strongswan/strongswan-5.2.2-5.3.0_unknown_payload.patch

From 7733b99198111ef1f30a964e15e93cb1e6d27a85 Mon Sep 17 00:00:00 2001
From: Tobias Brunner <tobias@strongswan.org>
Date: Fri, 15 May 2015 11:15:57 +0200
Subject: [PATCH] unknown-payload: Use a new private payload type and make
 original type available

This fixes a DoS and potential remote code execution vulnerability that was
caused because the original payload type that was returned previously was
used to cast such payload objects to payloads of the indicated type (e.g.
when logging notify payloads with a payload type for the wrong IKE version).

Fixes CVE-2015-3991.
---
 src/libcharon/encoding/message.c                  |  2 +-
 src/libcharon/encoding/payloads/payload.c         |  2 ++
 src/libcharon/encoding/payloads/payload.h         |  7 ++++++-
 src/libcharon/encoding/payloads/unknown_payload.c |  8 ++++++++
 src/libcharon/encoding/payloads/unknown_payload.h |  8 ++++++++
 src/libcharon/sa/ikev2/task_manager_v2.c          | 18 ++++++++++--------
 6 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/src/libcharon/encoding/message.c b/src/libcharon/encoding/message.c
index 1ee2cf81b035..478f531eae28 100644
--- a/src/libcharon/encoding/message.c
+++ b/src/libcharon/encoding/message.c
@@ -2513,7 +2513,7 @@ static status_t decrypt_payloads(private_message_t *this, keymat_t *keymat)
 			was_encrypted = "encrypted fragment payload";
 		}
 
-		if (payload_is_known(type, this->major_version) && !was_encrypted &&
+		if (type != PL_UNKNOWN && !was_encrypted &&
 			!is_connectivity_check(this, payload) &&
 			this->exchange_type != AGGRESSIVE)
 		{
diff --git a/src/libcharon/encoding/payloads/payload.c b/src/libcharon/encoding/payloads/payload.c
index a1cd2f945588..f7c2754e05c3 100644
--- a/src/libcharon/encoding/payloads/payload.c
+++ b/src/libcharon/encoding/payloads/payload.c
@@ -97,6 +97,7 @@ ENUM_NEXT(payload_type_names, PLV1_NAT_D_DRAFT_00_03, PLV1_FRAGMENT, PLV2_FRAGME
 #endif /* ME */
 ENUM_NEXT(payload_type_names, PL_HEADER, PLV1_ENCRYPTED, PLV1_FRAGMENT,
 	"HEADER",
+	"UNKNOWN",
 	"PROPOSAL_SUBSTRUCTURE",
 	"PROPOSAL_SUBSTRUCTURE_V1",
 	"TRANSFORM_SUBSTRUCTURE",
@@ -167,6 +168,7 @@ ENUM_NEXT(payload_type_short_names, PLV1_NAT_D_DRAFT_00_03, PLV1_FRAGMENT, PLV2_
 #endif /* ME */
 ENUM_NEXT(payload_type_short_names, PL_HEADER, PLV1_ENCRYPTED, PLV1_FRAGMENT,
 	"HDR",
+	"UNKN",
 	"PROP",
 	"PROP",
 	"TRANS",
diff --git a/src/libcharon/encoding/payloads/payload.h b/src/libcharon/encoding/payloads/payload.h
index 920779bd1032..72003894f307 100644
--- a/src/libcharon/encoding/payloads/payload.h
+++ b/src/libcharon/encoding/payloads/payload.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007 Tobias Brunner
+ * Copyright (C) 2007-2015 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -264,6 +264,11 @@ enum payload_type_t {
 	PL_HEADER = 256,
 
 	/**
+	 * Used to handle unknown or invalid payload types.
+	 */
+	PL_UNKNOWN,
+
+	/**
 	 * PLV2_PROPOSAL_SUBSTRUCTURE, IKEv2 proposals in a SA payload.
 	 */
 	PLV2_PROPOSAL_SUBSTRUCTURE,
diff --git a/src/libcharon/encoding/payloads/unknown_payload.c b/src/libcharon/encoding/payloads/unknown_payload.c
index 45b91fd0b32f..c69254fc008c 100644
--- a/src/libcharon/encoding/payloads/unknown_payload.c
+++ b/src/libcharon/encoding/payloads/unknown_payload.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2015 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -121,6 +122,12 @@ METHOD(payload_t, get_header_length, int,
 METHOD(payload_t, get_payload_type, payload_type_t,
 	private_unknown_payload_t *this)
 {
+	return PL_UNKNOWN;
+}
+
+METHOD(unknown_payload_t, get_type, payload_type_t,
+	private_unknown_payload_t *this)
+{
 	return this->type;
 }
 
@@ -181,6 +188,7 @@ unknown_payload_t *unknown_payload_create(payload_type_t type)
 				.destroy = _destroy,
 			},
 			.is_critical = _is_critical,
+			.get_type = _get_type,
 			.get_data = _get_data,
 			.destroy = _destroy,
 		},
diff --git a/src/libcharon/encoding/payloads/unknown_payload.h b/src/libcharon/encoding/payloads/unknown_payload.h
index 326b550cd872..09341bcc79b5 100644
--- a/src/libcharon/encoding/payloads/unknown_payload.h
+++ b/src/libcharon/encoding/payloads/unknown_payload.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2015 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -42,6 +43,13 @@ struct unknown_payload_t {
 	payload_t payload_interface;
 
 	/**
+	 * Get the original payload type as sent by the peer.
+	 *
+	 * @return				type of the original payload
+	 */
+	payload_type_t (*get_type) (unknown_payload_t *this);
+
+	/**
 	 * Get the raw data of this payload, without
 	 * the generic payload header.
 	 *
diff --git a/src/libcharon/sa/ikev2/task_manager_v2.c b/src/libcharon/sa/ikev2/task_manager_v2.c
index 298167703cbf..4676867dfec2 100644
--- a/src/libcharon/sa/ikev2/task_manager_v2.c
+++ b/src/libcharon/sa/ikev2/task_manager_v2.c
@@ -1184,15 +1184,17 @@ static status_t parse_message(private_task_manager_t *this, message_t *msg)
 		enumerator = msg->create_payload_enumerator(msg);
 		while (enumerator->enumerate(enumerator, &payload))
 		{
-			unknown = (unknown_payload_t*)payload;
-			type = payload->get_type(payload);
-			if (!payload_is_known(type, msg->get_major_version(msg)) &&
-				unknown->is_critical(unknown))
+			if (payload->get_type(payload) == PL_UNKNOWN)
 			{
-				DBG1(DBG_ENC, "payload type %N is not supported, "
-					 "but its critical!", payload_type_names, type);
-				status = NOT_SUPPORTED;
-				break;
+				unknown = (unknown_payload_t*)payload;
+				if (unknown->is_critical(unknown))
+				{
+					type = unknown->get_type(unknown);
+					DBG1(DBG_ENC, "payload type %N is not supported, "
+						 "but its critical!", payload_type_names, type);
+					status = NOT_SUPPORTED;
+					break;
+				}
 			}
 		}
 		enumerator->destroy(enumerator);
-- 
1.9.1