toxcore/toxdns/toxdns.h
2014-10-07 00:49:28 -04:00

97 lines
3.5 KiB
C

/* toxdns.h
*
* Tox secure username DNS toxid resolving functions.
*
* Copyright (C) 2014 Tox project All Rights Reserved.
*
* This file is part of Tox.
*
* Tox 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 3 of the License, or
* (at your option) any later version.
*
* Tox 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.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef TOXDNS_H
#define TOXDNS_H
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
/* Clients are encouraged to set this as the maximum length names can have. */
#define TOXDNS_MAX_RECOMMENDED_NAME_LENGTH 32
/* How to use this api to make secure tox dns3 requests:
*
* 1. Get the public key of a server that supports tox dns3.
* 2. use tox_dns3_new() to create a new object to create DNS requests
* and handle responses for that server.
* 3. Use tox_generate_dns3_string() to generate a string based on the name we want to query and a request_id
* that must be stored somewhere for when we want to decrypt the response.
* 4. take the string and use it for your DNS request like this:
* _4haaaaipr1o3mz0bxweox541airydbovqlbju51mb4p0ebxq.rlqdj4kkisbep2ks3fj2nvtmk4daduqiueabmexqva1jc._tox.utox.org
* 5. The TXT in the DNS you receive should look like this:
* v=tox3;id=2vgcxuycbuctvauik3plsv3d3aadv4zfjfhi3thaizwxinelrvigchv0ah3qjcsx5qhmaksb2lv2hm5cwbtx0yp
* 6. Take the id string and use it with tox_decrypt_dns3_TXT() and the request_id corresponding to the
* request we stored earlier to get the Tox id returned by the DNS server.
*/
/* Create a new tox_dns3 object for server with server_public_key of size TOX_CLIENT_ID_SIZE.
*
* return Null on failure.
* return pointer object on success.
*/
void *tox_dns3_new(uint8_t *server_public_key);
/* Destroy the tox dns3 object.
*/
void tox_dns3_kill(void *dns3_object);
/* Generate a dns3 string of string_max_len used to query the dns server referred to by to
* dns3_object for a tox id registered to user with name of name_len.
*
* the uint32_t pointed by request_id will be set to the request id which must be passed to
* tox_decrypt_dns3_TXT() to correctly decode the response.
*
* This is what the string returned looks like:
* 4haaaaipr1o3mz0bxweox541airydbovqlbju51mb4p0ebxq.rlqdj4kkisbep2ks3fj2nvtmk4daduqiueabmexqva1jc
*
* returns length of string on success.
* returns -1 on failure.
*/
int tox_generate_dns3_string(void *dns3_object, uint8_t *string, uint16_t string_max_len, uint32_t *request_id,
uint8_t *name, uint8_t name_len);
/* Decode and decrypt the id_record returned of length id_record_len into
* tox_id (needs to be at least TOX_FRIEND_ADDRESS_SIZE).
*
* request_id is the request id given by tox_generate_dns3_string() when creating the request.
*
* the id_record passed to this function should look somewhat like this:
* 2vgcxuycbuctvauik3plsv3d3aadv4zfjfhi3thaizwxinelrvigchv0ah3qjcsx5qhmaksb2lv2hm5cwbtx0yp
*
* returns -1 on failure.
* returns 0 on success.
*
*/
int tox_decrypt_dns3_TXT(void *dns3_object, uint8_t *tox_id, uint8_t *id_record, uint32_t id_record_len,
uint32_t request_id);
#ifdef __cplusplus
}
#endif
#endif