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![Werner Koch](/assets/img/avatar_default.png)
* configure.ac: Require at least Libgcrypt 1.9.0. Remove all GCRYPT_VERSION_NUMBER dependent code. -- Only Libgcrypt 1.9 implements EAX which is a mandatory algorithm in RFC4880bis. Signed-off-by: Werner Koch <wk@gnupg.org>
2506 lines
64 KiB
C
2506 lines
64 KiB
C
/* dns-stuff.c - DNS related code including CERT RR (rfc-4398)
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* Copyright (C) 2003, 2005, 2006, 2009 Free Software Foundation, Inc.
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* Copyright (C) 2005, 2006, 2009, 2015. 2016 Werner Koch
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*
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* This file is part of GnuPG.
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*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either
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*
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* - the GNU Lesser General Public License as published by the Free
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* Software Foundation; either version 3 of the License, or (at
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* your option) any later version.
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*
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* or
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*
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* - the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* or both in parallel, as here.
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*
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* This file is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <https://www.gnu.org/licenses/>.
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*/
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#include <config.h>
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#include <sys/types.h>
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#ifdef HAVE_W32_SYSTEM
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# define WIN32_LEAN_AND_MEAN
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# ifdef HAVE_WINSOCK2_H
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# include <winsock2.h>
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# endif
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# include <windows.h>
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# include <iphlpapi.h>
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#else
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# if HAVE_SYSTEM_RESOLVER
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# include <netinet/in.h>
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# include <arpa/nameser.h>
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# include <resolv.h>
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# endif
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# include <netdb.h>
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#endif
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#ifdef HAVE_STAT
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# include <sys/stat.h>
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#endif
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#include <string.h>
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#include <unistd.h>
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/* William Ahern's DNS library, included as a source copy. */
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#ifdef USE_LIBDNS
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# include "dns.h"
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#endif
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/* dns.c has a dns_p_free but it is not exported. We use our own
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* wrapper here so that we do not accidentally use xfree which would
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* be wrong for dns.c allocated data. */
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#define dns_free(a) free ((a))
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#ifdef WITHOUT_NPTH /* Give the Makefile a chance to build without Pth. */
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# undef USE_NPTH
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#endif
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#ifdef USE_NPTH
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# include <npth.h>
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#endif
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#include "./dirmngr-err.h"
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#include "../common/util.h"
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#include "../common/host2net.h"
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#include "dirmngr-status.h"
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#include "dns-stuff.h"
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#ifdef USE_NPTH
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# define my_unprotect() npth_unprotect ()
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# define my_protect() npth_protect ()
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#else
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# define my_unprotect() do { } while(0)
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# define my_protect() do { } while(0)
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#endif
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/* We allow the use of 0 instead of AF_UNSPEC - check this assumption. */
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#if AF_UNSPEC != 0
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# error AF_UNSPEC does not have the value 0
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#endif
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/* Windows does not support the AI_ADDRCONFIG flag - use zero instead. */
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#ifndef AI_ADDRCONFIG
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# define AI_ADDRCONFIG 0
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#endif
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/* Not every installation has gotten around to supporting SRVs or
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CERTs yet... */
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#ifndef T_SRV
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#define T_SRV 33
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#endif
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#undef T_CERT
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#define T_CERT 37
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/* The standard SOCKS and TOR ports. */
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#define SOCKS_PORT 1080
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#define TOR_PORT 9050
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#define TOR_PORT2 9150 /* (Used by the Tor browser) */
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/* The default nameserver used in Tor mode. */
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#define DEFAULT_NAMESERVER "8.8.8.8"
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/* The default timeout in seconds for libdns requests. */
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#define DEFAULT_TIMEOUT 30
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#define RESOLV_CONF_NAME "/etc/resolv.conf"
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/* Two flags to enable verbose and debug mode. */
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static int opt_verbose;
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static int opt_debug;
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/* The timeout in seconds for libdns requests. */
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static int opt_timeout;
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/* The flag to disable IPv4 access - right now this only skips
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* returned A records. */
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static int opt_disable_ipv4;
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/* The flag to disable IPv6 access - right now this only skips
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* returned AAAA records. */
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static int opt_disable_ipv6;
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/* If set force the use of the standard resolver. */
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static int standard_resolver;
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/* If set use recursive resolver when available. */
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static int recursive_resolver;
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/* If set Tor mode shall be used. */
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static int tor_mode;
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/* A string with the nameserver IP address used with Tor.
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(40 should be sufficient for v6 but we add some extra for a scope.) */
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static char tor_nameserver[40+20];
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/* Two strings to hold the credentials presented to Tor. */
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static char tor_socks_user[30];
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static char tor_socks_password[20];
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/* To avoid checking the interface too often we cache the result. */
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static struct
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{
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unsigned int valid:1;
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unsigned int v4:1;
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unsigned int v6:1;
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} cached_inet_support;
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#ifdef USE_LIBDNS
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/* Libdns global data. */
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struct libdns_s
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{
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struct dns_resolv_conf *resolv_conf;
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struct dns_hosts *hosts;
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struct dns_hints *hints;
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struct sockaddr_storage socks_host;
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} libdns;
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/* If this flag is set, libdns shall be reinited for the next use. */
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static int libdns_reinit_pending;
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/* The Tor port to be used. */
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static int libdns_tor_port;
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#endif /*USE_LIBDNS*/
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/* Calling this function with YES set to True forces the use of the
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* standard resolver even if dirmngr has been built with support for
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* an alternative resolver. */
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void
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enable_standard_resolver (int yes)
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{
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standard_resolver = yes;
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}
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/* Return true if the standard resolver is used. */
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int
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standard_resolver_p (void)
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{
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return standard_resolver;
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}
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/* Calling this function with YES switches libdns into recursive mode.
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* It has no effect on the standard resolver. */
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void
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enable_recursive_resolver (int yes)
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{
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recursive_resolver = yes;
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#ifdef USE_LIBDNS
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libdns_reinit_pending = 1;
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#endif
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}
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/* Return true iff the recursive resolver is used. */
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int
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recursive_resolver_p (void)
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{
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#if USE_LIBDNS
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return !standard_resolver && recursive_resolver;
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#else
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return 0;
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#endif
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}
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/* Puts this module eternally into Tor mode. When called agained with
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* NEW_CIRCUIT request a new TOR circuit for the next DNS query. */
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void
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enable_dns_tormode (int new_circuit)
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{
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if (!*tor_socks_user || new_circuit)
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{
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static unsigned int counter;
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gpgrt_snprintf (tor_socks_user, sizeof tor_socks_user,
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"dirmngr-%lu", (unsigned long)getpid ());
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gpgrt_snprintf (tor_socks_password, sizeof tor_socks_password,
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"p%u", counter);
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counter++;
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}
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tor_mode = 1;
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}
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/* Disable tor mode. */
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void
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disable_dns_tormode (void)
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{
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tor_mode = 0;
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}
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/* Set verbosity and debug mode for this module. */
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void
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set_dns_verbose (int verbose, int debug)
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{
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opt_verbose = verbose;
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opt_debug = debug;
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}
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/* Set the Disable-IPv4 flag so that the name resolver does not return
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* A addresses. */
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void
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set_dns_disable_ipv4 (int yes)
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{
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opt_disable_ipv4 = !!yes;
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}
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/* Set the Disable-IPv6 flag so that the name resolver does not return
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* AAAA addresses. */
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void
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set_dns_disable_ipv6 (int yes)
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{
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opt_disable_ipv6 = !!yes;
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}
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/* Set the timeout for libdns requests to SECONDS. A value of 0 sets
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* the default timeout and values are capped at 10 minutes. */
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void
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set_dns_timeout (int seconds)
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{
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if (!seconds)
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seconds = DEFAULT_TIMEOUT;
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else if (seconds < 1)
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seconds = 1;
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else if (seconds > 600)
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seconds = 600;
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opt_timeout = seconds;
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}
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/* Change the default IP address of the nameserver to IPADDR. The
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address needs to be a numerical IP address and will be used for the
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next DNS query. Note that this is only used in Tor mode. */
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void
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set_dns_nameserver (const char *ipaddr)
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{
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strncpy (tor_nameserver, ipaddr? ipaddr : DEFAULT_NAMESERVER,
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sizeof tor_nameserver -1);
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tor_nameserver[sizeof tor_nameserver -1] = 0;
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#ifdef USE_LIBDNS
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libdns_reinit_pending = 1;
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libdns_tor_port = 0; /* Start again with the default port. */
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#endif
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}
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/* Free an addressinfo linked list as returned by resolve_dns_name. */
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void
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free_dns_addrinfo (dns_addrinfo_t ai)
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{
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while (ai)
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{
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dns_addrinfo_t next = ai->next;
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xfree (ai);
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ai = next;
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}
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}
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#ifndef HAVE_W32_SYSTEM
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/* Return H_ERRNO mapped to a gpg-error code. Will never return 0. */
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static gpg_error_t
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get_h_errno_as_gpg_error (void)
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{
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gpg_err_code_t ec;
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switch (h_errno)
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{
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case HOST_NOT_FOUND: ec = GPG_ERR_NO_NAME; break;
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case TRY_AGAIN: ec = GPG_ERR_TRY_LATER; break;
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case NO_RECOVERY: ec = GPG_ERR_SERVER_FAILED; break;
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case NO_DATA: ec = GPG_ERR_NO_DATA; break;
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default: ec = GPG_ERR_UNKNOWN_ERRNO; break;
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}
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return gpg_error (ec);
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}
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#endif /*!HAVE_W32_SYSTEM*/
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static gpg_error_t
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map_eai_to_gpg_error (int ec)
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{
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gpg_error_t err;
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switch (ec)
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{
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case EAI_AGAIN: err = gpg_error (GPG_ERR_EAGAIN); break;
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case EAI_BADFLAGS: err = gpg_error (GPG_ERR_INV_FLAG); break;
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case EAI_FAIL: err = gpg_error (GPG_ERR_SERVER_FAILED); break;
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case EAI_MEMORY: err = gpg_error (GPG_ERR_ENOMEM); break;
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#ifdef EAI_NODATA
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case EAI_NODATA: err = gpg_error (GPG_ERR_NO_DATA); break;
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#endif
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case EAI_NONAME: err = gpg_error (GPG_ERR_NO_NAME); break;
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case EAI_SERVICE: err = gpg_error (GPG_ERR_NOT_SUPPORTED); break;
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case EAI_FAMILY: err = gpg_error (GPG_ERR_EAFNOSUPPORT); break;
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case EAI_SOCKTYPE: err = gpg_error (GPG_ERR_ESOCKTNOSUPPORT); break;
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#ifndef HAVE_W32_SYSTEM
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# ifdef EAI_ADDRFAMILY
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case EAI_ADDRFAMILY:err = gpg_error (GPG_ERR_EADDRNOTAVAIL); break;
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# endif
|
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case EAI_SYSTEM: err = gpg_error_from_syserror (); break;
|
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#endif
|
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default: err = gpg_error (GPG_ERR_UNKNOWN_ERRNO); break;
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}
|
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return err;
|
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}
|
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|
||
|
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#ifdef USE_LIBDNS
|
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static gpg_error_t
|
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libdns_error_to_gpg_error (int serr)
|
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{
|
||
gpg_err_code_t ec;
|
||
|
||
switch (serr)
|
||
{
|
||
case 0: ec = 0; break;
|
||
|
||
case DNS_ENOBUFS: ec = GPG_ERR_BUFFER_TOO_SHORT; break;
|
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case DNS_EILLEGAL: ec = GPG_ERR_INV_OBJ; break;
|
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case DNS_EORDER: ec = GPG_ERR_INV_ORDER; break;
|
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case DNS_ESECTION: ec = GPG_ERR_DNS_SECTION; break;
|
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case DNS_EUNKNOWN: ec = GPG_ERR_DNS_UNKNOWN; break;
|
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case DNS_EADDRESS: ec = GPG_ERR_DNS_ADDRESS; break;
|
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case DNS_ENOQUERY: ec = GPG_ERR_DNS_NO_QUERY; break;
|
||
case DNS_ENOANSWER:ec = GPG_ERR_DNS_NO_ANSWER; break;
|
||
case DNS_EFETCHED: ec = GPG_ERR_ALREADY_FETCHED; break;
|
||
case DNS_ESERVICE: ec = GPG_ERR_NOT_SUPPORTED; break;
|
||
case DNS_ENONAME: ec = GPG_ERR_NO_NAME; break;
|
||
case DNS_EFAIL: ec = GPG_ERR_SERVER_FAILED; break;
|
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case DNS_ECONNFIN: ec = GPG_ERR_DNS_CLOSED; break;
|
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case DNS_EVERIFY: ec = GPG_ERR_DNS_VERIFY; break;
|
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|
||
default:
|
||
if (serr >= 0)
|
||
ec = gpg_err_code_from_errno (serr);
|
||
else
|
||
ec = GPG_ERR_DNS_UNKNOWN;
|
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break;
|
||
}
|
||
return gpg_error (ec);
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* Return true if resolve.conf changed since it was last loaded. */
|
||
#ifdef USE_LIBDNS
|
||
static int
|
||
resolv_conf_changed_p (void)
|
||
{
|
||
#if defined(HAVE_W32_SYSTEM) || !defined(HAVE_STAT)
|
||
return 0;
|
||
#else
|
||
static time_t last_mtime;
|
||
const char *fname = RESOLV_CONF_NAME;
|
||
struct stat statbuf;
|
||
int changed = 0;
|
||
|
||
if (stat (fname, &statbuf))
|
||
{
|
||
log_error ("stat'ing '%s' failed: %s\n",
|
||
fname, gpg_strerror (gpg_error_from_syserror ()));
|
||
last_mtime = 1; /* Force a "changed" result the next time stat
|
||
* works. */
|
||
}
|
||
else if (!last_mtime)
|
||
last_mtime = statbuf.st_mtime;
|
||
else if (last_mtime != statbuf.st_mtime)
|
||
{
|
||
changed = 1;
|
||
last_mtime = statbuf.st_mtime;
|
||
}
|
||
|
||
return changed;
|
||
#endif
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Initialize libdns. Returns 0 on success; prints a diagnostic and
|
||
* returns an error code on failure. */
|
||
static gpg_error_t
|
||
libdns_init (ctrl_t ctrl)
|
||
{
|
||
gpg_error_t err;
|
||
struct libdns_s ld;
|
||
int derr;
|
||
char *cfgstr = NULL;
|
||
const char *fname = NULL;
|
||
|
||
if (libdns.resolv_conf)
|
||
return 0; /* Already initialized. */
|
||
|
||
memset (&ld, 0, sizeof ld);
|
||
|
||
ld.resolv_conf = dns_resconf_open (&derr);
|
||
if (!ld.resolv_conf)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
log_error ("failed to allocate DNS resconf object: %s\n",
|
||
gpg_strerror (err));
|
||
goto leave;
|
||
}
|
||
|
||
if (tor_mode)
|
||
{
|
||
if (!*tor_nameserver)
|
||
set_dns_nameserver (NULL);
|
||
|
||
if (!libdns_tor_port)
|
||
libdns_tor_port = TOR_PORT;
|
||
|
||
cfgstr = xtryasprintf ("[%s]:53", tor_nameserver);
|
||
if (!cfgstr)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
err = libdns_error_to_gpg_error
|
||
(dns_resconf_pton (&ld.resolv_conf->nameserver[0], cfgstr));
|
||
if (err)
|
||
log_error ("failed to set nameserver '%s': %s\n",
|
||
cfgstr, gpg_strerror (err));
|
||
if (err)
|
||
goto leave;
|
||
|
||
ld.resolv_conf->options.tcp = DNS_RESCONF_TCP_SOCKS;
|
||
|
||
xfree (cfgstr);
|
||
cfgstr = xtryasprintf ("[%s]:%d", "127.0.0.1", libdns_tor_port);
|
||
if (!cfgstr)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
err = libdns_error_to_gpg_error
|
||
(dns_resconf_pton (&ld.socks_host, cfgstr));
|
||
if (err)
|
||
{
|
||
log_error ("failed to set socks server '%s': %s\n",
|
||
cfgstr, gpg_strerror (err));
|
||
goto leave;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
#ifdef HAVE_W32_SYSTEM
|
||
ULONG ninfo_len;
|
||
PFIXED_INFO ninfo;
|
||
PIP_ADDR_STRING pip;
|
||
int idx;
|
||
|
||
ninfo_len = 2048;
|
||
ninfo = xtrymalloc (ninfo_len);
|
||
if (!ninfo)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
|
||
if (GetNetworkParams (ninfo, &ninfo_len))
|
||
{
|
||
log_error ("GetNetworkParms failed: %s\n", w32_strerror (-1));
|
||
err = gpg_error (GPG_ERR_GENERAL);
|
||
xfree (ninfo);
|
||
goto leave;
|
||
}
|
||
|
||
for (idx=0, pip = &(ninfo->DnsServerList);
|
||
pip && idx < DIM (ld.resolv_conf->nameserver);
|
||
pip = pip->Next)
|
||
{
|
||
if (opt_debug)
|
||
log_debug ("dns: dnsserver[%d] '%s'\n", idx, pip->IpAddress.String);
|
||
err = libdns_error_to_gpg_error
|
||
(dns_resconf_pton (&ld.resolv_conf->nameserver[idx],
|
||
pip->IpAddress.String));
|
||
if (err)
|
||
log_error ("failed to set nameserver[%d] '%s': %s\n",
|
||
idx, pip->IpAddress.String, gpg_strerror (err));
|
||
else
|
||
idx++;
|
||
}
|
||
xfree (ninfo);
|
||
|
||
#else /* Unix */
|
||
|
||
fname = RESOLV_CONF_NAME;
|
||
resolv_conf_changed_p (); /* Reset timestamp. */
|
||
err = libdns_error_to_gpg_error
|
||
(dns_resconf_loadpath (ld.resolv_conf, fname));
|
||
if (err)
|
||
{
|
||
log_error ("failed to load '%s': %s\n", fname, gpg_strerror (err));
|
||
goto leave;
|
||
}
|
||
|
||
fname = "/etc/nsswitch.conf";
|
||
err = libdns_error_to_gpg_error
|
||
(dns_nssconf_loadpath (ld.resolv_conf, fname));
|
||
if (err)
|
||
{
|
||
/* This is not a fatal error: nsswitch.conf is not used on
|
||
* all systems; assume classic behavior instead. */
|
||
if (gpg_err_code (err) != GPG_ERR_ENOENT)
|
||
log_error ("failed to load '%s': %s\n", fname, gpg_strerror (err));
|
||
if (opt_debug)
|
||
log_debug ("dns: fallback resolution order, files then DNS\n");
|
||
ld.resolv_conf->lookup[0] = 'f';
|
||
ld.resolv_conf->lookup[1] = 'b';
|
||
ld.resolv_conf->lookup[2] = '\0';
|
||
err = GPG_ERR_NO_ERROR;
|
||
}
|
||
else if (!strchr (ld.resolv_conf->lookup, 'b'))
|
||
{
|
||
/* No DNS resolution type found in the list. This might be
|
||
* due to systemd based systems which allow for custom
|
||
* keywords which are not known to us and thus we do not
|
||
* know whether DNS is wanted or not. Because DNS is
|
||
* important for our infrastructure, we forcefully append
|
||
* DNS to the end of the list. */
|
||
if (strlen (ld.resolv_conf->lookup)+2 < sizeof ld.resolv_conf->lookup)
|
||
{
|
||
if (opt_debug)
|
||
log_debug ("dns: appending DNS to resolution order\n");
|
||
strcat (ld.resolv_conf->lookup, "b");
|
||
}
|
||
else
|
||
log_error ("failed to append DNS to resolution order\n");
|
||
}
|
||
|
||
#endif /* Unix */
|
||
}
|
||
|
||
ld.hosts = dns_hosts_open (&derr);
|
||
if (!ld.hosts)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
log_error ("failed to initialize hosts file: %s\n", gpg_strerror (err));
|
||
goto leave;
|
||
}
|
||
|
||
{
|
||
#if HAVE_W32_SYSTEM
|
||
char *hosts_path = xtryasprintf ("%s\\System32\\drivers\\etc\\hosts",
|
||
getenv ("SystemRoot"));
|
||
if (! hosts_path)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
|
||
derr = dns_hosts_loadpath (ld.hosts, hosts_path);
|
||
xfree (hosts_path);
|
||
#else
|
||
derr = dns_hosts_loadpath (ld.hosts, "/etc/hosts");
|
||
#endif
|
||
if (derr)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
log_error ("failed to load hosts file: %s\n", gpg_strerror (err));
|
||
err = 0; /* Do not bail out - having no /etc/hosts is legal. */
|
||
}
|
||
}
|
||
|
||
ld.resolv_conf->options.recurse = recursive_resolver_p ();
|
||
|
||
/* dns_hints_local for stub mode, dns_hints_root for recursive. */
|
||
ld.hints = (recursive_resolver
|
||
? dns_hints_root (ld.resolv_conf, &derr)
|
||
: dns_hints_local (ld.resolv_conf, &derr));
|
||
if (!ld.hints)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
log_error ("failed to load DNS hints: %s\n", gpg_strerror (err));
|
||
fname = "[dns hints]";
|
||
goto leave;
|
||
}
|
||
|
||
/* All fine. Make the data global. */
|
||
libdns = ld;
|
||
|
||
if (opt_debug)
|
||
log_debug ("dns: libdns initialized%s\n", tor_mode?" (tor mode)":"");
|
||
|
||
leave:
|
||
if (!fname)
|
||
fname = cfgstr;
|
||
if (err && fname)
|
||
dirmngr_status_printf (ctrl, "WARNING",
|
||
"dns_config_problem %u"
|
||
" error accessing '%s': %s <%s>",
|
||
err, fname, gpg_strerror (err), gpg_strsource (err));
|
||
|
||
xfree (cfgstr);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Deinitialize libdns. */
|
||
static void
|
||
libdns_deinit (void)
|
||
{
|
||
struct libdns_s ld;
|
||
|
||
if (!libdns.resolv_conf)
|
||
return; /* Not initialized. */
|
||
|
||
ld = libdns;
|
||
memset (&libdns, 0, sizeof libdns);
|
||
dns_hints_close (ld.hints);
|
||
dns_hosts_close (ld.hosts);
|
||
dns_resconf_close (ld.resolv_conf);
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* SIGHUP action handler for this module. With FORCE set objects are
|
||
* all immediately released. */
|
||
void
|
||
reload_dns_stuff (int force)
|
||
{
|
||
#ifdef USE_LIBDNS
|
||
if (force)
|
||
{
|
||
libdns_deinit ();
|
||
libdns_reinit_pending = 0;
|
||
}
|
||
else
|
||
{
|
||
libdns_reinit_pending = 1;
|
||
libdns_tor_port = 0; /* Start again with the default port. */
|
||
}
|
||
#else
|
||
(void)force;
|
||
#endif
|
||
|
||
/* We also flush the IPv4/v6 support flag cache. */
|
||
cached_inet_support.valid = 0;
|
||
}
|
||
|
||
|
||
/* Called from time to time from the housekeeping thread. */
|
||
void
|
||
dns_stuff_housekeeping (void)
|
||
{
|
||
/* With the current housekeeping interval of 10 minutes we flush
|
||
* that case so that a new or removed interface will be detected not
|
||
* later than 10 minutes after it changed. This way the user does
|
||
* not need a reload. */
|
||
cached_inet_support.valid = 0;
|
||
}
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/*
|
||
* Initialize libdns if needed and open a dns_resolver context.
|
||
* Returns 0 on success and stores the new context at R_RES. On
|
||
* failure an error code is returned and NULL stored at R_RES.
|
||
*/
|
||
static gpg_error_t
|
||
libdns_res_open (ctrl_t ctrl, struct dns_resolver **r_res)
|
||
{
|
||
gpg_error_t err;
|
||
struct dns_resolver *res;
|
||
int derr;
|
||
struct dns_options opts = { 0 };
|
||
|
||
opts.socks_host = &libdns.socks_host;
|
||
opts.socks_user = tor_socks_user;
|
||
opts.socks_password = tor_socks_password;
|
||
|
||
*r_res = NULL;
|
||
|
||
/* Force a reload if resolv.conf has changed. */
|
||
if (resolv_conf_changed_p ())
|
||
{
|
||
if (opt_debug)
|
||
log_debug ("dns: resolv.conf changed - forcing reload\n");
|
||
libdns_reinit_pending = 1;
|
||
}
|
||
|
||
if (libdns_reinit_pending)
|
||
{
|
||
libdns_reinit_pending = 0;
|
||
libdns_deinit ();
|
||
}
|
||
|
||
err = libdns_init (ctrl);
|
||
if (err)
|
||
return err;
|
||
|
||
if (!opt_timeout)
|
||
set_dns_timeout (0);
|
||
|
||
res = dns_res_open (libdns.resolv_conf, libdns.hosts, libdns.hints, NULL,
|
||
&opts, &derr);
|
||
if (!res)
|
||
return libdns_error_to_gpg_error (derr);
|
||
|
||
*r_res = res;
|
||
return 0;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Helper to test whether we need to try again after having switched
|
||
* the Tor port. */
|
||
static int
|
||
libdns_switch_port_p (gpg_error_t err)
|
||
{
|
||
if (tor_mode && gpg_err_code (err) == GPG_ERR_ECONNREFUSED
|
||
&& libdns_tor_port == TOR_PORT)
|
||
{
|
||
/* Switch port and try again. */
|
||
if (opt_debug)
|
||
log_debug ("dns: switching from SOCKS port %d to %d\n",
|
||
TOR_PORT, TOR_PORT2);
|
||
libdns_tor_port = TOR_PORT2;
|
||
libdns_reinit_pending = 1;
|
||
return 1;
|
||
}
|
||
return 0;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Wrapper around dns_res_submit. */
|
||
static gpg_error_t
|
||
libdns_res_submit (struct dns_resolver *res, const char *qname,
|
||
enum dns_type qtype, enum dns_class qclass)
|
||
{
|
||
return libdns_error_to_gpg_error (dns_res_submit (res, qname, qtype, qclass));
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Standard event handling loop. */
|
||
gpg_error_t
|
||
libdns_res_wait (struct dns_resolver *res)
|
||
{
|
||
gpg_error_t err;
|
||
|
||
while ((err = libdns_error_to_gpg_error (dns_res_check (res)))
|
||
&& gpg_err_code (err) == GPG_ERR_EAGAIN)
|
||
{
|
||
if (dns_res_elapsed (res) > opt_timeout)
|
||
{
|
||
err = gpg_error (GPG_ERR_DNS_TIMEOUT);
|
||
break;
|
||
}
|
||
|
||
my_unprotect ();
|
||
dns_res_poll (res, 1);
|
||
my_protect ();
|
||
}
|
||
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
static gpg_error_t
|
||
resolve_name_libdns (ctrl_t ctrl, const char *name, unsigned short port,
|
||
int want_family, int want_socktype,
|
||
dns_addrinfo_t *r_dai, char **r_canonname)
|
||
{
|
||
gpg_error_t err;
|
||
dns_addrinfo_t daihead = NULL;
|
||
dns_addrinfo_t dai;
|
||
struct dns_resolver *res = NULL;
|
||
struct dns_addrinfo *ai = NULL;
|
||
struct addrinfo hints;
|
||
struct addrinfo *ent;
|
||
char portstr_[21];
|
||
char *portstr = NULL;
|
||
char *namebuf = NULL;
|
||
int derr;
|
||
|
||
*r_dai = NULL;
|
||
if (r_canonname)
|
||
*r_canonname = NULL;
|
||
|
||
memset (&hints, 0, sizeof hints);
|
||
hints.ai_family = want_family;
|
||
hints.ai_socktype = want_socktype;
|
||
hints.ai_flags = AI_ADDRCONFIG;
|
||
if (r_canonname)
|
||
hints.ai_flags |= AI_CANONNAME;
|
||
|
||
if (port)
|
||
{
|
||
snprintf (portstr_, sizeof portstr_, "%hu", port);
|
||
portstr = portstr_;
|
||
}
|
||
|
||
err = libdns_res_open (ctrl, &res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
|
||
if (is_ip_address (name))
|
||
{
|
||
hints.ai_flags |= AI_NUMERICHOST;
|
||
/* libdns does not grok brackets - remove them. */
|
||
if (*name == '[' && name[strlen(name)-1] == ']')
|
||
{
|
||
namebuf = xtrymalloc (strlen (name));
|
||
if (!namebuf)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
strcpy (namebuf, name+1);
|
||
namebuf[strlen (namebuf)-1] = 0;
|
||
name = namebuf;
|
||
}
|
||
}
|
||
|
||
ai = dns_ai_open (name, portstr, 0, &hints, res, &derr);
|
||
if (!ai)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
goto leave;
|
||
}
|
||
|
||
/* Loop over all records. */
|
||
for (;;)
|
||
{
|
||
err = libdns_error_to_gpg_error (dns_ai_nextent (&ent, ai));
|
||
if (gpg_err_code (err) == GPG_ERR_ENOENT)
|
||
{
|
||
if (daihead)
|
||
err = 0; /* We got some results, we're good. */
|
||
break; /* Ready. */
|
||
}
|
||
if (gpg_err_code (err) == GPG_ERR_EAGAIN)
|
||
{
|
||
if (dns_ai_elapsed (ai) > opt_timeout)
|
||
{
|
||
err = gpg_error (GPG_ERR_DNS_TIMEOUT);
|
||
goto leave;
|
||
}
|
||
|
||
my_unprotect ();
|
||
dns_ai_poll (ai, 1);
|
||
my_protect ();
|
||
continue;
|
||
}
|
||
if (err)
|
||
goto leave;
|
||
|
||
if (r_canonname && ! *r_canonname && ent && ent->ai_canonname)
|
||
{
|
||
*r_canonname = xtrystrdup (ent->ai_canonname);
|
||
if (!*r_canonname)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
/* Libdns appends the root zone part which is problematic
|
||
* for most other functions - strip it. */
|
||
if (**r_canonname && (*r_canonname)[strlen (*r_canonname)-1] == '.')
|
||
(*r_canonname)[strlen (*r_canonname)-1] = 0;
|
||
}
|
||
|
||
dai = xtrymalloc (sizeof *dai);
|
||
if (dai == NULL)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
|
||
dai->family = ent->ai_family;
|
||
dai->socktype = ent->ai_socktype;
|
||
dai->protocol = ent->ai_protocol;
|
||
dai->addrlen = ent->ai_addrlen;
|
||
memcpy (dai->addr, ent->ai_addr, ent->ai_addrlen);
|
||
dai->next = daihead;
|
||
daihead = dai;
|
||
|
||
xfree (ent);
|
||
}
|
||
|
||
leave:
|
||
dns_ai_close (ai);
|
||
dns_res_close (res);
|
||
|
||
if (err)
|
||
{
|
||
if (r_canonname)
|
||
{
|
||
xfree (*r_canonname);
|
||
*r_canonname = NULL;
|
||
}
|
||
free_dns_addrinfo (daihead);
|
||
}
|
||
else
|
||
*r_dai = daihead;
|
||
|
||
xfree (namebuf);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* Resolve a name using the standard system function. */
|
||
static gpg_error_t
|
||
resolve_name_standard (ctrl_t ctrl, const char *name, unsigned short port,
|
||
int want_family, int want_socktype,
|
||
dns_addrinfo_t *r_dai, char **r_canonname)
|
||
{
|
||
gpg_error_t err = 0;
|
||
dns_addrinfo_t daihead = NULL;
|
||
dns_addrinfo_t dai;
|
||
struct addrinfo *aibuf = NULL;
|
||
struct addrinfo hints, *ai;
|
||
char portstr[21];
|
||
int ret;
|
||
|
||
*r_dai = NULL;
|
||
if (r_canonname)
|
||
*r_canonname = NULL;
|
||
|
||
memset (&hints, 0, sizeof hints);
|
||
hints.ai_family = want_family;
|
||
hints.ai_socktype = want_socktype;
|
||
hints.ai_flags = AI_ADDRCONFIG;
|
||
if (r_canonname)
|
||
hints.ai_flags |= AI_CANONNAME;
|
||
if (is_ip_address (name))
|
||
hints.ai_flags |= AI_NUMERICHOST;
|
||
|
||
if (port)
|
||
snprintf (portstr, sizeof portstr, "%hu", port);
|
||
else
|
||
*portstr = 0;
|
||
|
||
/* We can't use the AI_IDN flag because that does the conversion
|
||
using the current locale. However, GnuPG always used UTF-8. To
|
||
support IDN we would need to make use of the libidn API. */
|
||
ret = getaddrinfo (name, *portstr? portstr : NULL, &hints, &aibuf);
|
||
if (ret)
|
||
{
|
||
aibuf = NULL;
|
||
err = map_eai_to_gpg_error (ret);
|
||
if (gpg_err_code (err) == GPG_ERR_NO_NAME)
|
||
{
|
||
/* There seems to be a bug in the glibc getaddrinfo function
|
||
if the CNAME points to a long list of A and AAAA records
|
||
in which case the function return NO_NAME. Let's do the
|
||
CNAME redirection again. */
|
||
char *cname;
|
||
|
||
if (get_dns_cname (ctrl, name, &cname))
|
||
goto leave; /* Still no success. */
|
||
|
||
ret = getaddrinfo (cname, *portstr? portstr : NULL, &hints, &aibuf);
|
||
xfree (cname);
|
||
if (ret)
|
||
{
|
||
aibuf = NULL;
|
||
err = map_eai_to_gpg_error (ret);
|
||
goto leave;
|
||
}
|
||
err = 0; /* Yep, now it worked. */
|
||
}
|
||
else
|
||
goto leave;
|
||
}
|
||
|
||
if (r_canonname && aibuf && aibuf->ai_canonname)
|
||
{
|
||
*r_canonname = xtrystrdup (aibuf->ai_canonname);
|
||
if (!*r_canonname)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
}
|
||
|
||
for (ai = aibuf; ai; ai = ai->ai_next)
|
||
{
|
||
if (ai->ai_family != AF_INET6 && ai->ai_family != AF_INET)
|
||
continue;
|
||
if (opt_disable_ipv4 && ai->ai_family == AF_INET)
|
||
continue;
|
||
if (opt_disable_ipv6 && ai->ai_family == AF_INET6)
|
||
continue;
|
||
|
||
dai = xtrymalloc (sizeof *dai);
|
||
dai->family = ai->ai_family;
|
||
dai->socktype = ai->ai_socktype;
|
||
dai->protocol = ai->ai_protocol;
|
||
dai->addrlen = ai->ai_addrlen;
|
||
memcpy (dai->addr, ai->ai_addr, ai->ai_addrlen);
|
||
dai->next = daihead;
|
||
daihead = dai;
|
||
}
|
||
|
||
leave:
|
||
if (aibuf)
|
||
freeaddrinfo (aibuf);
|
||
if (err)
|
||
{
|
||
if (r_canonname)
|
||
{
|
||
xfree (*r_canonname);
|
||
*r_canonname = NULL;
|
||
}
|
||
free_dns_addrinfo (daihead);
|
||
}
|
||
else
|
||
*r_dai = daihead;
|
||
return err;
|
||
}
|
||
|
||
|
||
/* This a wrapper around getaddrinfo with slightly different semantics.
|
||
* NAME is the name to resolve.
|
||
* PORT is the requested port or 0.
|
||
* WANT_FAMILY is either 0 (AF_UNSPEC), AF_INET6, or AF_INET4.
|
||
* WANT_SOCKETTYPE is either 0 for any socket type
|
||
* or SOCK_STREAM or SOCK_DGRAM.
|
||
*
|
||
* On success the result is stored in a linked list with the head
|
||
* stored at the address R_AI; the caller must call free_dns_addrinfo
|
||
* on this. If R_CANONNAME is not NULL the official name of the host
|
||
* is stored there as a malloced string; if that name is not available
|
||
* NULL is stored. */
|
||
gpg_error_t
|
||
resolve_dns_name (ctrl_t ctrl, const char *name, unsigned short port,
|
||
int want_family, int want_socktype,
|
||
dns_addrinfo_t *r_ai, char **r_canonname)
|
||
{
|
||
gpg_error_t err;
|
||
|
||
#ifdef USE_LIBDNS
|
||
if (!standard_resolver)
|
||
{
|
||
err = resolve_name_libdns (ctrl, name, port, want_family, want_socktype,
|
||
r_ai, r_canonname);
|
||
if (err && libdns_switch_port_p (err))
|
||
err = resolve_name_libdns (ctrl, name, port, want_family, want_socktype,
|
||
r_ai, r_canonname);
|
||
}
|
||
else
|
||
#endif /*USE_LIBDNS*/
|
||
err = resolve_name_standard (ctrl, name, port, want_family, want_socktype,
|
||
r_ai, r_canonname);
|
||
if (opt_debug)
|
||
log_debug ("dns: resolve_dns_name(%s): %s\n", name, gpg_strerror (err));
|
||
return err;
|
||
}
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Resolve an address using libdns. */
|
||
static gpg_error_t
|
||
resolve_addr_libdns (ctrl_t ctrl,
|
||
const struct sockaddr_storage *addr, int addrlen,
|
||
unsigned int flags, char **r_name)
|
||
{
|
||
gpg_error_t err;
|
||
char host[DNS_D_MAXNAME + 1];
|
||
struct dns_resolver *res = NULL;
|
||
struct dns_packet *ans = NULL;
|
||
struct dns_ptr ptr;
|
||
int derr;
|
||
|
||
*r_name = NULL;
|
||
|
||
/* First we turn ADDR into a DNS name (with ".arpa" suffix). */
|
||
err = 0;
|
||
if (addr->ss_family == AF_INET6)
|
||
{
|
||
const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *)addr;
|
||
if (!dns_aaaa_arpa (host, sizeof host, (void*)&a6->sin6_addr))
|
||
err = gpg_error (GPG_ERR_INV_OBJ);
|
||
}
|
||
else if (addr->ss_family == AF_INET)
|
||
{
|
||
const struct sockaddr_in *a4 = (const struct sockaddr_in *)addr;
|
||
if (!dns_a_arpa (host, sizeof host, (void*)&a4->sin_addr))
|
||
err = gpg_error (GPG_ERR_INV_OBJ);
|
||
}
|
||
else
|
||
err = gpg_error (GPG_ERR_EAFNOSUPPORT);
|
||
if (err)
|
||
goto leave;
|
||
|
||
|
||
err = libdns_res_open (ctrl, &res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
err = libdns_res_submit (res, host, DNS_T_PTR, DNS_C_IN);
|
||
if (err)
|
||
goto leave;
|
||
|
||
err = libdns_res_wait (res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
ans = dns_res_fetch (res, &derr);
|
||
if (!ans)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
goto leave;
|
||
}
|
||
|
||
/* Check the rcode. */
|
||
switch (dns_p_rcode (ans))
|
||
{
|
||
case DNS_RC_NOERROR:
|
||
break;
|
||
case DNS_RC_NXDOMAIN:
|
||
err = gpg_error (GPG_ERR_NO_NAME);
|
||
break;
|
||
default:
|
||
err = GPG_ERR_SERVER_FAILED;
|
||
goto leave;
|
||
}
|
||
|
||
/* Parse the result. */
|
||
if (!err)
|
||
{
|
||
struct dns_rr rr;
|
||
struct dns_rr_i rri;
|
||
|
||
memset (&rri, 0, sizeof rri);
|
||
dns_rr_i_init (&rri);
|
||
rri.section = DNS_S_ALL & ~DNS_S_QD;
|
||
rri.name = host;
|
||
rri.type = DNS_T_PTR;
|
||
|
||
if (!dns_rr_grep (&rr, 1, &rri, ans, &derr))
|
||
{
|
||
err = gpg_error (GPG_ERR_NOT_FOUND);
|
||
goto leave;
|
||
}
|
||
|
||
err = libdns_error_to_gpg_error (dns_ptr_parse (&ptr, &rr, ans));
|
||
if (err)
|
||
goto leave;
|
||
|
||
/* Copy result. */
|
||
*r_name = xtrystrdup (ptr.host);
|
||
if (!*r_name)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
/* Libdns appends the root zone part which is problematic
|
||
* for most other functions - strip it. */
|
||
if (**r_name && (*r_name)[strlen (*r_name)-1] == '.')
|
||
(*r_name)[strlen (*r_name)-1] = 0;
|
||
}
|
||
else /* GPG_ERR_NO_NAME */
|
||
{
|
||
char *buffer, *p;
|
||
int buflen;
|
||
int ec;
|
||
|
||
buffer = ptr.host;
|
||
buflen = sizeof ptr.host;
|
||
|
||
p = buffer;
|
||
if (addr->ss_family == AF_INET6 && (flags & DNS_WITHBRACKET))
|
||
{
|
||
*p++ = '[';
|
||
buflen -= 2;
|
||
}
|
||
ec = getnameinfo ((const struct sockaddr *)addr,
|
||
addrlen, p, buflen, NULL, 0, NI_NUMERICHOST);
|
||
if (ec)
|
||
{
|
||
err = map_eai_to_gpg_error (ec);
|
||
goto leave;
|
||
}
|
||
if (addr->ss_family == AF_INET6 && (flags & DNS_WITHBRACKET))
|
||
strcat (buffer, "]");
|
||
}
|
||
|
||
leave:
|
||
dns_free (ans);
|
||
dns_res_close (res);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* Resolve an address using the standard system function. */
|
||
static gpg_error_t
|
||
resolve_addr_standard (const struct sockaddr_storage *addr, int addrlen,
|
||
unsigned int flags, char **r_name)
|
||
{
|
||
gpg_error_t err;
|
||
int ec;
|
||
char *buffer, *p;
|
||
int buflen;
|
||
|
||
*r_name = NULL;
|
||
|
||
buflen = NI_MAXHOST;
|
||
buffer = xtrymalloc (buflen + 2 + 1);
|
||
if (!buffer)
|
||
return gpg_error_from_syserror ();
|
||
|
||
if ((flags & DNS_NUMERICHOST) || tor_mode)
|
||
ec = EAI_NONAME;
|
||
else
|
||
ec = getnameinfo ((const struct sockaddr *)addr,
|
||
addrlen, buffer, buflen, NULL, 0, NI_NAMEREQD);
|
||
|
||
if (!ec && *buffer == '[')
|
||
ec = EAI_FAIL; /* A name may never start with a bracket. */
|
||
else if (ec == EAI_NONAME)
|
||
{
|
||
p = buffer;
|
||
if (addr->ss_family == AF_INET6 && (flags & DNS_WITHBRACKET))
|
||
{
|
||
*p++ = '[';
|
||
buflen -= 2;
|
||
}
|
||
ec = getnameinfo ((const struct sockaddr *)addr,
|
||
addrlen, p, buflen, NULL, 0, NI_NUMERICHOST);
|
||
if (!ec && addr->ss_family == AF_INET6 && (flags & DNS_WITHBRACKET))
|
||
strcat (buffer, "]");
|
||
}
|
||
|
||
if (ec)
|
||
err = map_eai_to_gpg_error (ec);
|
||
else
|
||
{
|
||
p = xtryrealloc (buffer, strlen (buffer)+1);
|
||
if (!p)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
{
|
||
buffer = p;
|
||
err = 0;
|
||
}
|
||
}
|
||
|
||
if (err)
|
||
xfree (buffer);
|
||
else
|
||
*r_name = buffer;
|
||
|
||
return err;
|
||
}
|
||
|
||
|
||
/* A wrapper around getnameinfo. */
|
||
gpg_error_t
|
||
resolve_dns_addr (ctrl_t ctrl,
|
||
const struct sockaddr_storage *addr, int addrlen,
|
||
unsigned int flags, char **r_name)
|
||
{
|
||
gpg_error_t err;
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* Note that we divert to the standard resolver for NUMERICHOST. */
|
||
if (!standard_resolver && !(flags & DNS_NUMERICHOST))
|
||
{
|
||
err = resolve_addr_libdns (ctrl, addr, addrlen, flags, r_name);
|
||
if (err && libdns_switch_port_p (err))
|
||
err = resolve_addr_libdns (ctrl, addr, addrlen, flags, r_name);
|
||
}
|
||
else
|
||
#endif /*USE_LIBDNS*/
|
||
err = resolve_addr_standard (addr, addrlen, flags, r_name);
|
||
|
||
if (opt_debug)
|
||
log_debug ("dns: resolve_dns_addr(): %s\n", gpg_strerror (err));
|
||
return err;
|
||
}
|
||
|
||
|
||
/* Check whether NAME is an IP address. Returns a true if it is
|
||
* either an IPv6 or a IPv4 numerical address. The actual return
|
||
* values can also be used to identify whether it is v4 or v6: The
|
||
* true value will surprisingly be 4 for IPv4 and 6 for IPv6. */
|
||
int
|
||
is_ip_address (const char *name)
|
||
{
|
||
const char *s;
|
||
int ndots, dblcol, n;
|
||
|
||
if (*name == '[')
|
||
return 6; /* yes: A legal DNS name may not contain this character;
|
||
this must be bracketed v6 address. */
|
||
if (*name == '.')
|
||
return 0; /* No. A leading dot is not a valid IP address. */
|
||
|
||
/* Check whether this is a v6 address. */
|
||
ndots = n = dblcol = 0;
|
||
for (s=name; *s; s++)
|
||
{
|
||
if (*s == ':')
|
||
{
|
||
ndots++;
|
||
if (s[1] == ':')
|
||
{
|
||
ndots++;
|
||
if (dblcol)
|
||
return 0; /* No: Only one "::" allowed. */
|
||
dblcol++;
|
||
if (s[1])
|
||
s++;
|
||
}
|
||
n = 0;
|
||
}
|
||
else if (*s == '.')
|
||
goto legacy;
|
||
else if (!strchr ("0123456789abcdefABCDEF", *s))
|
||
return 0; /* No: Not a hex digit. */
|
||
else if (++n > 4)
|
||
return 0; /* To many digits in a group. */
|
||
}
|
||
if (ndots > 7)
|
||
return 0; /* No: Too many colons. */
|
||
else if (ndots > 1)
|
||
return 6; /* Yes: At least 2 colons indicate an v6 address. */
|
||
|
||
legacy:
|
||
/* Check whether it is legacy IP address. */
|
||
ndots = n = 0;
|
||
for (s=name; *s; s++)
|
||
{
|
||
if (*s == '.')
|
||
{
|
||
if (s[1] == '.')
|
||
return 0; /* No: Double dot. */
|
||
if (atoi (s+1) > 255)
|
||
return 0; /* No: Ipv4 byte value too large. */
|
||
ndots++;
|
||
n = 0;
|
||
}
|
||
else if (!strchr ("0123456789", *s))
|
||
return 0; /* No: Not a digit. */
|
||
else if (++n > 3)
|
||
return 0; /* No: More than 3 digits. */
|
||
}
|
||
return (ndots == 3)? 4 : 0;
|
||
}
|
||
|
||
|
||
/* Return true if NAME is an onion address. */
|
||
int
|
||
is_onion_address (const char *name)
|
||
{
|
||
size_t len;
|
||
|
||
len = name? strlen (name) : 0;
|
||
if (len < 8 || strcmp (name + len - 6, ".onion"))
|
||
return 0;
|
||
/* Note that we require at least 2 characters before the suffix. */
|
||
return 1; /* Yes. */
|
||
}
|
||
|
||
|
||
/* libdns version of get_dns_cert. */
|
||
#ifdef USE_LIBDNS
|
||
static gpg_error_t
|
||
get_dns_cert_libdns (ctrl_t ctrl, const char *name, int want_certtype,
|
||
void **r_key, size_t *r_keylen,
|
||
unsigned char **r_fpr, size_t *r_fprlen, char **r_url)
|
||
{
|
||
gpg_error_t err;
|
||
struct dns_resolver *res = NULL;
|
||
struct dns_packet *ans = NULL;
|
||
struct dns_rr rr;
|
||
struct dns_rr_i rri;
|
||
char host[DNS_D_MAXNAME + 1];
|
||
int derr;
|
||
int qtype;
|
||
|
||
/* Get the query type from WANT_CERTTYPE (which in general indicates
|
||
* the subtype we want). */
|
||
qtype = (want_certtype < DNS_CERTTYPE_RRBASE
|
||
? T_CERT
|
||
: (want_certtype - DNS_CERTTYPE_RRBASE));
|
||
|
||
|
||
err = libdns_res_open (ctrl, &res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
if (dns_d_anchor (host, sizeof host, name, strlen (name)) >= sizeof host)
|
||
{
|
||
err = gpg_error (GPG_ERR_ENAMETOOLONG);
|
||
goto leave;
|
||
}
|
||
|
||
err = libdns_res_submit (res, name, qtype, DNS_C_IN);
|
||
if (err)
|
||
goto leave;
|
||
|
||
err = libdns_res_wait (res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
ans = dns_res_fetch (res, &derr);
|
||
if (!ans)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
goto leave;
|
||
}
|
||
|
||
/* Check the rcode. */
|
||
switch (dns_p_rcode (ans))
|
||
{
|
||
case DNS_RC_NOERROR: break;
|
||
case DNS_RC_NXDOMAIN: err = gpg_error (GPG_ERR_NO_NAME); break;
|
||
default: err = GPG_ERR_SERVER_FAILED; break;
|
||
}
|
||
if (err)
|
||
goto leave;
|
||
|
||
memset (&rri, 0, sizeof rri);
|
||
dns_rr_i_init (&rri);
|
||
rri.section = DNS_S_ALL & ~DNS_S_QD;
|
||
rri.name = host;
|
||
rri.type = qtype;
|
||
|
||
err = gpg_error (GPG_ERR_NOT_FOUND);
|
||
while (dns_rr_grep (&rr, 1, &rri, ans, &derr))
|
||
{
|
||
unsigned char *rp = ans->data + rr.rd.p;
|
||
unsigned short len = rr.rd.len;
|
||
u16 subtype;
|
||
|
||
if (!len)
|
||
{
|
||
/* Definitely too short - skip. */
|
||
}
|
||
else if (want_certtype >= DNS_CERTTYPE_RRBASE
|
||
&& rr.type == (want_certtype - DNS_CERTTYPE_RRBASE)
|
||
&& r_key)
|
||
{
|
||
*r_key = xtrymalloc (len);
|
||
if (!*r_key)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
{
|
||
memcpy (*r_key, rp, len);
|
||
*r_keylen = len;
|
||
err = 0;
|
||
}
|
||
goto leave;
|
||
}
|
||
else if (want_certtype >= DNS_CERTTYPE_RRBASE)
|
||
{
|
||
/* We did not found the requested RR - skip. */
|
||
}
|
||
else if (rr.type == T_CERT && len > 5)
|
||
{
|
||
/* We got a CERT type. */
|
||
subtype = buf16_to_u16 (rp);
|
||
rp += 2; len -= 2;
|
||
|
||
/* Skip the CERT key tag and algo which we don't need. */
|
||
rp += 3; len -= 3;
|
||
|
||
if (want_certtype && want_certtype != subtype)
|
||
; /* Not the requested subtype - skip. */
|
||
else if (subtype == DNS_CERTTYPE_PGP && len && r_key && r_keylen)
|
||
{
|
||
/* PGP subtype */
|
||
*r_key = xtrymalloc (len);
|
||
if (!*r_key)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
{
|
||
memcpy (*r_key, rp, len);
|
||
*r_keylen = len;
|
||
err = 0;
|
||
}
|
||
goto leave;
|
||
}
|
||
else if (subtype == DNS_CERTTYPE_IPGP
|
||
&& len && len < 1023 && len >= rp[0] + 1)
|
||
{
|
||
/* IPGP type */
|
||
*r_fprlen = rp[0];
|
||
if (*r_fprlen)
|
||
{
|
||
*r_fpr = xtrymalloc (*r_fprlen);
|
||
if (!*r_fpr)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
memcpy (*r_fpr, rp+1, *r_fprlen);
|
||
}
|
||
else
|
||
*r_fpr = NULL;
|
||
|
||
if (len > *r_fprlen + 1)
|
||
{
|
||
*r_url = xtrymalloc (len - (*r_fprlen + 1) + 1);
|
||
if (!*r_url)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
xfree (*r_fpr);
|
||
*r_fpr = NULL;
|
||
goto leave;
|
||
}
|
||
memcpy (*r_url, rp + *r_fprlen + 1, len - (*r_fprlen + 1));
|
||
(*r_url)[len - (*r_fprlen + 1)] = 0;
|
||
}
|
||
else
|
||
*r_url = NULL;
|
||
|
||
err = 0;
|
||
goto leave;
|
||
}
|
||
else
|
||
{
|
||
/* Unknown subtype or record too short - skip. */
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Not a requested type - skip. */
|
||
}
|
||
}
|
||
|
||
leave:
|
||
dns_free (ans);
|
||
dns_res_close (res);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* Standard resolver version of get_dns_cert. */
|
||
static gpg_error_t
|
||
get_dns_cert_standard (const char *name, int want_certtype,
|
||
void **r_key, size_t *r_keylen,
|
||
unsigned char **r_fpr, size_t *r_fprlen, char **r_url)
|
||
{
|
||
#ifdef HAVE_SYSTEM_RESOLVER
|
||
gpg_error_t err;
|
||
unsigned char *answer;
|
||
int r;
|
||
u16 count;
|
||
|
||
/* Allocate a 64k buffer which is the limit for an DNS response. */
|
||
answer = xtrymalloc (65536);
|
||
if (!answer)
|
||
return gpg_error_from_syserror ();
|
||
|
||
err = gpg_error (GPG_ERR_NOT_FOUND);
|
||
r = res_query (name, C_IN,
|
||
(want_certtype < DNS_CERTTYPE_RRBASE
|
||
? T_CERT
|
||
: (want_certtype - DNS_CERTTYPE_RRBASE)),
|
||
answer, 65536);
|
||
/* Not too big, not too small, no errors and at least 1 answer. */
|
||
if (r >= sizeof (HEADER) && r <= 65536
|
||
&& (((HEADER *)(void *) answer)->rcode) == NOERROR
|
||
&& (count = ntohs (((HEADER *)(void *) answer)->ancount)))
|
||
{
|
||
int rc;
|
||
unsigned char *pt, *emsg;
|
||
|
||
emsg = &answer[r];
|
||
|
||
pt = &answer[sizeof (HEADER)];
|
||
|
||
/* Skip over the query */
|
||
|
||
rc = dn_skipname (pt, emsg);
|
||
if (rc == -1)
|
||
{
|
||
err = gpg_error (GPG_ERR_INV_OBJ);
|
||
goto leave;
|
||
}
|
||
pt += rc + QFIXEDSZ;
|
||
|
||
/* There are several possible response types for a CERT request.
|
||
We're interested in the PGP (a key) and IPGP (a URI) types.
|
||
Skip all others. TODO: A key is better than a URI since
|
||
we've gone through all this bother to fetch it, so favor that
|
||
if we have both PGP and IPGP? */
|
||
|
||
while (count-- > 0 && pt < emsg)
|
||
{
|
||
u16 type, class, dlen, ctype;
|
||
|
||
rc = dn_skipname (pt, emsg); /* the name we just queried for */
|
||
if (rc == -1)
|
||
{
|
||
err = gpg_error (GPG_ERR_INV_OBJ);
|
||
goto leave;
|
||
}
|
||
|
||
pt += rc;
|
||
|
||
/* Truncated message? 15 bytes takes us to the point where
|
||
we start looking at the ctype. */
|
||
if ((emsg - pt) < 15)
|
||
break;
|
||
|
||
type = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
|
||
class = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
|
||
if (class != C_IN)
|
||
break;
|
||
|
||
/* ttl */
|
||
pt += 4;
|
||
|
||
/* data length */
|
||
dlen = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
|
||
/* Check the type and parse. */
|
||
if (want_certtype >= DNS_CERTTYPE_RRBASE
|
||
&& type == (want_certtype - DNS_CERTTYPE_RRBASE)
|
||
&& r_key)
|
||
{
|
||
*r_key = xtrymalloc (dlen);
|
||
if (!*r_key)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
{
|
||
memcpy (*r_key, pt, dlen);
|
||
*r_keylen = dlen;
|
||
err = 0;
|
||
}
|
||
goto leave;
|
||
}
|
||
else if (want_certtype >= DNS_CERTTYPE_RRBASE)
|
||
{
|
||
/* We did not found the requested RR. */
|
||
pt += dlen;
|
||
}
|
||
else if (type == T_CERT)
|
||
{
|
||
/* We got a CERT type. */
|
||
ctype = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
|
||
/* Skip the CERT key tag and algo which we don't need. */
|
||
pt += 3;
|
||
|
||
dlen -= 5;
|
||
|
||
/* 15 bytes takes us to here */
|
||
if (want_certtype && want_certtype != ctype)
|
||
; /* Not of the requested certtype. */
|
||
else if (ctype == DNS_CERTTYPE_PGP && dlen && r_key && r_keylen)
|
||
{
|
||
/* PGP type */
|
||
*r_key = xtrymalloc (dlen);
|
||
if (!*r_key)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
{
|
||
memcpy (*r_key, pt, dlen);
|
||
*r_keylen = dlen;
|
||
err = 0;
|
||
}
|
||
goto leave;
|
||
}
|
||
else if (ctype == DNS_CERTTYPE_IPGP
|
||
&& dlen && dlen < 1023 && dlen >= pt[0] + 1)
|
||
{
|
||
/* IPGP type */
|
||
*r_fprlen = pt[0];
|
||
if (*r_fprlen)
|
||
{
|
||
*r_fpr = xtrymalloc (*r_fprlen);
|
||
if (!*r_fpr)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
memcpy (*r_fpr, &pt[1], *r_fprlen);
|
||
}
|
||
else
|
||
*r_fpr = NULL;
|
||
|
||
if (dlen > *r_fprlen + 1)
|
||
{
|
||
*r_url = xtrymalloc (dlen - (*r_fprlen + 1) + 1);
|
||
if (!*r_url)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
xfree (*r_fpr);
|
||
*r_fpr = NULL;
|
||
goto leave;
|
||
}
|
||
memcpy (*r_url, &pt[*r_fprlen + 1],
|
||
dlen - (*r_fprlen + 1));
|
||
(*r_url)[dlen - (*r_fprlen + 1)] = '\0';
|
||
}
|
||
else
|
||
*r_url = NULL;
|
||
|
||
err = 0;
|
||
goto leave;
|
||
}
|
||
|
||
/* No subtype matches, so continue with the next answer. */
|
||
pt += dlen;
|
||
}
|
||
else
|
||
{
|
||
/* Not a requested type - might be a CNAME. Try next item. */
|
||
pt += dlen;
|
||
}
|
||
}
|
||
}
|
||
|
||
leave:
|
||
xfree (answer);
|
||
return err;
|
||
|
||
#else /*!HAVE_SYSTEM_RESOLVER*/
|
||
|
||
(void)name;
|
||
(void)want_certtype;
|
||
(void)r_key;
|
||
(void)r_keylen;
|
||
(void)r_fpr;
|
||
(void)r_fprlen;
|
||
(void)r_url;
|
||
return gpg_error (GPG_ERR_NOT_SUPPORTED);
|
||
|
||
#endif /*!HAVE_SYSTEM_RESOLVER*/
|
||
}
|
||
|
||
|
||
/* Returns 0 on success or an error code. If a PGP CERT record was
|
||
found, the malloced data is returned at (R_KEY, R_KEYLEN) and
|
||
the other return parameters are set to NULL/0. If an IPGP CERT
|
||
record was found the fingerprint is stored as an allocated block at
|
||
R_FPR and its length at R_FPRLEN; an URL is allocated as a
|
||
string and returned at R_URL. If WANT_CERTTYPE is 0 this function
|
||
returns the first CERT found with a supported type; it is expected
|
||
that only one CERT record is used. If WANT_CERTTYPE is one of the
|
||
supported certtypes only records with this certtype are considered
|
||
and the first found is returned. (R_KEY,R_KEYLEN) are optional. */
|
||
gpg_error_t
|
||
get_dns_cert (ctrl_t ctrl, const char *name, int want_certtype,
|
||
void **r_key, size_t *r_keylen,
|
||
unsigned char **r_fpr, size_t *r_fprlen, char **r_url)
|
||
{
|
||
gpg_error_t err;
|
||
|
||
if (r_key)
|
||
*r_key = NULL;
|
||
if (r_keylen)
|
||
*r_keylen = 0;
|
||
*r_fpr = NULL;
|
||
*r_fprlen = 0;
|
||
*r_url = NULL;
|
||
|
||
#ifdef USE_LIBDNS
|
||
if (!standard_resolver)
|
||
{
|
||
err = get_dns_cert_libdns (ctrl, name, want_certtype, r_key, r_keylen,
|
||
r_fpr, r_fprlen, r_url);
|
||
if (err && libdns_switch_port_p (err))
|
||
err = get_dns_cert_libdns (ctrl, name, want_certtype, r_key, r_keylen,
|
||
r_fpr, r_fprlen, r_url);
|
||
}
|
||
else
|
||
#endif /*USE_LIBDNS*/
|
||
err = get_dns_cert_standard (name, want_certtype, r_key, r_keylen,
|
||
r_fpr, r_fprlen, r_url);
|
||
|
||
if (opt_debug)
|
||
log_debug ("dns: get_dns_cert(%s): %s\n", name, gpg_strerror (err));
|
||
return err;
|
||
}
|
||
|
||
|
||
static int
|
||
priosort(const void *a,const void *b)
|
||
{
|
||
const struct srventry *sa=a,*sb=b;
|
||
if(sa->priority>sb->priority)
|
||
return 1;
|
||
else if(sa->priority<sb->priority)
|
||
return -1;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Libdns based helper for getsrv. Note that it is expected that NULL
|
||
* is stored at the address of LIST and 0 is stored at the address of
|
||
* R_COUNT. */
|
||
#ifdef USE_LIBDNS
|
||
static gpg_error_t
|
||
getsrv_libdns (ctrl_t ctrl,
|
||
const char *name, struct srventry **list, unsigned int *r_count)
|
||
{
|
||
gpg_error_t err;
|
||
struct dns_resolver *res = NULL;
|
||
struct dns_packet *ans = NULL;
|
||
struct dns_rr rr;
|
||
struct dns_rr_i rri;
|
||
char host[DNS_D_MAXNAME + 1];
|
||
int derr;
|
||
unsigned int srvcount = 0;
|
||
|
||
err = libdns_res_open (ctrl, &res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
if (dns_d_anchor (host, sizeof host, name, strlen (name)) >= sizeof host)
|
||
{
|
||
err = gpg_error (GPG_ERR_ENAMETOOLONG);
|
||
goto leave;
|
||
}
|
||
|
||
err = libdns_res_submit (res, name, DNS_T_SRV, DNS_C_IN);
|
||
if (err)
|
||
goto leave;
|
||
|
||
err = libdns_res_wait (res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
ans = dns_res_fetch (res, &derr);
|
||
if (!ans)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
goto leave;
|
||
}
|
||
|
||
/* Check the rcode. */
|
||
switch (dns_p_rcode (ans))
|
||
{
|
||
case DNS_RC_NOERROR: break;
|
||
case DNS_RC_NXDOMAIN: err = gpg_error (GPG_ERR_NO_NAME); break;
|
||
default: err = GPG_ERR_SERVER_FAILED; break;
|
||
}
|
||
if (err)
|
||
goto leave;
|
||
|
||
memset (&rri, 0, sizeof rri);
|
||
dns_rr_i_init (&rri);
|
||
rri.section = DNS_S_ALL & ~DNS_S_QD;
|
||
rri.name = host;
|
||
rri.type = DNS_T_SRV;
|
||
|
||
while (dns_rr_grep (&rr, 1, &rri, ans, &derr))
|
||
{
|
||
struct dns_srv dsrv;
|
||
struct srventry *srv;
|
||
struct srventry *newlist;
|
||
|
||
err = libdns_error_to_gpg_error (dns_srv_parse(&dsrv, &rr, ans));
|
||
if (err)
|
||
goto leave;
|
||
|
||
newlist = xtryrealloc (*list, (srvcount+1)*sizeof(struct srventry));
|
||
if (!newlist)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
*list = newlist;
|
||
memset (&(*list)[srvcount], 0, sizeof(struct srventry));
|
||
srv = &(*list)[srvcount];
|
||
srvcount++;
|
||
srv->priority = dsrv.priority;
|
||
srv->weight = dsrv.weight;
|
||
srv->port = dsrv.port;
|
||
mem2str (srv->target, dsrv.target, sizeof srv->target);
|
||
/* Libdns appends the root zone part which is problematic for
|
||
* most other functions - strip it. */
|
||
if (*srv->target && (srv->target)[strlen (srv->target)-1] == '.')
|
||
(srv->target)[strlen (srv->target)-1] = 0;
|
||
}
|
||
|
||
*r_count = srvcount;
|
||
|
||
leave:
|
||
if (err)
|
||
{
|
||
xfree (*list);
|
||
*list = NULL;
|
||
}
|
||
dns_free (ans);
|
||
dns_res_close (res);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* Standard resolver based helper for getsrv. Note that it is
|
||
* expected that NULL is stored at the address of LIST and 0 is stored
|
||
* at the address of R_COUNT. */
|
||
static gpg_error_t
|
||
getsrv_standard (const char *name,
|
||
struct srventry **list, unsigned int *r_count)
|
||
{
|
||
#ifdef HAVE_SYSTEM_RESOLVER
|
||
union {
|
||
unsigned char ans[2048];
|
||
HEADER header[1];
|
||
} res;
|
||
unsigned char *answer = res.ans;
|
||
HEADER *header = res.header;
|
||
unsigned char *pt, *emsg;
|
||
int r, rc;
|
||
u16 dlen;
|
||
unsigned int srvcount = 0;
|
||
u16 count;
|
||
|
||
/* Do not allow a query using the standard resolver in Tor mode. */
|
||
if (tor_mode)
|
||
return gpg_error (GPG_ERR_NOT_ENABLED);
|
||
|
||
my_unprotect ();
|
||
r = res_query (name, C_IN, T_SRV, answer, sizeof res.ans);
|
||
my_protect ();
|
||
if (r < 0)
|
||
return get_h_errno_as_gpg_error ();
|
||
if (r < sizeof (HEADER))
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
if (r > sizeof res.ans)
|
||
return gpg_error (GPG_ERR_SYSTEM_BUG);
|
||
if (header->rcode != NOERROR || !(count=ntohs (header->ancount)))
|
||
return gpg_error (GPG_ERR_NO_NAME); /* Error or no record found. */
|
||
|
||
emsg = &answer[r];
|
||
pt = &answer[sizeof(HEADER)];
|
||
|
||
/* Skip over the query */
|
||
rc = dn_skipname (pt, emsg);
|
||
if (rc == -1)
|
||
goto fail;
|
||
|
||
pt += rc + QFIXEDSZ;
|
||
|
||
while (count-- > 0 && pt < emsg)
|
||
{
|
||
struct srventry *srv;
|
||
u16 type, class;
|
||
struct srventry *newlist;
|
||
|
||
newlist = xtryrealloc (*list, (srvcount+1)*sizeof(struct srventry));
|
||
if (!newlist)
|
||
goto fail;
|
||
*list = newlist;
|
||
memset (&(*list)[srvcount], 0, sizeof(struct srventry));
|
||
srv = &(*list)[srvcount];
|
||
srvcount++;
|
||
|
||
rc = dn_skipname (pt, emsg); /* The name we just queried for. */
|
||
if (rc == -1)
|
||
goto fail;
|
||
pt += rc;
|
||
|
||
/* Truncated message? */
|
||
if ((emsg-pt) < 16)
|
||
goto fail;
|
||
|
||
type = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
/* We asked for SRV and got something else !? */
|
||
if (type != T_SRV)
|
||
goto fail;
|
||
|
||
class = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
/* We asked for IN and got something else !? */
|
||
if (class != C_IN)
|
||
goto fail;
|
||
|
||
pt += 4; /* ttl */
|
||
dlen = buf16_to_u16 (pt);
|
||
pt += 2;
|
||
|
||
srv->priority = buf16_to_ushort (pt);
|
||
pt += 2;
|
||
srv->weight = buf16_to_ushort (pt);
|
||
pt += 2;
|
||
srv->port = buf16_to_ushort (pt);
|
||
pt += 2;
|
||
|
||
/* Get the name. 2782 doesn't allow name compression, but
|
||
* dn_expand still works to pull the name out of the packet. */
|
||
rc = dn_expand (answer, emsg, pt, srv->target, sizeof srv->target);
|
||
if (rc == 1 && srv->target[0] == 0) /* "." */
|
||
{
|
||
xfree(*list);
|
||
*list = NULL;
|
||
return 0;
|
||
}
|
||
if (rc == -1)
|
||
goto fail;
|
||
pt += rc;
|
||
/* Corrupt packet? */
|
||
if (dlen != rc+6)
|
||
goto fail;
|
||
}
|
||
|
||
*r_count = srvcount;
|
||
return 0;
|
||
|
||
fail:
|
||
xfree (*list);
|
||
*list = NULL;
|
||
return gpg_error (GPG_ERR_GENERAL);
|
||
|
||
#else /*!HAVE_SYSTEM_RESOLVER*/
|
||
|
||
(void)name;
|
||
(void)list;
|
||
(void)r_count;
|
||
return gpg_error (GPG_ERR_NOT_SUPPORTED);
|
||
|
||
#endif /*!HAVE_SYSTEM_RESOLVER*/
|
||
}
|
||
|
||
|
||
/* Query a SRV record for SERVICE and PROTO for NAME. If SERVICE is
|
||
* NULL, NAME is expected to contain the full query name. Note that
|
||
* we do not return NONAME but simply store 0 at R_COUNT. On error an
|
||
* error code is returned and 0 stored at R_COUNT. */
|
||
gpg_error_t
|
||
get_dns_srv (ctrl_t ctrl,
|
||
const char *name, const char *service, const char *proto,
|
||
struct srventry **list, unsigned int *r_count)
|
||
{
|
||
gpg_error_t err;
|
||
char *namebuffer = NULL;
|
||
unsigned int srvcount;
|
||
int i;
|
||
|
||
*list = NULL;
|
||
*r_count = 0;
|
||
srvcount = 0;
|
||
|
||
/* If SERVICE is given construct the query from it and PROTO. */
|
||
if (service)
|
||
{
|
||
namebuffer = xtryasprintf ("_%s._%s.%s",
|
||
service, proto? proto:"tcp", name);
|
||
if (!namebuffer)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
goto leave;
|
||
}
|
||
name = namebuffer;
|
||
}
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
if (!standard_resolver)
|
||
{
|
||
err = getsrv_libdns (ctrl, name, list, &srvcount);
|
||
if (err && libdns_switch_port_p (err))
|
||
err = getsrv_libdns (ctrl, name, list, &srvcount);
|
||
}
|
||
else
|
||
#endif /*USE_LIBDNS*/
|
||
err = getsrv_standard (name, list, &srvcount);
|
||
|
||
if (err)
|
||
{
|
||
if (gpg_err_code (err) == GPG_ERR_NO_NAME)
|
||
err = 0;
|
||
goto leave;
|
||
}
|
||
|
||
/* Now we have an array of all the srv records. */
|
||
|
||
/* Order by priority */
|
||
qsort(*list,srvcount,sizeof(struct srventry),priosort);
|
||
|
||
/* For each priority, move the zero-weighted items first. */
|
||
for (i=0; i < srvcount; i++)
|
||
{
|
||
int j;
|
||
|
||
for (j=i;j < srvcount && (*list)[i].priority == (*list)[j].priority; j++)
|
||
{
|
||
if((*list)[j].weight==0)
|
||
{
|
||
/* Swap j with i */
|
||
if(j!=i)
|
||
{
|
||
struct srventry temp;
|
||
|
||
memcpy (&temp,&(*list)[j],sizeof(struct srventry));
|
||
memcpy (&(*list)[j],&(*list)[i],sizeof(struct srventry));
|
||
memcpy (&(*list)[i],&temp,sizeof(struct srventry));
|
||
}
|
||
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Run the RFC-2782 weighting algorithm. We don't need very high
|
||
quality randomness for this, so regular libc srand/rand is
|
||
sufficient. */
|
||
|
||
{
|
||
static int done;
|
||
if (!done)
|
||
{
|
||
done = 1;
|
||
srand (time (NULL)*getpid());
|
||
}
|
||
}
|
||
|
||
for (i=0; i < srvcount; i++)
|
||
{
|
||
int j;
|
||
float prio_count=0,chose;
|
||
|
||
for (j=i; j < srvcount && (*list)[i].priority == (*list)[j].priority; j++)
|
||
{
|
||
prio_count+=(*list)[j].weight;
|
||
(*list)[j].run_count=prio_count;
|
||
}
|
||
|
||
chose=prio_count*rand()/(float)RAND_MAX;
|
||
|
||
for (j=i;j<srvcount && (*list)[i].priority==(*list)[j].priority;j++)
|
||
{
|
||
if (chose<=(*list)[j].run_count)
|
||
{
|
||
/* Swap j with i */
|
||
if(j!=i)
|
||
{
|
||
struct srventry temp;
|
||
|
||
memcpy(&temp,&(*list)[j],sizeof(struct srventry));
|
||
memcpy(&(*list)[j],&(*list)[i],sizeof(struct srventry));
|
||
memcpy(&(*list)[i],&temp,sizeof(struct srventry));
|
||
}
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
leave:
|
||
if (opt_debug)
|
||
{
|
||
if (err)
|
||
log_debug ("dns: getsrv(%s): %s\n", name, gpg_strerror (err));
|
||
else
|
||
log_debug ("dns: getsrv(%s) -> %u records\n", name, srvcount);
|
||
}
|
||
if (!err)
|
||
*r_count = srvcount;
|
||
xfree (namebuffer);
|
||
return err;
|
||
}
|
||
|
||
|
||
|
||
#ifdef USE_LIBDNS
|
||
/* libdns version of get_dns_cname. */
|
||
gpg_error_t
|
||
get_dns_cname_libdns (ctrl_t ctrl, const char *name, char **r_cname)
|
||
{
|
||
gpg_error_t err;
|
||
struct dns_resolver *res;
|
||
struct dns_packet *ans = NULL;
|
||
struct dns_cname cname;
|
||
int derr;
|
||
|
||
err = libdns_res_open (ctrl, &res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
err = libdns_res_submit (res, name, DNS_T_CNAME, DNS_C_IN);
|
||
if (err)
|
||
goto leave;
|
||
|
||
err = libdns_res_wait (res);
|
||
if (err)
|
||
goto leave;
|
||
|
||
ans = dns_res_fetch (res, &derr);
|
||
if (!ans)
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
goto leave;
|
||
}
|
||
|
||
/* Check the rcode. */
|
||
switch (dns_p_rcode (ans))
|
||
{
|
||
case DNS_RC_NOERROR: break;
|
||
case DNS_RC_NXDOMAIN: err = gpg_error (GPG_ERR_NO_NAME); break;
|
||
default: err = GPG_ERR_SERVER_FAILED; break;
|
||
}
|
||
if (err)
|
||
goto leave;
|
||
|
||
/* Parse the result into CNAME. */
|
||
err = libdns_error_to_gpg_error (dns_p_study (ans));
|
||
if (err)
|
||
goto leave;
|
||
|
||
if (!dns_d_cname (&cname, sizeof cname, name, strlen (name), ans, &derr))
|
||
{
|
||
err = libdns_error_to_gpg_error (derr);
|
||
goto leave;
|
||
}
|
||
|
||
/* Copy result. */
|
||
*r_cname = xtrystrdup (cname.host);
|
||
if (!*r_cname)
|
||
err = gpg_error_from_syserror ();
|
||
else
|
||
{
|
||
/* Libdns appends the root zone part which is problematic
|
||
* for most other functions - strip it. */
|
||
if (**r_cname && (*r_cname)[strlen (*r_cname)-1] == '.')
|
||
(*r_cname)[strlen (*r_cname)-1] = 0;
|
||
}
|
||
|
||
leave:
|
||
dns_free (ans);
|
||
dns_res_close (res);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
|
||
/* Standard resolver version of get_dns_cname. */
|
||
gpg_error_t
|
||
get_dns_cname_standard (const char *name, char **r_cname)
|
||
{
|
||
#ifdef HAVE_SYSTEM_RESOLVER
|
||
gpg_error_t err;
|
||
int rc;
|
||
union {
|
||
unsigned char ans[2048];
|
||
HEADER header[1];
|
||
} res;
|
||
unsigned char *answer = res.ans;
|
||
HEADER *header = res.header;
|
||
unsigned char *pt, *emsg;
|
||
int r;
|
||
char *cname;
|
||
int cnamesize = 1025;
|
||
u16 count;
|
||
|
||
/* Do not allow a query using the standard resolver in Tor mode. */
|
||
if (tor_mode)
|
||
return -1;
|
||
|
||
my_unprotect ();
|
||
r = res_query (name, C_IN, T_CERT, answer, sizeof res.ans);
|
||
my_protect ();
|
||
if (r < 0)
|
||
return get_h_errno_as_gpg_error ();
|
||
if (r < sizeof (HEADER))
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
if (r > sizeof res.ans)
|
||
return gpg_error (GPG_ERR_SYSTEM_BUG);
|
||
if (header->rcode != NOERROR || !(count=ntohs (header->ancount)))
|
||
return gpg_error (GPG_ERR_NO_NAME); /* Error or no record found. */
|
||
if (count != 1)
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
|
||
emsg = &answer[r];
|
||
pt = &answer[sizeof(HEADER)];
|
||
rc = dn_skipname (pt, emsg);
|
||
if (rc == -1)
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
|
||
pt += rc + QFIXEDSZ;
|
||
if (pt >= emsg)
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
|
||
rc = dn_skipname (pt, emsg);
|
||
if (rc == -1)
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
pt += rc + 2 + 2 + 4;
|
||
if (pt+2 >= emsg)
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
pt += 2; /* Skip rdlen */
|
||
|
||
cname = xtrymalloc (cnamesize);
|
||
if (!cname)
|
||
return gpg_error_from_syserror ();
|
||
|
||
rc = dn_expand (answer, emsg, pt, cname, cnamesize -1);
|
||
if (rc == -1)
|
||
{
|
||
xfree (cname);
|
||
return gpg_error (GPG_ERR_SERVER_FAILED);
|
||
}
|
||
*r_cname = xtryrealloc (cname, strlen (cname)+1);
|
||
if (!*r_cname)
|
||
{
|
||
err = gpg_error_from_syserror ();
|
||
xfree (cname);
|
||
return err;
|
||
}
|
||
return 0;
|
||
|
||
#else /*!HAVE_SYSTEM_RESOLVER*/
|
||
|
||
(void)name;
|
||
(void)r_cname;
|
||
return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
|
||
|
||
#endif /*!HAVE_SYSTEM_RESOLVER*/
|
||
}
|
||
|
||
|
||
gpg_error_t
|
||
get_dns_cname (ctrl_t ctrl, const char *name, char **r_cname)
|
||
{
|
||
gpg_error_t err;
|
||
|
||
*r_cname = NULL;
|
||
|
||
#ifdef USE_LIBDNS
|
||
if (!standard_resolver)
|
||
{
|
||
err = get_dns_cname_libdns (ctrl, name, r_cname);
|
||
if (err && libdns_switch_port_p (err))
|
||
err = get_dns_cname_libdns (ctrl, name, r_cname);
|
||
return err;
|
||
}
|
||
#endif /*USE_LIBDNS*/
|
||
|
||
err = get_dns_cname_standard (name, r_cname);
|
||
if (opt_debug)
|
||
log_debug ("get_dns_cname(%s)%s%s\n", name,
|
||
err ? ": " : " -> ",
|
||
err ? gpg_strerror (err) : *r_cname);
|
||
return err;
|
||
}
|
||
|
||
|
||
/* Check whether the machine has any usable inet devices up and
|
||
* running. We put this into dns because on Windows this is
|
||
* implemented using getaddrinfo and thus easiest done here. */
|
||
void
|
||
check_inet_support (int *r_v4, int *r_v6)
|
||
{
|
||
if (cached_inet_support.valid)
|
||
{
|
||
*r_v4 = cached_inet_support.v4;
|
||
*r_v6 = cached_inet_support.v6;
|
||
return;
|
||
}
|
||
|
||
*r_v4 = *r_v6 = 0;
|
||
|
||
#ifdef HAVE_W32_SYSTEM
|
||
{
|
||
gpg_error_t err;
|
||
int ret;
|
||
struct addrinfo *aibuf = NULL;
|
||
struct addrinfo *ai;
|
||
|
||
ret = getaddrinfo ("..localmachine", NULL, NULL, &aibuf);
|
||
if (ret)
|
||
{
|
||
err = map_eai_to_gpg_error (ret);
|
||
log_error ("%s: getaddrinfo failed: %s\n",__func__, gpg_strerror (err));
|
||
aibuf = NULL;
|
||
}
|
||
|
||
for (ai = aibuf; ai; ai = ai->ai_next)
|
||
{
|
||
if (opt_debug)
|
||
{
|
||
log_debug ("%s: family: %d\n", __func__, ai->ai_family);
|
||
if (ai->ai_family == AF_INET6 || ai->ai_family == AF_INET)
|
||
{
|
||
char buffer[46];
|
||
DWORD buflen;
|
||
buflen = sizeof buffer;
|
||
if (WSAAddressToString (ai->ai_addr, (DWORD)ai->ai_addrlen,
|
||
NULL, buffer, &buflen))
|
||
log_debug ("%s: WSAAddressToString failed: ec=%u\n",
|
||
__func__, (unsigned int)WSAGetLastError ());
|
||
else
|
||
log_debug ("%s: addr: %s\n", __func__, buffer);
|
||
}
|
||
}
|
||
}
|
||
|
||
for (ai = aibuf; ai; ai = ai->ai_next)
|
||
{
|
||
if (ai->ai_family == AF_INET)
|
||
*r_v4 = 1;
|
||
}
|
||
for (ai = aibuf; ai; ai = ai->ai_next)
|
||
{
|
||
if (ai->ai_family == AF_INET6)
|
||
{
|
||
struct sockaddr_in6 *v6addr = (struct sockaddr_in6 *)ai->ai_addr;
|
||
if (!IN6_IS_ADDR_LINKLOCAL (&v6addr->sin6_addr)
|
||
&& (!*r_v4 || !IN6_IS_ADDR_LOOPBACK (&v6addr->sin6_addr)))
|
||
{
|
||
/* We only assume v6 if we do not have a v4 address or
|
||
* if the address is not ::1. Linklocal never
|
||
* indicates v6 support. */
|
||
*r_v6 = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (aibuf)
|
||
freeaddrinfo (aibuf);
|
||
}
|
||
#else /*!HAVE_W32_SYSTEM*/
|
||
{
|
||
/* For now we assume that we have both protocols. */
|
||
*r_v4 = *r_v6 = 1;
|
||
}
|
||
#endif /*!HAVE_W32_SYSTEM*/
|
||
|
||
if (opt_verbose)
|
||
log_info ("detected interfaces:%s%s\n",
|
||
*r_v4? " IPv4":"", *r_v6? " IPv6":"");
|
||
|
||
cached_inet_support.valid = 1;
|
||
cached_inet_support.v4 = *r_v4;
|
||
cached_inet_support.v6 = *r_v6;
|
||
}
|