From 5dc91f44a90b72f5c0a79ab9a19d0f2fa0bbac1f Mon Sep 17 00:00:00 2001
From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date: Mon, 6 Apr 2020 10:41:36 +0200
Subject: [PATCH] Fix the error handling in EC_POINTs_mul
This was pointed out by a false-positive
-fsanitizer warning ;-)
However from the cryptographical POV the
code is wrong:
A point R^0 on the wrong curve
is infinity on the wrong curve.
[extended tests]
Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/11475)
(cherry picked from commit 1eb9b54af7e00fa12196411964ce742ea8677766)
---
crypto/ec/ec_lib.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/crypto/ec/ec_lib.c b/crypto/ec/ec_lib.c
index 3554ada827..22b00e203d 100644
--- a/crypto/ec/ec_lib.c
+++ b/crypto/ec/ec_lib.c
@@ -1007,14 +1007,14 @@ int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
size_t i = 0;
BN_CTX *new_ctx = NULL;
- if ((scalar == NULL) && (num == 0)) {
- return EC_POINT_set_to_infinity(group, r);
- }
-
if (!ec_point_is_compat(r, group)) {
ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
return 0;
}
+
+ if (scalar == NULL && num == 0)
+ return EC_POINT_set_to_infinity(group, r);
+
for (i = 0; i < num; i++) {
if (!ec_point_is_compat(points[i], group)) {
ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
--
2.25.1