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/*
* Copyright (C) 2012 Tobias Brunner
* Copyright (C) 2012 Giuliano Grassi
* Copyright (C) 2012 Ralf Sager
* 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 esp_packet esp_packet
* @{ @ingroup libipsec
*/
#ifndef ESP_PACKET_H_
#define ESP_PACKET_H_
#include "ip_packet.h"
#include "esp_context.h"
#include <library.h>
#include <networking/host.h>
#include <networking/packet.h>
typedef struct esp_packet_t esp_packet_t;
/**
* ESP packet
*/
struct esp_packet_t {
/**
* Implements packet_t interface to access the raw ESP packet
*/
packet_t packet;
/**
* Get the source address of this packet
*
* @return source host
*/
host_t *(*get_source)(esp_packet_t *this);
/**
* Get the destination address of this packet
*
* @return destination host
*/
host_t *(*get_destination)(esp_packet_t *this);
/**
* Parse the packet header before decryption. Tries to read the SPI
* from the packet to find a corresponding SA.
*
* @param spi parsed SPI, in network byte order
* @return TRUE when successful, FALSE otherwise (e.g. when the
* length of the packet is invalid)
*/
bool (*parse_header)(esp_packet_t *this, u_int32_t *spi);
/**
* Authenticate and decrypt the packet. Also verifies the sequence number
* using the supplied ESP context and updates the anti-replay window.
*
* @param esp_context ESP context of corresponding inbound IPsec SA
* @return - SUCCESS if successfully authenticated,
* decrypted and parsed
* - PARSE_ERROR if the length of the packet or the
* padding is invalid
* - VERIFY_ERROR if the sequence number
* verification failed
* - FAILED if the ICV (MAC) check or the actual
* decryption failed
*/
status_t (*decrypt)(esp_packet_t *this, esp_context_t *esp_context);
/**
* Encapsulate and encrypt the packet. The sequence number will be generated
* using the supplied ESP context.
*
* @param esp_context ESP context of corresponding outbound IPsec SA
* @param spi SPI value to use, in network byte order
* @return - SUCCESS if encrypted
* - FAILED if sequence number cycled or any of the
* cryptographic functions failed
* - NOT_FOUND if no suitable RNG could be found
*/
status_t (*encrypt)(esp_packet_t *this, esp_context_t *esp_context,
u_int32_t spi);
/**
* Get the next header field of a packet.
*
* @note Packet has to be in the decrypted state.
*
* @return next header field
*/
u_int8_t (*get_next_header)(esp_packet_t *this);
/**
* Get the plaintext payload of this packet.
*
* @return plaintext payload (internal data),
* NULL if not decrypted
*/
ip_packet_t *(*get_payload)(esp_packet_t *this);
/**
* Extract the plaintext payload from this packet.
*
* @return plaintext payload (has to be destroyed),
* NULL if not decrypted
*/
ip_packet_t *(*extract_payload)(esp_packet_t *this);
/**
* Destroy an esp_packet_t
*/
void (*destroy)(esp_packet_t *this);
};
/**
* Create an ESP packet out of data from the wire.
*
* @param packet the packet data as received, gets owned
* @return esp_packet_t instance
*/
esp_packet_t *esp_packet_create_from_packet(packet_t *packet);
/**
* Create an ESP packet from a plaintext payload
*
* @param src source address
* @param dst destination address
* @param payload plaintext payload, gets owned
* @return esp_packet_t instance
*/
esp_packet_t *esp_packet_create_from_payload(host_t *src, host_t *dst,
ip_packet_t *payload);
#endif /** ESP_PACKET_H_ @}*/
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