Handle BN_CTX at the EC API boundary.

The EC API allows callers to optionally pass in a BN_CTX, which means that
any code needing a BN_CTX has to check if one was provided, allocate one if
not, then free it again. Rather than doing this dance throughout the EC
code, handle the BN_CTX existance at the EC API boundary. This means that
lower level implementation code can simply assume that the BN_CTX is
available.

ok tb@

1 files changed, 4 insertions, 10 deletions

diff --git a/src/lib/libcrypto/ec/ec2_mult.c b/src/lib/libcrypto/ec/ec2_mult.c
index d32b7442c4..d7cbd933f2 100644
--- a/src/lib/libcrypto/ec/ec2_mult.c
+++ b/src/lib/libcrypto/ec/ec2_mult.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec2_mult.c,v 1.16 2023/03/27 10:25:02 tb Exp $ */
+/* $OpenBSD: ec2_mult.c,v 1.17 2023/04/11 18:58:20 jsing Exp $ */
 /* ====================================================================
  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  *
@@ -375,17 +375,11 @@ int
 ec_GF2m_simple_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
     size_t num, const EC_POINT *points[], const BIGNUM *scalars[], BN_CTX *ctx)
 {
-        BN_CTX *new_ctx = NULL;
-        int ret = 0;
-        size_t i;
         EC_POINT *p = NULL;
         EC_POINT *acc = NULL;
+        size_t i;
+        int ret = 0;
 
-        if (ctx == NULL) {
-                ctx = new_ctx = BN_CTX_new();
-                if (ctx == NULL)
-                        return 0;
-        }
         /*
          * This implementation is more efficient than the wNAF implementation
          * for 2 or fewer points.  Use the ec_wNAF_mul implementation for 3
@@ -432,7 +426,7 @@ ec_GF2m_simple_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
  err:
         EC_POINT_free(p);
         EC_POINT_free(acc);
-        BN_CTX_free(new_ctx);
+
         return ret;
 }