From: tb <tb@openbsd.org>
Date: Thu, 30 Jun 2022 11:17:49 +0000 (+0000)
Subject: Add checks to ensure we do not initiate or negotiate handshakes with
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=89b4969be43c01345df772032714802a00b107d0;p=openbsd

Add checks to ensure we do not initiate or negotiate handshakes with
versions below the minimum required by the security level.

input & ok jsing
---

diff --git a/lib/libssl/ssl_clnt.c b/lib/libssl/ssl_clnt.c
index d49d8ef0560..604b55277cf 100644
--- a/lib/libssl/ssl_clnt.c
+++ b/lib/libssl/ssl_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_clnt.c,v 1.148 2022/06/29 08:34:04 tb Exp $ */
+/* $OpenBSD: ssl_clnt.c,v 1.149 2022/06/30 11:17:49 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -221,6 +221,13 @@ ssl3_connect(SSL *s)
 				goto end;
 			}
 
+			if (!ssl_security_version(s,
+			    s->s3->hs.our_min_tls_version)) {
+				SSLerror(s, SSL_R_VERSION_TOO_LOW);
+				ret = -1;
+				goto end;
+			}
+
 			if (!ssl3_setup_init_buffer(s)) {
 				ret = -1;
 				goto end;
diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index b46e37f5eb0..d466b596422 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.407 2022/06/29 21:18:04 tb Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.408 2022/06/30 11:17:49 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1301,6 +1301,7 @@ int ssl_ctx_security(const SSL_CTX *ctx, int op, int bits, int nid,
 int ssl_security(const SSL *ssl, int op, int bits, int nid, void *other);
 int ssl_ctx_security_dh(const SSL_CTX *ctx, DH *dh);
 int ssl_security_dh(const SSL *ssl, DH *dh);
+int ssl_security_version(const SSL *ssl, int version);
 int ssl_security_cert(const SSL_CTX *ctx, const SSL *ssl, X509 *x509,
     int is_peer, int *out_error);
 int ssl_security_cert_chain(const SSL *ssl, STACK_OF(X509) *sk,
diff --git a/lib/libssl/ssl_seclevel.c b/lib/libssl/ssl_seclevel.c
index b174f57f0cf..2fe6e3f222a 100644
--- a/lib/libssl/ssl_seclevel.c
+++ b/lib/libssl/ssl_seclevel.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ssl_seclevel.c,v 1.11 2022/06/30 07:09:45 tb Exp $ */
+/*	$OpenBSD: ssl_seclevel.c,v 1.12 2022/06/30 11:17:49 tb Exp $ */
 /*
  * Copyright (c) 2020 Theo Buehler <tb@openbsd.org>
  *
@@ -232,6 +232,12 @@ ssl_security(const SSL *ssl, int op, int bits, int nid, void *other)
 	    ssl->cert->security_ex_data);
 }
 
+int
+ssl_security_version(const SSL *ssl, int tls_version)
+{
+	return ssl_security(ssl, SSL_SECOP_VERSION, 0, tls_version, NULL);
+}
+
 int
 ssl_ctx_security_dh(const SSL_CTX *ctx, DH *dh)
 {
diff --git a/lib/libssl/ssl_srvr.c b/lib/libssl/ssl_srvr.c
index e37f9cfdb7a..8f110831e49 100644
--- a/lib/libssl/ssl_srvr.c
+++ b/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.145 2022/06/29 08:27:51 tb Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.146 2022/06/30 11:17:50 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -223,6 +223,13 @@ ssl3_accept(SSL *s)
 				goto end;
 			}
 
+			if (!ssl_security_version(s,
+			    s->s3->hs.our_min_tls_version)) {
+				SSLerror(s, SSL_R_VERSION_TOO_LOW);
+				ret = -1;
+				goto end;
+			}
+
 			if (!ssl3_setup_init_buffer(s)) {
 				ret = -1;
 				goto end;
diff --git a/lib/libssl/ssl_versions.c b/lib/libssl/ssl_versions.c
index 4069670dc94..06e26b80591 100644
--- a/lib/libssl/ssl_versions.c
+++ b/lib/libssl/ssl_versions.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_versions.c,v 1.22 2022/02/05 14:54:10 jsing Exp $ */
+/* $OpenBSD: ssl_versions.c,v 1.23 2022/06/30 11:17:50 tb Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  *
@@ -329,6 +329,9 @@ ssl_max_shared_version(SSL *s, uint16_t peer_ver, uint16_t *max_ver)
 			return 0;
 	}
 
+	if (!ssl_security_version(s, shared_version))
+		return 0;
+
 	*max_ver = shared_version;
 
 	return 1;
@@ -352,8 +355,11 @@ ssl_check_version_from_server(SSL *s, uint16_t server_version)
 	    &max_tls_version))
 		return 0;
 
-	return (server_tls_version >= min_tls_version &&
-	    server_tls_version <= max_tls_version);
+	if (server_tls_version < min_tls_version ||
+	    server_tls_version > max_tls_version)
+		return 0;
+
+	return ssl_security_version(s, server_tls_version);
 }
 
 int