strongswan/src/libcharon/encoding/payloads/proposal_substructure.c

486 lines
13 KiB
C

/*
* Copyright (C) 2005-2010 Martin Willi
* Copyright (C) 2005 Jan Hutter
* 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 "proposal_substructure.h"
#include <encoding/payloads/encodings.h>
#include <encoding/payloads/transform_substructure.h>
#include <library.h>
#include <utils/linked_list.h>
#include <daemon.h>
/**
* IKEv1 Value for a proposal payload.
*/
#define PROPOSAL_TYPE_VALUE 2
typedef struct private_proposal_substructure_t private_proposal_substructure_t;
/**
* Private data of an proposal_substructure_t object.
*/
struct private_proposal_substructure_t {
/**
* Public proposal_substructure_t interface.
*/
proposal_substructure_t public;
/**
* Next payload type.
*/
u_int8_t next_payload;
/**
* reserved byte
*/
u_int8_t reserved;
/**
* Length of this payload.
*/
u_int16_t proposal_length;
/**
* Proposal number.
*/
u_int8_t proposal_number;
/**
* Protocol ID.
*/
u_int8_t protocol_id;
/**
* SPI size of the following SPI.
*/
u_int8_t spi_size;
/**
* Number of transforms.
*/
u_int8_t transforms_count;
/**
* SPI is stored as chunk.
*/
chunk_t spi;
/**
* Transforms are stored in a linked_list_t.
*/
linked_list_t * transforms;
};
/**
* Encoding rules to parse or generate a Proposal substructure.
*
* The defined offsets are the positions in a object of type
* private_proposal_substructure_t.
*/
encoding_rule_t proposal_substructure_encodings[] = {
/* 1 Byte next payload type, stored in the field next_payload */
{ U_INT_8, offsetof(private_proposal_substructure_t, next_payload) },
/* 1 Reserved Byte */
{ RESERVED_BYTE, offsetof(private_proposal_substructure_t, reserved) },
/* Length of the whole proposal substructure payload*/
{ PAYLOAD_LENGTH, offsetof(private_proposal_substructure_t, proposal_length) },
/* proposal number is a number of 8 bit */
{ U_INT_8, offsetof(private_proposal_substructure_t, proposal_number) },
/* protocol ID is a number of 8 bit */
{ U_INT_8, offsetof(private_proposal_substructure_t, protocol_id) },
/* SPI Size has its own type */
{ SPI_SIZE, offsetof(private_proposal_substructure_t, spi_size) },
/* Number of transforms is a number of 8 bit */
{ U_INT_8, offsetof(private_proposal_substructure_t, transforms_count) },
/* SPI is a chunk of variable size*/
{ SPI, offsetof(private_proposal_substructure_t, spi) },
/* Transforms are stored in a transform substructure,
offset points to a linked_list_t pointer */
{ TRANSFORMS, offsetof(private_proposal_substructure_t, transforms) }
};
/*
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! 0 (last) or 2 ! RESERVED ! Proposal Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Proposal # ! Protocol ID ! SPI Size !# of Transforms!
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ SPI (variable) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! !
~ <Transforms> ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
METHOD(payload_t, verify, status_t,
private_proposal_substructure_t *this)
{
status_t status = SUCCESS;
enumerator_t *enumerator;
payload_t *current;
if (this->next_payload != NO_PAYLOAD && this->next_payload != 2)
{
/* must be 0 or 2 */
DBG1(DBG_ENC, "inconsistent next payload");
return FAILED;
}
if (this->transforms_count != this->transforms->get_count(this->transforms))
{
/* must be the same! */
DBG1(DBG_ENC, "transform count invalid");
return FAILED;
}
switch (this->protocol_id)
{
case PROTO_AH:
case PROTO_ESP:
if (this->spi.len != 4)
{
DBG1(DBG_ENC, "invalid SPI length in %N proposal",
protocol_id_names, this->protocol_id);
return FAILED;
}
break;
case PROTO_IKE:
if (this->spi.len != 0 && this->spi.len != 8)
{
DBG1(DBG_ENC, "invalid SPI length in IKE proposal");
return FAILED;
}
break;
default:
break;
}
enumerator = this->transforms->create_enumerator(this->transforms);
while (enumerator->enumerate(enumerator, &current))
{
status = current->verify(current);
if (status != SUCCESS)
{
DBG1(DBG_ENC, "TRANSFORM_SUBSTRUCTURE verification failed");
break;
}
}
enumerator->destroy(enumerator);
/* proposal number is checked in SA payload */
return status;
}
METHOD(payload_t, get_encoding_rules, void,
private_proposal_substructure_t *this, encoding_rule_t **rules,
size_t *rule_count)
{
*rules = proposal_substructure_encodings;
*rule_count = countof(proposal_substructure_encodings);
}
METHOD(payload_t, get_type, payload_type_t,
private_proposal_substructure_t *this)
{
return PROPOSAL_SUBSTRUCTURE;
}
METHOD(payload_t, get_next_type, payload_type_t,
private_proposal_substructure_t *this)
{
return this->next_payload;
}
METHOD(payload_t, set_next_type, void,
private_proposal_substructure_t *this, payload_type_t type)
{
}
/**
* (re-)compute the length of the payload.
*/
static void compute_length(private_proposal_substructure_t *this)
{
enumerator_t *enumerator;
payload_t *transform;
this->transforms_count = 0;
this->proposal_length = PROPOSAL_SUBSTRUCTURE_HEADER_LENGTH + this->spi.len;
enumerator = this->transforms->create_enumerator(this->transforms);
while (enumerator->enumerate(enumerator, &transform))
{
this->proposal_length += transform->get_length(transform);
this->transforms_count++;
}
enumerator->destroy(enumerator);
}
METHOD(payload_t, get_length, size_t,
private_proposal_substructure_t *this)
{
return this->proposal_length;
}
/**
* Add a transform substructure to the proposal
*/
static void add_transform_substructure(private_proposal_substructure_t *this,
transform_substructure_t *transform)
{
if (this->transforms->get_count(this->transforms) > 0)
{
transform_substructure_t *last;
this->transforms->get_last(this->transforms, (void **)&last);
last->set_is_last_transform(last, FALSE);
}
transform->set_is_last_transform(transform,TRUE);
this->transforms->insert_last(this->transforms, transform);
compute_length(this);
}
METHOD(proposal_substructure_t, set_is_last_proposal, void,
private_proposal_substructure_t *this, bool is_last)
{
this->next_payload = is_last ? 0 : PROPOSAL_TYPE_VALUE;
}
METHOD(proposal_substructure_t, set_proposal_number, void,
private_proposal_substructure_t *this,u_int8_t proposal_number)
{
this->proposal_number = proposal_number;
}
METHOD(proposal_substructure_t, get_proposal_number, u_int8_t,
private_proposal_substructure_t *this)
{
return this->proposal_number;
}
METHOD(proposal_substructure_t, set_protocol_id, void,
private_proposal_substructure_t *this,u_int8_t protocol_id)
{
this->protocol_id = protocol_id;
}
METHOD(proposal_substructure_t, get_protocol_id, u_int8_t,
private_proposal_substructure_t *this)
{
return this->protocol_id;
}
METHOD(proposal_substructure_t, set_spi, void,
private_proposal_substructure_t *this, chunk_t spi)
{
free(this->spi.ptr);
this->spi = chunk_clone(spi);
this->spi_size = spi.len;
compute_length(this);
}
METHOD(proposal_substructure_t, get_spi, chunk_t,
private_proposal_substructure_t *this)
{
return this->spi;
}
METHOD(proposal_substructure_t, get_proposal, proposal_t*,
private_proposal_substructure_t *this)
{
enumerator_t *enumerator;
transform_substructure_t *transform;
proposal_t *proposal;
u_int64_t spi;
proposal = proposal_create(this->protocol_id, this->proposal_number);
enumerator = this->transforms->create_enumerator(this->transforms);
while (enumerator->enumerate(enumerator, &transform))
{
transform_type_t transform_type;
u_int16_t transform_id;
u_int16_t key_length = 0;
transform_type = transform->get_transform_type(transform);
transform_id = transform->get_transform_id(transform);
transform->get_key_length(transform, &key_length);
proposal->add_algorithm(proposal, transform_type, transform_id, key_length);
}
enumerator->destroy(enumerator);
switch (this->spi.len)
{
case 4:
spi = *((u_int32_t*)this->spi.ptr);
break;
case 8:
spi = *((u_int64_t*)this->spi.ptr);
break;
default:
spi = 0;
}
proposal->set_spi(proposal, spi);
return proposal;
}
METHOD(proposal_substructure_t, create_substructure_enumerator, enumerator_t*,
private_proposal_substructure_t *this)
{
return this->transforms->create_enumerator(this->transforms);
}
METHOD2(payload_t, proposal_substructure_t, destroy, void,
private_proposal_substructure_t *this)
{
this->transforms->destroy_offset(this->transforms,
offsetof(transform_substructure_t, destroy));
chunk_free(&this->spi);
free(this);
}
/*
* Described in header.
*/
proposal_substructure_t *proposal_substructure_create()
{
private_proposal_substructure_t *this;
INIT(this,
.public = {
.payload_interface = {
.verify = _verify,
.get_encoding_rules = _get_encoding_rules,
.get_length = _get_length,
.get_next_type = _get_next_type,
.set_next_type = _set_next_type,
.get_type = _get_type,
.destroy = _destroy,
},
.set_proposal_number = _set_proposal_number,
.get_proposal_number = _get_proposal_number,
.set_protocol_id = _set_protocol_id,
.get_protocol_id = _get_protocol_id,
.set_is_last_proposal = _set_is_last_proposal,
.get_proposal = _get_proposal,
.create_substructure_enumerator = _create_substructure_enumerator,
.set_spi = _set_spi,
.get_spi = _get_spi,
.destroy = _destroy,
},
.next_payload = NO_PAYLOAD,
.proposal_length = PROPOSAL_SUBSTRUCTURE_HEADER_LENGTH,
.transforms = linked_list_create(),
);
return &this->public;
}
/*
* Described in header.
*/
proposal_substructure_t *proposal_substructure_create_from_proposal(
proposal_t *proposal)
{
transform_substructure_t *transform;
private_proposal_substructure_t *this;
u_int16_t alg, key_size;
enumerator_t *enumerator;
this = (private_proposal_substructure_t*)proposal_substructure_create();
/* encryption algorithm is only available in ESP */
enumerator = proposal->create_enumerator(proposal, ENCRYPTION_ALGORITHM);
while (enumerator->enumerate(enumerator, &alg, &key_size))
{
transform = transform_substructure_create_type(ENCRYPTION_ALGORITHM,
alg, key_size);
add_transform_substructure(this, transform);
}
enumerator->destroy(enumerator);
/* integrity algorithms */
enumerator = proposal->create_enumerator(proposal, INTEGRITY_ALGORITHM);
while (enumerator->enumerate(enumerator, &alg, &key_size))
{
transform = transform_substructure_create_type(INTEGRITY_ALGORITHM,
alg, key_size);
add_transform_substructure(this, transform);
}
enumerator->destroy(enumerator);
/* prf algorithms */
enumerator = proposal->create_enumerator(proposal, PSEUDO_RANDOM_FUNCTION);
while (enumerator->enumerate(enumerator, &alg, &key_size))
{
transform = transform_substructure_create_type(PSEUDO_RANDOM_FUNCTION,
alg, key_size);
add_transform_substructure(this, transform);
}
enumerator->destroy(enumerator);
/* dh groups */
enumerator = proposal->create_enumerator(proposal, DIFFIE_HELLMAN_GROUP);
while (enumerator->enumerate(enumerator, &alg, NULL))
{
transform = transform_substructure_create_type(DIFFIE_HELLMAN_GROUP,
alg, 0);
add_transform_substructure(this, transform);
}
enumerator->destroy(enumerator);
/* extended sequence numbers */
enumerator = proposal->create_enumerator(proposal, EXTENDED_SEQUENCE_NUMBERS);
while (enumerator->enumerate(enumerator, &alg, NULL))
{
transform = transform_substructure_create_type(EXTENDED_SEQUENCE_NUMBERS,
alg, 0);
add_transform_substructure(this, transform);
}
enumerator->destroy(enumerator);
/* add SPI, if necessary */
switch (proposal->get_protocol(proposal))
{
case PROTO_AH:
case PROTO_ESP:
this->spi_size = this->spi.len = 4;
this->spi.ptr = malloc(this->spi_size);
*((u_int32_t*)this->spi.ptr) = proposal->get_spi(proposal);
break;
case PROTO_IKE:
if (proposal->get_spi(proposal))
{ /* IKE only uses SPIS when rekeying, but on initial setup */
this->spi_size = this->spi.len = 8;
this->spi.ptr = malloc(this->spi_size);
*((u_int64_t*)this->spi.ptr) = proposal->get_spi(proposal);
}
break;
default:
break;
}
this->proposal_number = proposal->get_number(proposal);
this->protocol_id = proposal->get_protocol(proposal);
compute_length(this);
return &this->public;
}