Merge 2fca4789ca into bb3daafe96

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

changelogs/client_server/newsfragments/2278.feature

@@ -0,0 +1 @@
+Add administrator endpoints to lock and suspend server-local users and add the `m.account_management` capability, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323).

changelogs/client_server/newsfragments/2278.new.1

@@ -0,0 +1 @@
+Add `GET /_matrix/client/v1/admin/suspend/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323).

changelogs/client_server/newsfragments/2278.new.2

@@ -0,0 +1 @@
+Add `PUT /_matrix/client/v1/admin/suspend/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323).

changelogs/client_server/newsfragments/2278.new.3

@@ -0,0 +1 @@
+Add `GET /_matrix/client/v1/admin/lock/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323).

changelogs/client_server/newsfragments/2278.new.4

@@ -0,0 +1 @@
+Add `PUT /_matrix/client/v1/admin/lock/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323).

changelogs/client_server/newsfragments/2301.feature

@@ -0,0 +1 @@
+Add recommendation about excluding non-cross-signed devices from encrypted conversations, as per [MSC4153](https://github.com/matrix-org/matrix-spec-proposals/pull/4153).

content/client-server-api/_index.md

@@ -2394,9 +2394,12 @@ where feasible. The Matrix-specific actions are:
 Server administrators may apply locks to prevent users from usefully
 using their accounts, for instance, due to safety or security concerns.
 In contrast to account deactivation, locking is a non-destructive action
-that can be reversed. This specification describes the behaviour of clients
-and servers when an account is locked. It deliberately leaves the methods
-for locking and unlocking accounts as a server implementation detail.
+that can be reversed.
+
+{{% added-in v="1.18" %}} To lock or unlock an account, administrators
+SHOULD use the [`PUT /admin/lock/{userId}`](#put_matrixclientv1adminlockuserid)
+endpoint. They MAY also use [`GET /admin/lock/{userId}`](#get_matrixclientv1adminlockuserid)
+to check whether a user's account is locked.
 
 When an account is locked, servers MUST return a `401 Unauthorized` error
 response with an `M_USER_LOCKED` error code and [`soft_logout`](#soft-logout)
@@ -2445,6 +2448,11 @@ from that account. The effect is similar to [locking](#account-locking), though
 without risk of the client losing state from a logout. Suspensions are reversible,
 like locks and unlike deactivations.
 
+{{% added-in v="1.18" %}} To suspend or unsuspend an account, administrators
+SHOULD use the [`PUT /admin/suspend/{userId}`](#put_matrixclientv1adminsuspenduserid)
+endpoint. They MAY also use [`GET /admin/suspend/{userId}`](#get_matrixclientv1adminsuspenduserid)
+to check whether a user's account is suspended.
+
 The actions a user can perform while suspended is deliberately left as an
 implementation detail. Servers SHOULD permit the user to perform at least the
 following, however:
@@ -2500,9 +2508,6 @@ Content-Type: application/json
 }
 ```
 
-APIs for initiating suspension or unsuspension are not included in this version
-of the specification, and left as an implementation detail.
-
 ### Adding Account Administrative Contact Information
 
 A homeserver may keep some contact information for administrative use.

content/client-server-api/modules/end_to_end_encryption.md

@@ -5,6 +5,91 @@ Matrix optionally supports end-to-end encryption, allowing rooms to be
 created whose conversation contents are not decryptable or interceptable
 on any of the participating homeservers.
 
+#### Recommended client behaviour
+
+{{% added-in v="1.18" %}}
+
+While clients are able to choose what encryption features they implement based
+on their threat model, this section recommends behaviours that will improve the
+overall user experience and security of encrypted conversations.
+
+While a user may be unable to [verify](#device-verification) every other user
+that they communicate with, or may be unaware of the need to verify other users,
+[cross-signing](#cross-signing) gives some measure of protection and so SHOULD
+be used where possible. In particular, clients SHOULD implement the following
+recommendations.
+
+* Clients SHOULD create new [cross-signing keys](#cross-signing) for users who
+  do not yet have cross-signing keys.
+* Clients SHOULD encourage users to set up their [Secret Storage](#storage) to
+  avoid needing to reset their cryptographic identity in case the user does not
+  have an existing device that can [share the secrets](#sharing) with the new
+  device. The user's Secret Storage SHOULD contain the user's cross-signing
+  private keys and the [key backup](#server-side-key-backups) decryption key
+  (if the user is using key backup). The user's Secret Storage SHOULD have a
+  [default key](#key-storage) (a key referred to by
+  `m.secret_storage.default_key`) that encrypts the private cross-signing keys
+  and key backup decryption key (if available).
+* Clients SHOULD encourage users to [cross-sign](#cross-signing) their devices.
+  This includes both when logging in a new device, and for existing devices.
+  Clients MAY even go so  far as to require cross-signing of devices by
+  preventing the user from using  the client until the device is cross-signed.
+  If the user cannot cross-sign their device (for example, if they have
+  forgotten their Secret Storage key), the client can allow users to reset their
+  [Secret Storage](#storage), cross-signing keys, and [key backup](#server-side-key-backups).
+* When Alice [verifies](#device-verification) Bob, the verification SHOULD
+  verify their [cross-signing keys](#cross-signing). Any flow between different
+  users that does not verify the users' cross-signing keys (it verifies only the
+  device keys) is deprecated.
+* Clients SHOULD flag when [cross-signing keys](#cross-signing) change. If
+  Alice's cross-signing keys change, Alice's own devices MUST alert her to this
+  fact, and prompt her to re-cross-sign those devices. If Bob is in an
+  encrypted room with Alice,  Bob's devices SHOULD inform him of Alice's key
+  change and SHOULD prevent him from sending an encrypted message to Alice
+  without acknowledging the change. Bob's clients may behave differently
+  depending on whether Bob had previously [verified](#device-verification)
+  Alice or not. For example, if Bob had previously verified Alice, and Alice's
+  keys change, Bob's client may require Bob to re-verify, or may display a more
+  aggressive warning.
+* Clients SHOULD NOT send encrypted [to-device](#send-to-device-messaging)
+  messages, such as [room keys](#sharing-keys-between-devices) or [secrets](#secrets)
+  (via [Secret Sharing](#sharing)), to [non-cross-signed](#cross-signing)
+  devices by default. Non-cross-signed devices don't provide any assurance that
+  the device belongs to the user, and server admins can trivially create new
+  devices for users. When sending room keys, clients can use a
+  [`m.room_key.withheld`](#mroom_keywithheld) message with a code of
+  `m.unverified` to indicate to the non-cross-signed device why it is not
+  receiving the room key.
+
+  Note that clients cannot selectively send room events only to cross-signed
+  devices. The only way to exclude non-cross-signed devices from encrypted
+  conversations is to not send the room keys so those devices won't be able to
+  decrypt the messages.
+* Similarly, messages sent from [non-cross-signed](#cross-signing) devices
+  cannot be trusted and SHOULD NOT be displayed to the user. Clients have no
+  assurance that encrypted messages sent from non-cross-signed devices were sent
+  by the user, rather than an impersonator.
+* Matrix clients MUST NOT consider non-cryptographic devices (devices which do
+  not have [device identity keys](#device-keys) uploaded to the homeserver) to
+  be equivalent to [non-cross-signed](#cross-signing) cryptographic devices for
+  purposes of enforcing E2EE policy. For example, clients SHOULD NOT warn nor
+  refuse to send messages due to the presence of non-cryptographic devices. For
+  all intents and purposes, non-cryptographic devices are a completely separate
+  concept and do not exist from the perspective of the cryptography layer since
+  they do not have identity keys, so it is impossible to send them decryption
+  keys.
+* Clients MAY make provisions for encrypted bridges. Some bridges are structured
+  in a way such that only one user controlled by the bridge (often called the
+  bridge bot) participates in encryption, and encrypted messages from other
+  bridge users are encrypted by the bridge bot. Thus encrypted messages sent by
+  one user could be encrypted by a [Megolm](#mmegolmv1aes-sha2) session sent by
+  a different user. Clients MAY accept such messages, provided the session
+  creator's device is [cross-signed](#cross-signing). However, the client MUST
+  annotate the message with a warning, unless the client has a way to check that
+  the bridge bot is permitted to encrypt messages on behalf of the user. Future
+  MSCs such as [MSC4350](https://github.com/matrix-org/matrix-spec-proposals/pull/4350)
+  may provide a secure way to allow such impersonation.
+
 #### Key Distribution
 
 Encryption and Authentication in Matrix is based around public-key
@@ -674,8 +759,11 @@ The process between Alice and Bob verifying each other would be:
     their devices if they match or not.
 15. Assuming they match, Alice and Bob's devices each calculate Message
     Authentication Codes (MACs) for:
-    * Each of the keys that they wish the other user to verify (usually their
-      device ed25519 key and their master cross-signing key).
+    * {{% changed-in v="1.18" %}} Each of the keys that they wish the other user
+      to verify (usually their device ed25519 key and their master cross-signing
+      key). The master cross-signing key SHOULD be included when two different
+      users are verifying each other. Verifying individual devices of other
+      users is deprecated.
     * The complete list of key IDs that they wish the other user to verify.
 
     The MAC calculation is defined [below](#mac-calculation).

data/api/client-server/admin.yaml

@@ -16,7 +16,7 @@ info:
   title: Matrix Client-Server Administration API
   version: 1.0.0
 paths:
-  "/admin/whois/{userId}":
+  "/v3/admin/whois/{userId}":
     get:
       summary: Gets information about a particular user.
       description: |-
@@ -107,6 +107,391 @@ paths:
                   }
       tags:
         - Server administration
+  "/v1/admin/suspend/{userId}":
+    get:
+      summary: Gets information about the suspended status of a particular user.
+      x-addedInMatrixVersion: "1.18"
+      description: |-
+        Gets information about the suspended status of a particular server-local user.
+
+        The user calling this endpoint MUST be a server admin.
+
+        In order to prevent user enumeration, servers MUST ensure that authorization is checked
+        prior to trying to do account lookups.
+      operationId: getAdminSuspendUser
+      security:
+        - accessTokenQuery: []
+        - accessTokenBearer: []
+      parameters:
+        - in: path
+          name: userId
+          description: The user to look up.
+          required: true
+          example: "@peter:rabbit.rocks"
+          schema:
+            type: string
+            format: mx-user-id
+            pattern: "^@"
+
+      responses:
+        "200":
+          description: The lookup was successful.
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  suspended:
+                    type: boolean
+                    description: Whether the target account is suspended.
+                    example: true
+                required:
+                  - suspended
+              examples:
+                response:
+                  value: {
+                    "suspended": true,
+                  }
+        "400":
+          description: |-
+            The user ID does not belong to the local server. The errcode is `M_INVALID_PARAM`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_INVALID_PARAM",
+                    "error": "User does not belong to the local server."
+                  }
+        "403":
+          description: |-
+            The requesting user is not a server administrator, or the target user is another
+            administrator. The errcode is `M_FORBIDDEN`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_FORBIDDEN",
+                    "error": "Requesting user is not a server administrator."
+                  }
+        "404":
+          description: |-
+            The user ID is not found, or is deactivated. The errcode is `M_NOT_FOUND`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_NOT_FOUND",
+                    "error": "User not found."
+                  }
+      tags:
+        - Server administration
+    put:
+      summary: Set the suspended status of a particular user.
+      x-addedInMatrixVersion: "1.18"
+      description: |-
+        Sets the suspended status of a particular server-local user.
+
+        The user calling this endpoint MUST be a server admin. The client SHOULD check that the user
+        is allowed to suspend other users at the [`GET /capabilities`](/client-server-api/#get_matrixclientv3capabilities)
+        endpoint prior to using this endpoint.
+
+        In order to prevent user enumeration, servers MUST ensure that authorization is checked
+        prior to trying to do account lookups.
+      operationId: setAdminSuspendUser
+      security:
+        - accessTokenQuery: []
+        - accessTokenBearer: []
+      parameters:
+        - in: path
+          name: userId
+          description: The user to change the suspended status of.
+          required: true
+          example: "@peter:rabbit.rocks"
+          schema:
+            type: string
+            format: mx-user-id
+            pattern: "^@"
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                suspended:
+                  type: boolean
+                  description: Whether to suspend the target account.
+                  example: true
+              required:
+                - suspended
+            examples:
+                request:
+                  value: {
+                    "suspended": true,
+                  }
+        required: true
+
+      responses:
+        "200":
+          description: The action was successful.
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  suspended:
+                    type: boolean
+                    description: Whether the target account is suspended.
+                    example: true
+                required:
+                  - suspended
+              examples:
+                response:
+                  value: {
+                    "suspended": true,
+                  }
+        "400":
+          description: |-
+            The user ID does not belong to the local server. The errcode is `M_INVALID_PARAM`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_INVALID_PARAM",
+                    "error": "User does not belong to the local server."
+                  }
+        "403":
+          description: |-
+            The requesting user is not a server administrator, is trying to suspend their own
+            account, or the target user is another administrator. The errcode is `M_FORBIDDEN`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_FORBIDDEN",
+                    "error": "Requesting user is not a server administrator."
+                  }
+        "404":
+          description: |-
+            The user ID is not found, or is deactivated. The errcode is `M_NOT_FOUND`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_NOT_FOUND",
+                    "error": "User not found."
+                  }
+      tags:
+        - Server administration
+  "/v1/admin/lock/{userId}":
+    get:
+      summary: Gets information about the locked status of a particular user.
+      x-addedInMatrixVersion: "1.18"
+      description: |-
+        Gets information about the locked status of a particular server-local user.
+
+        The user calling this endpoint MUST be a server admin.
+
+        In order to prevent user enumeration, servers MUST ensure that authorization is checked
+        prior to trying to do account lookups.
+      operationId: getAdminLockUser
+      security:
+        - accessTokenQuery: []
+        - accessTokenBearer: []
+      parameters:
+        - in: path
+          name: userId
+          description: The user to look up.
+          required: true
+          example: "@peter:rabbit.rocks"
+          schema:
+            type: string
+            format: mx-user-id
+            pattern: "^@"
+
+      responses:
+        "200":
+          description: The lookup was successful.
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  locked:
+                    type: boolean
+                    description: Whether the target account is locked.
+                required:
+                  - locked
+              examples:
+                response:
+                  value: {
+                    "locked": true,
+                  }
+        "400":
+          description: |-
+            The user ID does not belong to the local server. The errcode is `M_INVALID_PARAM`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_INVALID_PARAM",
+                    "error": "User does not belong to the local server."
+                  }
+        "403":
+          description: |-
+            The requesting user is not a server administrator, or the target user is another
+            administrator. The errcode is `M_FORBIDDEN`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_FORBIDDEN",
+                    "error": "Requesting user is not a server administrator."
+                  }
+        "404":
+          description: |-
+            The user ID is not found, or is deactivated. The errcode is `M_NOT_FOUND`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_NOT_FOUND",
+                    "error": "User not found."
+                  }
+      tags:
+        - Server administration
+    put:
+      summary: Set the locked status of a particular user.
+      x-addedInMatrixVersion: "1.18"
+      description: |-
+        Sets the locked status of a particular server-local user.
+
+        The user calling this endpoint MUST be a server admin. The client SHOULD check that the user
+        is allowed to lock other users at the [`GET /capabilities`](/client-server-api/#get_matrixclientv3capabilities)
+        endpoint prior to using this endpoint.
+
+        In order to prevent user enumeration, servers MUST ensure that authorization is checked
+        prior to trying to do account lookups.
+      operationId: setAdminLockUser
+      security:
+        - accessTokenQuery: []
+        - accessTokenBearer: []
+      parameters:
+        - in: path
+          name: userId
+          description: The user to change the locked status of.
+          required: true
+          example: "@peter:rabbit.rocks"
+          schema:
+            type: string
+            format: mx-user-id
+            pattern: "^@"
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                locked:
+                  type: boolean
+                  description: Whether to lock the target account.
+                  example: true
+              required:
+                - locked
+            examples:
+                request:
+                  value: {
+                    "locked": true,
+                  }
+        required: true
+
+      responses:
+        "200":
+          description: The action was successful.
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  locked:
+                    type: boolean
+                    description: Whether the target account is locked.
+                    example: true
+                required:
+                  - locked
+              examples:
+                response:
+                  value: {
+                    "locked": true,
+                  }
+        "400":
+          description: |-
+            The user ID does not belong to the local server. The errcode is `M_INVALID_PARAM`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_INVALID_PARAM",
+                    "error": "User does not belong to the local server."
+                  }
+        "403":
+          description: |-
+            The requesting user is not a server administrator, is trying to lock their own
+            account, or the target user is another administrator. The errcode is `M_FORBIDDEN`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_FORBIDDEN",
+                    "error": "Requesting user is not a server administrator."
+                  }
+        "404":
+          description: |-
+            The user ID is not found, or is deactivated. The errcode is `M_NOT_FOUND`.
+          content:
+            application/json:
+              schema:
+                $ref: definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_NOT_FOUND",
+                    "error": "User not found."
+                  }
+      tags:
+        - Server administration
 servers:
   - url: "{protocol}://{hostname}{basePath}"
     variables:
@@ -118,7 +503,7 @@ servers:
       hostname:
         default: localhost:8008
       basePath:
-        default: /_matrix/client/v3
+        default: /_matrix/client
 components:
   securitySchemes:
     accessTokenQuery:

data/api/client-server/capabilities.yaml

@@ -84,7 +84,7 @@ paths:
                         description: |
                           **Deprecated:** Capability to indicate if the user can change their display name.
                           Refer to `m.profile_fields` for extended profile management.
-                          
+
                           For backwards compatibility, servers that directly or indirectly include the
                           `displayname` profile field in the `m.profile_fields` capability MUST also
                           set this capability accordingly.
@@ -121,7 +121,7 @@ paths:
                             description: |
                               If present, a list of profile fields that clients are allowed to create, modify or delete,
                               provided `enabled` is `true`; no other profile fields may be changed.
-                              
+
                               If absent, clients may set all profile fields except those forbidden by the `disallowed`
                               list, where present.
                             items:
@@ -133,7 +133,7 @@ paths:
                             type: array
                             description:  |
                               This property has no meaning if `allowed` is also specified.
-                              
+
                               Otherwise, if present, a list of profile fields that clients are _not_ allowed to create, modify or delete.
                               Provided `enabled` is `true`, clients MAY assume that they can set any profile field which is not
                               included in this list.
@@ -147,6 +147,34 @@ paths:
                             example: true
                         required:
                           - enabled
+                      m.account_moderation:
+                        x-addedInMatrixVersion: "1.18"
+                        type: object
+                        title: AccountModerationCapability
+                        description: |-
+                          Capability to indicate if the user can perform account moderation actions
+                          via [server administration](/client-server-api/#server-administration)
+                          endpoints.
+
+                          This property should be omitted altogether if `suspend` and `lock` would
+                          be `false`.
+                        properties:
+                          suspend:
+                            type: boolean
+                            description: |-
+                              `true` if the user can suspend a user via [`PUT /admin/suspend/{userId}`](/client-server-api/#put_matrixclientv1adminsuspenduserid),
+                              `false` otherwise.
+
+                              Defaults to `false`.
+                            example: true
+                          lock:
+                            type: boolean
+                            description: |-
+                              `true` if the user can lock a user via [`PUT /admin/lock/{userId}`](/client-server-api/#put_matrixclientv1adminlockuserid),
+                              `false` otherwise.
+
+                              Defaults to `false`.
+                            example: true
               examples:
                 response:
                   value: {