From a561d12d24c2c8bb0f825d4a3a55a5e47e845853 Mon Sep 17 00:00:00 2001
Message-Id: <a561d12d24c2c8bb0f825d4a3a55a5e47e845853.1652450863.git.davide.caratti@gmail.com>
From: Jouni Malinen <quic_jouni@quicinc.com>
Date: Wed, 4 May 2022 23:55:38 +0300
Subject: [PATCH] EAP peer status notification for server not supporting RFC
 5746

Add a notification message to indicate reason for TLS handshake failure
due to the server not supporting safe renegotiation (RFC 5746).

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>
---
 src/ap/authsrv.c         |  3 +++
 src/crypto/tls.h         |  3 ++-
 src/crypto/tls_openssl.c | 15 +++++++++++++--
 src/eap_peer/eap.c       |  5 +++++
 4 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/ap/authsrv.c b/src/ap/authsrv.c
index 516c1da74..fd9c96fad 100644
--- a/src/ap/authsrv.c
+++ b/src/ap/authsrv.c
@@ -169,6 +169,9 @@ static void authsrv_tls_event(void *ctx, enum tls_event ev,
 			wpa_printf(MSG_DEBUG, "authsrv: remote TLS alert: %s",
 				   data->alert.description);
 		break;
+	case TLS_UNSAFE_RENEGOTIATION_DISABLED:
+		/* Not applicable to TLS server */
+		break;
 	}
 }
 #endif /* EAP_TLS_FUNCS */
diff --git a/src/crypto/tls.h b/src/crypto/tls.h
index 7ea32ee4a..7a2ee32df 100644
--- a/src/crypto/tls.h
+++ b/src/crypto/tls.h
@@ -22,7 +22,8 @@ enum tls_event {
 	TLS_CERT_CHAIN_SUCCESS,
 	TLS_CERT_CHAIN_FAILURE,
 	TLS_PEER_CERTIFICATE,
-	TLS_ALERT
+	TLS_ALERT,
+	TLS_UNSAFE_RENEGOTIATION_DISABLED,
 };
 
 /*
diff --git a/src/crypto/tls_openssl.c b/src/crypto/tls_openssl.c
index 0d23f44ad..912471ba2 100644
--- a/src/crypto/tls_openssl.c
+++ b/src/crypto/tls_openssl.c
@@ -4443,6 +4443,7 @@ int tls_connection_get_eap_fast_key(void *tls_ctx, struct tls_connection *conn,
 static struct wpabuf *
 openssl_handshake(struct tls_connection *conn, const struct wpabuf *in_data)
 {
+	struct tls_context *context = conn->context;
 	int res;
 	struct wpabuf *out_data;
 
@@ -4472,7 +4473,19 @@ openssl_handshake(struct tls_connection *conn, const struct wpabuf *in_data)
 			wpa_printf(MSG_DEBUG, "SSL: SSL_connect - want to "
 				   "write");
 		else {
+			unsigned long error = ERR_peek_last_error();
+
 			tls_show_errors(MSG_INFO, __func__, "SSL_connect");
+
+			if (context->event_cb &&
+			    ERR_GET_LIB(error) == ERR_LIB_SSL &&
+			    ERR_GET_REASON(error) ==
+			    SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED) {
+				context->event_cb(
+					context->cb_ctx,
+					TLS_UNSAFE_RENEGOTIATION_DISABLED,
+					NULL);
+			}
 			conn->failed++;
 			if (!conn->server && !conn->client_hello_generated) {
 				/* The server would not understand TLS Alert
@@ -4495,8 +4508,6 @@ openssl_handshake(struct tls_connection *conn, const struct wpabuf *in_data)
 	if ((conn->flags & TLS_CONN_SUITEB) && !conn->server &&
 	    os_strncmp(SSL_get_cipher(conn->ssl), "DHE-", 4) == 0 &&
 	    conn->server_dh_prime_len < 3072) {
-		struct tls_context *context = conn->context;
-
 		/*
 		 * This should not be reached since earlier cert_cb should have
 		 * terminated the handshake. Keep this check here for extra
diff --git a/src/eap_peer/eap.c b/src/eap_peer/eap.c
index 429b20d3a..729388f4f 100644
--- a/src/eap_peer/eap.c
+++ b/src/eap_peer/eap.c
@@ -2172,6 +2172,11 @@ static void eap_peer_sm_tls_event(void *ctx, enum tls_event ev,
 			eap_notify_status(sm, "remote TLS alert",
 					  data->alert.description);
 		break;
+	case TLS_UNSAFE_RENEGOTIATION_DISABLED:
+		wpa_printf(MSG_INFO,
+			   "TLS handshake failed due to the server not supporting safe renegotiation (RFC 5746); phase1 parameter allow_unsafe_renegotiation=1 can be used to work around this");
+		eap_notify_status(sm, "unsafe server renegotiation", "failure");
+		break;
 	}
 
 	os_free(hash_hex);
-- 
2.35.1