Revert accidental addition of cofactor ECDH support

This snuck in with ech_key.c r1.33 because I committed from a dirty tree.

1 files changed, 2 insertions, 16 deletions

diff --git a/src/lib/libcrypto/ecdh/ecdh.c b/src/lib/libcrypto/ecdh/ecdh.c
index 0781c30e09..ecb849c135 100644
--- a/src/lib/libcrypto/ecdh/ecdh.c
+++ b/src/lib/libcrypto/ecdh/ecdh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ecdh.c,v 1.4 2023/07/07 13:54:45 beck Exp $ */
+/* $OpenBSD: ecdh.c,v 1.5 2023/07/12 08:54:18 tb Exp $ */
 /* ====================================================================
  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  *
@@ -151,7 +151,7 @@ ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key, EC_KEY *ecdh
     void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
 {
         BN_CTX *ctx;
-        BIGNUM *cofactor, *x;
+        BIGNUM *x;
         const BIGNUM *priv_key;
         const EC_GROUP *group;
         EC_POINT *point = NULL;
@@ -172,8 +172,6 @@ ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key, EC_KEY *ecdh
 
         if ((x = BN_CTX_get(ctx)) == NULL)
                 goto err;
-        if ((cofactor = BN_CTX_get(ctx)) == NULL)
-                goto err;
 
         if ((group = EC_KEY_get0_group(ecdh)) == NULL)
                 goto err;
@@ -191,18 +189,6 @@ ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key, EC_KEY *ecdh
                 goto err;
         }
 
-        if ((EC_KEY_get_flags(ecdh) & EC_FLAG_COFACTOR_ECDH) != 0) {
-                if (!EC_GROUP_get_cofactor(group, cofactor, NULL)) {
-                        ECerror(ERR_R_EC_LIB);
-                        goto err;
-                }
-                if (!BN_mul(cofactor, cofactor, priv_key, ctx)) {
-                        ECerror(ERR_R_BN_LIB);
-                        goto err;
-                }
-                priv_key = cofactor;
-        }
-
         if (!EC_POINT_mul(group, point, NULL, pub_key, priv_key, ctx)) {
                 ECerror(EC_R_POINT_ARITHMETIC_FAILURE);
                 goto err;