Check the security of DH key shares

ok beck, looks good to jsing

1 files changed, 7 insertions, 1 deletions

diff --git a/src/lib/libssl/ssl_clnt.c b/src/lib/libssl/ssl_clnt.c
index c509771cc3..5291175235 100644
--- a/src/lib/libssl/ssl_clnt.c
+++ b/src/lib/libssl/ssl_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_clnt.c,v 1.146 2022/06/07 17:45:13 tb Exp $ */
+/* $OpenBSD: ssl_clnt.c,v 1.147 2022/06/29 08:27:51 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1248,6 +1248,12 @@ ssl3_get_server_kex_dhe(SSL *s, CBS *cbs)
                 goto err;
         }
 
+        if (!tls_key_share_peer_security(s, s->s3->hs.key_share)) {
+                SSLerror(s, SSL_R_DH_KEY_TOO_SMALL);
+                ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+                return 0;
+        }
+
         return 1;
 
  err: