feat: Add queue in enc/dec group message (#191)

WASignalGroup/group_cipher.js

@@ -1,3 +1,4 @@
+const queue_job = require('./queue_job');
 const SenderKeyMessage = require('./sender_key_message');
 const crypto = require('libsignal/src/crypto');
 
@@ -7,11 +8,22 @@ class GroupCipher {
     this.senderKeyName = senderKeyName;
   }
 
+  queueJob(awaitable) {
+    return queue_job(this.senderKeyName.toString(), awaitable)
+  }
+
   async encrypt(paddedPlaintext) {
-    try {
+    return await this.queueJob(async () => {
       const record = await this.senderKeyStore.loadSenderKey(this.senderKeyName);
+      if (!record) {
+        throw new Error("No SenderKeyRecord found for encryption")
+      }
       const senderKeyState = record.getSenderKeyState();
-      const senderKey = senderKeyState.getSenderChainKey().getSenderMessageKey();
+      if (!senderKeyState) {
+        throw new Error("No session to encrypt message");
+      }
+      const iteration = senderKeyState.getSenderChainKey().getIteration()
+      const senderKey = this.getSenderKey(senderKeyState, iteration === 0 ? 0 : iteration + 1)
 
       const ciphertext = await this.getCipherText(
         senderKey.getIv(),
@@ -25,35 +37,37 @@ class GroupCipher {
         ciphertext,
         senderKeyState.getSigningKeyPrivate()
       );
-      senderKeyState.setSenderChainKey(senderKeyState.getSenderChainKey().getNext());
       await this.senderKeyStore.storeSenderKey(this.senderKeyName, record);
-      return senderKeyMessage.serialize();
-    } catch (e) {
-      //console.log(e.stack);
-      throw new Error('NoSessionException');
-    }
+      return senderKeyMessage.serialize()
+    })
   }
 
   async decrypt(senderKeyMessageBytes) {
-    const record = await this.senderKeyStore.loadSenderKey(this.senderKeyName);
-    if (!record) throw new Error(`No sender key for: ${this.senderKeyName}`);
+    return await this.queueJob(async () => {
+      const record = await this.senderKeyStore.loadSenderKey(this.senderKeyName);
+      if (!record) {
+        throw new Error("No SenderKeyRecord found for decryption")
+      }
+      const senderKeyMessage = new SenderKeyMessage(null, null, null, null, senderKeyMessageBytes);
+      const senderKeyState = record.getSenderKeyState(senderKeyMessage.getKeyId());
+      if (!senderKeyState) {
+        throw new Error("No session found to decrypt message")
+      }
 
-    const senderKeyMessage = new SenderKeyMessage(null, null, null, null, senderKeyMessageBytes);
+      senderKeyMessage.verifySignature(senderKeyState.getSigningKeyPublic());
+      const senderKey = this.getSenderKey(senderKeyState, senderKeyMessage.getIteration());
+      // senderKeyState.senderKeyStateStructure.senderSigningKey.private =
 
-    const senderKeyState = record.getSenderKeyState(senderKeyMessage.getKeyId());
-    senderKeyMessage.verifySignature(senderKeyState.getSigningKeyPublic());
-    const senderKey = this.getSenderKey(senderKeyState, senderKeyMessage.getIteration());
-    // senderKeyState.senderKeyStateStructure.senderSigningKey.private =
+      const plaintext = await this.getPlainText(
+        senderKey.getIv(),
+        senderKey.getCipherKey(),
+        senderKeyMessage.getCipherText()
+      );
 
-    const plaintext = await this.getPlainText(
-      senderKey.getIv(),
-      senderKey.getCipherKey(),
-      senderKeyMessage.getCipherText()
-    );
+      await this.senderKeyStore.storeSenderKey(this.senderKeyName, record);
 
-    await this.senderKeyStore.storeSenderKey(this.senderKeyName, record);
-
-    return plaintext;
+      return plaintext;
+    })
   }
 
   getSenderKey(senderKeyState, iteration) {
@@ -67,7 +81,7 @@ class GroupCipher {
       );
     }
 
-    if (senderChainKey.getIteration() - iteration > 2000) {
+    if (iteration - senderChainKey.getIteration() > 2000) {
       throw new Error('Over 2000 messages into the future!');
     }
 

WASignalGroup/queue_job.js

@@ -0,0 +1,69 @@
+// vim: ts=4:sw=4:expandtab
+
+/*
+ * jobQueue manages multiple queues indexed by device to serialize
+ * session io ops on the database.
+ */
+'use strict';
+
+
+const _queueAsyncBuckets = new Map();
+const _gcLimit = 10000;
+
+async function _asyncQueueExecutor(queue, cleanup) {
+    let offt = 0;
+    while (true) {
+        let limit = Math.min(queue.length, _gcLimit); // Break up thundering hurds for GC duty.
+        for (let i = offt; i < limit; i++) {
+            const job = queue[i];
+            try {
+                job.resolve(await job.awaitable());
+            } catch (e) {
+                job.reject(e);
+            }
+        }
+        if (limit < queue.length) {
+            /* Perform lazy GC of queue for faster iteration. */
+            if (limit >= _gcLimit) {
+                queue.splice(0, limit);
+                offt = 0;
+            } else {
+                offt = limit;
+            }
+        } else {
+            break;
+        }
+    }
+    cleanup();
+}
+
+module.exports = function (bucket, awaitable) {
+    /* Run the async awaitable only when all other async calls registered
+     * here have completed (or thrown).  The bucket argument is a hashable
+     * key representing the task queue to use. */
+    if (!awaitable.name) {
+        // Make debuging easier by adding a name to this function.
+        Object.defineProperty(awaitable, 'name', { writable: true });
+        if (typeof bucket === 'string') {
+            awaitable.name = bucket;
+        } else {
+            console.warn("Unhandled bucket type (for naming):", typeof bucket, bucket);
+        }
+    }
+    let inactive;
+    if (!_queueAsyncBuckets.has(bucket)) {
+        _queueAsyncBuckets.set(bucket, []);
+        inactive = true;
+    }
+    const queue = _queueAsyncBuckets.get(bucket);
+    const job = new Promise((resolve, reject) => queue.push({
+        awaitable,
+        resolve,
+        reject
+    }));
+    if (inactive) {
+        /* An executor is not currently active; Start one now. */
+        _asyncQueueExecutor(queue, () => _queueAsyncBuckets.delete(bucket));
+    }
+    return job;
+};

WASignalGroup/sender_key_record.js

@@ -22,18 +22,20 @@ class SenderKeyRecord {
     }
   
     getSenderKeyState(keyId) {
-      if (!keyId && this.senderKeyStates.length) return this.senderKeyStates[0];
+      if (!keyId && this.senderKeyStates.length) return this.senderKeyStates[this.senderKeyStates.length - 1];
       for (let i = 0; i < this.senderKeyStates.length; i++) {
         const state = this.senderKeyStates[i];
         if (state.getKeyId() === keyId) {
           return state;
         }
       }
-      throw new Error(`No keys for: ${keyId}`);
     }
   
     addSenderKeyState(id, iteration, chainKey, signatureKey) {
       this.senderKeyStates.push(new SenderKeyState(id, iteration, chainKey, null, signatureKey));
+      if (this.senderKeyStates.length > 5) {
+        this.senderKeyStates.shift()
+      }
     }
   
     setSenderKeyState(id, iteration, chainKey, keyPair) {