finalize multi-device

WASignalGroup/sender_key_distribution_message.js

@@ -0,0 +1,78 @@
+const CiphertextMessage = require('./ciphertext_message');
+const protobufs = require('./protobufs');
+
+class SenderKeyDistributionMessage extends CiphertextMessage {
+  constructor(
+    id = null,
+    iteration = null,
+    chainKey = null,
+    signatureKey = null,
+    serialized = null
+  ) {
+    super();
+    if (serialized) {
+      try {
+        const version = serialized[0];
+        const message = serialized.slice(1);
+
+        const distributionMessage = protobufs.SenderKeyDistributionMessage.decode(
+          message
+        ).toJSON();
+        this.serialized = serialized;
+        this.id = distributionMessage.id;
+        this.iteration = distributionMessage.iteration;
+        this.chainKey = distributionMessage.chainKey;
+        this.signatureKey = distributionMessage.signingKey;
+      } catch (e) {
+        throw new Error(e);
+      }
+    } else {
+      const version = this.intsToByteHighAndLow(this.CURRENT_VERSION, this.CURRENT_VERSION);
+      this.id = id;
+      this.iteration = iteration;
+      this.chainKey = chainKey;
+      this.signatureKey = signatureKey;
+      const message = protobufs.SenderKeyDistributionMessage.encode(
+        protobufs.SenderKeyDistributionMessage.create({
+          id,
+          iteration,
+          chainKey,
+          signingKey: this.signatureKey,
+        })
+      ).finish();
+      this.serialized = Buffer.concat([Buffer.from([version]), message]);
+    }
+  }
+
+  intsToByteHighAndLow(highValue, lowValue) {
+    return (((highValue << 4) | lowValue) & 0xff) % 256;
+  }
+
+  serialize() {
+    return this.serialized;
+  }
+
+  getType() {
+    return this.SENDERKEY_DISTRIBUTION_TYPE;
+  }
+
+  getIteration() {
+    return this.iteration;
+  }
+
+  getChainKey() {
+    return typeof this.chainKey === 'string' ? Buffer.from(this.chainKey, 'base64') : this.chainKey;
+  }
+
+  getSignatureKey() {
+    return typeof this.signatureKey === 'string'
+      ? Buffer.from(this.signatureKey, 'base64')
+      : this.signatureKey;
+  }
+
+  getId() {
+    return this.id;
+  }
+}
+
+module.exports = SenderKeyDistributionMessage;