Support new ShieldStateCode.MismatchedSender

Author: richvdh

spec/unit/rust-crypto/rust-crypto.spec.ts

@@ -1140,6 +1140,11 @@ describe("RustCrypto", () => {
                 RustSdkCryptoJs.ShieldStateCode.VerificationViolation,
                 EventShieldReason.VERIFICATION_VIOLATION,
             ],
+            [
+                "Mismatched sender",
+                RustSdkCryptoJs.ShieldStateCode.MismatchedSender,
+                EventShieldReason.MISMATCHED_SENDER,
+            ],
         ])("gets the right shield reason (%s)", async (rustReason, rustCode, expectedReason) => {
             // suppress the warning from the unknown shield reason
             jest.spyOn(console, "warn").mockImplementation(() => {});

src/crypto-api/index.ts

@@ -1355,6 +1355,12 @@ export enum EventShieldReason {
      * The sender was previously verified but changed their identity.
      */
     VERIFICATION_VIOLATION,
+
+    /**
+     * The `sender` field on the event does not match the owner of the device
+     * that established the Megolm session.
+     */
+    MISMATCHED_SENDER,
 }
 
 /** The result of a call to {@link CryptoApi.getOwnDeviceKeys} */

src/rust-crypto/rust-crypto.ts

@@ -2277,6 +2277,12 @@ function rustEncryptionInfoToJsEncryptionInfo(
         case RustSdkCryptoJs.ShieldStateCode.VerificationViolation:
             shieldReason = EventShieldReason.VERIFICATION_VIOLATION;
             break;
+        case RustSdkCryptoJs.ShieldStateCode.MismatchedSender:
+            shieldReason = EventShieldReason.MISMATCHED_SENDER;
+            break;
+        default:
+            shieldReason = EventShieldReason.UNKNOWN_DEVICE;
+            break;
     }
 
     return { shieldColour, shieldReason };