Pass NULL peer identity to omit TLS peer authentication, added eap-ttls.request_peer_auth option

src/libcharon/plugins/eap_ttls/eap_ttls.c

@@ -405,6 +405,11 @@ static eap_ttls_t *eap_ttls_create(identification_t *server,
 		.is_server = is_server,
 	);
 
+	if (is_server && !lib->settings->get_bool(lib->settings,
+							"charon.plugins.eap-ttls.request_peer_auth", FALSE))
+	{	/* don't request peer authentication */
+		peer = NULL;
+	}
 	this->tls = tls_create(is_server, server, peer,
 						   TLS_PURPOSE_EAP_TTLS, application);
 	if (!this->tls)

src/libcharon/plugins/eap_ttls/eap_ttls_avp.c

@@ -110,7 +110,7 @@ METHOD(eap_ttls_avp_t, process, status_t,
 		}
 
 		/* parse AVP header */
-		header = tls_reader_create(this->input);	
+		header = tls_reader_create(this->input);
 		success = header->read_uint32(header, &avp_code) &&
 				  header->read_uint8(header, &avp_flags) &&
 				  header->read_uint24(header, &avp_len);
@@ -154,7 +154,7 @@ METHOD(eap_ttls_avp_t, process, status_t,
 	this->inpos = 0;
 	this->process_header = TRUE;
 
-	return SUCCESS;	
+	return SUCCESS;
 }
 
 METHOD(eap_ttls_avp_t, destroy, void,

src/libtls/tls.c

@@ -268,7 +268,7 @@ METHOD(tls_t, destroy, void,
 	this->fragmentation->destroy(this->fragmentation);
 	this->crypto->destroy(this->crypto);
 	this->handshake->destroy(this->handshake);
-	this->peer->destroy(this->peer);
+	DESTROY_IF(this->peer);
 	this->server->destroy(this->server);
 	DESTROY_IF(this->application);
 	this->alert->destroy(this->alert);
@@ -309,7 +309,7 @@ tls_t *tls_create(bool is_server, identification_t *server,
 		.is_server = is_server,
 		.version = TLS_1_2,
 		.server = server->clone(server),
-		.peer = peer->clone(peer),
+		.peer = peer ? peer->clone(peer) : NULL,
 		.application = application,
 		.purpose = purpose,
 	);

src/libtls/tls.h

@@ -96,12 +96,8 @@ enum tls_purpose_t {
 	TLS_PURPOSE_EAP_TLS,
 	/** outer authentication and protection in EAP-TTLS */
 	TLS_PURPOSE_EAP_TTLS,
-	/** EAP-TTLS with client authentication */
+	/** non-EAP TLS */
-	TLS_PURPOSE_EAP_TTLS_CLIENT_AUTH,
-	/** non-EAP TLS without client authentication */
 	TLS_PURPOSE_GENERIC,
-	/** non-EAP TLS with client authentication */
-	TLS_PURPOSE_GENERIC_CLIENT_AUTH,
 };
 
 /**
@@ -185,7 +181,7 @@ struct tls_t {
  *
  * @param is_server			TRUE to act as server, FALSE for client
  * @param server			server identity
- * @param peer				peer identity
+ * @param peer				peer identity, NULL for no client authentication
  * @param purpse			purpose this TLS stack instance is used for
  * @param application		higher layer application or NULL if none
  * @return					TLS stack

src/libtls/tls_crypto.c

@@ -929,13 +929,11 @@ tls_crypto_t *tls_crypto_create(tls_t *tls)
 			build_cipher_suite_list(this, FALSE);
 			break;
 		case TLS_PURPOSE_EAP_TTLS:
-		case TLS_PURPOSE_EAP_TTLS_CLIENT_AUTH:
 			/* MSK PRF ASCII constant label according to EAP-TTLS RFC 5281 */
 			this->msk_label = "ttls keying material";
 			build_cipher_suite_list(this, TRUE);
 			break;
 		case TLS_PURPOSE_GENERIC:
-		case TLS_PURPOSE_GENERIC_CLIENT_AUTH:
 			build_cipher_suite_list(this, TRUE);
 			break;
 	}

src/libtls/tls_peer.c

@@ -63,7 +63,7 @@ struct private_tls_peer_t {
 	tls_alert_t *alert;
 
 	/**
-	 * Peer identity
+	 * Peer identity, NULL for no client authentication
 	 */
 	identification_t *peer;
 
@@ -87,11 +87,6 @@ struct private_tls_peer_t {
 	 */
 	char server_random[32];
 
-	/**
-	 * Does the server request a peer authentication?
-	 */
-	bool peer_auth_requested;
-
 	/**
 	 * Auth helper for peer authentication
 	 */
@@ -219,7 +214,7 @@ static status_t process_certificate(private_tls_peer_t *this,
 }
 
 /**
- * Process a Certificate message
+ * Process a Certificate Request message
  */
 static status_t process_certreq(private_tls_peer_t *this, tls_reader_t *reader)
 {
@@ -228,6 +223,13 @@ static status_t process_certreq(private_tls_peer_t *this, tls_reader_t *reader)
 	identification_t *id;
 	certificate_t *cert;
 
+	if (!this->peer)
+	{
+		DBG1(DBG_TLS, "server requested a certificate, but client "
+			 "authentication disabled");
+		this->alert->add(this->alert, TLS_FATAL, TLS_HANDSHAKE_FAILURE);
+		return NEED_MORE;
+	}
 	this->crypto->append_handshake(this->crypto,
 								TLS_CERTIFICATE_REQUEST, reader->peek(reader));
 
@@ -351,9 +353,9 @@ METHOD(tls_handshake_t, process, status_t,
 		case STATE_CERT_RECEIVED:
 			if (type == TLS_CERTIFICATE_REQUEST)
 			{
-				this->peer_auth_requested = TRUE;
 				return process_certreq(this, reader);
 			}
+			this->peer = NULL;
 			/* fall through since TLS_CERTIFICATE_REQUEST is optional */
 		case STATE_CERTREQ_RECEIVED:
 			if (type == TLS_SERVER_HELLO_DONE)
@@ -441,13 +443,15 @@ static status_t send_certificate(private_tls_peer_t *this,
 	tls_writer_t *certs;
 	chunk_t data;
 
-	this->private = lib->credmgr->get_private(lib->credmgr,
+	if (this->peer)
+	{
+		this->private = lib->credmgr->get_private(lib->credmgr,
 										KEY_ANY, this->peer, this->peer_auth);
+	}
 	if (!this->private)
 	{
 		DBG1(DBG_TLS, "no TLS peer certificate found for '%Y'", this->peer);
-		this->alert->add(this->alert, TLS_FATAL, TLS_INTERNAL_ERROR);
+		return FAILED;
-		return NEED_MORE;
 	}
 
 	/* generate certificate payload */
@@ -601,7 +605,7 @@ METHOD(tls_handshake_t, build, status_t,
 		case STATE_INIT:
 			return send_client_hello(this, type, writer);
 		case STATE_HELLO_DONE:
-			if (this->peer_auth_requested)
+			if (this->peer)
 			{
 				return send_certificate(this, type, writer);
 			}
@@ -609,7 +613,7 @@ METHOD(tls_handshake_t, build, status_t,
 		case STATE_CERT_SENT:
 			return send_key_exchange(this, type, writer);
 		case STATE_KEY_EXCHANGE_SENT:
-			if (this->peer_auth_requested)
+			if (this->peer)
 			{
 				return send_certificate_verify(this, type, writer);
 			}
@@ -627,8 +631,8 @@ METHOD(tls_handshake_t, build, status_t,
 METHOD(tls_handshake_t, cipherspec_changed, bool,
 	private_tls_peer_t *this)
 {
-	if ((this->peer_auth_requested && this->state == STATE_VERIFY_SENT) ||
+	if ((this->peer && this->state == STATE_VERIFY_SENT) ||
-	   (!this->peer_auth_requested && this->state == STATE_KEY_EXCHANGE_SENT))
+	   (!this->peer && this->state == STATE_KEY_EXCHANGE_SENT))
 	{
 		this->crypto->change_cipher(this->crypto, FALSE);
 		this->state = STATE_CIPHERSPEC_CHANGED_OUT;

src/libtls/tls_server.c

@@ -70,7 +70,7 @@ struct private_tls_server_t {
 	identification_t *server;
 
 	/**
-	 * Peer identity
+	 * Peer identity, NULL for no client authentication
 	 */
 	identification_t *peer;
 
@@ -89,11 +89,6 @@ struct private_tls_server_t {
 	 */
 	char server_random[32];
 
-	/**
-	 * Does the server request a peer authentication?
-	 */
-	bool request_peer_auth;
-
 	/**
 	 * Auth helper for peer authentication
 	 */
@@ -359,7 +354,7 @@ METHOD(tls_handshake_t, process, status_t,
 			{
 				return process_certificate(this, reader);
 			}
-			if (this->request_peer_auth)
+			if (this->peer)
 			{
 				expected = TLS_CERTIFICATE;
 				break;
@@ -377,7 +372,7 @@ METHOD(tls_handshake_t, process, status_t,
 			{
 				return process_cert_verify(this, reader);
 			}
-			if (this->request_peer_auth)
+			if (this->peer)
 			{
 				expected = TLS_CERTIFICATE_VERIFY;
 				break;
@@ -591,7 +586,7 @@ METHOD(tls_handshake_t, build, status_t,
 		case STATE_HELLO_SENT:
 			return send_certificate(this, type, writer);
 		case STATE_CERT_SENT:
-			if (this->request_peer_auth)
+			if (this->peer)
 			{
 				return send_certificate_request(this, type, writer);
 			}
@@ -622,8 +617,8 @@ METHOD(tls_handshake_t, cipherspec_changed, bool,
 METHOD(tls_handshake_t, change_cipherspec, bool,
 	private_tls_server_t *this)
 {
-	if ((this->request_peer_auth && this->state == STATE_CERT_VERIFY_RECEIVED) ||
+	if ((this->peer && this->state == STATE_CERT_VERIFY_RECEIVED) ||
-	   (!this->request_peer_auth && this->state == STATE_KEY_EXCHANGE_RECEIVED))
+	   (!this->peer && this->state == STATE_KEY_EXCHANGE_RECEIVED))
 	{
 		this->crypto->change_cipher(this->crypto, TRUE);
 		this->state = STATE_CIPHERSPEC_CHANGED_IN;
@@ -677,16 +672,5 @@ tls_server_t *tls_server_create(tls_t *tls,
 		.server_auth = auth_cfg_create(),
 	);
 
-	switch (tls->get_purpose(tls))
-	{
-		case TLS_PURPOSE_EAP_TLS:
-		case TLS_PURPOSE_EAP_TTLS_CLIENT_AUTH:
-		case TLS_PURPOSE_GENERIC_CLIENT_AUTH:
-			this->request_peer_auth = TRUE;
-			break;
-		case TLS_PURPOSE_EAP_TTLS:
-		case TLS_PURPOSE_GENERIC:
-			break;
-	}
 	return &this->public;
 }