Check return values in ssl_print_tmp_key()

Use EVP_PKEY_get0_EC_KEY() instead of the get1 version to avoid an
EVP_PKEY_free(). Check return values: if either EVP_PKEY_get0_EC_KEY()
or EC_KEY_get0_group() fail, a NULL dereference occurs.

CID 43289

ok jsing

diff --git a/usr.bin/openssl/s_cb.c b/usr.bin/openssl/s_cb.c
index ffaa4c5..73f45c2 100644 (file)
--- a/usr.bin/openssl/s_cb.c
+++ b/usr.bin/openssl/s_cb.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s_cb.c,v 1.19 2022/08/30 20:40:14 tb Exp $ */
+/* $OpenBSD: s_cb.c,v 1.20 2022/08/31 07:12:30 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -264,6 +264,7 @@ ssl_print_tmp_key(BIO *out, SSL *s)
        const char *cname;
        EVP_PKEY *pkey;
        EC_KEY *ec;
+       const EC_GROUP *group;
        int nid;
 
        if (!SSL_get_server_tmp_key(s, &pkey))
@@ -276,9 +277,12 @@ ssl_print_tmp_key(BIO *out, SSL *s)
                break;
 
        case EVP_PKEY_EC:
-               ec = EVP_PKEY_get1_EC_KEY(pkey);
-               nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec));
-               EC_KEY_free(ec);
+               if ((ec = EVP_PKEY_get0_EC_KEY(pkey)) == NULL)
+                       goto err;
+               if ((group = EC_KEY_get0_group(ec)) == NULL)
+                       goto err;
+
+               nid = EC_GROUP_get_curve_name(group);
 
                if ((cname = EC_curve_nid2nist(nid)) == NULL)
                        cname = OBJ_nid2sn(nid);
@@ -291,6 +295,7 @@ ssl_print_tmp_key(BIO *out, SSL *s)
                    EVP_PKEY_bits(pkey));
        }
 
+ err:
        EVP_PKEY_free(pkey);
        return 1;
 }