From 3499d33614d54e7f41c89eff4aaa214b7ffb1f74 Mon Sep 17 00:00:00 2001 From: kokke Date: Tue, 5 Dec 2017 14:41:18 +0100 Subject: [PATCH] Update ecdh.c --- ecdh.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/ecdh.c b/ecdh.c index c3d95dd..d9fe5b4 100644 --- a/ecdh.c +++ b/ecdh.c @@ -58,7 +58,11 @@ #include #endif -/* Use (some) constant-time operations? */ +/* Use (some) constant-time operations? + NOTE: The library is _not_ capable of operating in constant-time and leaks information via timing. + Even if all operations are written const-time-style, it requires the hardware is able to multiply in constant time. + Multiplication on ARM Cortex-M processors takes a variable number of cycles depending on the operands... +*/ #ifndef CONST_TIME #define CONST_TIME 0 #endif