Merge 2fca4789ca into e9f219d53b

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

changelogs/client_server/newsfragments/2298.feature

@@ -0,0 +1 @@
+Add support for `m.room.redaction` events at the `PUT /rooms/{roomId}/send/{eventType}/{txnId}` endpoint, as per [MSC4169](https://github.com/matrix-org/matrix-spec-proposals/pull/4169).

content/client-server-api/_index.md

@@ -3315,6 +3315,14 @@ the topic to be removed from the room.
 
 #### Client behaviour
 
+{{% changed-in v="1.18" %}}
+
+If the server advertises support for a spec version that supports it, clients
+MAY use the [`PUT /rooms/{roomId}/send/{eventType}/{txnId}`](#put_matrixclientv3roomsroomidsendeventtypetxnid)
+endpoint to send `m.room.redaction` events in all room versions.
+
+They can also use the following endpoint.
+
 {{% http-api spec="client-server" api="redaction" %}}
 
 ### Forming relationships between events

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

@@ -21,14 +21,15 @@ recommendations.
 
 * Clients SHOULD create new [cross-signing keys](#cross-signing) for users who
   do not yet have cross-signing keys.
-* Users SHOULD have [Secret Storage](#storage) set up to avoid needing to reset
+* Clients SHOULD encourage users to set up their [Secret Storage](#storage) to
-  their cryptographic identity in case the user does not have an existing device
+  avoid needing to reset their cryptographic identity in case the user does not
-  that can [share the secrets](#sharing) with the new device. The user's Secret
+  have an existing device that can [share the secrets](#sharing) with the new
-  Storage SHOULD contain the user's cross-signing private keys and the [key
+  device. The user's Secret Storage SHOULD contain the user's cross-signing
-  backup](#server-side-key-backups) decryption key (if the user is using key
+  private keys and the [key backup](#server-side-key-backups) decryption key
-  backup). The user's Secret Storage SHOULD have a [default key](#key-storage)
+  (if the user is using key backup). The user's Secret Storage SHOULD have a
-  (a key referred to by `m.secret_storage.default_key`) that encrypts the
+  [default key](#key-storage) (a key referred to by
-  private cross-signing keys and key backup decryption key (if available).
+  `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
@@ -59,6 +60,11 @@ recommendations.
   [`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
@@ -80,7 +86,9 @@ recommendations.
   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.
+  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
 

data/api/client-server/room_send.yaml

@@ -20,6 +20,10 @@ paths:
   "/rooms/{roomId}/send/{eventType}/{txnId}":
     put:
       summary: Send a message event to the given room.
+      x-changedInMatrixVersion:
+        "1.18": |-
+          Homeservers must support sending `m.room.redaction` events with this endpoint
+          for all room versions.
       description: |-
         This endpoint is used to send a message event to a room. Message events
         allow access to historical events and pagination, making them suited
@@ -28,6 +32,11 @@ paths:
         The body of the request should be the content object of the event; the
         fields in this object will vary depending on the type of event. See
         [Room Events](/client-server-api/#room-events) for the m. event specification.
+
+        Homeservers MUST allow clients to send `m.room.redaction` events with this
+        endpoint for all room versions. In rooms with a version older than 11 they
+        MUST move the `redacts` property inside the `content` to the top level of
+        the event.
       operationId: sendMessage
       security:
         - accessTokenQuery: []