1 files changed, 22 insertions, 25 deletions

diff --git a/src/lib/libcrypto/ecdsa/ecs_lib.c b/src/lib/libcrypto/ecdsa/ecs_lib.c
index c688a95f3b..18eecba704 100644
--- a/src/lib/libcrypto/ecdsa/ecs_lib.c
+++ b/src/lib/libcrypto/ecdsa/ecs_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ecs_lib.c,v 1.13 2018/04/14 07:09:21 tb Exp $ */
+/* $OpenBSD: ecs_lib.c,v 1.14 2022/08/31 13:01:01 tb Exp $ */
 /* ====================================================================
  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
  *
@@ -197,36 +197,33 @@ ecdsa_check(EC_KEY *key)
 int
 ECDSA_size(const EC_KEY *r)
 {
-        int ret, i;
-        ASN1_INTEGER bs;
-        BIGNUM  *order = NULL;
-        unsigned char buf[4];
+        BIGNUM *order = NULL;
         const EC_GROUP *group;
+        ECDSA_SIG signature;
+        int ret = 0;
 
         if (r == NULL)
-                return 0;
-        group = EC_KEY_get0_group(r);
-        if (group == NULL)
-                return 0;
+                goto err;
+
+        if ((group = EC_KEY_get0_group(r)) == NULL)
+                goto err;
 
         if ((order = BN_new()) == NULL)
-                return 0;
-        if (!EC_GROUP_get_order(group, order, NULL)) {
-                BN_clear_free(order);
-                return 0;
-        }
-        i = BN_num_bits(order);
-        bs.length = (i + 7) / 8;
-        bs.data = buf;
-        bs.type = V_ASN1_INTEGER;
-        /* If the top bit is set the asn1 encoding is 1 larger. */
-        buf[0] = 0xff;
-
-        i = i2d_ASN1_INTEGER(&bs, NULL);
-        i += i; /* r and s */
-        ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
+                goto err;
+
+        if (!EC_GROUP_get_order(group, order, NULL))
+                goto err;
+
+        signature.r = order;
+        signature.s = order;
+
+        if ((ret = i2d_ECDSA_SIG(&signature, NULL)) < 0)
+                ret = 0;
+
+ err:
         BN_clear_free(order);
-        return (ret);
+
+        return ret;
 }
 
 int