From 84bf4229e40df695c48284b7a0127408f17b655d Mon Sep 17 00:00:00 2001
From: Christophe Diederichs <chris.d.itunes@gmail.com>
Date: Tue, 16 Jun 2020 16:02:42 +0200
Subject: [PATCH] add: crypto_box_seed_keypair

---
 crypto_box.js | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/crypto_box.js b/crypto_box.js
index 12a9e44..b189045 100644
--- a/crypto_box.js
+++ b/crypto_box.js
@@ -1,8 +1,24 @@
 const { crypto_hash_sha512 } = require('./crypto_hash')
+const { crypto_scalarmult, crypto_scalarmult_base } = require('./crypto_scalarmult')
+const { randombytes } = require('./randombytes')
+const { crypto_generichash_batch } = require('./crypto_generichash')
+const { crypto_secretbox_open_easy, crypto_secretbox_easy } = require('./crypto_secretbox')
+const xsalsa20 = require('xsalsa20')
 const { memzero } = require('./')
 
+var crypto_box_PUBLICKEYBYTES = 32,
+    crypto_box_SECRETKEYBYTES = 32,
+    crypto_box_BEFORENMBYTES = 32,
+    crypto_box_NONCEBYTES = 24,
+    crypto_box_ZEROBYTES = 32,
+    crypto_box_BOXZEROBYTES = 16,
+    crypto_box_SEALBYTES = 48,
+    crypto_box_SEEDBYTES = 32,
+    crypto_box_BEFORENMBYTES = 32
+
 module.exports = {
   crypto_box_keypair,
+  crypto_box_seed_keypair,
   crypto_box_seal,
   crypto_box_seal_open,
   crypto_box_PUBLICKEYBYTES,
@@ -12,6 +28,7 @@ module.exports = {
   crypto_box_ZEROBYTES,
   crypto_box_BOXZEROBYTES,
   crypto_box_SEALBYTES,
+  crypto_box_SEEDBYTES,
   crypto_box_BEFORENMBYTES
 }
 
@@ -29,7 +46,7 @@ function crypto_box_seed_keypair(pk, sk, seed) {
 
   const hash = Buffer.alloc(64)
   crypto_hash_sha512(hash, seed, 32)
-  sk.set(hash, 0, 0, 32)
+  hash.copy(sk, 0, 0, 32)
   memzero(hash)
 
   return crypto_scalarmult_base(pk, sk)
@@ -44,7 +61,7 @@ function crypto_box_seal(c, m, pk) {
   crypto_box_keypair(epk, esk)
 
   var n = new Uint8Array(crypto_box_NONCEBYTES)
-  sodium.crypto_generichash_batch(n, [ epk, pk ])
+  crypto_generichash_batch(n, [ epk, pk ])
 
   var s = new Uint8Array(crypto_box_PUBLICKEYBYTES)
   crypto_scalarmult(s, esk, pk)
@@ -67,7 +84,7 @@ function crypto_box_seal_open(m, c, pk, sk) {
   var epk = c.subarray(0, crypto_box_PUBLICKEYBYTES)
 
   var n = new Uint8Array(crypto_box_NONCEBYTES)
-  sodium.crypto_generichash_batch(n, [ epk, pk ])
+  crypto_generichash_batch(n, [ epk, pk ])
 
   var s = new Uint8Array(crypto_box_PUBLICKEYBYTES)
   crypto_scalarmult(s, sk, epk)
@@ -83,11 +100,6 @@ function check (buf, len) {
   if (!buf || (len && buf.length < len)) throw new Error('Argument must be a buffer' + (len ? ' of length ' + len : ''))
 }
 
-var crypto_box_PUBLICKEYBYTES = 32,
-    crypto_box_SECRETKEYBYTES = 32,
-    crypto_box_BEFORENMBYTES = 32,
-    crypto_box_NONCEBYTES = 24,
-    crypto_box_ZEROBYTES = 32,
-    crypto_box_BOXZEROBYTES = 16,
-    crypto_box_SEALBYTES = 48,
-    crypto_box_BEFORENMBYTES = 32
+function cleanup(arr) {
+  for (var i = 0; i < arr.length; i++) arr[i] = 0;
+}