From 9b8038c6f08ed6f189a3bf8e2c8ba13b3c8e9afe Mon Sep 17 00:00:00 2001
From: "Alan T. DeKok" <aland@freeradius.org>
Date: Wed, 9 Apr 2014 11:54:42 -0400
Subject: [PATCH] Check for invalid TLS handshake

If the system has a vulnerable version of OpenSSL, and the
admin has told us to allow it, we want to catch and stop
the problem.
---
 src/modules/rlm_eap/libeap/cb.c      | 18 ++++++++++++++++++
 src/modules/rlm_eap/libeap/eap_tls.h |  2 ++
 src/modules/rlm_eap/libeap/tls.c     |  2 ++
 3 files changed, 22 insertions(+)

diff --git a/src/modules/rlm_eap/libeap/cb.c b/src/modules/rlm_eap/libeap/cb.c
index f7a0beb..7048f6e 100644
--- a/src/modules/rlm_eap/libeap/cb.c
+++ b/src/modules/rlm_eap/libeap/cb.c
@@ -118,7 +118,25 @@ void cbtls_msg(int write_p, int msg_version, int content_type,
 		state->info.handshake_type = ((const unsigned char*)buf)[0];
 		state->info.alert_level = 0x00;
 		state->info.alert_description = 0x00;
+
+#ifdef SSL3_RT_HEARTBEAT
+	} else if (content_type == TLS1_RT_HEARTBEAT) {
+		uint8_t *p = buf;
+
+		if ((len >= 3) && (p[0] == 1)) {
+			size_t payload_len;
+
+			payload_len = (p[1] << 8) | p[2];
+
+			if ((payload_len + 3) > len) {
+				state->invalid_hb_used = TRUE;
+				ERROR("OpenSSL Heartbeat attack detected.  Closing connection");
+				return;
+			}
+		}
+#endif
 	}
+
 	tls_session_information(state);
 }
 
diff --git a/src/modules/rlm_eap/libeap/eap_tls.h b/src/modules/rlm_eap/libeap/eap_tls.h
index a32f232..48c2333 100644
--- a/src/modules/rlm_eap/libeap/eap_tls.h
+++ b/src/modules/rlm_eap/libeap/eap_tls.h
@@ -158,6 +158,8 @@ typedef struct _tls_session_t {
 					unsigned int size);
 
 
+	int		invalid_hb_used;
+
 	/*
 	 * Framed-MTU attribute in RADIUS,
 	 * if present, can also be used to set this
diff --git a/src/modules/rlm_eap/libeap/tls.c b/src/modules/rlm_eap/libeap/tls.c
index 88530ac..da73230 100644
--- a/src/modules/rlm_eap/libeap/tls.c
+++ b/src/modules/rlm_eap/libeap/tls.c
@@ -183,6 +183,8 @@ int tls_handshake_recv(REQUEST *request, tls_session_t *ssn)
 {
 	int err;
 
+	if (ssn->invalid_hb_used) return 0;
+
 	BIO_write(ssn->into_ssl, ssn->dirty_in.data, ssn->dirty_in.used);
 
 	err = SSL_read(ssn->ssl, ssn->clean_out.data + ssn->clean_out.used,
-- 
2.1.4