From b0bb5d516d39c61ae1274d5809547165f6c4f616 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 25 Jul 2016 22:11:32 -0700
Subject: [PATCH] chachapoly: do not reinitialize state.

---
 lib/bcoin/bip151.js     |  5 ++---
 lib/bcoin/chachapoly.js | 24 +++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/bcoin/bip151.js b/lib/bcoin/bip151.js
index c2d29e1f..8ae82ea0 100644
--- a/lib/bcoin/bip151.js
+++ b/lib/bcoin/bip151.js
@@ -104,9 +104,8 @@ BIP151Stream.prototype.rekey = function rekey() {
 
 BIP151Stream.prototype.sequence = function sequence() {
   this.seq++;
-  this.chacha.init(this.k1, this.iv());
-  this.aead.init(this.k2, this.iv());
-  this.aead.aad(this.sid);
+  this.chacha.init(null, this.iv());
+  this.aead.init(null, this.iv());
 };
 
 BIP151Stream.prototype.iv = function iv() {
diff --git a/lib/bcoin/chachapoly.js b/lib/bcoin/chachapoly.js
index f36b79e7..fbee45c4 100644
--- a/lib/bcoin/chachapoly.js
+++ b/lib/bcoin/chachapoly.js
@@ -34,6 +34,19 @@ function ChaCha20() {
  */
 
 ChaCha20.prototype.init = function init(key, iv, counter) {
+  if (key)
+    this.initKey(key);
+
+  if (iv)
+    this.initIV(iv, counter);
+};
+
+/**
+ * Set key.
+ * @param {Buffer} key
+ */
+
+ChaCha20.prototype.initKey = function initKey(key) {
   this.state[0] = 0x61707865;
   this.state[1] = 0x3320646e;
   this.state[2] = 0x79622d32;
@@ -50,6 +63,16 @@ ChaCha20.prototype.init = function init(key, iv, counter) {
 
   this.state[12] = 0;
 
+  this.pos = 0xffffffff;
+};
+
+/**
+ * Set IV and counter.
+ * @param {Buffer} iv
+ * @param {Number} counter
+ */
+
+ChaCha20.prototype.initIV = function initIV(iv, counter) {
   if (iv.length === 8) {
     this.state[13] = 0;
     this.state[14] = iv.readUInt32LE(0, true);
@@ -62,7 +85,6 @@ ChaCha20.prototype.init = function init(key, iv, counter) {
     assert(false, 'Bad iv size.');
   }
 
-  this.pos = 0xffffffff;
   this.ivSize = iv.length * 8;
 
   this.setCounter(counter);