Send EAP-Nak with supported types if requested type is unsupported

src/libcharon/encoding/payloads/eap_payload.c

@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2005-2010 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -20,6 +21,7 @@
 
 #include <daemon.h>
 #include <eap/eap.h>
+#include <bio/bio_writer.h>
 
 typedef struct private_eap_payload_t private_eap_payload_t;
 
@@ -313,15 +315,75 @@ eap_payload_t *eap_payload_create_code(eap_code_t code, u_int8_t identifier)
 	return eap_payload_create_data(data);
 }
 
+/**
+ * Write the given type either expanded or not
+ */
+static void write_type(bio_writer_t *writer, eap_type_t type, u_int32_t vendor,
+					   bool expanded)
+{
+	if (expanded)
+	{
+		writer->write_uint8(writer, EAP_EXPANDED);
+		writer->write_uint24(writer, vendor);
+		writer->write_uint32(writer, type);
+	}
+	else
+	{
+		writer->write_uint8(writer, type);
+	}
+}
+
 /*
  * Described in header
  */
-eap_payload_t *eap_payload_create_nak(u_int8_t identifier)
+eap_payload_t *eap_payload_create_nak(u_int8_t identifier, bool expanded)
 {
-	chunk_t data;
+	enumerator_t *enumerator;
+	eap_type_t reg_type;
+	u_int32_t reg_vendor;
+	bio_writer_t *writer;
+	chunk_t length, data;
+	bool added_any = FALSE, found_vendor = FALSE;
+	eap_payload_t *payload;
 
-	data = chunk_from_chars(EAP_RESPONSE, identifier, 0, 0, EAP_NAK);
-	htoun16(data.ptr + 2, data.len);
-	return eap_payload_create_data(data);
+	writer = bio_writer_create(12);
+	writer->write_uint8(writer, EAP_RESPONSE);
+	writer->write_uint8(writer, identifier);
+	length = writer->skip(writer, 2);
+
+	write_type(writer, EAP_NAK, 0, expanded);
+
+	enumerator = charon->eap->create_enumerator(charon->eap, EAP_PEER);
+	while (enumerator->enumerate(enumerator, &reg_type, &reg_vendor))
+	{
+		if (!reg_vendor || expanded)
+		{
+			write_type(writer, reg_type, reg_vendor, expanded);
+			added_any = TRUE;
+		}
+		else if (reg_vendor)
+		{	/* found vendor specifc method, but this is not an expanded Nak */
+			found_vendor = TRUE;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	if (found_vendor)
+	{	/* request an expanded authentication type */
+		write_type(writer, EAP_EXPANDED, 0, expanded);
+		added_any = TRUE;
+	}
+	if (!added_any)
+	{	/* no methods added */
+		write_type(writer, 0, 0, expanded);
+	}
+
+	/* set length */
+	data = writer->get_buf(writer);
+	htoun16(length.ptr, data.len);
+
+	payload = eap_payload_create_data(data);
+	writer->destroy(writer);
+	return payload;
 }
 

src/libcharon/encoding/payloads/eap_payload.h

@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -126,8 +127,10 @@ eap_payload_t *eap_payload_create_code(eap_code_t code, u_int8_t identifier);
  * Creates an eap_payload_t EAP_RESPONSE containing an EAP_NAK.
  *
  * @param identifier	EAP identifier to use in payload
+ * @param expanded		TRUE to send an expanded Nak (as response to an expanded
+ * 						request, i.e. one with vendor specific type)
  * @return 				eap_payload_t object
  */
-eap_payload_t *eap_payload_create_nak(u_int8_t identifier);
+eap_payload_t *eap_payload_create_nak(u_int8_t identifier, bool expanded);
 
 #endif /** EAP_PAYLOAD_H_ @}*/

src/libcharon/plugins/eap_peap/eap_peap_peer.c

@@ -85,7 +85,7 @@ METHOD(tls_application_t, process, status_t,
 		default:
 			return FAILED;
 	}
- 		
+
 	in = eap_payload_create_data(data);
 	DBG3(DBG_IKE, "%B", &data);
 	chunk_free(&data);
@@ -151,7 +151,8 @@ METHOD(tls_application_t, process, status_t,
 		if (!this->ph2_method)
 		{
 			DBG1(DBG_IKE, "EAP method not supported");
-			this->out = eap_payload_create_nak(in->get_identifier(in));
+			this->out = eap_payload_create_nak(in->get_identifier(in),
+											   received_vendor != 0);
 			in->destroy(in);
 			return NEED_MORE;
 		}

src/libcharon/plugins/eap_ttls/eap_ttls_peer.c

@@ -138,7 +138,7 @@ METHOD(tls_application_t, process, status_t,
 		chunk_free(&avp_data);
 	}
 	while (eap_pos < eap_data.len);
- 		
+
 	in = eap_payload_create_data(eap_data);
 	chunk_free(&eap_data);
 	payload = (payload_t*)in;
@@ -192,7 +192,8 @@ METHOD(tls_application_t, process, status_t,
 		if (!this->method)
 		{
 			DBG1(DBG_IKE, "EAP method not supported");
-			this->out = eap_payload_create_nak(in->get_identifier(in));
+			this->out = eap_payload_create_nak(in->get_identifier(in),
+											   received_vendor != 0);
 			in->destroy(in);
 			return NEED_MORE;
 		}

src/libcharon/sa/ikev2/authenticators/eap_authenticator.c

@@ -357,9 +357,11 @@ static eap_payload_t* client_process_eap(private_eap_authenticator_t *this,
 			this->method->destroy(this->method);
 			this->method = NULL;
 		}
+		/* FIXME: sending a Nak is not correct here as EAP_IDENTITY (1) is no
+		 * EAP method (types 3-253, 255) */
 		DBG1(DBG_IKE, "%N not supported, sending EAP_NAK",
 			 eap_type_names, type);
-		return eap_payload_create_nak(in->get_identifier(in));
+		return eap_payload_create_nak(in->get_identifier(in), FALSE);
 	}
 	if (this->method == NULL)
 	{
@@ -377,7 +379,7 @@ static eap_payload_t* client_process_eap(private_eap_authenticator_t *this,
 		if (!this->method)
 		{
 			DBG1(DBG_IKE, "EAP method not supported, sending EAP_NAK");
-			return eap_payload_create_nak(in->get_identifier(in));
+			return eap_payload_create_nak(in->get_identifier(in), vendor != 0);
 		}
 	}