tor-android/external/badvpn_dns/client/SPProtoDecoder.h

172 lines
5.7 KiB
C

/**
* @file SPProtoDecoder.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* Object which decodes packets according to SPProto.
*/
#ifndef BADVPN_CLIENT_SPPROTODECODER_H
#define BADVPN_CLIENT_SPPROTODECODER_H
#include <stdint.h>
#include <misc/debug.h>
#include <base/DebugObject.h>
#include <base/BLog.h>
#include <protocol/spproto.h>
#include <security/BEncryption.h>
#include <security/OTPChecker.h>
#include <flow/PacketPassInterface.h>
/**
* Handler called when OTP generation for a new seed is finished.
*
* @param user as in {@link SPProtoDecoder_Init}
*/
typedef void (*SPProtoDecoder_otp_handler) (void *user);
/**
* Object which decodes packets according to SPProto.
* Input is with {@link PacketPassInterface}.
* Output is with {@link PacketPassInterface}.
*/
typedef struct {
PacketPassInterface *output;
struct spproto_security_params sp_params;
BThreadWorkDispatcher *twd;
void *user;
BLog_logfunc logfunc;
int output_mtu;
int hash_size;
int enc_block_size;
int enc_key_size;
int input_mtu;
uint8_t *buf;
PacketPassInterface input;
OTPChecker otpchecker;
int have_encryption_key;
BEncryption encryptor;
uint8_t *in;
int in_len;
int tw_have;
BThreadWork tw;
uint16_t tw_out_seed_id;
otp_t tw_out_otp;
uint8_t *tw_out;
int tw_out_len;
DebugObject d_obj;
} SPProtoDecoder;
/**
* Initializes the object.
* {@link BSecurity_GlobalInitThreadSafe} must have been done if
* {@link BThreadWorkDispatcher_UsingThreads}(twd) = 1.
*
* @param o the object
* @param output output interface. Its MTU must not be too large, i.e. this must hold:
* spproto_carrier_mtu_for_payload_mtu(sp_params, output MTU) >= 0
* @param sp_params SPProto parameters
* @param encryption_key if using encryption, the encryption key
* @param num_otp_seeds if using OTPs, how many OTP seeds to keep for checking
* receiving packets. Must be >=2 if using OTPs.
* @param pg pending group
* @param twd thread work dispatcher
* @param user argument to handlers
* @param logfunc function which prepends the log prefix using {@link BLog_Append}
* @return 1 on success, 0 on failure
*/
int SPProtoDecoder_Init (SPProtoDecoder *o, PacketPassInterface *output, struct spproto_security_params sp_params, int num_otp_seeds, BPendingGroup *pg, BThreadWorkDispatcher *twd, void *user, BLog_logfunc logfunc) WARN_UNUSED;
/**
* Frees the object.
*
* @param o the object
*/
void SPProtoDecoder_Free (SPProtoDecoder *o);
/**
* Returns the input interface.
* The MTU of the input interface will depend on the output MTU and security parameters,
* that is spproto_carrier_mtu_for_payload_mtu(sp_params, output MTU).
*
* @param o the object
* @return input interface
*/
PacketPassInterface * SPProtoDecoder_GetInput (SPProtoDecoder *o);
/**
* Sets an encryption key for decrypting packets.
* Encryption must be enabled.
*
* @param o the object
* @param encryption_key key to use
*/
void SPProtoDecoder_SetEncryptionKey (SPProtoDecoder *o, uint8_t *encryption_key);
/**
* Removes an encryption key if one is configured.
* Encryption must be enabled.
*
* @param o the object
*/
void SPProtoDecoder_RemoveEncryptionKey (SPProtoDecoder *o);
/**
* Starts generating OTPs for a seed to check received packets against.
* OTPs for this seed will not be recognized until the {@link SPProtoDecoder_otp_handler} handler
* is called.
* If OTPs are still being generated for the previous seed, it will be forgotten.
* OTPs must be enabled.
*
* @param o the object
* @param seed_id seed identifier
* @param key OTP encryption key
* @param iv OTP initialization vector
*/
void SPProtoDecoder_AddOTPSeed (SPProtoDecoder *o, uint16_t seed_id, uint8_t *key, uint8_t *iv);
/**
* Removes all OTP seeds for checking received packets against.
* OTPs must be enabled.
*
* @param o the object
*/
void SPProtoDecoder_RemoveOTPSeeds (SPProtoDecoder *o);
/**
* Sets handlers.
*
* @param o the object
* @param otp_handler handler called when OTP generation is finished
* @param user argument to handler
*/
void SPProtoDecoder_SetHandlers (SPProtoDecoder *o, SPProtoDecoder_otp_handler otp_handler, void *user);
#endif