src/libcharon/encoding/payloads/sa_payload.c - manifest_repos/strongswan - Git at Google

 /*
  * Copyright (C) 2012-2020 Tobias Brunner
  * Copyright (C) 2005-2010 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * HSR Hochschule fuer Technik Rapperswil
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
  * Free Software Foundation; either version 2 of the License, or (at your
  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * for more details.
  */

 #include <stddef.h>

 #include "sa_payload.h"

 #include <encoding/payloads/encodings.h>
 #include <collections/linked_list.h>
 #include <daemon.h>

 /* IKEv1 situation */
 #define SIT_IDENTITY_ONLY 1

 typedef struct private_sa_payload_t private_sa_payload_t;

 /**
  * Private data of an sa_payload_t object.
  */
 struct private_sa_payload_t {

 	/**
 	 * Public sa_payload_t interface.
 	 */
 	sa_payload_t public;

 	/**
 	 * Next payload type.
 	 */
 	uint8_t  next_payload;

 	/**
 	 * Critical flag.
 	 */
 	bool critical;

 	/**
 	 * Reserved bits
 	 */
 	bool reserved[8];

 	/**
 	 * Length of this payload.
 	 */
 	uint16_t payload_length;

 	/**
 	 * Proposals in this payload are stored in a linked_list_t.
 	 */
 	linked_list_t *proposals;

 	/**
 	 * Type of this payload, V1 or V2
 	 */
 	payload_type_t type;

 	/**
 	 * IKEv1 DOI
 	 */
 	uint32_t doi;

 	/**
 	 * IKEv1 situation
 	 */
 	uint32_t situation;
 };

 /**
  * Encoding rules for IKEv1 SA payload
  */
 static encoding_rule_t encodings_v1[] = {
 	/* 1 Byte next payload type, stored in the field next_payload */
 	{ U_INT_8,			offsetof(private_sa_payload_t, next_payload)	},
 	/* 8 reserved bits */
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[0])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[1])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[2])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[3])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[4])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[5])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[6])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[7])			},
 	/* Length of the whole SA payload*/
 	{ PAYLOAD_LENGTH,	offsetof(private_sa_payload_t, payload_length)	},
 	/* DOI*/
 	{ U_INT_32,			offsetof(private_sa_payload_t, doi)				},
 	/* Situation*/
 	{ U_INT_32,			offsetof(private_sa_payload_t, situation)		},
 	/* Proposals are stored in a proposal substructure list */
 	{ PAYLOAD_LIST + PLV1_PROPOSAL_SUBSTRUCTURE,
 						offsetof(private_sa_payload_t, proposals)		},
 };

 /*
                            1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ! Next Payload  !    RESERVED   !         Payload Length        !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       !                           DOI                                 !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       !                           Situation                           !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       !                                                               !
       ~                          <Proposals>                          ~
       !                                                               !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */

 /**
  * Encoding rules for IKEv2 SA payload
  */
 static encoding_rule_t encodings_v2[] = {
 	/* 1 Byte next payload type, stored in the field next_payload */
 	{ U_INT_8,			offsetof(private_sa_payload_t, next_payload)		},
 	/* the critical bit */
 	{ FLAG,				offsetof(private_sa_payload_t, critical)			},
 	/* 7 Bit reserved bits */
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[0])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[1])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[2])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[3])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[4])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[5])			},
 	{ RESERVED_BIT,		offsetof(private_sa_payload_t, reserved[6])			},
 	/* Length of the whole SA payload*/
 	{ PAYLOAD_LENGTH,	offsetof(private_sa_payload_t, payload_length)		},
 	/* Proposals are stored in a proposal substructure list */
 	{ PAYLOAD_LIST + PLV2_PROPOSAL_SUBSTRUCTURE,
 						offsetof(private_sa_payload_t, proposals)			},
 };

 /*
                            1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ! Next Payload  !C!  RESERVED   !         Payload Length        !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       !                                                               !
       ~                          <Proposals>                          ~
       !                                                               !
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */

 METHOD(payload_t, verify, status_t,
 	private_sa_payload_t *this)
 {
 	int expected_number = 0, current_number;
 	status_t status = SUCCESS;
 	enumerator_t *enumerator;
 	proposal_substructure_t *substruct;

 	if (this->type == PLV2_SECURITY_ASSOCIATION)
 	{
 		expected_number = 1;
 	}

 	/* check proposal numbering */
 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, (void**)&substruct))
 	{
 		current_number = substruct->get_proposal_number(substruct);
 		if (current_number < expected_number)
 		{
 			DBG1(DBG_ENC, "proposal number smaller than previous");
 			status = FAILED;
 			break;
 		}

 		status = substruct->payload_interface.verify(&substruct->payload_interface);
 		if (status != SUCCESS)
 		{
 			DBG1(DBG_ENC, "PROPOSAL_SUBSTRUCTURE verification failed");
 			break;
 		}
 		expected_number = current_number;
 	}
 	enumerator->destroy(enumerator);
 	return status;
 }

 METHOD(payload_t, get_encoding_rules, int,
 	private_sa_payload_t *this, encoding_rule_t **rules)
 {
 	if (this->type == PLV1_SECURITY_ASSOCIATION)
 	{
 		*rules = encodings_v1;
 		return countof(encodings_v1);
 	}
 	*rules = encodings_v2;
 	return countof(encodings_v2);
 }

 METHOD(payload_t, get_header_length, int,
 	private_sa_payload_t *this)
 {
 	if (this->type == PLV1_SECURITY_ASSOCIATION)
 	{
 		return 12;
 	}
 	return 4;
 }

 METHOD(payload_t, get_type, payload_type_t,
 	private_sa_payload_t *this)
 {
 	return this->type;
 }

 METHOD(payload_t, get_next_type, payload_type_t,
 	private_sa_payload_t *this)
 {
 	return this->next_payload;
 }

 METHOD(payload_t, set_next_type, void,
 	private_sa_payload_t *this,payload_type_t type)
 {
 	this->next_payload = type;
 }

 /**
  * recompute length of the payload.
  */
 static void compute_length(private_sa_payload_t *this)
 {
 	enumerator_t *enumerator;
 	payload_t *current;

 	this->payload_length = get_header_length(this);

 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, (void **)&current))
 	{
 		this->payload_length += current->get_length(current);
 	}
 	enumerator->destroy(enumerator);
 }

 METHOD(payload_t, get_length, size_t,
 	private_sa_payload_t *this)
 {
 	return this->payload_length;
 }

 /**
  * Create a transform substructure from a proposal, add to payload
  */
 static void add_proposal_v2(private_sa_payload_t *this, proposal_t *proposal)
 {
 	proposal_substructure_t *substruct, *last;
 	u_int count;

 	substruct = proposal_substructure_create_from_proposal_v2(proposal);
 	count = this->proposals->get_count(this->proposals);
 	if (count > 0)
 	{
 		this->proposals->get_last(this->proposals, (void**)&last);
 		/* last transform is now not anymore last one */
 		last->set_is_last_proposal(last, FALSE);
 	}
 	substruct->set_is_last_proposal(substruct, TRUE);
 	if (proposal->get_number(proposal))
 	{	/* use the selected proposals number, if any */
 		substruct->set_proposal_number(substruct, proposal->get_number(proposal));
 	}
 	else
 	{
 		substruct->set_proposal_number(substruct, count + 1);
 	}
 	this->proposals->insert_last(this->proposals, substruct);
 	compute_length(this);
 }

 METHOD(sa_payload_t, get_proposals, linked_list_t*,
 	private_sa_payload_t *this)
 {
 	int struct_number = 0;
 	int ignore_struct_number = 0;
 	enumerator_t *enumerator;
 	proposal_substructure_t *substruct;
 	linked_list_t *substructs, *list;

 	if (this->type == PLV1_SECURITY_ASSOCIATION)
 	{	/* IKEv1 proposals may start with 0 or 1 (or any other number really) */
 		struct_number = ignore_struct_number = -1;
 	}

 	/* we do not support proposals split up to two proposal substructures, as
 	 * AH+ESP bundles are not supported in RFC4301 anymore.
 	 * To handle such structures safely, we just skip proposals with multiple
 	 * protocols.
 	 */
 	substructs = linked_list_create();
 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, &substruct))
 	{
 		int current_number = substruct->get_proposal_number(substruct);

 		/* check if a proposal has a single protocol */
 		if (current_number == struct_number)
 		{
 			if (ignore_struct_number < struct_number)
 			{	/* remove an already added substruct, if first of series */
 				substructs->remove_last(substructs, (void**)&substruct);
 				ignore_struct_number = struct_number;
 			}
 			continue;
 		}
 		/* for IKEv1 the numbers don't have to be consecutive, for IKEv2 they do
 		 * but since we don't really care for the actual number we accept them
 		 * anyway. we already verified that they increase monotonically. */
 		struct_number = current_number;
 		substructs->insert_last(substructs, substruct);
 	}
 	enumerator->destroy(enumerator);

 	/* generate proposals from substructs */
 	list = linked_list_create();
 	enumerator = substructs->create_enumerator(substructs);
 	while (enumerator->enumerate(enumerator, &substruct))
 	{
 		substruct->get_proposals(substruct, list);
 	}
 	enumerator->destroy(enumerator);
 	substructs->destroy(substructs);
 	return list;
 }

 METHOD(sa_payload_t, get_ipcomp_proposals, linked_list_t*,
 	private_sa_payload_t *this, uint16_t *cpi)
 {
 	int current_proposal = -1, unsupported_proposal = -1;
 	enumerator_t *enumerator;
 	proposal_substructure_t *substruct, *espah = NULL, *ipcomp = NULL;
 	linked_list_t *list;

 	/* we currently only support the combination ESP|AH+IPComp, find the first */
 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, &substruct))
 	{
 		uint8_t proposal_number = substruct->get_proposal_number(substruct);
 		uint8_t protocol_id = substruct->get_protocol_id(substruct);

 		if (proposal_number == unsupported_proposal)
 		{
 			continue;
 		}
 		if (protocol_id != PROTO_ESP && protocol_id != PROTO_AH &&
 			protocol_id != PROTO_IPCOMP)
 		{	/* unsupported combination */
 			espah = ipcomp = NULL;
 			unsupported_proposal = current_proposal;
 			continue;
 		}
 		if (proposal_number != current_proposal)
 		{	/* start of a new proposal */
 			if (espah && ipcomp && ipcomp->get_cpi(ipcomp, NULL))
 			{	/* previous proposal is valid */
 				break;
 			}
 			espah = ipcomp = NULL;
 			current_proposal = proposal_number;
 		}
 		switch (protocol_id)
 		{
 			case PROTO_ESP:
 			case PROTO_AH:
 				espah = substruct;
 				break;
 			case PROTO_IPCOMP:
 				ipcomp = substruct;
 				break;
 		}
 	}
 	enumerator->destroy(enumerator);

 	list = linked_list_create();
 	if (espah && ipcomp && ipcomp->get_cpi(ipcomp, cpi))
 	{
 		espah->get_proposals(espah, list);
 	}
 	return list;
 }

 METHOD(sa_payload_t, create_substructure_enumerator, enumerator_t*,
 	private_sa_payload_t *this)
 {
 	return this->proposals->create_enumerator(this->proposals);
 }

 METHOD(sa_payload_t, get_lifetime, uint32_t,
 	private_sa_payload_t *this, proposal_t *proposal)
 {
 	proposal_substructure_t *substruct;
 	enumerator_t *enumerator;
 	uint8_t number = proposal->get_number(proposal);
 	uint32_t lifetime = 0;

 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, &substruct))
 	{
 		if (substruct->get_proposal_number(substruct) == number)
 		{
 			lifetime = substruct->get_lifetime(substruct,
 									proposal->get_transform_number(proposal));
 			break;
 		}
 	}
 	enumerator->destroy(enumerator);

 	return lifetime;
 }

 METHOD(sa_payload_t, get_lifebytes, uint64_t,
 	private_sa_payload_t *this, proposal_t *proposal)
 {
 	proposal_substructure_t *substruct;
 	enumerator_t *enumerator;
 	uint8_t number = proposal->get_number(proposal);
 	uint64_t lifebytes = 0;

 	enumerator = this->proposals->create_enumerator(this->proposals);
 	while (enumerator->enumerate(enumerator, &substruct))
 	{
 		if (substruct->get_proposal_number(substruct) == number)
 		{
 			lifebytes = substruct->get_lifebytes(substruct,
 									proposal->get_transform_number(proposal));
 			break;
 		}
 	}
 	enumerator->destroy(enumerator);

 	return lifebytes;
 }

 METHOD(sa_payload_t, get_auth_method, auth_method_t,
 	private_sa_payload_t *this)
 {
 	proposal_substructure_t *substruct;
 	enumerator_t *enumerator;
 	auth_method_t method = AUTH_NONE;

 	enumerator = this->proposals->create_enumerator(this->proposals);
 	if (enumerator->enumerate(enumerator, &substruct))
 	{
 		method = substruct->get_auth_method(substruct);
 	}
 	enumerator->destroy(enumerator);

 	return method;
 }

 METHOD(sa_payload_t, get_encap_mode, ipsec_mode_t,
 	private_sa_payload_t *this, bool *udp)
 {
 	proposal_substructure_t *substruct;
 	enumerator_t *enumerator;
 	ipsec_mode_t mode = MODE_NONE;

 	enumerator = this->proposals->create_enumerator(this->proposals);
 	if (enumerator->enumerate(enumerator, &substruct))
 	{
 		mode = substruct->get_encap_mode(substruct, udp);
 	}
 	enumerator->destroy(enumerator);

 	return mode;
 }

 METHOD2(payload_t, sa_payload_t, destroy, void,
 	private_sa_payload_t *this)
 {
 	this->proposals->destroy_offset(this->proposals,
 									offsetof(payload_t, destroy));
 	free(this);
 }

 /*
  * Described in header.
  */
 sa_payload_t *sa_payload_create(payload_type_t type)
 {
 	private_sa_payload_t *this;

 	INIT(this,
 		.public = {
 			.payload_interface = {
 				.verify = _verify,
 				.get_encoding_rules = _get_encoding_rules,
 				.get_header_length = _get_header_length,
 				.get_length = _get_length,
 				.get_next_type = _get_next_type,
 				.set_next_type = _set_next_type,
 				.get_type = _get_type,
 				.destroy = _destroy,
 			},
 			.get_proposals = _get_proposals,
 			.get_ipcomp_proposals = _get_ipcomp_proposals,
 			.create_substructure_enumerator = _create_substructure_enumerator,
 			.get_lifetime = _get_lifetime,
 			.get_lifebytes = _get_lifebytes,
 			.get_auth_method = _get_auth_method,
 			.get_encap_mode = _get_encap_mode,
 			.destroy = _destroy,
 		},
 		.next_payload = PL_NONE,
 		.proposals = linked_list_create(),
 		.type = type,
 		/* for IKEv1 only */
 		.doi = IKEV1_DOI_IPSEC,
 		.situation = SIT_IDENTITY_ONLY,
 	);

 	compute_length(this);

 	return &this->public;
 }

 /*
  * Described in header.
  */
 sa_payload_t *sa_payload_create_from_proposals_v2(linked_list_t *proposals)
 {
 	private_sa_payload_t *this;
 	enumerator_t *enumerator;
 	proposal_t *proposal;

 	this = (private_sa_payload_t*)sa_payload_create(PLV2_SECURITY_ASSOCIATION);
 	enumerator = proposals->create_enumerator(proposals);
 	while (enumerator->enumerate(enumerator, &proposal))
 	{
 		add_proposal_v2(this, proposal);
 	}
 	enumerator->destroy(enumerator);

 	return &this->public;
 }

 /*
  * Described in header.
  */
 sa_payload_t *sa_payload_create_from_proposal_v2(proposal_t *proposal)
 {
 	private_sa_payload_t *this;

 	this = (private_sa_payload_t*)sa_payload_create(PLV2_SECURITY_ASSOCIATION);
 	add_proposal_v2(this, proposal);

 	return &this->public;

 }

 /*
  * Described in header.
  */
 sa_payload_t *sa_payload_create_from_proposals_v1(linked_list_t *proposals,
 								uint32_t lifetime, uint64_t lifebytes,
 								auth_method_t auth, ipsec_mode_t mode,
 								encap_t udp, uint16_t cpi)
 {
 	proposal_substructure_t *substruct;
 	private_sa_payload_t *this;

 	this = (private_sa_payload_t*)sa_payload_create(PLV1_SECURITY_ASSOCIATION);

 	if (!proposals || !proposals->get_count(proposals))
 	{
 		return &this->public;
 	}

 	/* IKEv1 encodes multiple proposals in a single substructure
 	 * TODO-IKEv1: Encode ESP+AH proposals in two substructs with same num */
 	substruct = proposal_substructure_create_from_proposals_v1(proposals,
 										lifetime, lifebytes, auth, mode, udp);
 	this->proposals->insert_last(this->proposals, substruct);
 	substruct->set_is_last_proposal(substruct, FALSE);
 	if (cpi)
 	{
 		uint8_t proposal_number = substruct->get_proposal_number(substruct);

 		substruct = proposal_substructure_create_for_ipcomp_v1(lifetime,
 					lifebytes, cpi, mode, udp, proposal_number);
 		this->proposals->insert_last(this->proposals, substruct);
 		substruct->set_is_last_proposal(substruct, FALSE);
 		/* add the proposals again without IPComp */
 		substruct = proposal_substructure_create_from_proposals_v1(proposals,
 										lifetime, lifebytes, auth, mode, udp);
 		substruct->set_proposal_number(substruct, proposal_number + 1);
 		this->proposals->insert_last(this->proposals, substruct);
 	}
 	substruct->set_is_last_proposal(substruct, TRUE);
 	compute_length(this);

 	return &this->public;
 }

 /*
  * Described in header.
  */
 sa_payload_t *sa_payload_create_from_proposal_v1(proposal_t *proposal,
 								uint32_t lifetime, uint64_t lifebytes,
 								auth_method_t auth, ipsec_mode_t mode,
 								encap_t udp, uint16_t cpi)
 {
 	private_sa_payload_t *this;
 	linked_list_t *proposals;

 	proposals = linked_list_create();
 	proposals->insert_last(proposals, proposal);
 	this = (private_sa_payload_t*)sa_payload_create_from_proposals_v1(proposals,
 									lifetime, lifebytes, auth, mode, udp, cpi);
 	proposals->destroy(proposals);
 	return &this->public;
 }
	/*
	* Copyright (C) 2012-2020 Tobias Brunner
	* Copyright (C) 2005-2010 Martin Willi
	* Copyright (C) 2005 Jan Hutter
	* HSR Hochschule fuer Technik Rapperswil
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* for more details.
	*/

	#include <stddef.h>

	#include "sa_payload.h"

	#include <encoding/payloads/encodings.h>
	#include <collections/linked_list.h>
	#include <daemon.h>

	/* IKEv1 situation */
	#define SIT_IDENTITY_ONLY 1

	typedef struct private_sa_payload_t private_sa_payload_t;

	/**
	* Private data of an sa_payload_t object.
	*/
	struct private_sa_payload_t {

	/**
	* Public sa_payload_t interface.
	*/
	sa_payload_t public;

	/**
	* Next payload type.
	*/
	uint8_t next_payload;

	/**
	* Critical flag.
	*/
	bool critical;

	/**
	* Reserved bits
	*/
	bool reserved[8];

	/**
	* Length of this payload.
	*/
	uint16_t payload_length;

	/**
	* Proposals in this payload are stored in a linked_list_t.
	*/
	linked_list_t *proposals;

	/**
	* Type of this payload, V1 or V2
	*/
	payload_type_t type;

	/**
	* IKEv1 DOI
	*/
	uint32_t doi;

	/**
	* IKEv1 situation
	*/
	uint32_t situation;
	};

	/**
	* Encoding rules for IKEv1 SA payload
	*/
	static encoding_rule_t encodings_v1[] = {
	/* 1 Byte next payload type, stored in the field next_payload */
	{ U_INT_8, offsetof(private_sa_payload_t, next_payload) },
	/* 8 reserved bits */
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[0]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[1]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[2]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[3]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[4]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[5]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[6]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[7]) },
	/* Length of the whole SA payload*/
	{ PAYLOAD_LENGTH, offsetof(private_sa_payload_t, payload_length) },
	/* DOI*/
	{ U_INT_32, offsetof(private_sa_payload_t, doi) },
	/* Situation*/
	{ U_INT_32, offsetof(private_sa_payload_t, situation) },
	/* Proposals are stored in a proposal substructure list */
	{ PAYLOAD_LIST + PLV1_PROPOSAL_SUBSTRUCTURE,
	offsetof(private_sa_payload_t, proposals) },
	};

	/*
	1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! Next Payload ! RESERVED ! Payload Length !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! DOI !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! Situation !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! !
	~ <Proposals> ~
	! !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	*/

	/**
	* Encoding rules for IKEv2 SA payload
	*/
	static encoding_rule_t encodings_v2[] = {
	/* 1 Byte next payload type, stored in the field next_payload */
	{ U_INT_8, offsetof(private_sa_payload_t, next_payload) },
	/* the critical bit */
	{ FLAG, offsetof(private_sa_payload_t, critical) },
	/* 7 Bit reserved bits */
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[0]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[1]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[2]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[3]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[4]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[5]) },
	{ RESERVED_BIT, offsetof(private_sa_payload_t, reserved[6]) },
	/* Length of the whole SA payload*/
	{ PAYLOAD_LENGTH, offsetof(private_sa_payload_t, payload_length) },
	/* Proposals are stored in a proposal substructure list */
	{ PAYLOAD_LIST + PLV2_PROPOSAL_SUBSTRUCTURE,
	offsetof(private_sa_payload_t, proposals) },
	};

	/*
	1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! Next Payload !C! RESERVED ! Payload Length !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	! !
	~ <Proposals> ~
	! !
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	*/

	METHOD(payload_t, verify, status_t,
	private_sa_payload_t *this)
	{
	int expected_number = 0, current_number;
	status_t status = SUCCESS;
	enumerator_t *enumerator;
	proposal_substructure_t *substruct;

	if (this->type == PLV2_SECURITY_ASSOCIATION)
	{
	expected_number = 1;
	}

	/* check proposal numbering */
	enumerator = this->proposals->create_enumerator(this->proposals);
	while (enumerator->enumerate(enumerator, (void**)&substruct))
	{
	current_number = substruct->get_proposal_number(substruct);
	if (current_number < expected_number)
	{
	DBG1(DBG_ENC, "proposal number smaller than previous");
	status = FAILED;
	break;
	}

	status = substruct->payload_interface.verify(&substruct->payload_interface);
	if (status != SUCCESS)
	{
	DBG1(DBG_ENC, "PROPOSAL_SUBSTRUCTURE verification failed");
	break;
	}
	expected_number = current_number;
	}
	enumerator->destroy(enumerator);
	return status;
	}

	METHOD(payload_t, get_encoding_rules, int,
	private_sa_payload_t this, encoding_rule_t *rules)
	{
	if (this->type == PLV1_SECURITY_ASSOCIATION)
	{
	*rules = encodings_v1;
	return countof(encodings_v1);
	}
	*rules = encodings_v2;
	return countof(encodings_v2);
	}

	METHOD(payload_t, get_header_length, int,
	private_sa_payload_t *this)
	{
	if (this->type == PLV1_SECURITY_ASSOCIATION)
	{
	return 12;
	}
	return 4;
	}

	METHOD(payload_t, get_type, payload_type_t,
	private_sa_payload_t *this)
	{
	return this->type;
	}

	METHOD(payload_t, get_next_type, payload_type_t,
	private_sa_payload_t *this)
	{
	return this->next_payload;
	}

	METHOD(payload_t, set_next_type, void,
	private_sa_payload_t *this,payload_type_t type)
	{
	this->next_payload = type;
	}

	/**
	* recompute length of the payload.
	*/
	static void compute_length(private_sa_payload_t *this)
	{
	enumerator_t *enumerator;
	payload_t *current;

	this->payload_length = get_header_length(this);

	enumerator = this->proposals->create_enumerator(this->proposals);
	while (enumerator->enumerate(enumerator, (void **)&current))
	{
	this->payload_length += current->get_length(current);
	}
	enumerator->destroy(enumerator);
	}

	METHOD(payload_t, get_length, size_t,
	private_sa_payload_t *this)
	{
	return this->payload_length;
	}

	/**
	* Create a transform substructure from a proposal, add to payload
	*/
	static void add_proposal_v2(private_sa_payload_t this, proposal_t proposal)
	{
	proposal_substructure_t substruct, last;
	u_int count;

	substruct = proposal_substructure_create_from_proposal_v2(proposal);
	count = this->proposals->get_count(this->proposals);
	if (count > 0)
	{
	this->proposals->get_last(this->proposals, (void**)&last);
	/* last transform is now not anymore last one */
	last->set_is_last_proposal(last, FALSE);
	}
	substruct->set_is_last_proposal(substruct, TRUE);
	if (proposal->get_number(proposal))
	{ /* use the selected proposals number, if any */
	substruct->set_proposal_number(substruct, proposal->get_number(proposal));
	}
	else
	{
	substruct->set_proposal_number(substruct, count + 1);
	}
	this->proposals->insert_last(this->proposals, substruct);
	compute_length(this);
	}

	METHOD(sa_payload_t, get_proposals, linked_list_t*,
	private_sa_payload_t *this)
	{
	int struct_number = 0;
	int ignore_struct_number = 0;
	enumerator_t *enumerator;
	proposal_substructure_t *substruct;
	linked_list_t substructs, list;

	if (this->type == PLV1_SECURITY_ASSOCIATION)
	{ /* IKEv1 proposals may start with 0 or 1 (or any other number really) */
	struct_number = ignore_struct_number = -1;
	}

	/* we do not support proposals split up to two proposal substructures, as
	* AH+ESP bundles are not supported in RFC4301 anymore.
	* To handle such structures safely, we just skip proposals with multiple
	* protocols.
	*/
	substructs = linked_list_create();
	enumerator = this->proposals->create_enumerator(this->proposals);
	while (enumerator->enumerate(enumerator, &substruct))
	{
	int current_number = substruct->get_proposal_number(substruct);

	/* check if a proposal has a single protocol */
	if (current_number == struct_number)
	{
	if (ignore_struct_number < struct_number)
	{ /* remove an already added substruct, if first of series */
	substructs->remove_last(substructs, (void**)&substruct);
	ignore_struct_number = struct_number;
	}
	continue;
	}
	/* for IKEv1 the numbers don't have to be consecutive, for IKEv2 they do
	* but since we don't really care for the actual number we accept them
	* anyway. we already verified that they increase monotonically. */
	struct_number = current_number;
	substructs->insert_last(substructs, substruct);
	}
	enumerator->destroy(enumerator);

	/* generate proposals from substructs */
	list = linked_list_create();
	enumerator = substructs->create_enumerator(substructs);
	while (enumerator->enumerate(enumerator, &substruct))
	{
	substruct->get_proposals(substruct, list);
	}
	enumerator->destroy(enumerator);
	substructs->destroy(substructs);
	return list;
	}

	METHOD(sa_payload_t, get_ipcomp_proposals, linked_list_t*,
	private_sa_payload_t this, uint16_t cpi)
	{
	int current_proposal = -1, unsupported_proposal = -1;
	enumerator_t *enumerator;
	proposal_substructure_t substruct, espah = NULL, *ipcomp = NULL;
	linked_list_t *list;

	/* we currently only support the combination ESP\|AH+IPComp, find the first */
	enumerator = this->proposals->create_enumerator(this->proposals);
	while (enumerator->enumerate(enumerator, &substruct))
	{
	uint8_t proposal_number = substruct->get_proposal_number(substruct);
	uint8_t protocol_id = substruct->get_protocol_id(substruct);

	if (proposal_number == unsupported_proposal)
	{
	continue;
	}
	if (protocol_id != PROTO_ESP && protocol_id != PROTO_AH &&
	protocol_id != PROTO_IPCOMP)
	{ /* unsupported combination */
	espah = ipcomp = NULL;
	unsupported_proposal = current_proposal;
	continue;
	}
	if (proposal_number != current_proposal)
	{ /* start of a new proposal */
	if (espah && ipcomp && ipcomp->get_cpi(ipcomp, NULL))
	{ /* previous proposal is valid */
	break;
	}
	espah = ipcomp = NULL;
	current_proposal = proposal_number;
	}
	switch (protocol_id)
	{
	case PROTO_ESP:
	case PROTO_AH:
	espah = substruct;
	break;
	case PROTO_IPCOMP:
	ipcomp = substruct;
	break;
	}
	}
	enumerator->destroy(enumerator);

	list = linked_list_create();
	if (espah && ipcomp && ipcomp->get_cpi(ipcomp, cpi))
	{
	espah->get_proposals(espah, list);
	}
	return list;
	}

	METHOD(sa_payload_t, create_substructure_enumerator, enumerator_t*,
	private_sa_payload_t *this)
	{
	return this->proposals->create_enumerator(this->proposals);
	}

	METHOD(sa_payload_t, get_lifetime, uint32_t,
	private_sa_payload_t this, proposal_t proposal)
	{
	proposal_substructure_t *substruct;
	enumerator_t *enumerator;
	uint8_t number = proposal->get_number(proposal);
	uint32_t lifetime = 0;

	enumerator = this->proposals->create_enumerator(this->proposals);
	while (enumerator->enumerate(enumerator, &substruct))
	{
	if (substruct->get_proposal_number(substruct) == number)
	{
	lifetime = substruct->get_lifetime(substruct,
	proposal->get_transform_number(proposal));
	break;
	}
	}
	enumerator->destroy(enumerator);

	return lifetime;
	}

	METHOD(sa_payload_t, get_lifebytes, uint64_t,
	private_sa_payload_t this, proposal_t proposal)
	{
	proposal_substructure_t *substruct;
	enumerator_t *enumerator;
	uint8_t number = proposal->get_number(proposal);
	uint64_t lifebytes = 0;

	enumerator = this->proposals->create_enumerator(this->proposals);
	while (enumerator->enumerate(enumerator, &substruct))
	{
	if (substruct->get_proposal_number(substruct) == number)
	{
	lifebytes = substruct->get_lifebytes(substruct,
	proposal->get_transform_number(proposal));
	break;
	}
	}
	enumerator->destroy(enumerator);

	return lifebytes;
	}

	METHOD(sa_payload_t, get_auth_method, auth_method_t,
	private_sa_payload_t *this)
	{
	proposal_substructure_t *substruct;
	enumerator_t *enumerator;
	auth_method_t method = AUTH_NONE;

	enumerator = this->proposals->create_enumerator(this->proposals);
	if (enumerator->enumerate(enumerator, &substruct))
	{
	method = substruct->get_auth_method(substruct);
	}
	enumerator->destroy(enumerator);

	return method;
	}

	METHOD(sa_payload_t, get_encap_mode, ipsec_mode_t,
	private_sa_payload_t this, bool udp)
	{
	proposal_substructure_t *substruct;
	enumerator_t *enumerator;
	ipsec_mode_t mode = MODE_NONE;

	enumerator = this->proposals->create_enumerator(this->proposals);
	if (enumerator->enumerate(enumerator, &substruct))
	{
	mode = substruct->get_encap_mode(substruct, udp);
	}
	enumerator->destroy(enumerator);

	return mode;
	}

	METHOD2(payload_t, sa_payload_t, destroy, void,
	private_sa_payload_t *this)
	{
	this->proposals->destroy_offset(this->proposals,
	offsetof(payload_t, destroy));
	free(this);
	}

	/*
	* Described in header.
	*/
	sa_payload_t *sa_payload_create(payload_type_t type)
	{
	private_sa_payload_t *this;

	INIT(this,
	.public = {
	.payload_interface = {
	.verify = _verify,
	.get_encoding_rules = _get_encoding_rules,
	.get_header_length = _get_header_length,
	.get_length = _get_length,
	.get_next_type = _get_next_type,
	.set_next_type = _set_next_type,
	.get_type = _get_type,
	.destroy = _destroy,
	},
	.get_proposals = _get_proposals,
	.get_ipcomp_proposals = _get_ipcomp_proposals,
	.create_substructure_enumerator = _create_substructure_enumerator,
	.get_lifetime = _get_lifetime,
	.get_lifebytes = _get_lifebytes,
	.get_auth_method = _get_auth_method,
	.get_encap_mode = _get_encap_mode,
	.destroy = _destroy,
	},
	.next_payload = PL_NONE,
	.proposals = linked_list_create(),
	.type = type,
	/* for IKEv1 only */
	.doi = IKEV1_DOI_IPSEC,
	.situation = SIT_IDENTITY_ONLY,
	);

	compute_length(this);

	return &this->public;
	}

	/*
	* Described in header.
	*/
	sa_payload_t sa_payload_create_from_proposals_v2(linked_list_t proposals)
	{
	private_sa_payload_t *this;
	enumerator_t *enumerator;
	proposal_t *proposal;

	this = (private_sa_payload_t*)sa_payload_create(PLV2_SECURITY_ASSOCIATION);
	enumerator = proposals->create_enumerator(proposals);
	while (enumerator->enumerate(enumerator, &proposal))
	{
	add_proposal_v2(this, proposal);
	}
	enumerator->destroy(enumerator);

	return &this->public;
	}

	/*
	* Described in header.
	*/
	sa_payload_t sa_payload_create_from_proposal_v2(proposal_t proposal)
	{
	private_sa_payload_t *this;

	this = (private_sa_payload_t*)sa_payload_create(PLV2_SECURITY_ASSOCIATION);
	add_proposal_v2(this, proposal);

	return &this->public;

	}

	/*
	* Described in header.
	*/
	sa_payload_t sa_payload_create_from_proposals_v1(linked_list_t proposals,
	uint32_t lifetime, uint64_t lifebytes,
	auth_method_t auth, ipsec_mode_t mode,
	encap_t udp, uint16_t cpi)
	{
	proposal_substructure_t *substruct;
	private_sa_payload_t *this;

	this = (private_sa_payload_t*)sa_payload_create(PLV1_SECURITY_ASSOCIATION);

	if (!proposals \|\| !proposals->get_count(proposals))
	{
	return &this->public;
	}

	/* IKEv1 encodes multiple proposals in a single substructure
	* TODO-IKEv1: Encode ESP+AH proposals in two substructs with same num */
	substruct = proposal_substructure_create_from_proposals_v1(proposals,
	lifetime, lifebytes, auth, mode, udp);
	this->proposals->insert_last(this->proposals, substruct);
	substruct->set_is_last_proposal(substruct, FALSE);
	if (cpi)
	{
	uint8_t proposal_number = substruct->get_proposal_number(substruct);

	substruct = proposal_substructure_create_for_ipcomp_v1(lifetime,
	lifebytes, cpi, mode, udp, proposal_number);
	this->proposals->insert_last(this->proposals, substruct);
	substruct->set_is_last_proposal(substruct, FALSE);
	/* add the proposals again without IPComp */
	substruct = proposal_substructure_create_from_proposals_v1(proposals,
	lifetime, lifebytes, auth, mode, udp);
	substruct->set_proposal_number(substruct, proposal_number + 1);
	this->proposals->insert_last(this->proposals, substruct);
	}
	substruct->set_is_last_proposal(substruct, TRUE);
	compute_length(this);

	return &this->public;
	}

	/*
	* Described in header.
	*/
	sa_payload_t sa_payload_create_from_proposal_v1(proposal_t proposal,
	uint32_t lifetime, uint64_t lifebytes,
	auth_method_t auth, ipsec_mode_t mode,
	encap_t udp, uint16_t cpi)
	{
	private_sa_payload_t *this;
	linked_list_t *proposals;

	proposals = linked_list_create();
	proposals->insert_last(proposals, proposal);
	this = (private_sa_payload_t*)sa_payload_create_from_proposals_v1(proposals,
	lifetime, lifebytes, auth, mode, udp, cpi);
	proposals->destroy(proposals);
	return &this->public;
	}