check_discriminant: make the assumptions on p, a, b more explicit

requested by jsing

1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libcrypto/ec/ec_lib.c b/src/lib/libcrypto/ec/ec_lib.c
index a50b1e5633..322662a1e6 100644
--- a/src/lib/libcrypto/ec/ec_lib.c
+++ b/src/lib/libcrypto/ec/ec_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec_lib.c,v 1.103 2025/01/07 08:30:52 tb Exp $ */
+/* $OpenBSD: ec_lib.c,v 1.104 2025/01/09 06:51:11 tb Exp $ */
 /*
  * Originally written by Bodo Moeller for the OpenSSL project.
  */
@@ -623,7 +623,8 @@ EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx_in)
                 goto err;
 
         /*
-         * Check that the discriminant 4a^3 + 27b^2 is non-zero modulo p.
+         * Check that the discriminant 4a^3 + 27b^2 is non-zero modulo p
+         * assuming that p > 3 is prime and that a and b are in [0, p).
          */
 
         if (BN_is_zero(a) && BN_is_zero(b))