strongswan/src/libcharon/config/proposal.h

222 lines
6.0 KiB
C

/*
* Copyright (C) 2006 Martin Willi
* 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.
*/
/**
* @defgroup proposal proposal
* @{ @ingroup config
*/
#ifndef PROPOSAL_H_
#define PROPOSAL_H_
typedef enum protocol_id_t protocol_id_t;
typedef enum extended_sequence_numbers_t extended_sequence_numbers_t;
typedef struct proposal_t proposal_t;
#include <library.h>
#include <utils/identification.h>
#include <utils/linked_list.h>
#include <utils/host.h>
#include <crypto/transform.h>
#include <crypto/crypters/crypter.h>
#include <crypto/signers/signer.h>
#include <crypto/diffie_hellman.h>
#include <selectors/traffic_selector.h>
/**
* Protocol ID of a proposal.
*/
enum protocol_id_t {
PROTO_NONE = 0,
PROTO_IKE = 1,
PROTO_AH = 2,
PROTO_ESP = 3,
};
/**
* enum names for protocol_id_t
*/
extern enum_name_t *protocol_id_names;
/**
* Stores a set of algorithms used for an SA.
*
* A proposal stores algorithms for a specific
* protocol. It can store algorithms for one protocol.
* Proposals with multiple protocols are not supported,
* as it's not specified in RFC4301 anymore.
*/
struct proposal_t {
/**
* Add an algorithm to the proposal.
*
* The algorithms are stored by priority, first added
* is the most preferred.
* Key size is only needed for encryption algorithms
* with variable key size (such as AES). Must be set
* to zero if key size is not specified.
* The alg parameter accepts encryption_algorithm_t,
* integrity_algorithm_t, dh_group_number_t and
* extended_sequence_numbers_t.
*
* @param type kind of algorithm
* @param alg identifier for algorithm
* @param key_size key size to use
*/
void (*add_algorithm) (proposal_t *this, transform_type_t type,
u_int16_t alg, u_int16_t key_size);
/**
* Get an enumerator over algorithms for a specifc algo type.
*
* @param type kind of algorithm
* @return enumerator over u_int16_t alg, u_int16_t key_size
*/
enumerator_t *(*create_enumerator) (proposal_t *this, transform_type_t type);
/**
* Get the algorithm for a type to use.
*
* If there are multiple algorithms, only the first is returned.
*
* @param type kind of algorithm
* @param alg pointer which receives algorithm
* @param key_size pointer which receives the key size
* @return TRUE if algorithm of this kind available
*/
bool (*get_algorithm) (proposal_t *this, transform_type_t type,
u_int16_t *alg, u_int16_t *key_size);
/**
* Check if the proposal has a specific DH group.
*
* @param group group to check for
* @return TRUE if algorithm included
*/
bool (*has_dh_group) (proposal_t *this, diffie_hellman_group_t group);
/**
* Strip DH groups from proposal to use it without PFS.
*/
void (*strip_dh)(proposal_t *this);
/**
* Compare two proposal, and select a matching subset.
*
* If the proposals are for the same protocols (AH/ESP), they are
* compared. If they have at least one algorithm of each type
* in common, a resulting proposal of this kind is created.
*
* @param other proposal to compare against
* @param private accepts algorithms allocated in a private range
* @return selected proposal, NULL if proposals don't match
*/
proposal_t *(*select) (proposal_t *this, proposal_t *other, bool private);
/**
* Get the protocol ID of the proposal.
*
* @return protocol of the proposal
*/
protocol_id_t (*get_protocol) (proposal_t *this);
/**
* Get the SPI of the proposal.
*
* @return spi for proto
*/
u_int64_t (*get_spi) (proposal_t *this);
/**
* Set the SPI of the proposal.
*
* @param spi spi to set for proto
*/
void (*set_spi) (proposal_t *this, u_int64_t spi);
/**
* Get the proposal number, as encoded in SA payload
*
* @return proposal number
*/
u_int (*get_number)(proposal_t *this);
/**
* Check for the eqality of two proposals.
*
* @param other other proposal to check for equality
* @return TRUE if other equal to this
*/
bool (*equals)(proposal_t *this, proposal_t *other);
/**
* Clone a proposal.
*
* @return clone of proposal
*/
proposal_t *(*clone) (proposal_t *this);
/**
* Destroys the proposal object.
*/
void (*destroy) (proposal_t *this);
};
/**
* Create a child proposal for AH, ESP or IKE.
*
* @param protocol protocol, such as PROTO_ESP
* @param number proposal number, as encoded in SA payload
* @return proposal_t object
*/
proposal_t *proposal_create(protocol_id_t protocol, u_int number);
/**
* Create a default proposal if nothing further specified.
*
* @param protocol protocol, such as PROTO_ESP
* @return proposal_t object
*/
proposal_t *proposal_create_default(protocol_id_t protocol);
/**
* Create a proposal from a string identifying the algorithms.
*
* The string is in the same form as a in the ipsec.conf file.
* E.g.: aes128-sha2_256-modp2048
* 3des-md5
* An additional '!' at the end of the string forces this proposal,
* without it the peer may choose another algorithm we support.
*
* @param protocol protocol, such as PROTO_ESP
* @param algs algorithms as string
* @return proposal_t object
*/
proposal_t *proposal_create_from_string(protocol_id_t protocol, const char *algs);
/**
* printf hook function for proposal_t.
*
* Arguments are:
* proposal_t *proposal
* With the #-specifier, arguments are:
* linked_list_t *list containing proposal_t*
*/
int proposal_printf_hook(char *dst, size_t len, printf_hook_spec_t *spec,
const void *const *args);
#endif /** PROPOSAL_H_ @}*/