// Copyright (c) 2014-2017, The Monero Project // // All rights reserved. // // 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 copyright holder 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 COPYRIGHT HOLDER OR CONTRIBUTORS 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. #pragma once #include #include #include "cryptonote_basic/cryptonote_basic.h" namespace tools { // RFC defines for record types and classes for DNS, gleaned from ldns source const static int DNS_CLASS_IN = 1; const static int DNS_TYPE_A = 1; const static int DNS_TYPE_TXT = 16; const static int DNS_TYPE_AAAA = 8; struct DNSResolverData; /** * @brief Provides high-level access to DNS resolution * * This class is designed to provide a high-level abstraction to DNS resolution * functionality, including access to TXT records and such. It will also * handle DNSSEC validation of the results. */ class DNSResolver { private: /** * @brief Constructs an instance of DNSResolver * * Constructs a class instance and does setup stuff for the backend resolver. */ DNSResolver(); public: /** * @brief takes care of freeing C pointers and such */ ~DNSResolver(); /** * @brief gets ipv4 addresses from DNS query of a URL * * returns a vector of all IPv4 "A" records for given URL. * If no "A" records found, returns an empty vector. * * @param url A string containing a URL to query for * * @param dnssec_available * * @return vector of strings containing ipv4 addresses */ std::vector get_ipv4(const std::string& url, bool& dnssec_available, bool& dnssec_valid); /** * @brief gets ipv6 addresses from DNS query * * returns a vector of all IPv6 "A" records for given URL. * If no "A" records found, returns an empty vector. * * @param url A string containing a URL to query for * * @return vector of strings containing ipv6 addresses */ std::vector get_ipv6(const std::string& url, bool& dnssec_available, bool& dnssec_valid); /** * @brief gets all TXT records from a DNS query for the supplied URL; * if no TXT record present returns an empty vector. * * @param url A string containing a URL to query for * * @return A vector of strings containing a TXT record; or an empty vector */ // TODO: modify this to accommodate DNSSEC std::vector get_txt_record(const std::string& url, bool& dnssec_available, bool& dnssec_valid); /** * @brief Gets a DNS address from OpenAlias format * * If the address looks good, but contains one @ symbol, replace that with a . * e.g. donate@getmonero.org becomes donate.getmonero.org * * @param oa_addr OpenAlias address * * @return dns_addr DNS address */ std::string get_dns_format_from_oa_address(const std::string& oa_addr); /** * @brief Gets the singleton instance of DNSResolver * * @return returns a pointer to the singleton */ static DNSResolver& instance(); /** * @brief Gets a new instance of DNSResolver * * @return returns a pointer to the new object */ static DNSResolver create(); private: /** * @brief gets all records of a given type from a DNS query for the supplied URL; * if no such record is present returns an empty vector. * * @param url A string containing a URL to query for * @param record_type the record type to retrieve (DNS_TYPE_A, etc) * @param reader a function that converts a record data to a string * * @return A vector of strings containing the requested record; or an empty vector */ // TODO: modify this to accommodate DNSSEC std::vector get_record(const std::string& url, int record_type, std::string (*reader)(const char *,size_t), bool& dnssec_available, bool& dnssec_valid); /** * @brief Checks a string to see if it looks like a URL * * @param addr the string to be checked * * @return true if it looks enough like a URL, false if not */ bool check_address_syntax(const char *addr) const; DNSResolverData *m_data; }; // class DNSResolver namespace dns_utils { std::string address_from_txt_record(const std::string& s); std::vector addresses_from_url(const std::string& url, bool& dnssec_valid); std::string get_account_address_as_str_from_url(const std::string& url, bool& dnssec_valid, std::function&, bool)> confirm_dns); bool load_txt_records_from_dns(std::vector &records, const std::vector &dns_urls); } // namespace tools::dns_utils } // namespace tools