From 7121040790b611ca3fbc400a1bbcd4364ef57233 Mon Sep 17 00:00:00 2001

From: Roy Marples <roy@marples.name>

Date: Fri, 19 Apr 2019 21:40:14 +0100

Subject: [PATCH] auth: Use consttime_memequal(3) to compare hashes

This stops any attacker from trying to infer secrets from latency.

Thanks to Maxime Villard <max@m00nbsd.net>

---

 src/auth.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/auth.c b/src/auth.c

index 9e24998c..ce97051e 100644

--- a/src/auth.c

+++ b/src/auth.c

@@ -354,7 +354,7 @@ gottoken:

 	}

 	free(mm);

-	if (memcmp(d, &hmac_code, dlen)) {

+	if (!consttime_memequal(d, &hmac_code, dlen)) {

 		errno = EPERM;

 		return NULL;

 	}

-- 

2.21.0