Rename redecryption-related function arguments for clarity (#2709)

src/crypto/algorithms/megolm.ts

@@ -1795,12 +1795,17 @@ class MegolmDecryption extends DecryptionAlgorithm {
      * @private
      * @param {String} senderKey
      * @param {String} sessionId
-     * @param {Boolean} keyTrusted
+     * @param {Boolean} forceRedecryptIfUntrusted whether messages that were already
+     *     successfully decrypted using untrusted keys should be re-decrypted
      *
      * @return {Boolean} whether all messages were successfully
      *     decrypted with trusted keys
      */
-    private async retryDecryption(senderKey: string, sessionId: string, keyTrusted?: boolean): Promise<boolean> {
+    private async retryDecryption(
+        senderKey: string,
+        sessionId: string,
+        forceRedecryptIfUntrusted?: boolean,
+    ): Promise<boolean> {
         const senderPendingEvents = this.pendingEvents.get(senderKey);
         if (!senderPendingEvents) {
             return true;
@@ -1815,7 +1820,7 @@ class MegolmDecryption extends DecryptionAlgorithm {
 
         await Promise.all([...pending].map(async (ev) => {
             try {
-                await ev.attemptDecryption(this.crypto, { isRetry: true, keyTrusted });
+                await ev.attemptDecryption(this.crypto, { isRetry: true, forceRedecryptIfUntrusted });
             } catch (e) {
                 // don't die if something goes wrong
             }

src/models/event.ts

@@ -151,7 +151,7 @@ interface IKeyRequestRecipient {
 export interface IDecryptOptions {
     emit?: boolean;
     isRetry?: boolean;
-    keyTrusted?: boolean;
+    forceRedecryptIfUntrusted?: boolean;
 }
 
 /**
@@ -678,6 +678,8 @@ export class MatrixEvent extends TypedEventEmitter<EmittedEvents, MatrixEventHan
      * @param {object} options
      * @param {boolean} options.isRetry True if this is a retry (enables more logging)
      * @param {boolean} options.emit Emits "event.decrypted" if set to true
+     * @param {boolean} options.forceRedecryptIfUntrusted whether the message should be
+     *     re-decrypted if it was previously successfully decrypted with an untrusted key
      *
      * @returns {Promise} promise which resolves (to undefined) when the decryption
      * attempt is completed.
@@ -696,7 +698,9 @@ export class MatrixEvent extends TypedEventEmitter<EmittedEvents, MatrixEventHan
             throw new Error("Attempt to decrypt event which isn't encrypted");
         }
 
-        if (this.clearEvent && !this.isDecryptionFailure() && !(this.isKeySourceUntrusted() && options.keyTrusted)) {
+        const alreadyDecrypted = this.clearEvent && !this.isDecryptionFailure();
+        const forceRedecrypt = options.forceRedecryptIfUntrusted && this.isKeySourceUntrusted();
+        if (alreadyDecrypted && !forceRedecrypt) {
             // we may want to just ignore this? let's start with rejecting it.
             throw new Error(
                 "Attempt to decrypt event which has already been decrypted",