From 3ba939cf288194f330bab0830f7d8328d9309fdb Mon Sep 17 00:00:00 2001
From: tb <>
Date: Mon, 1 Jun 2020 08:04:02 +0000
Subject: Send an illegal_parameter alert if a client sends us invalid DH key
shares. Previously we would fail and just close the pipe.
Fixes the remaining failing test-dhe-rsa-key-exchange-with-bad-messages.py
tests of tlsfuzzer.
ok beck (earlier version) jsing
---
src/lib/libssl/ssl_srvr.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
(limited to 'src/lib')
diff --git a/src/lib/libssl/ssl_srvr.c b/src/lib/libssl/ssl_srvr.c
index fac24f4d00..15dfdc35b1 100644
--- a/src/lib/libssl/ssl_srvr.c
+++ b/src/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.77 2020/05/31 16:36:35 jsing Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.78 2020/06/01 08:04:02 tb Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
@@ -1778,7 +1778,8 @@ ssl3_get_client_kex_rsa(SSL *s, CBS *cbs)
static int
ssl3_get_client_kex_dhe(SSL *s, CBS *cbs)
{
- int key_size = 0, key_len, al;
+ int key_size = 0;
+ int key_is_invalid, key_len, al;
unsigned char *key = NULL;
BIGNUM *bn = NULL;
CBS dh_Yc;
@@ -1809,9 +1810,20 @@ ssl3_get_client_kex_dhe(SSL *s, CBS *cbs)
SSLerror(s, ERR_R_MALLOC_FAILURE);
goto err;
}
+ if (!DH_check_pub_key(dh, bn, &key_is_invalid)) {
+ al = SSL_AD_INTERNAL_ERROR;
+ SSLerror(s, ERR_R_DH_LIB);
+ goto f_err;
+ }
+ if (key_is_invalid) {
+ al = SSL_AD_ILLEGAL_PARAMETER;
+ SSLerror(s, ERR_R_DH_LIB);
+ goto f_err;
+ }
if ((key_len = DH_compute_key(key, bn, dh)) <= 0) {
+ al = SSL_AD_INTERNAL_ERROR;
SSLerror(s, ERR_R_DH_LIB);
- goto err;
+ goto f_err;
}
s->session->master_key_length = tls1_generate_master_secret(s,
--
cgit v1.2.3-55-g6feb