[PATCH 1/2] EAP-TTLS/PEAP peer: fix failure using session tickets under TLS 1.3

[Alexander Clouter]

eap_peer does not expect data present when beginning phase2 in
EAP-{TTLS,PEAP} which occurs when using under TLSv1.3

Discussed in https://www.spinics.net/lists/hostap/msg05376.html

Signed-off-by: Alexander Clouter <alex at digriz.org.uk>

---
 src/crypto/tls_openssl.c | 17 +++++++++++++----
 src/eap_peer/eap_peap.c  |  4 ++++
 src/eap_peer/eap_ttls.c  |  5 +++++
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/crypto/tls_openssl.c b/src/crypto/tls_openssl.c
index 0f9664ec5..5f854a3c2 100644
--- a/src/crypto/tls_openssl.c
+++ b/src/crypto/tls_openssl.c
@@ -1045,6 +1045,8 @@ void * tls_init(const struct tls_config *conf)
 	SSL_CTX_set_options(ssl, SSL_OP_NO_SSLv2);
 	SSL_CTX_set_options(ssl, SSL_OP_NO_SSLv3);
 
+	SSL_CTX_set_mode(ssl, SSL_MODE_AUTO_RETRY);
+
 #ifdef SSL_MODE_NO_AUTO_CHAIN
 	/* Number of deployed use cases assume the default OpenSSL behavior of
 	 * auto chaining the local certificate is in use. BoringSSL removed this
@@ -4530,10 +4532,17 @@ struct wpabuf * tls_connection_decrypt(void *tls_ctx,
 		return NULL;
 	res = SSL_read(conn->ssl, wpabuf_mhead(buf), wpabuf_size(buf));
 	if (res < 0) {
-		tls_show_errors(MSG_INFO, __func__,
-				"Decryption failed - SSL_read");
-		wpabuf_free(buf);
-		return NULL;
+		int err = SSL_get_error(conn->ssl, res);
+		if (err == SSL_ERROR_WANT_READ) {
+			wpa_printf(MSG_DEBUG, "SSL: SSL_connect - want "
+				   "more data");
+			res = 0;
+		} else {
+			tls_show_errors(MSG_INFO, __func__,
+					"Decryption failed - SSL_read");
+			wpabuf_free(buf);
+			return NULL;
+		}
 	}
 	wpabuf_put(buf, res);
 
diff --git a/src/eap_peer/eap_peap.c b/src/eap_peer/eap_peap.c
index 7c3704369..a13428d37 100644
--- a/src/eap_peer/eap_peap.c
+++ b/src/eap_peer/eap_peap.c
@@ -803,6 +803,10 @@ static int eap_peap_decrypt(struct eap_sm *sm, struct eap_peap_data *data,
 	res = eap_peer_tls_decrypt(sm, &data->ssl, in_data, &in_decrypted);
 	if (res)
 		return res;
+	if (wpabuf_len(in_decrypted) == 0) {
+		wpabuf_free(in_decrypted);
+		return 1;
+	}
 
 continue_req:
 	wpa_hexdump_buf(MSG_DEBUG, "EAP-PEAP: Decrypted Phase 2 EAP",
diff --git a/src/eap_peer/eap_ttls.c b/src/eap_peer/eap_ttls.c
index 642d179c6..3bf1e97e6 100644
--- a/src/eap_peer/eap_ttls.c
+++ b/src/eap_peer/eap_ttls.c
@@ -1441,6 +1441,7 @@ static int eap_ttls_decrypt(struct eap_sm *sm, struct eap_ttls_data *data,
 
 	if ((in_data == NULL || wpabuf_len(in_data) == 0) &&
 	    data->phase2_start) {
+start:
 		return eap_ttls_phase2_start(sm, data, ret, identifier,
 					     out_data);
 	}
@@ -1455,6 +1456,10 @@ static int eap_ttls_decrypt(struct eap_sm *sm, struct eap_ttls_data *data,
 	retval = eap_peer_tls_decrypt(sm, &data->ssl, in_data, &in_decrypted);
 	if (retval)
 		goto done;
+	if (wpabuf_len(in_decrypted) == 0) {
+		wpabuf_free(in_decrypted);
+		goto start;
+	}
 
 continue_req:
 	data->phase2_start = 0;
-- 
2.20.1