignore error, list will be empty in error case
+	return m.enrichUser(ctx, user), nil
-
-	user.LinkedPeerCount = len(peers)
-
-	return user, nil
 }
 
 // GetUserByWebAuthnCredential returns the user for the given WebAuthn credential.
 func (m Manager) GetUserByWebAuthnCredential(ctx context.Context, credentialIdBase64 string) (*domain.User, error) {
-
 	user, err := m.users.GetUserByWebAuthnCredential(ctx, credentialIdBase64)
 	if err != nil {
 		return nil, fmt.Errorf("unable to load user for webauthn credential %s: %w", credentialIdBase64, err)
@@ -143,11 +126,7 @@ func (m Manager) GetUserByWebAuthnCredential(ctx context.Context, credentialIdBa
 		return nil, err
 	}
 
-	peers, _ := m.peers.GetUserPeers(ctx, user.Identifier) // ignore error, list will be empty in error case
+	return m.enrichUser(ctx, user), nil
-
-	user.LinkedPeerCount = len(peers)
-
-	return user, nil
 }
 
 // GetAllUsers returns all users.
@@ -169,8 +148,7 @@ func (m Manager) GetAllUsers(ctx context.Context) ([]domain.User, error) {
 		go func() {
 			defer wg.Done()
 			for user := range ch {
-				peers, _ := m.peers.GetUserPeers(ctx, user.Identifier) // ignore error, list will be empty in error case
+				m.enrichUser(ctx, user)
-				user.LinkedPeerCount = len(peers)
 			}
 		}()
 	}
@@ -194,77 +172,29 @@ func (m Manager) UpdateUser(ctx context.Context, user *domain.User) (*domain.Use
 		return nil, fmt.Errorf("unable to load existing user %s: %w", user.Identifier, err)
 	}
 
-	if err := m.validateModifications(ctx, existingUser, user); err != nil {
+	user.CopyCalculatedAttributes(existingUser, true) // ensure that crucial attributes stay the same
-		return nil, fmt.Errorf("update not allowed: %w", err)
+
+	return m.update(ctx, existingUser, user, true)
 }
 
-	user.CopyCalculatedAttributes(existingUser)
+// UpdateUserInternal updates the user with the given identifier. This function must never be called from external.
-	err = user.HashPassword()
+// This function allows to override authentications and webauthn credentials.
+func (m Manager) UpdateUserInternal(ctx context.Context, user *domain.User) (*domain.User, error) {
+	existingUser, err := m.users.GetUser(ctx, user.Identifier)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("unable to load existing user %s: %w", user.Identifier, err)
-	}
-	if user.Password == "" { // keep old password
-		user.Password = existingUser.Password
 	}
 
-	err = m.users.SaveUser(ctx, existingUser.Identifier, func(u *domain.User) (*domain.User, error) {
+	return m.update(ctx, existingUser, user, false)
-		user.CopyCalculatedAttributes(u)
-		return user, nil
-	})
-	if err != nil {
-		return nil, fmt.Errorf("update failure: %w", err)
-	}
-
-	m.bus.Publish(app.TopicUserUpdated, *user)
-
-	switch {
-	case !existingUser.IsDisabled() && user.IsDisabled():
-		m.bus.Publish(app.TopicUserDisabled, *user)
-	case existingUser.IsDisabled() && !user.IsDisabled():
-		m.bus.Publish(app.TopicUserEnabled, *user)
-	}
-
-	return user, nil
 }
 
 // CreateUser creates a new user.
 func (m Manager) CreateUser(ctx context.Context, user *domain.User) (*domain.User, error) {
-	if user.Identifier == "" {
-		return nil, errors.New("missing user identifier")
-	}
-
 	if err := domain.ValidateAdminAccessRights(ctx); err != nil {
 		return nil, err
 	}
 
-	existingUser, err := m.users.GetUser(ctx, user.Identifier)
+	return m.create(ctx, user)
-	if err != nil && !errors.Is(err, domain.ErrNotFound) {
-		return nil, fmt.Errorf("unable to load existing user %s: %w", user.Identifier, err)
-	}
-	if existingUser != nil {
-		return nil, errors.Join(fmt.Errorf("user %s already exists", user.Identifier), domain.ErrDuplicateEntry)
-	}
-
-	if err := m.validateCreation(ctx, user); err != nil {
-		return nil, fmt.Errorf("creation not allowed: %w", err)
-	}
-
-	err = user.HashPassword()
-	if err != nil {
-		return nil, err
-	}
-
-	err = m.users.SaveUser(ctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
-		user.CopyCalculatedAttributes(u)
-		return user, nil
-	})
-	if err != nil {
-		return nil, fmt.Errorf("creation failure: %w", err)
-	}
-
-	m.bus.Publish(app.TopicUserCreated, *user)
-
-	return user, nil
 }
 
 // DeleteUser deletes the user with the given identifier.
@@ -307,15 +237,10 @@ func (m Manager) ActivateApi(ctx context.Context, id domain.UserIdentifier) (*do
 	user.ApiToken = uuid.New().String()
 	user.ApiTokenCreated = &now
 
-	err = m.users.SaveUser(ctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
+	user, err = m.update(ctx, user, user, true) // self-update
-		user.CopyCalculatedAttributes(u)
-		return user, nil
-	})
 	if err != nil {
-		return nil, fmt.Errorf("update failure: %w", err)
+		return nil, err
 	}
-
-	m.bus.Publish(app.TopicUserUpdated, *user)
 	m.bus.Publish(app.TopicUserApiEnabled, *user)
 
 	return user, nil
@@ -335,15 +260,10 @@ func (m Manager) DeactivateApi(ctx context.Context, id domain.UserIdentifier) (*
 	user.ApiToken = ""
 	user.ApiTokenCreated = nil
 
-	err = m.users.SaveUser(ctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
+	user, err = m.update(ctx, user, user, true) // self-update
-		user.CopyCalculatedAttributes(u)
-		return user, nil
-	})
 	if err != nil {
-		return nil, fmt.Errorf("update failure: %w", err)
+		return nil, err
 	}
-
-	m.bus.Publish(app.TopicUserUpdated, *user)
 	m.bus.Publish(app.TopicUserApiDisabled, *user)
 
 	return user, nil
@@ -380,10 +300,6 @@ func (m Manager) validateModifications(ctx context.Context, old, new *domain.Use
 		return fmt.Errorf("cannot lock own user: %w", domain.ErrInvalidData)
 	}
 
-	if old.Source != new.Source {
-		return fmt.Errorf("cannot change user source: %w", domain.ErrInvalidData)
-	}
-
 	return nil
 }
 
@@ -414,14 +330,19 @@ func (m Manager) validateCreation(ctx context.Context, new *domain.User) error {
 		return fmt.Errorf("reserved user identifier: %w", domain.ErrInvalidData)
 	}
 
+	if len(new.Authentications) != 1 {
+		return fmt.Errorf("invalid number of authentications: %d, expected 1: %w",
+			len(new.Authentications), domain.ErrInvalidData)
+	}
+
 	// Admins are allowed to create users for arbitrary sources.
-	if new.Source != domain.UserSourceDatabase && !currentUser.IsAdmin {
+	if new.Authentications[0].Source != domain.UserSourceDatabase && !currentUser.IsAdmin {
 		return fmt.Errorf("invalid user source: %s, only %s is allowed: %w",
-			new.Source, domain.UserSourceDatabase, domain.ErrInvalidData)
+			new.Authentications[0].Source, domain.UserSourceDatabase, domain.ErrInvalidData)
 	}
 
 	// database users must have a password
-	if new.Source == domain.UserSourceDatabase && string(new.Password) == "" {
+	if new.Authentications[0].Source == domain.UserSourceDatabase && string(new.Password) == "" {
 		return fmt.Errorf("missing password: %w", domain.ErrInvalidData)
 	}
 
@@ -460,214 +381,112 @@ func (m Manager) validateApiChange(ctx context.Context, user *domain.User) error
 	return nil
 }
 
-func (m Manager) runLdapSynchronizationService(ctx context.Context) {
+// region internal-modifiers
-	ctx = domain.SetUserInfo(ctx, domain.LdapSyncContextUserInfo()) // switch to service context for LDAP sync
-
-	for _, ldapCfg := range m.cfg.Auth.Ldap { // LDAP Auth providers
-		go func(cfg config.LdapProvider) {
-			syncInterval := cfg.SyncInterval
-			if syncInterval == 0 {
-				slog.Debug("sync disabled for LDAP server", "provider", cfg.ProviderName)
-				return
-			}
-
-			// perform initial sync
-			err := m.synchronizeLdapUsers(ctx, &cfg)
-			if err != nil {
-				slog.Error("failed to synchronize LDAP users", "provider", cfg.ProviderName, "error", err)
-			} else {
-				slog.Debug("initial LDAP user sync completed", "provider", cfg.ProviderName)
-			}
-
-			// start periodic sync
-			running := true
-			for running {
-				select {
-				case <-ctx.Done():
-					running = false
-					continue
-				case <-time.After(syncInterval):
-					// select blocks until one of the cases evaluate to true
-				}
-
-				err := m.synchronizeLdapUsers(ctx, &cfg)
-				if err != nil {
-					slog.Error("failed to synchronize LDAP users", "provider", cfg.ProviderName, "error", err)
-				}
-			}
-		}(ldapCfg)
-	}
-}
-
-func (m Manager) synchronizeLdapUsers(ctx context.Context, provider *config.LdapProvider) error {
-	slog.Debug("starting to synchronize users", "provider", provider.ProviderName)
-
-	dn, err := ldap.ParseDN(provider.AdminGroupDN)
-	if err != nil {
-		return fmt.Errorf("failed to parse admin group DN: %w", err)
-	}
-	provider.ParsedAdminGroupDN = dn
-
-	conn, err := internal.LdapConnect(provider)
-	if err != nil {
-		return fmt.Errorf("failed to setup LDAP connection: %w", err)
-	}
-	defer internal.LdapDisconnect(conn)
-
-	rawUsers, err := internal.LdapFindAllUsers(conn, provider.BaseDN, provider.SyncFilter, &provider.FieldMap)
-	if err != nil {
-		return err
-	}
-
-	slog.Debug("fetched raw ldap users", "count", len(rawUsers), "provider", provider.ProviderName)
-
-	// Update existing LDAP users
-	err = m.updateLdapUsers(ctx, provider, rawUsers, &provider.FieldMap, provider.ParsedAdminGroupDN)
-	if err != nil {
-		return err
-	}
-
-	// Disable missing LDAP users
-	if provider.DisableMissing {
-		err = m.disableMissingLdapUsers(ctx, provider.ProviderName, rawUsers, &provider.FieldMap)
-		if err != nil {
-			return err
-		}
-	}
 
+func (m Manager) enrichUser(ctx context.Context, user *domain.User) *domain.User {
+	if user == nil {
 		return nil
 	}
-
+	peers, _ := m.peers.GetUserPeers(ctx, user.Identifier) // ignore error, list will be empty in error case
-func (m Manager) updateLdapUsers(
+	user.LinkedPeerCount = len(peers)
-	ctx context.Context,
+	return user
-	provider *config.LdapProvider,
-	rawUsers []internal.RawLdapUser,
-	fields *config.LdapFields,
-	adminGroupDN *ldap.DN,
-) error {
-	for _, rawUser := range rawUsers {
-		user, err := convertRawLdapUser(provider.ProviderName, rawUser, fields, adminGroupDN)
-		if err != nil && !errors.Is(err, domain.ErrNotFound) {
-			return fmt.Errorf("failed to convert LDAP data for %v: %w", rawUser["dn"], err)
 }
 
-		if provider.SyncLogUserInfo {
+func (m Manager) getUser(ctx context.Context, id domain.UserIdentifier) (*domain.User, error) {
-			slog.Debug("ldap user data",
+	user, err := m.users.GetUser(ctx, id)
-				"raw-user", rawUser, "user", user.Identifier,
+	if err != nil {
-				"is-admin", user.IsAdmin, "provider", provider.ProviderName)
+		return nil, fmt.Errorf("unable to load user %s: %w", id, err)
+	}
+	return m.enrichUser(ctx, user), nil
+}
+
+func (m Manager) update(ctx context.Context, existingUser, user *domain.User, keepAuthentications bool) (
+	*domain.User,
+	error,
+) {
+	if err := m.validateModifications(ctx, existingUser, user); err != nil {
+		return nil, fmt.Errorf("update not allowed: %w", err)
+	}
+
+	err := user.HashPassword()
+	if err != nil {
+		return nil, err
+	}
+	if user.Password == "" { // keep old password
+		user.Password = existingUser.Password
+	}
+
+	err = m.users.SaveUser(ctx, existingUser.Identifier, func(u *domain.User) (*domain.User, error) {
+		user.CopyCalculatedAttributes(u, keepAuthentications)
+		return user, nil
+	})
+	if err != nil {
+		return nil, fmt.Errorf("update failure: %w", err)
+	}
+
+	m.bus.Publish(app.TopicUserUpdated, *user)
+
+	switch {
+	case !existingUser.IsDisabled() && user.IsDisabled():
+		m.bus.Publish(app.TopicUserDisabled, *user)
+	case existingUser.IsDisabled() && !user.IsDisabled():
+		m.bus.Publish(app.TopicUserEnabled, *user)
+	}
+
+	return user, nil
+}
+
+func (m Manager) create(ctx context.Context, user *domain.User) (*domain.User, error) {
+	if user.Identifier == "" {
+		return nil, errors.New("missing user identifier")
 	}
 
 	existingUser, err := m.users.GetUser(ctx, user.Identifier)
 	if err != nil && !errors.Is(err, domain.ErrNotFound) {
-			return fmt.Errorf("find error for user id %s: %w", user.Identifier, err)
+		return nil, fmt.Errorf("unable to load existing user %s: %w", user.Identifier, err)
+	}
+	if existingUser != nil {
+		return nil, errors.Join(fmt.Errorf("user %s already exists", user.Identifier), domain.ErrDuplicateEntry)
 	}
 
-		tctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	// Add default authentication if missing
-		tctx = domain.SetUserInfo(tctx, domain.SystemAdminContextUserInfo())
+	if len(user.Authentications) == 0 {
-
+		ctxUserInfo := domain.GetUserInfo(ctx)
-		if existingUser == nil {
-			// create new user
-			slog.Debug("creating new user from provider", "user", user.Identifier, "provider", provider.ProviderName)
-
-			_, err := m.CreateUser(tctx, user)
-			if err != nil {
-				cancel()
-				return fmt.Errorf("create error for user id %s: %w", user.Identifier, err)
-			}
-		} else {
-			// update existing user
-			if provider.AutoReEnable && existingUser.DisabledReason == domain.DisabledReasonLdapMissing {
-				user.Disabled = nil
-				user.DisabledReason = ""
-			} else {
-				user.Disabled = existingUser.Disabled
-				user.DisabledReason = existingUser.DisabledReason
-			}
-			if existingUser.Source == domain.UserSourceLdap && userChangedInLdap(existingUser, user) {
-				err := m.users.SaveUser(tctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
-					u.UpdatedAt = time.Now()
-					u.UpdatedBy = domain.CtxSystemLdapSyncer
-					u.Source = user.Source
-					u.ProviderName = user.ProviderName
-					u.Email = user.Email
-					u.Firstname = user.Firstname
-					u.Lastname = user.Lastname
-					u.Phone = user.Phone
-					u.Department = user.Department
-					u.IsAdmin = user.IsAdmin
-					u.Disabled = nil
-					u.DisabledReason = ""
-
-					return u, nil
-				})
-				if err != nil {
-					cancel()
-					return fmt.Errorf("update error for user id %s: %w", user.Identifier, err)
-				}
-
-				if existingUser.IsDisabled() && !user.IsDisabled() {
-					m.bus.Publish(app.TopicUserEnabled, *user)
-				}
-			}
-		}
-
-		cancel()
-	}
-
-	return nil
-}
-
-func (m Manager) disableMissingLdapUsers(
-	ctx context.Context,
-	providerName string,
-	rawUsers []internal.RawLdapUser,
-	fields *config.LdapFields,
-) error {
-	allUsers, err := m.users.GetAllUsers(ctx)
-	if err != nil {
-		return err
-	}
-	for _, user := range allUsers {
-		if user.Source != domain.UserSourceLdap {
-			continue // ignore non ldap users
-		}
-		if user.ProviderName != providerName {
-			continue // user was synchronized through different provider
-		}
-		if user.IsDisabled() {
-			continue // ignore deactivated
-		}
-
-		existsInLDAP := false
-		for _, rawUser := range rawUsers {
-			userId := domain.UserIdentifier(internal.MapDefaultString(rawUser, fields.UserIdentifier, ""))
-			if user.Identifier == userId {
-				existsInLDAP = true
-				break
-			}
-		}
-
-		if existsInLDAP {
-			continue
-		}
-
-		slog.Debug("user is missing in ldap provider, disabling", "user", user.Identifier, "provider", providerName)
-
 		now := time.Now()
-		user.Disabled = &now
+		user.Authentications = []domain.UserAuthentication{
-		user.DisabledReason = domain.DisabledReasonLdapMissing
+			{
+				BaseModel: domain.BaseModel{
+					CreatedBy: ctxUserInfo.UserId(),
+					UpdatedBy: ctxUserInfo.UserId(),
+					CreatedAt: now,
+					UpdatedAt: now,
+				},
+				UserIdentifier: user.Identifier,
+				Source:         domain.UserSourceDatabase,
+				ProviderName:   "",
+			},
+		}
+	}
 
-		err := m.users.SaveUser(ctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
+	if err := m.validateCreation(ctx, user); err != nil {
-			u.Disabled = user.Disabled
+		return nil, fmt.Errorf("creation not allowed: %w", err)
-			u.DisabledReason = user.DisabledReason
+	}
-			return u, nil
+
+	err = user.HashPassword()
+	if err != nil {
+		return nil, err
+	}
+
+	err = m.users.SaveUser(ctx, user.Identifier, func(u *domain.User) (*domain.User, error) {
+		return user, nil
 	})
 	if err != nil {
-			return fmt.Errorf("disable error for user id %s: %w", user.Identifier, err)
+		return nil, fmt.Errorf("creation failure: %w", err)
 	}
 
-		m.bus.Publish(app.TopicUserDisabled, user)
+	m.bus.Publish(app.TopicUserCreated, *user)
+
+	return user, nil
 }
 
-	return nil
+// endregion internal-modifiers
-}

internal/app/webhooks/models/user.go

@@ -3,6 +3,7 @@ package models
 import (
 	"time"
 
+	"github.com/h44z/wg-portal/internal"
 	"github.com/h44z/wg-portal/internal/domain"
 )
 
@@ -15,8 +16,7 @@ type User struct {
 
 	Identifier  string           `json:"Identifier"`
 	Email       string           `json:"Email"`
-	Source       string `json:"Source"`
+	AuthSources []UserAuthSource `json:"AuthSources"`
-	ProviderName string `json:"ProviderName"`
 	IsAdmin     bool             `json:"IsAdmin"`
 
 	Firstname  string `json:"Firstname,omitempty"`
@@ -31,8 +31,22 @@ type User struct {
 	LockedReason   string     `json:"LockedReason,omitempty"`
 }
 
+// UserAuthSource represents a single authentication source for a user.
+// For details about the fields, see the domain.UserAuthentication struct.
+type UserAuthSource struct {
+	Source       string `json:"Source"`
+	ProviderName string `json:"ProviderName"`
+}
+
 // NewUser creates a new User model from a domain.User
 func NewUser(src domain.User) User {
+	authSources := internal.Map(src.Authentications, func(authentication domain.UserAuthentication) UserAuthSource {
+		return UserAuthSource{
+			Source:       string(authentication.Source),
+			ProviderName: authentication.ProviderName,
+		}
+	})
+
 	return User{
 		CreatedBy:      src.CreatedBy,
 		UpdatedBy:      src.UpdatedBy,
@@ -40,8 +54,7 @@ func NewUser(src domain.User) User {
 		UpdatedAt:      src.UpdatedAt,
 		Identifier:     string(src.Identifier),
 		Email:          src.Email,
-		Source:         string(src.Source),
+		AuthSources:    authSources,
-		ProviderName:   src.ProviderName,
 		IsAdmin:        src.IsAdmin,
 		Firstname:      src.Firstname,
 		Lastname:       src.Lastname,

internal/domain/auth.go

@@ -17,4 +17,5 @@ type AuthenticatorUserInfo struct {
 	Phone              string
 	Department         string
 	IsAdmin            bool
+	AdminInfoAvailable bool // true if the IsAdmin flag is valid
 }

internal/domain/context.go

@@ -14,6 +14,7 @@ const (
 	CtxSystemLdapSyncer = "_WG_SYS_LDAP_SYNCER_"
 	CtxSystemWgImporter = "_WG_SYS_WG_IMPORTER_"
 	CtxSystemV1Migrator = "_WG_SYS_V1_MIGRATOR_"
+	CtxSystemDBMigrator = "_WG_SYS_DB_MIGRATOR_"
 )
 
 type ContextUserInfo struct {

internal/domain/user.go

@@ -25,6 +25,14 @@ type UserIdentifier string
 
 type UserSource string
 
+type UserAuthentication struct {
+	BaseModel
+
+	UserIdentifier UserIdentifier `gorm:"primaryKey;column:user_identifier"` // sAMAccountName, sub, etc.
+	Source         UserSource     `gorm:"primaryKey;column:source"`
+	ProviderName   string         `gorm:"primaryKey;column:provider_name"`
+}
+
 // User is the user model that gets linked to peer entries, by default an empty user model with only the email address is created
 type User struct {
 	BaseModel
@@ -32,10 +40,15 @@ type User struct {
 	// required fields
 	Identifier   UserIdentifier `gorm:"primaryKey;column:identifier"`
 	Email        string         `form:"email" binding:"required,email"`
-	Source       UserSource
+	Source       UserSource     // deprecated: moved to Authentications.Source
-	ProviderName string
+	ProviderName string         // deprecated: moved to Authentications.ProviderName
 	IsAdmin      bool
 
+	// authentication sources
+	Authentications []UserAuthentication `gorm:"foreignKey:user_identifier"`
+	// synchronization behavior
+	PersistLocalChanges bool `gorm:"column:persist_local_changes"`
+
 	// optional fields
 	Firstname  string `form:"firstname" binding:"omitempty"`
 	Lastname   string `form:"lastname" binding:"omitempty"`
@@ -81,15 +94,19 @@ func (u *User) IsApiEnabled() bool {
 }
 
 func (u *User) CanChangePassword() error {
-	if u.Source == UserSourceDatabase {
+	if slices.ContainsFunc(u.Authentications, func(e UserAuthentication) bool {
-		return nil
+		return e.Source == UserSourceDatabase
+	}) {
+		return nil // password can be changed for database users
 	}
 
 	return errors.New("password change only allowed for database source")
 }
 
 func (u *User) HasWeakPassword(minLength int) error {
-	if u.Source != UserSourceDatabase {
+	if !slices.ContainsFunc(u.Authentications, func(e UserAuthentication) bool {
+		return e.Source == UserSourceDatabase
+	}) {
 		return nil // password is not required for non-database users, so no check needed
 	}
 
@@ -105,13 +122,16 @@ func (u *User) HasWeakPassword(minLength int) error {
 }
 
 func (u *User) EditAllowed(new *User) error {
-	if u.Source == UserSourceDatabase {
+	if len(u.Authentications) == 1 && u.Authentications[0].Source == UserSourceDatabase {
-		return nil
+		return nil // database-only users can be edited always
+	}
+
+	if new.PersistLocalChanges {
+		return nil // if changes will be persisted locally, they can be edited always
 	}
 
 	// for users which are not database users, only the notes field and the disabled flag can be updated
 	updateOk := u.Identifier == new.Identifier
-	updateOk = updateOk && u.Source == new.Source
 	updateOk = updateOk && u.IsAdmin == new.IsAdmin
 	updateOk = updateOk && u.Email == new.Email
 	updateOk = updateOk && u.Firstname == new.Firstname
@@ -120,7 +140,7 @@ func (u *User) EditAllowed(new *User) error {
 	updateOk = updateOk && u.Department == new.Department
 
 	if !updateOk {
-		return errors.New("edit only allowed for database source")
+		return errors.New("edit only allowed for reserved fields")
 	}
 
 	return nil
@@ -131,8 +151,10 @@ func (u *User) DeleteAllowed() error {
 }
 
 func (u *User) CheckPassword(password string) error {
-	if u.Source != UserSourceDatabase {
+	if !slices.ContainsFunc(u.Authentications, func(e UserAuthentication) bool {
-		return errors.New("invalid user source")
+		return e.Source == UserSourceDatabase
+	}) {
+		return errors.New("invalid user source") // password can only be checked for database users
 	}
 
 	if u.IsDisabled() {
@@ -180,9 +202,24 @@ func (u *User) HashPassword() error {
 	return nil
 }
 
-func (u *User) CopyCalculatedAttributes(src *User) {
+func (u *User) CopyCalculatedAttributes(src *User, withAuthentications bool) {
 	u.BaseModel = src.BaseModel
 	u.LinkedPeerCount = src.LinkedPeerCount
+	if withAuthentications {
+		u.Authentications = src.Authentications
+		u.WebAuthnId = src.WebAuthnId
+		u.WebAuthnCredentialList = src.WebAuthnCredentialList
+	}
+}
+
+// MergeAuthSources merges the given authentication sources with the existing ones.
+// Already existing sources are not overwritten, nor will be added any duplicates.
+func (u *User) MergeAuthSources(extSources ...UserAuthentication) {
+	for _, src := range extSources {
+		if !slices.Contains(u.Authentications, src) {
+			u.Authentications = append(u.Authentications, src)
+		}
+	}
 }
 
 // DisplayName returns the display name of the user.

internal/domain/user_test.go

@@ -35,19 +35,25 @@ func TestUser_IsApiEnabled(t *testing.T) {
 }
 
 func TestUser_CanChangePassword(t *testing.T) {
-	user := &User{Source: UserSourceDatabase}
+	user := &User{Authentications: []UserAuthentication{{Source: UserSourceDatabase}}}
 	assert.NoError(t, user.CanChangePassword())
 
-	user.Source = UserSourceLdap
+	user.Authentications = []UserAuthentication{{Source: UserSourceLdap}}
 	assert.Error(t, user.CanChangePassword())
 
-	user.Source = UserSourceOauth
+	user.Authentications = []UserAuthentication{{Source: UserSourceOauth}}
 	assert.Error(t, user.CanChangePassword())
+
+	user.Authentications = []UserAuthentication{{Source: UserSourceLdap}, {Source: UserSourceDatabase}}
+	assert.NoError(t, user.CanChangePassword())
+
+	user.Authentications = []UserAuthentication{{Source: UserSourceOauth}, {Source: UserSourceDatabase}}
+	assert.NoError(t, user.CanChangePassword())
 }
 
 func TestUser_EditAllowed(t *testing.T) {
-	user := &User{Source: UserSourceDatabase}
+	user := &User{Authentications: []UserAuthentication{{Source: UserSourceDatabase}}}
-	newUser := &User{Source: UserSourceDatabase}
+	newUser := &User{Authentications: []UserAuthentication{{Source: UserSourceDatabase}}}
 	assert.NoError(t, user.EditAllowed(newUser))
 
 	newUser.Notes = "notes can be changed"
@@ -59,8 +65,8 @@ func TestUser_EditAllowed(t *testing.T) {
 	newUser.Lastname = "lastname or other fields can be changed"
 	assert.NoError(t, user.EditAllowed(newUser))
 
-	user.Source = UserSourceLdap
+	user.Authentications = []UserAuthentication{{Source: UserSourceLdap}}
-	newUser.Source = UserSourceLdap
+	newUser.Authentications = []UserAuthentication{{Source: UserSourceLdap}}
 	newUser.Disabled = nil
 	newUser.Lastname = ""
 	newUser.Notes = "notes can be changed"
@@ -72,8 +78,8 @@ func TestUser_EditAllowed(t *testing.T) {
 	newUser.Lastname = "lastname or other fields can not be changed"
 	assert.Error(t, user.EditAllowed(newUser))
 
-	user.Source = UserSourceOauth
+	user.Authentications = []UserAuthentication{{Source: UserSourceOauth}}
-	newUser.Source = UserSourceOauth
+	newUser.Authentications = []UserAuthentication{{Source: UserSourceOauth}}
 	newUser.Disabled = nil
 	newUser.Lastname = ""
 	newUser.Notes = "notes can be changed"
@@ -84,6 +90,20 @@ func TestUser_EditAllowed(t *testing.T) {
 
 	newUser.Lastname = "lastname or other fields can not be changed"
 	assert.Error(t, user.EditAllowed(newUser))
+
+	user.Authentications = []UserAuthentication{{Source: UserSourceOauth}, {Source: UserSourceDatabase}}
+	newUser.Authentications = []UserAuthentication{{Source: UserSourceOauth}, {Source: UserSourceDatabase}}
+	newUser.PersistLocalChanges = true
+	newUser.Disabled = nil
+	newUser.Lastname = ""
+	newUser.Notes = "notes can be changed"
+	assert.NoError(t, user.EditAllowed(newUser))
+
+	newUser.Disabled = &time.Time{}
+	assert.NoError(t, user.EditAllowed(newUser))
+
+	newUser.Lastname = "lastname or other fields can be changed"
+	assert.NoError(t, user.EditAllowed(newUser))
 }
 
 func TestUser_DeleteAllowed(t *testing.T) {
@@ -95,13 +115,15 @@ func TestUser_CheckPassword(t *testing.T) {
 	password := "password"
 	hashedPassword, _ := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
 
-	user := &User{Source: UserSourceDatabase, Password: PrivateString(hashedPassword)}
+	user := &User{
+		Authentications: []UserAuthentication{{Source: UserSourceDatabase}}, Password: PrivateString(hashedPassword),
+	}
 	assert.NoError(t, user.CheckPassword(password))
 
 	user.Password = ""
 	assert.Error(t, user.CheckPassword(password))
 
-	user.Source = UserSourceLdap
+	user.Authentications = []UserAuthentication{{Source: UserSourceLdap}}
 	assert.Error(t, user.CheckPassword(password))
 }
 

internal/util.go

@@ -168,3 +168,12 @@ func BoolToFloat64(b bool) float64 {
 	}
 	return 0.0
 }
+
+// Map applies the given function to each element of the given slice and returns the resulting slice
+func Map[T, V any](ts []T, fn func(T) V) []V {
+	result := make([]V, len(ts))
+	for i, t := range ts {
+		result[i] = fn(t)
+	}
+	return result
+}

mkdocs.yml

@@ -85,7 +85,8 @@ nav:
       - Usage:
           - General: documentation/usage/general.md
           - Backends: documentation/usage/backends.md
-          - LDAP: documentation/usage/ldap.md
+          - Authentication: documentation/usage/authentication.md
+          - User Management: documentation/usage/user-sync.md
           - Security: documentation/usage/security.md
           - Webhooks: documentation/usage/webhooks.md
           - Mail Templates: documentation/usage/mail-templates.md