crypto: define new WithheldCode for MSC4268

Author: richvdh

crates/matrix-sdk-common/src/deserialized_responses.rs

@@ -1200,6 +1200,13 @@ pub enum WithheldCode {
     #[ruma_enum(rename = "m.no_olm")]
     NoOlm,
 
+    /// Normally used when sharing history, per [MSC4268]: indicates
+    /// that the session was not marked as "shared_history".
+    ///
+    /// [MSC4268]: https://github.com/matrix-org/matrix-spec-proposals/pull/4268
+    #[ruma_enum(rename = "io.element.msc4268.history_not_shared", alias = "m.history_not_shared")]
+    HistoryNotShared,
+
     #[doc(hidden)]
     _Custom(PrivOwnedStr),
 }
@@ -1212,6 +1219,7 @@ impl fmt::Display for WithheldCode {
             WithheldCode::Unauthorised => "You are not authorised to read the message.",
             WithheldCode::Unavailable => "The requested key was not found.",
             WithheldCode::NoOlm => "Unable to establish a secure channel.",
+            WithheldCode::HistoryNotShared => "The sender disabled sharing encrypted history.",
             _ => self.as_str(),
         };
 

crates/matrix-sdk-crypto/src/types/events/room_key_withheld.rs

@@ -65,7 +65,8 @@ macro_rules! construct_withheld_content {
             WithheldCode::Blacklisted
             | WithheldCode::Unverified
             | WithheldCode::Unauthorised
-            | WithheldCode::Unavailable => {
+            | WithheldCode::Unavailable
+            | WithheldCode::HistoryNotShared => {
                 let content = CommonWithheldCodeContent {
                     $room_id,
                     $session_id,
@@ -84,7 +85,9 @@ macro_rules! construct_withheld_content {
                         .into(),
                 ))
             }
-            _ => unreachable!("Can't create an unknown withheld code content"),
+            WithheldCode::_Custom(_) => {
+                unreachable!("Can't create an unknown withheld code content")
+            }
         }
     };
 }
@@ -180,6 +183,9 @@ pub enum MegolmV1AesSha2WithheldContent {
     Unauthorised(Box<CommonWithheldCodeContent>),
     /// The `m.unavailable` variant of the withheld code content.
     Unavailable(Box<CommonWithheldCodeContent>),
+    /// The `m.history_not_shared` variant of the withheld code content (cf
+    /// [MSC4268](https://github.com/matrix-org/matrix-spec-proposals/pull/4268)).
+    HistoryNotShared(Box<CommonWithheldCodeContent>),
     /// The `m.no_olm` variant of the withheld code content.
     NoOlm(Box<NoOlmWithheldContent>),
 }
@@ -231,7 +237,10 @@ impl MegolmV1AesSha2WithheldContent {
             MegolmV1AesSha2WithheldContent::BlackListed(content)
             | MegolmV1AesSha2WithheldContent::Unverified(content)
             | MegolmV1AesSha2WithheldContent::Unauthorised(content)
-            | MegolmV1AesSha2WithheldContent::Unavailable(content) => Some(&content.session_id),
+            | MegolmV1AesSha2WithheldContent::Unavailable(content)
+            | MegolmV1AesSha2WithheldContent::HistoryNotShared(content) => {
+                Some(&content.session_id)
+            }
             MegolmV1AesSha2WithheldContent::NoOlm(_) => None,
         }
     }
@@ -242,7 +251,8 @@ impl MegolmV1AesSha2WithheldContent {
             MegolmV1AesSha2WithheldContent::BlackListed(content)
             | MegolmV1AesSha2WithheldContent::Unverified(content)
             | MegolmV1AesSha2WithheldContent::Unauthorised(content)
-            | MegolmV1AesSha2WithheldContent::Unavailable(content) => Some(&content.room_id),
+            | MegolmV1AesSha2WithheldContent::Unavailable(content)
+            | MegolmV1AesSha2WithheldContent::HistoryNotShared(content) => Some(&content.room_id),
             MegolmV1AesSha2WithheldContent::NoOlm(_) => None,
         }
     }
@@ -254,6 +264,7 @@ impl MegolmV1AesSha2WithheldContent {
             MegolmV1AesSha2WithheldContent::Unverified(_) => WithheldCode::Unverified,
             MegolmV1AesSha2WithheldContent::Unauthorised(_) => WithheldCode::Unauthorised,
             MegolmV1AesSha2WithheldContent::Unavailable(_) => WithheldCode::Unavailable,
+            MegolmV1AesSha2WithheldContent::HistoryNotShared(_) => WithheldCode::HistoryNotShared,
             MegolmV1AesSha2WithheldContent::NoOlm(_) => WithheldCode::NoOlm,
         }
     }
@@ -266,7 +277,10 @@ impl MegolmV1AesSha2WithheldContent {
             WithheldCode::Unverified => Self::Unverified(content),
             WithheldCode::Unauthorised => Self::Unauthorised(content),
             WithheldCode::Unavailable => Self::Unavailable(content),
-            _ => unreachable!("This constructor requires one of the common withheld codes"),
+            WithheldCode::HistoryNotShared => Self::HistoryNotShared(content),
+            WithheldCode::NoOlm | WithheldCode::_Custom(_) => {
+                unreachable!("This constructor requires one of the common withheld codes")
+            }
         }
     }
 }
@@ -349,14 +363,15 @@ impl TryFrom<WithheldHelper> for RoomKeyWithheldContent {
                 WithheldCode::Blacklisted
                 | WithheldCode::Unverified
                 | WithheldCode::Unauthorised
-                | WithheldCode::Unavailable => {
+                | WithheldCode::Unavailable
+                | WithheldCode::HistoryNotShared => {
                     let content: CommonWithheldCodeContent = serde_json::from_value(value.other)?;
 
                     Self::MegolmV1AesSha2(MegolmV1AesSha2WithheldContent::from_code_and_content(
                         value.code, content,
                     ))
                 }
-                _ => unknown(value)?,
+                WithheldCode::_Custom(_) => unknown(value)?,
             },
             #[cfg(feature = "experimental-algorithms")]
             EventEncryptionAlgorithm::MegolmV2AesSha2 => match value.code {
@@ -367,14 +382,15 @@ impl TryFrom<WithheldHelper> for RoomKeyWithheldContent {
                 WithheldCode::Blacklisted
                 | WithheldCode::Unverified
                 | WithheldCode::Unauthorised
-                | WithheldCode::Unavailable => {
+                | WithheldCode::Unavailable
+                | WithheldCode::HistoryNotShared => {
                     let content: CommonWithheldCodeContent = serde_json::from_value(value.other)?;
 
                     Self::MegolmV1AesSha2(MegolmV1AesSha2WithheldContent::from_code_and_content(
                         value.code, content,
                     ))
                 }
-                _ => unknown(value)?,
+                WithheldCode::_Custom(_) => unknown(value)?,
             },
             _ => unknown(value)?,
         })
@@ -397,7 +413,8 @@ impl Serialize for RoomKeyWithheldContent {
                     MegolmV1AesSha2WithheldContent::BlackListed(content)
                     | MegolmV1AesSha2WithheldContent::Unverified(content)
                     | MegolmV1AesSha2WithheldContent::Unauthorised(content)
-                    | MegolmV1AesSha2WithheldContent::Unavailable(content) => WithheldHelper {
+                    | MegolmV1AesSha2WithheldContent::Unavailable(content)
+                    | MegolmV1AesSha2WithheldContent::HistoryNotShared(content) => WithheldHelper {
                         algorithm,
                         code,
                         reason,
@@ -420,7 +437,8 @@ impl Serialize for RoomKeyWithheldContent {
                     MegolmV1AesSha2WithheldContent::BlackListed(content)
                     | MegolmV1AesSha2WithheldContent::Unverified(content)
                     | MegolmV1AesSha2WithheldContent::Unauthorised(content)
-                    | MegolmV1AesSha2WithheldContent::Unavailable(content) => WithheldHelper {
+                    | MegolmV1AesSha2WithheldContent::Unavailable(content)
+                    | MegolmV1AesSha2WithheldContent::HistoryNotShared(content) => WithheldHelper {
                         algorithm,
                         code,
                         reason,
@@ -534,6 +552,7 @@ pub(super) mod tests {
             WithheldCode::Blacklisted,
             WithheldCode::Unauthorised,
             WithheldCode::Unavailable,
+            WithheldCode::HistoryNotShared,
         ];
         for code in codes {
             let json = json(&code);

crates/matrix-sdk-crypto/src/types/events/utd_cause.rs

@@ -150,6 +150,7 @@ impl UtdCause {
                     WithheldCode::Blacklisted
                     | WithheldCode::Unauthorised
                     | WithheldCode::Unavailable
+                    | WithheldCode::HistoryNotShared
                     | WithheldCode::NoOlm
                     | WithheldCode::_Custom(_) => UtdCause::WithheldBySender,
                 }