user management: document TFA lockout

[pve-docs.git] / pveum.adoc

[[chapter_user_management]]

[[user_mgmt]]

ifdef::manvolnum[]
pveum(1)
========
:pve-toplevel:

NAME
----

pveum - Proxmox VE User Manager


SYNOPSIS
--------

include::pveum.1-synopsis.adoc[]


DESCRIPTION
-----------
endif::manvolnum[]
ifndef::manvolnum[]
User Management
===============
:pve-toplevel:
endif::manvolnum[]

// Copied from pve wiki: Revision as of 16:10, 27 October 2015

{pve} supports multiple authentication sources, for example Linux PAM,
an integrated Proxmox VE authentication server, LDAP, Microsoft Active
Directory and OpenID Connect.

By using role-based user and permission management for all objects (VMs,
Storage, nodes, etc.), granular access can be defined.


[[pveum_users]]
Users
-----

{pve} stores user attributes in `/etc/pve/user.cfg`.
Passwords are not stored here; users are instead associated with the
<<pveum_authentication_realms,authentication realms>> described below.
Therefore, a user is often internally identified by their username and
realm in the form `<userid>@<realm>`.

Each user entry in this file contains the following information:

* First name
* Last name
* E-mail address
* Group memberships
* An optional expiration date
* A comment or note about this user
* Whether this user is enabled or disabled
* Optional two-factor authentication keys

CAUTION: When you disable or delete a user, or if the expiry date set is
in the past, this user will not be able to log in to new sessions or start new
tasks. All tasks which have already been started by this user (for example,
terminal sessions) will **not** be terminated automatically by any such event.


System administrator
~~~~~~~~~~~~~~~~~~~~

The system's root user can always log in via the Linux PAM realm and is an
unconfined administrator. This user cannot be deleted, but attributes can
still be changed. System mails will be sent to the email address
assigned to this user.


[[pveum_groups]]
Groups
------

Each user can be a member of several groups. Groups are the preferred
way to organize access permissions. You should always grant permissions
to groups instead of individual users. That way you will get a
much more maintainable access control list.

[[pveum_tokens]]
API Tokens
----------

API tokens allow stateless access to most parts of the REST API from another
system, software or API client. Tokens can be generated for individual users
and can be given separate permissions and expiration dates to limit the scope
and duration of the access. Should the API token get compromised, it can be
revoked without disabling the user itself.

API tokens come in two basic types:

* Separated privileges: The token needs to be given explicit access with ACLs.
  Its effective permissions are calculated by intersecting user and token
  permissions.
* Full privileges: The token's permissions are identical to that of the
  associated user.

CAUTION: The token value is only displayed/returned once when the token is
generated. It cannot be retrieved again over the API at a later time!

To use an API token, set the HTTP header 'Authorization' to the displayed value
of the form `PVEAPIToken=USER@REALM!TOKENID=UUID` when making API requests, or
refer to your API client's documentation.

[[pveum_resource_pools]]
Resource Pools
--------------

[thumbnail="screenshot/gui-datacenter-pool-window.png"]

A resource pool is a set of virtual machines, containers, and storage
devices. It is useful for permission handling in cases where certain users
should have controlled access to a specific set of resources, as it allows for a
single permission to be applied to a set of elements, rather than having to
manage this on a per-resource basis. Resource pools are often used in tandem
with groups, so that the members of a group have permissions on a set of
machines and storage.

[[pveum_authentication_realms]]
Authentication Realms
---------------------

As {pve} users are just counterparts for users existing on some external
realm, the realms have to be configured in `/etc/pve/domains.cfg`.
The following realms (authentication methods) are available:

Linux PAM Standard Authentication::

Linux PAM is a framework for system-wide user authentication. These users are
created on the host system with commands such as `adduser`. If PAM users exist
on the {pve} host system, corresponding entries can be added to {pve}, to allow
these users to log in via their system username and password.

{pve} Authentication Server::

This is a Unix-like password store, which stores hashed passwords in
`/etc/pve/priv/shadow.cfg`. Passwords are hashed using the SHA-256 hashing
algorithm. This is the most convenient realm for small-scale (or even
mid-scale) installations, where users do not need access to anything outside of
{pve}. In this case, users are fully managed by {pve} and are able to change
their own passwords via the GUI.

LDAP::

LDAP (Lightweight Directory Access Protocol) is an open, cross-platform protocol
for authentication using directory services. OpenLDAP is a popular open-source
implementations of the LDAP protocol.

Microsoft Active Directory (AD)::

Microsoft Active Directory (AD) is a directory service for Windows domain
networks and is supported as an authentication realm for {pve}. It supports LDAP
as an authentication protocol.

OpenID Connect::

OpenID Connect is implemented as an identity layer on top of the OATH 2.0
protocol. It allows clients to verify the identity of the user, based on
authentication performed by an external authorization server.

[[user-realms-pam]]
Linux PAM Standard Authentication
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As Linux PAM corresponds to host system users, a system user must exist on each
node which the user is allowed to log in on. The user authenticates with their
usual system password. This realm is added by default and can't be removed. In
terms of configurability, an administrator can choose to require two-factor
authentication with logins from the realm and to set the realm as the default
authentication realm.


[[user-realms-pve]]
{pve} Authentication Server
~~~~~~~~~~~~~~~~~~~~~~~~~~~

The {pve} authentication server realm is a simple Unix-like password store.
The realm is created by default, and as with Linux PAM, the only configuration
items available are the ability to require two-factor authentication for users
of the realm, and to set it as the default realm for login.

Unlike the other {pve} realm types, users are created and authenticated entirely
through {pve}, rather than authenticating against another system. Hence, you are
required to set a password for this type of user upon creation.


[[user-realms-ldap]]
LDAP
~~~~

You can also use an external LDAP server for user authentication (for examle,
OpenLDAP). In this realm type, users are searched under a 'Base Domain Name'
(`base_dn`), using the username attribute specified in the 'User Attribute Name'
(`user_attr`) field.

A server and optional fallback server can be configured, and the connection can
be encrypted via SSL. Furthermore, filters can be configured for directories and
groups. Filters allow you to further limit the scope of the realm.

For instance, if a user is represented via the following LDIF dataset:

----
# user1 of People at ldap-test.com
dn: uid=user1,ou=People,dc=ldap-test,dc=com
objectClass: top
objectClass: person
objectClass: organizationalPerson
objectClass: inetOrgPerson
uid: user1
cn: Test User 1
sn: Testers
description: This is the first test user.
----

The 'Base Domain Name' would be `ou=People,dc=ldap-test,dc=com` and the user
attribute would be `uid`.

If {pve} needs to authenticate (bind) to the LDAP server before being
able to query and authenticate users, a bind domain name can be
configured via the `bind_dn` property in `/etc/pve/domains.cfg`. Its
password then has to be stored in `/etc/pve/priv/ldap/<realmname>.pw`
(for example, `/etc/pve/priv/ldap/my-ldap.pw`). This file should contain a
single line with the raw password.

To verify certificates, you need to set `capath`. You can set it either
directly to the CA certificate of your LDAP server, or to the system path
containing all trusted CA certificates (`/etc/ssl/certs`).
Additionally, you need to set the `verify` option, which can also be done over
the web interface.

The main configuration options for an LDAP server realm are as follows:

* `Realm` (`realm`): The realm identifier for {pve} users

* `Base Domain Name` (`base_dn`): The directory which users are searched under

* `User Attribute Name` (`user_attr`): The LDAP attribute containing the
  username that users will log in with

* `Server` (`server1`): The server hosting the LDAP directory

* `Fallback Server` (`server2`): An optional fallback server address, in case
  the primary server is unreachable

* `Port` (`port`): The port that the LDAP server listens on

NOTE: In order to allow a particular user to authenticate using the LDAP server,
you must also add them as a user of that realm from the {pve} server. This can
be carried out automatically with <<pveum_ldap_sync, syncing>>.


[[user-realms-ad]]
Microsoft Active Directory (AD)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To set up Microsoft AD as a realm, a server address and authentication domain
need to be specified. Active Directory supports most of the same properties as
LDAP, such as an optional fallback server, port, and SSL encryption.
Furthermore, users can be added to {pve} automatically via
<<pveum_ldap_sync, sync>> operations, after configuration.

As with LDAP, if {pve} needs to authenticate before it binds to the AD server,
you must configure the 'Bind User' (`bind_dn`) property. This property is
typically required by default for Microsoft AD.

The main configuration settings for Microsoft Active Directory are:

* `Realm` (`realm`): The realm identifier for {pve} users

* `Domain` (`domain`): The AD domain of the server

* `Server` (`server1`): The FQDN or IP address of the server

* `Fallback Server` (`server2`): An optional fallback server address, in case
  the primary server is unreachable

* `Port` (`port`): The port that the Microsoft AD server listens on

[[pveum_ldap_sync]]
Syncing LDAP-Based Realms
~~~~~~~~~~~~~~~~~~~~~~~~~

[thumbnail="screenshot/gui-datacenter-realm-add-ldap.png"]

It's possible to automatically sync users and groups for LDAP-based realms (LDAP
& Microsoft Active Directory), rather than having to add them to {pve} manually.
You can access the sync options from the Add/Edit window of the web interface's
`Authentication` panel or via the `pveum realm add/modify` commands. You can
then carry out the sync operation from the `Authentication` panel of the GUI or
using the following command:

----
pveum realm sync <realm>
----

Users and groups are synced to the cluster-wide configuration file,
`/etc/pve/user.cfg`.


Attributes to Properties
^^^^^^^^^^^^^^^^^^^^^^^^

If the sync response includes user attributes, they will be synced into the
matching user property in the `user.cfg`. For example: `firstname` or
`lastname`.

If the names of the attributes are not matching the {pve} properties, you can
set a custom field-to-field map in the config by using the `sync_attributes`
option.

How such properties are handled if anything vanishes can be controlled via the
sync options, see below.

Sync Configuration
^^^^^^^^^^^^^^^^^^

The configuration options for syncing LDAP-based realms can be found in the
`Sync Options` tab of the Add/Edit window.

The configuration options are as follows:

* `Bind User` (`bind_dn`): Refers to the LDAP account used to query users
  and groups. This account needs access to all desired entries. If it's set, the
  search will be carried out via binding; otherwise, the search will be carried
  out anonymously. The user must be a complete LDAP formatted distinguished name
  (DN), for example, `cn=admin,dc=example,dc=com`.

* Groupname attr. (group_name_attr): Represents the
  users' groups. Only entries which adhere to the usual character limitations of
  the `user.cfg` are synced. Groups are synced with `-$realm` attached to the
  name, in order to avoid naming conflicts. Please ensure that a sync does not
  overwrite manually created groups.

* `User classes` (`user_classes`): Objects classes associated with users.

* `Group classes` (`group_classes`): Objects classes associated with groups.

* `E-Mail attribute`: If the LDAP-based server specifies user email addresses,
  these can also be included in the sync by setting the associated attribute
  here. From the command line, this is achievable through the
  `--sync_attributes` parameter.

* `User Filter` (`filter`): For further filter options to target specific users.

* `Group Filter` (`group_filter`): For further filter options to target specific
  groups.

NOTE: Filters allow you to create a set of additional match criteria, to narrow
down the scope of a sync. Information on available LDAP filter types and their
usage can be found at https://ldap.com/ldap-filters/[ldap.com].

[[pveum_ldap_sync_options]]
Sync Options
^^^^^^^^^^^^

[thumbnail="screenshot/gui-datacenter-realm-add-ldap-sync-options.png"]

In addition to the options specified in the previous section, you can also
configure further options that describe the behavior of the sync operation.

These options are either set as parameters before the sync, or as defaults via
the realm option `sync-defaults-options`.

The main options for syncing are:

* `Scope` (`scope`): The scope of what to sync. It can be either `users`,
  `groups` or `both`.

* `Enable new` (`enable-new`): If set, the newly synced users are enabled and
  can log in. The default is `true`.

* `Remove Vanished` (`remove-vanished`): This is a list of options which, when
  activated, determine if they are removed when they are not returned from
  the sync response. The options are:

    - `ACL` (`acl)`: Remove ACLs of users and groups which were not returned
      returned in the sync response. This most often makes sense together with
      `Entry`.

    - `Entry` (`entry`): Removes entries (i.e. users and groups) when they are
      not returned in the sync response.

    - `Properties` (`properties`): Removes properties of entries where the user
      in the sync response did not contain those attributes. This includes
      all properties, even those never set by a sync. Exceptions are tokens
      and the enable flag, these will be retained even with this option enabled.

* `Preview` (`dry-run`): No data is written to the config. This is useful if you
  want to see which users and groups would get synced to the `user.cfg`.

[[pveum_ldap_reserved_characters]]
Reserved characters
^^^^^^^^^^^^^^^^^^^

Certain characters are reserved (see https://www.ietf.org/rfc/rfc2253.txt[RFC2253]) and cannot be
easily used in attribute values in DNs without being escaped properly.

Following characters need escaping:

* Space ( ) at the beginning or end
* Number sign (`#`) at the beginning
* Comma (`,`)
* Plus sign (`+`)
* Double quote (`"`)
* Forward slashes (`/`)
* Angle brackets (`<>`)
* Semicolon (`;`)
* Equals sign (`=`)

To use such characters in DNs, surround the attribute value in double quotes.
For example, to bind with a user with the CN (Common Name) `Example, User`, use
`CN="Example, User",OU=people,DC=example,DC=com` as value for `bind_dn`.

This applies to the `base_dn`, `bind_dn`, and `group_dn` attributes.

NOTE: Users with colons and forward slashes cannot be synced since these are
reserved characters in usernames.

[[pveum_openid]]
OpenID Connect
~~~~~~~~~~~~~~

The main OpenID Connect configuration options are:

* `Issuer URL` (`issuer-url`): This is the URL of the authorization server.
Proxmox uses the OpenID Connect Discovery protocol to automatically configure
further details.
+
While it is possible to use unencrypted `http://` URLs, we strongly recommend to
use encrypted `https://` connections.

* `Realm` (`realm`): The realm identifier for {pve} users

* `Client ID` (`client-id`):  OpenID Client ID.

* `Client Key` (`client-key`): Optional OpenID Client Key.

* `Autocreate Users` (`autocreate`): Automatically create users if they do not
exist. While authentication is done at the OpenID server, all users still need
an entry in the {pve} user configuration. You can either add them manually, or
use the `autocreate` option to automatically add new users.

* `Username Claim` (`username-claim`): OpenID claim used to generate the unique
username (`subject`, `username` or `email`).

Username mapping
^^^^^^^^^^^^^^^^

The OpenID Connect specification defines a single unique attribute
('claim' in OpenID terms) named `subject`. By default, we use the
value of this attribute to generate {pve} usernames, by simple adding
`@` and the realm name: `${subject}@${realm}`.

Unfortunately, most OpenID servers use random strings for `subject`, like
`DGH76OKH34BNG3245SB`, so a typical username would look like
`DGH76OKH34BNG3245SB@yourrealm`. While unique, it is difficult for
humans to remember such random strings, making it quite impossible to
associate real users with this.

The `username-claim` setting allows you to use other attributes for
the username mapping. Setting it to `username` is preferred if the
OpenID Connect server provides that attribute and guarantees its
uniqueness.

Another option is to use `email`, which also yields human readable
usernames. Again, only use this setting if the server guarantees the
uniqueness of this attribute.

Examples
^^^^^^^^

Here is an example of creating an OpenID realm using Google. You need to
replace `--client-id` and `--client-key` with the values
from your Google OpenID settings.

----
pveum realm add myrealm1 --type openid --issuer-url  https://accounts.google.com --client-id XXXX --client-key YYYY --username-claim email
----

The above command uses `--username-claim email`, so that the usernames on the
{pve} side look like `example.user@google.com@myrealm1`.

Keycloak (https://www.keycloak.org/) is a popular open source Identity
and Access Management tool, which supports OpenID Connect. In the following
example, you need to replace the `--issuer-url` and `--client-id` with
your information:

----
pveum realm add myrealm2 --type openid --issuer-url  https://your.server:8080/realms/your-realm --client-id XXX --username-claim username
----

Using `--username-claim username` enables simple usernames on the
{pve} side, like `example.user@myrealm2`.

WARNING: You need to ensure that the user is not allowed to edit
the username setting themselves (on the Keycloak server).


[[pveum_tfa_auth]]
Two-Factor Authentication
-------------------------

There are two ways to use two-factor authentication:

It can be required by the authentication realm, either via 'TOTP'
(Time-based One-Time Password) or 'YubiKey OTP'. In this case, a newly
created user needs to have their keys added immediately, as there is no way to
log in without the second factor. In the case of 'TOTP', users can
also change the 'TOTP' later on, provided they can log in first.

Alternatively, users can choose to opt-in to two-factor authentication
later on, even if the realm does not enforce it.

Available Second Factors
~~~~~~~~~~~~~~~~~~~~~~~~

You can set up multiple second factors, in order to avoid a situation in
which losing your smartphone or security key locks you out of your
account permanently.

The following two-factor authentication methods are available in
addition to realm-enforced TOTP and YubiKey OTP:

* User configured TOTP
  (https://en.wikipedia.org/wiki/Time-based_One-Time_Password[Time-based One-Time Password]).
  A short code derived from a shared secret and the current time, it changes
  every 30 seconds.
* WebAuthn (https://en.wikipedia.org/wiki/WebAuthn[Web Authentication]).
  A general standard for authentication. It is implemented by various
  security devices, like hardware keys or trusted platform modules (TPM)
  from a computer or smart phone.
* Single use Recovery Keys. A list of keys which should either be
  printed out and locked in a secure place or saved digitally in an
  electronic vault. Each key can be used only once. These are perfect for
  ensuring that you are not locked out, even if all of your other second
  factors are lost or corrupt.

Before WebAuthn was supported, U2F could be setup by the user. Existing
U2F factors can still be used, but it is recommended to switch to
WebAuthn, once it is configured on the server.

Realm Enforced Two-Factor Authentication
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This can be done by selecting one of the available methods via the
'TFA' dropdown box when adding or editing an Authentication Realm.
When a realm has TFA enabled, it becomes a requirement, and only users
with configured TFA will be able to log in.

Currently there are two methods available:

Time-based OATH (TOTP):: This uses the standard HMAC-SHA1 algorithm,
where the current time is hashed with the user's configured key. The
time step and password length parameters are configurable.
+
A user can have multiple keys configured (separated by spaces), and the keys
can be specified in Base32 (RFC3548) or hexadecimal notation.
+
{pve} provides a key generation tool (`oathkeygen`) which prints out a random
key in Base32 notation, that can be used directly with various OTP tools, such
as the `oathtool` command line tool, or on Android Google Authenticator,
FreeOTP, andOTP or similar applications.

YubiKey OTP::
For authenticating via a YubiKey a Yubico API ID, API KEY and validation
server URL must be configured, and users must have a YubiKey available. In
order to get the key ID from a YubiKey, you can trigger the YubiKey once
after connecting it via USB, and copy the first 12 characters of the typed
password into the user's 'Key IDs' field.

Please refer to the https://developers.yubico.com/OTP/[YubiKey OTP]
documentation for how to use the
https://www.yubico.com/products/services-software/yubicloud/[YubiCloud] or
https://developers.yubico.com/Software_Projects/Yubico_OTP/YubiCloud_Validation_Servers/[host your own verification server].

[[pveum_tfa_lockout]]
Limits and lockout of Two-Factor Authentication
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A second factor is meant to protect users if their password is somehow leaked
or guessed. However, some factors could still be broken by brute force. For
this reason, users will be locked out after too many failed 2nd factor login
attempts.

For TOTP 8 failed attempts will disable the user's TOTP factors. They are
unlocked when logging in with a recovery key. If TOTP was the only available
factor, admin intervention is required, and it is highly recommended to require
the user to change their password immediately.

Since FIDO2/Webauthn and recovery keys are less susceptible to brute force
attacks, the limit there is higher, but block all second factors for an hour
when exceeded.

An admin can unlock a user's Two-Factor Authentication at any time via the user
list in the UI or the command line:

[source,bash]
 pveum user tfa unlock joe@pve

[[pveum_user_configured_totp]]
User Configured TOTP Authentication
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Users can choose to enable 'TOTP' or 'WebAuthn' as a second factor on login, via
the 'TFA' button in the user list (unless the realm enforces 'YubiKey OTP').

Users can always add and use one time 'Recovery Keys'.

[thumbnail="screenshot/gui-datacenter-two-factor.png"]

After opening the 'TFA' window, the user is presented with a dialog to set up
'TOTP' authentication. The 'Secret' field contains the key, which can be
randomly generated via the 'Randomize' button. An optional 'Issuer Name' can be
added to provide information to the 'TOTP' app about what the key belongs to.
Most 'TOTP' apps will show the issuer name together with the corresponding
'OTP' values. The username is also included in the QR code for the 'TOTP' app.

After generating a key, a QR code will be displayed, which can be used with most
OTP apps such as FreeOTP. The user then needs to verify the current user
password (unless logged in as 'root'), as well as the ability to correctly use
the 'TOTP' key, by typing the current 'OTP' value into the 'Verification Code'
field and pressing the 'Apply' button.

[[user_tfa_setup_totp]]
=== TOTP

[thumbnail="screenshot/pve-gui-tfa-add-totp.png"]

There is no server setup required. Simply install a TOTP app on your
smartphone (for example, https://freeotp.github.io/[FreeOTP]) and use
the Proxmox Backup Server web-interface to add a TOTP factor.

[[user_tfa_setup_webauthn]]
=== WebAuthn

For WebAuthn to work, you need to have two things:

* A trusted HTTPS certificate (for example, by using
  https://pve.proxmox.com/wiki/Certificate_Management[Let's Encrypt]).
  While it probably works with an untrusted certificate, some browsers may
  warn or refuse WebAuthn operations if it is not trusted.
* Setup the WebAuthn configuration (see *Datacenter -> Options ->
  WebAuthn Settings* in the Proxmox VE web interface). This can be
  auto-filled in most setups.

Once you have fulfilled both of these requirements, you can add a WebAuthn
configuration in the *Two Factor* panel under *Datacenter -> Permissions -> Two
Factor*.

[[user_tfa_setup_recovery_keys]]
=== Recovery Keys

[thumbnail="screenshot/pve-gui-tfa-add-recovery-keys.png"]

Recovery key codes do not need any preparation; you can simply create a
set of recovery keys in the *Two Factor* panel under *Datacenter -> Permissions
-> Two Factor*.

NOTE: There can only be one set of single-use recovery keys per user at any
time.


[[pveum_configure_webauthn]]
Server Side Webauthn Configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[thumbnail="screenshot/gui-datacenter-webauthn-edit.png"]

To allow users to use 'WebAuthn' authentication, it is necessaary to use a valid
domain with a valid SSL certificate, otherwise some browsers may warn or refuse
to authenticate altogether.

NOTE: Changing the 'WebAuthn' configuration may render all existing 'WebAuthn'
registrations unusable!

This is done via `/etc/pve/datacenter.cfg`. For instance:

----
webauthn: rp=mypve.example.com,origin=https://mypve.example.com:8006,id=mypve.example.com
----

[[pveum_configure_u2f]]
Server Side U2F Configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

NOTE: It is recommended to use WebAuthn instead.

To allow users to use 'U2F' authentication, it may be necessary to use a valid
domain with a valid SSL certificate, otherwise, some browsers may print
a warning or reject U2F usage altogether. Initially, an 'AppId'
footnote:[AppId https://developers.yubico.com/U2F/App_ID.html]
needs to be configured.

NOTE: Changing the 'AppId' will render all existing 'U2F' registrations
unusable!

This is done via `/etc/pve/datacenter.cfg`. For instance:

----
u2f: appid=https://mypve.example.com:8006
----

For a single node, the 'AppId' can simply be the address of the web-interface,
exactly as it is used in the browser, including the 'https://' and the port, as
shown above. Please note that some browsers may be more strict than others when
matching 'AppIds'.

When using multiple nodes, it is best to have a separate `https` server
providing an `appid.json`
footnote:[Multi-facet apps: https://developers.yubico.com/U2F/App_ID.html]
file, as it seems to be compatible with most
browsers. If all nodes use subdomains of the same top level domain, it may be
enough to use the TLD as 'AppId'. It should however be noted that some browsers
may not accept this.

NOTE: A bad 'AppId' will usually produce an error, but we have encountered
situations when this does not happen, particularly when using a top level domain
'AppId' for a node that is accessed via a subdomain in Chromium. For this reason
it is recommended to test the configuration with multiple browsers, as changing
the 'AppId' later will render existing 'U2F' registrations unusable.

[[pveum_user_configured_u2f]]
Activating U2F as a User
~~~~~~~~~~~~~~~~~~~~~~~~

To enable 'U2F' authentication, open the 'TFA' window's 'U2F' tab, type in the
current password (unless logged in as root), and press the 'Register' button.
If the server is set up correctly and the browser accepts the server's provided
'AppId', a message will appear prompting the user to press the button on the
'U2F' device (if it is a 'YubiKey', the button light should be toggling on and
off steadily, roughly twice per second).

Firefox users may need to enable 'security.webauth.u2f' via 'about:config'
before they can use a 'U2F' token.

[[pveum_permission_management]]
Permission Management
---------------------

In order for a user to perform an action (such as listing, modifying or
deleting parts of a VM's configuration), the user needs to have the
appropriate permissions.

{pve} uses a role and path based permission management system. An entry in
the permissions table allows a user, group or token to take on a specific role
when accessing an 'object' or 'path'. This means that such an access rule can
be represented as a triple of '(path, user, role)', '(path, group,
role)' or '(path, token, role)', with the role containing a set of allowed
actions, and the path representing the target of these actions.


[[pveum_roles]]
Roles
~~~~~

A role is simply a list of privileges. Proxmox VE comes with a number
of predefined roles, which satisfy most requirements.

* `Administrator`: has full privileges
* `NoAccess`: has no privileges (used to forbid access)
* `PVEAdmin`: can do most tasks, but has no rights to modify system settings (`Sys.PowerMgmt`, `Sys.Modify`, `Realm.Allocate`)
* `PVEAuditor`: has read only access
* `PVEDatastoreAdmin`: create and allocate backup space and templates
* `PVEDatastoreUser`: allocate backup space and view storage
* `PVEPoolAdmin`: allocate pools
* `PVESysAdmin`: User ACLs, audit, system console and system logs
* `PVETemplateUser`: view and clone templates
* `PVEUserAdmin`: manage users
* `PVEVMAdmin`: fully administer VMs
* `PVEVMUser`: view, backup, configure CD-ROM, VM console, VM power management

You can see the whole set of predefined roles in the GUI.

You can add new roles via the GUI or the command line.

[thumbnail="screenshot/gui-datacenter-role-add.png"]
From the GUI, navigate to the 'Permissions -> Roles' tab from 'Datacenter' and
click on the 'Create' button. There you can set a role name and select any
desired privileges from the 'Privileges' drop-down menu.

To add a role through the command line, you can use the 'pveum' CLI tool, for
example:
[source,bash]
----
pveum role add PVE_Power-only --privs "VM.PowerMgmt VM.Console"
pveum role add Sys_Power-only --privs "Sys.PowerMgmt Sys.Console"
----


Privileges
~~~~~~~~~~

A privilege is the right to perform a specific action. To simplify
management, lists of privileges are grouped into roles, which can then
be used in the permission table. Note that privileges cannot be directly
assigned to users and paths without being part of a role.

We currently support the following privileges:

Node / System related privileges::

* `Permissions.Modify`: modify access permissions
* `Sys.PowerMgmt`: node power management (start, stop, reset, shutdown, ...)
* `Sys.Console`: console access to node
* `Sys.Syslog`: view syslog
* `Sys.Audit`: view node status/config, Corosync cluster config, and HA config
* `Sys.Modify`: create/modify/remove node network parameters
* `Sys.Incoming`: allow incoming data streams from other clusters (experimental)
* `Group.Allocate`: create/modify/remove groups
* `Pool.Allocate`: create/modify/remove a pool
* `Pool.Audit`: view a pool
* `Realm.Allocate`: create/modify/remove authentication realms
* `Realm.AllocateUser`: assign user to a realm
* `User.Modify`: create/modify/remove user access and details.

Virtual machine related privileges::

* `VM.Allocate`: create/remove VM on a server
* `VM.Migrate`: migrate VM to alternate server on cluster
* `VM.PowerMgmt`: power management (start, stop, reset, shutdown, ...)
* `VM.Console`: console access to VM
* `VM.Monitor`: access to VM monitor (kvm)
* `VM.Backup`: backup/restore VMs
* `VM.Audit`: view VM config
* `VM.Clone`: clone/copy a VM
* `VM.Config.Disk`: add/modify/remove disks
* `VM.Config.CDROM`: eject/change CD-ROM
* `VM.Config.CPU`: modify CPU settings
* `VM.Config.Memory`: modify memory settings
* `VM.Config.Network`: add/modify/remove network devices
* `VM.Config.HWType`: modify emulated hardware types
* `VM.Config.Options`: modify any other VM configuration
* `VM.Config.Cloudinit`: modify Cloud-init parameters
* `VM.Snapshot`: create/delete VM snapshots

Storage related privileges::

* `Datastore.Allocate`: create/modify/remove a datastore and delete volumes
* `Datastore.AllocateSpace`: allocate space on a datastore
* `Datastore.AllocateTemplate`: allocate/upload templates and ISO images
* `Datastore.Audit`: view/browse a datastore


Objects and Paths
~~~~~~~~~~~~~~~~~

Access permissions are assigned to objects, such as virtual machines,
storages or resource pools.
We use file system like paths to address these objects. These paths form a
natural tree, and permissions of higher levels (shorter paths) can
optionally be propagated down within this hierarchy.

[[pveum_templated_paths]]
Paths can be templated. When an API call requires permissions on a
templated path, the path may contain references to parameters of the API
call. These references are specified in curly braces. Some parameters are
implicitly taken from the API call's URI. For instance, the permission path
`/nodes/{node}` when calling '/nodes/mynode/status' requires permissions on
`/nodes/mynode`, while the path `{path}` in a PUT request to `/access/acl`
refers to the method's `path` parameter.

Some examples are:

* `/nodes/{node}`: Access to {pve} server machines
* `/vms`: Covers all VMs
* `/vms/{vmid}`: Access to specific VMs
* `/storage/{storeid}`: Access to a specific storage
* `/pool/{poolname}`: Access to resources contained in a specific <<pveum_pools,pool>>
* `/access/groups`: Group administration
* `/access/realms/{realmid}`: Administrative access to realms


Inheritance
^^^^^^^^^^^

As mentioned earlier, object paths form a file system like tree, and
permissions can be inherited by objects down that tree (the propagate flag is
set by default). We use the following inheritance rules:

* Permissions for individual users always replace group permissions.
* Permissions for groups apply when the user is member of that group.
* Permissions on deeper levels replace those inherited from an upper level.

Additionally, privilege separated tokens can never have permissions on any
given path that their associated user does not have.

[[pveum_pools]]
Pools
~~~~~

Pools can be used to group a set of virtual machines and datastores. You can
then simply set permissions on pools (`/pool/{poolid}`), which are inherited by
all pool members. This is a great way to simplify access control.


Which Permissions Do I Need?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The required API permissions are documented for each individual
method, and can be found at https://pve.proxmox.com/pve-docs/api-viewer/.

The permissions are specified as a list, which can be interpreted as a
tree of logic and access-check functions:

`["and", <subtests>...]` and `["or", <subtests>...]`::
Each(`and`) or any(`or`) further element in the current list has to be true.

`["perm", <path>, [ <privileges>... ], <options>...]`::
The `path` is a templated parameter (see
<<pveum_templated_paths,Objects and Paths>>). All (or, if the `any`
option is used, any) of the listed
privileges must be allowed on the specified path. If a `require-param`
option is specified, then its specified parameter is required even if the
API call's schema otherwise lists it as being optional.

`["userid-group", [ <privileges>... ], <options>...]`::
The caller must have any of the listed privileges on `/access/groups`. In
addition, there are two possible checks, depending on whether the
`groups_param` option is set:
+
* `groups_param` is set: The API call has a non-optional `groups` parameter
and the caller must have any of the listed privileges on all of the listed
groups.
* `groups_param` is not set: The user passed via the `userid` parameter
must exist and be part of a group on which the caller has any of the listed
privileges (via the `/access/groups/<group>` path).

`["userid-param", "self"]`::
The value provided for the API call's `userid` parameter must refer to the
user performing the action (usually in conjunction with `or`, to allow
users to perform an action on themselves, even if they don't have elevated
privileges).

`["userid-param", "Realm.AllocateUser"]`::
The user needs `Realm.AllocateUser` access to `/access/realm/<realm>`, with
`<realm>` referring to the realm of the user passed via the `userid`
parameter. Note that the user does not need to exist in order to be
associated with a realm, since user IDs are passed in the form of
`<username>@<realm>`.

`["perm-modify", <path>]`::
The `path` is a templated parameter (see
<<pveum_templated_paths,Objects and Paths>>). The user needs either the
`Permissions.Modify` privilege or,
depending on the path, the following privileges as a possible substitute:
+
* `/storage/...`: requires 'Datastore.Allocate`
* `/vms/...`: requires 'VM.Allocate`
* `/pool/...`: requires 'Pool.Allocate`
+
If the path is empty, `Permission.Modify` on `/access` is required.

Command Line Tool
-----------------

Most users will simply use the GUI to manage users. But there is also
a fully featured command line tool called `pveum` (short for ``**P**roxmox
**VE** **U**ser **M**anager''). Please note that all Proxmox VE command
line tools are wrappers around the API, so you can also access those
functions through the REST API.

Here are some simple usage examples. To show help, type:

[source,bash]
 pveum

or (to show detailed help about a specific command)

[source,bash]
 pveum help user add

Create a new user:

[source,bash]
 pveum user add testuser@pve -comment "Just a test"

Set or change the password (not all realms support this):

[source,bash]
 pveum passwd testuser@pve

Disable a user:

[source,bash]
 pveum user modify testuser@pve -enable 0

Create a new group:

[source,bash]
 pveum group add testgroup

Create a new role:

[source,bash]
 pveum role add PVE_Power-only -privs "VM.PowerMgmt VM.Console"


Real World Examples
-------------------


Administrator Group
~~~~~~~~~~~~~~~~~~~

It is possible that an administrator would want to create a group of users with
full administrator rights (without using the root account).

To do this, first define the group:

[source,bash]
 pveum group add admin -comment "System Administrators"

Then assign the role:

[source,bash]
 pveum acl modify / -group admin -role Administrator

Finally, you can add users to the new 'admin' group:

[source,bash]
 pveum user modify testuser@pve -group admin


Auditors
~~~~~~~~

You can give read only access to users by assigning the `PVEAuditor`
role to users or groups.

Example 1: Allow user `joe@pve` to see everything

[source,bash]
 pveum acl modify / -user joe@pve -role PVEAuditor

Example 2: Allow user `joe@pve` to see all virtual machines

[source,bash]
 pveum acl modify /vms -user joe@pve -role PVEAuditor


Delegate User Management
~~~~~~~~~~~~~~~~~~~~~~~~

If you want to delegate user management to user `joe@pve`, you can do
that with:

[source,bash]
 pveum acl modify /access -user joe@pve -role PVEUserAdmin

User `joe@pve` can now add and remove users, and change other user attributes,
such as passwords. This is a very powerful role, and you most
likely want to limit it to selected realms and groups. The following
example allows `joe@pve` to modify users within the realm `pve`, if they
are members of group `customers`:

[source,bash]
 pveum acl modify /access/realm/pve -user joe@pve -role PVEUserAdmin
 pveum acl modify /access/groups/customers -user joe@pve -role PVEUserAdmin

NOTE: The user is able to add other users, but only if they are
members of the group `customers` and within the realm `pve`.

Limited API Token for Monitoring
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Permissions on API tokens are always a subset of those of their corresponding
user, meaning that an API token can't be used to carry out a task that the
backing user has no permission to do. This section will demonstrate how you can
use an API token with separate privileges, to limit the token owner's
permissions further.

Give the user `joe@pve` the role PVEVMAdmin on all VMs:

[source,bash]
 pveum acl modify /vms -user joe@pve -role PVEVMAdmin

Add a new API token with separate privileges, which is only allowed to view VM
information (for example, for monitoring purposes):

[source,bash]
 pveum user token add joe@pve monitoring -privsep 1
 pveum acl modify /vms -token 'joe@pve!monitoring' -role PVEAuditor

Verify the permissions of the user and token:

[source,bash]
 pveum user permissions joe@pve
 pveum user token permissions joe@pve monitoring

Resource Pools
~~~~~~~~~~~~~~

An enterprise is usually structured into several smaller departments, and it is
common that you want to assign resources and delegate management tasks to each
of these. Let's assume that you want to set up a pool for a software development
department. First, create a group:

[source,bash]
 pveum group add developers -comment "Our software developers"

Now we create a new user which is a member of that group:

[source,bash]
 pveum user add developer1@pve -group developers -password

NOTE: The "-password" parameter will prompt you for a password

Then we create a resource pool for our development department to use:

[source,bash]
 pveum pool add dev-pool --comment "IT development pool"

Finally, we can assign permissions to that pool:

[source,bash]
 pveum acl modify /pool/dev-pool/ -group developers -role PVEAdmin

Our software developers can now administer the resources assigned to
that pool.


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