From 68bd4b4a68980ec883e6f86f09bb6dcf1d8ad020 Mon Sep 17 00:00:00 2001
From: Christophe Diederichs <chris.d.itunes@gmail.com>
Date: Wed, 17 Jun 2020 12:50:27 +0200
Subject: [PATCH] chacha: readUint32Le generalised for uint8array; aead:
 standard fix

---
 crypto_aead.js            |  2 +-
 crypto_stream_chacha20.js | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/crypto_aead.js b/crypto_aead.js
index 8c6321e..561984b 100644
--- a/crypto_aead.js
+++ b/crypto_aead.js
@@ -89,7 +89,7 @@ function crypto_aead_chacha20poly1305_ietf_decrypt (m, nsec, c, ad, npub, k) {
     return c.length - crypto_aead_chacha20poly1305_ietf_ABYTES
   }
 
-  return ret;
+  return ret
 }
 
 function crypto_aead_chacha20poly1305_ietf_decrypt_detached (m, nsec, c, mac, ad, npub, k) {
diff --git a/crypto_stream_chacha20.js b/crypto_stream_chacha20.js
index f098a67..73b9b0b 100644
--- a/crypto_stream_chacha20.js
+++ b/crypto_stream_chacha20.js
@@ -95,18 +95,18 @@ function Chacha20 (n, k, counter) {
   this.state = new Uint32Array(16)
 
   for (let i = 0; i < 4; i++) this.state[i] = constant[i]
-  for (let i = 0; i < 8; i++) this.state[4 + i] = k.readUInt32LE(4 * i)
+  for (let i = 0; i < 8; i++) this.state[4 + i] = readUInt32LE(k, 4 * i)
 
   this.state[12] = counter & 0xffffffff
 
   if (n.byteLength === 8) {
     this.state[13] = (counter && 0xffffffff00000000) >> 32
-    this.state[14] = n.readUInt32LE(0)
-    this.state[15] = n.readUInt32LE(4)
+    this.state[14] = readUInt32LE(n, 0)
+    this.state[15] = readUInt32LE(n, 4)
   } else {
-    this.state[13] = n.readUInt32LE(0)
-    this.state[14] = n.readUInt32LE(4)
-    this.state[15] = n.readUInt32LE(8)
+    this.state[13] = readUInt32LE(n, 0)
+    this.state[14] = readUInt32LE(n, 4)
+    this.state[15] = readUInt32LE(n, 8)
   }
 
   return this
@@ -207,3 +207,13 @@ function QR (obj, a, b, c, d) {
   obj[b] ^= obj[c]
   obj[b] = rotl(obj[b], 7)
 }
+
+function readUInt32LE (buf, offset) {
+  if (Buffer.isBuffer(buf)) return buf.readUInt32LE(offset)
+  else if (buf instanceof Uint8Array) {
+    var ret = 0
+    for (let i = 0; i < 4; i++) ret |= buf[offset + i] << (8 * i)
+    return ret
+  }
+  assert(false, 'buf should be a Buffer or a Uint8Array')
+}