Check the return from EVP_PKEY_get0_DH()

Fixes #5934

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5983)

diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c
index 7e033ceb16ad10d7706de64568322edd98f51e7d..aa38fada7002633e161ef433c58dfd2ef46eb3c5 100644 (file)
--- a/ssl/statem/statem_srvr.c
+++ b/ssl/statem/statem_srvr.c
@@ -2481,6 +2481,12 @@ int tls_construct_server_key_exchange(SSL *s, WPACKET *pkt)
         }
 
         dh = EVP_PKEY_get0_DH(s->s3->tmp.pkey);
+        if (dh == NULL) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
 
         EVP_PKEY_free(pkdh);
         pkdh = NULL;