From 008351573a518ab92aea5431363e9d45414ec26a Mon Sep 17 00:00:00 2001
From: Cloud Wu <cloudwu@gmail.com>
Date: Fri, 18 Sep 2015 14:13:16 +0800
Subject: [PATCH] raise error when DH param is 0

---
 lualib-src/lua-crypt.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/lualib-src/lua-crypt.c b/lualib-src/lua-crypt.c
index 2cb11f40..405679a9 100644
--- a/lualib-src/lua-crypt.c
+++ b/lualib-src/lua-crypt.c
@@ -725,10 +725,8 @@ ldhsecret(lua_State *L) {
 	read64(L, x, y);
 	uint64_t xx = (uint64_t)x[0] | (uint64_t)x[1]<<32;
 	uint64_t yy = (uint64_t)y[0] | (uint64_t)y[1]<<32;
-	if (xx == 0)
-		xx = 1;
-	if (yy == 0)
-		yy = 1;
+	if (xx == 0 || yy == 0)
+		return luaL_error(L, "Can't be 0");
 	uint64_t r = powmodp(xx, yy);
 
 	push64(L, r);
@@ -751,7 +749,7 @@ ldhexchange(lua_State *L) {
 
 	uint64_t x64 = (uint64_t)xx[0] | (uint64_t)xx[1]<<32;
 	if (x64 == 0)
-		x64 = 1;
+		return luaL_error(L, "Can't be 0");
 
 	uint64_t r = powmodp(5,	x64);
 	push64(L, r);