1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file command.c Client authentication and server commands. */
5 #include <netinet/in.h>
6 #include <sys/socket.h>
11 #include <arpa/inet.h>
16 #include "server.lsg.h"
35 #include "server_cmd.lsg.h"
36 #include "user_list.h"
40 #define SERVER_CMD_AUX_INFO(_arg) _arg,
41 static const unsigned server_command_perms[] = {LSG_SERVER_CMD_AUX_INFOS};
42 #undef SERVER_CMD_AUX_INFO
43 #define SERVER_CMD_AUX_INFO(_arg) #_arg,
44 static const char * const server_command_perms_txt[] = {LSG_SERVER_CMD_AUX_INFOS};
45 #undef SERVER_CMD_AUX_INFO
47 /** Commands including options must be shorter than this. */
48 #define MAX_COMMAND_LEN 32768
51 extern struct misc_meta_data *mmd;
52 int send_afs_status(struct command_context *cc, int parser_friendly);
53 static bool subcmd_should_die;
55 static void command_handler_sighandler(int s)
59 PARA_EMERG_LOG("terminating on signal %d\n", SIGTERM);
60 subcmd_should_die = true;
64 * Compute human readable vss status text.
66 * We can't call vss_playing() and friends here because those functions read
67 * the flags from the primary mmd structure, so calling them from command
68 * handler context would require to take the mmd lock. At the time the function
69 * is called we already took a copy of the mmd structure and want to use the
70 * flags value of the copy for computing the vss status text.
72 static char *vss_status_tohuman(unsigned int flags)
74 if (flags & VSS_PLAYING)
75 return para_strdup("playing");
77 return para_strdup("stopped");
78 return para_strdup("paused");
84 static char *vss_get_status_flags(unsigned int flags)
86 char *msg = para_malloc(5 * sizeof(char));
88 msg[0] = (flags & VSS_PLAYING)? 'P' : '_';
89 msg[1] = (flags & VSS_NOMORE)? 'O' : '_';
90 msg[2] = (flags & VSS_NEXT)? 'N' : '_';
91 msg[3] = (flags & VSS_REPOS)? 'R' : '_';
96 static unsigned get_status(struct misc_meta_data *nmmd, bool parser_friendly,
99 char *status, *flags; /* vss status info */
100 /* nobody updates our version of "now" */
101 long offset = (nmmd->offset + 500) / 1000;
102 struct timeval current_time;
103 struct para_buffer b = {.flags = parser_friendly? PBF_SIZE_PREFIX : 0};
105 /* report real status */
106 status = vss_status_tohuman(nmmd->vss_status_flags);
107 flags = vss_get_status_flags(nmmd->vss_status_flags);
108 clock_get_realtime(¤t_time);
110 * The calls to WRITE_STATUS_ITEM() below never fail because
111 * b->max_size is zero (unlimited), see \ref para_printf(). However,
112 * clang is not smart enough to prove this and complains nevertheless.
113 * Casting the return value to void silences clang.
115 (void)WRITE_STATUS_ITEM(&b, SI_status, "%s\n", status);
116 (void)WRITE_STATUS_ITEM(&b, SI_status_flags, "%s\n", flags);
117 (void)WRITE_STATUS_ITEM(&b, SI_offset, "%li\n", offset);
118 (void)WRITE_STATUS_ITEM(&b, SI_afs_mode, "%s\n", mmd->afs_mode_string);
119 (void)WRITE_STATUS_ITEM(&b, SI_stream_start, "%lu.%lu\n",
120 (long unsigned)nmmd->stream_start.tv_sec,
121 (long unsigned)nmmd->stream_start.tv_usec);
122 (void)WRITE_STATUS_ITEM(&b, SI_current_time, "%lu.%lu\n",
123 (long unsigned)current_time.tv_sec,
124 (long unsigned)current_time.tv_usec);
132 * Send a sideband packet through a blocking file descriptor.
134 * \param scc fd and crypto keys.
135 * \param buf The buffer to send.
136 * \param numbytes The size of \a buf.
137 * \param band The sideband designator of this packet.
138 * \param dont_free If true, never deallocate \a buf.
140 * The nonblock flag must be disabled for the file descriptor given by \a scc.
142 * Stream cipher encryption is automatically activated if necessary via the
143 * sideband transformation, depending on the value of \a band.
147 * \sa \ref send_sb_va().
149 int send_sb(struct stream_cipher_context *scc, void *buf, size_t numbytes,
150 int band, bool dont_free)
153 struct sb_context *sbc;
155 sb_transformation trafo = band < SBD_PROCEED? NULL : sc_trafo;
156 struct sb_buffer sbb = SBB_INIT(band, buf, numbytes);
158 sbc = sb_new_send(&sbb, dont_free, trafo, scc->send);
160 ret = sb_get_send_buffers(sbc, iov);
161 ret = xwritev(scc->fd, iov, ret);
164 } while (sb_sent(sbc, ret) == false);
172 * Create a variable sized buffer and send it as a sideband packet.
174 * \param scc Passed to \ref send_sb.
175 * \param band See \ref send_sb.
176 * \param fmt The format string.
178 * \return The return value of the underlying call to \ref send_sb.
180 __printf_3_4 int send_sb_va(struct stream_cipher_context *scc, int band,
181 const char *fmt, ...)
188 ret = xvasprintf(&msg, fmt, ap);
190 return send_sb(scc, msg, ret, band, false);
194 * Send an error message to a client.
196 * \param cc Client info.
197 * \param err The (positive) error code.
199 * \return The return value of the underlying call to send_sb_va().
201 int send_strerror(struct command_context *cc, int err)
203 return send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err));
207 * Send an error context to a client,
209 * \param cc Client info.
210 * \param errctx The error context string.
212 * \return The return value of the underlying call to send_sb_va().
214 * This function frees the error context string after it was sent.
216 int send_errctx(struct command_context *cc, char *errctx)
222 ret = send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", errctx);
227 static int check_sender_args(struct command_context *cc,
228 struct lls_parse_result *lpr, struct sender_command_data *scd)
231 const char * const subcmds[] = {SENDER_SUBCOMMANDS};
234 unsigned num_inputs = lls_num_inputs(lpr);
236 scd->sender_num = -1;
237 ret = lls(lls_check_arg_count(lpr, 2, INT_MAX, &errctx));
239 send_errctx(cc, errctx);
242 arg = lls_input(0, lpr);
244 if (strcmp(senders[i]->name, arg) == 0)
247 return -E_COMMAND_SYNTAX;
249 arg = lls_input(1, lpr);
250 for (i = 0; i < NUM_SENDER_CMDS; i++)
251 if (!strcmp(subcmds[i], arg))
253 if (i == NUM_SENDER_CMDS)
254 return -E_COMMAND_SYNTAX;
256 if (!senders[scd->sender_num]->client_cmds[scd->cmd_num])
257 return -E_SENDER_CMD;
258 switch (scd->cmd_num) {
262 return -E_COMMAND_SYNTAX;
266 if (num_inputs != 3 || parse_cidr(lls_input(2, lpr), scd->host,
267 sizeof(scd->host), &scd->netmask) == NULL)
268 return -E_COMMAND_SYNTAX;
273 return -E_COMMAND_SYNTAX;
274 return parse_fec_url(lls_input(2, lpr), scd);
276 return -E_COMMAND_SYNTAX;
282 * Receive a sideband packet from a blocking file descriptor.
284 * \param scc fd and crypto keys.
285 * \param expected_band The expected band designator.
286 * \param max_size Passed to \ref sb_new_recv().
287 * \param result Body of the sideband packet is returned here.
289 * If \a expected_band is not \p SBD_ANY, the band designator of the received
290 * sideband packet is compared to \a expected_band and a mismatch is considered
295 int recv_sb(struct stream_cipher_context *scc,
296 enum sb_designator expected_band,
297 size_t max_size, struct iovec *result)
300 struct sb_context *sbc;
302 struct sb_buffer sbb;
303 sb_transformation trafo;
305 trafo = expected_band != SBD_ANY && expected_band < SBD_PROCEED?
307 sbc = sb_new_recv(max_size, trafo, scc->recv);
309 sb_get_recv_buffer(sbc, &iov);
310 ret = recv_bin_buffer(scc->fd, iov.iov_base, iov.iov_len);
315 ret = sb_received(sbc, ret, &sbb);
322 if (expected_band != SBD_ANY && sbb.band != expected_band)
331 static int com_sender(struct command_context *cc, struct lls_parse_result *lpr)
335 struct sender_command_data scd;
337 if (lls_num_inputs(lpr) == 0) {
340 ret = xasprintf(&tmp, "%s%s\n", msg? msg : "",
345 return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
347 ret = check_sender_args(cc, lpr, &scd);
349 if (scd.sender_num < 0)
351 if (strcmp(lls_input(1, lpr), "status") == 0)
352 msg = senders[scd.sender_num]->status();
354 msg = senders[scd.sender_num]->help();
355 return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
358 switch (scd.cmd_num) {
361 assert(senders[scd.sender_num]->resolve_target);
362 ret = senders[scd.sender_num]->resolve_target(lls_input(2, lpr),
368 for (i = 0; i < 10; i++) {
369 mutex_lock(mmd_mutex);
370 if (mmd->sender_cmd_data.cmd_num >= 0) {
371 /* another sender command is active, retry in 100ms */
372 struct timespec ts = {.tv_nsec = 100 * 1000 * 1000};
373 mutex_unlock(mmd_mutex);
374 nanosleep(&ts, NULL);
377 mmd->sender_cmd_data = scd;
378 mutex_unlock(mmd_mutex);
381 return (i < 10)? 1 : -E_LOCK;
383 EXPORT_SERVER_CMD_HANDLER(sender);
385 static int com_si(struct command_context *cc,
386 __a_unused struct lls_parse_result *lpr)
391 ut = daemon_get_uptime_str(now);
392 mutex_lock(mmd_mutex);
393 ret = xasprintf(&msg,
394 "up: %s\nplayed: %u\n"
397 "connections (active/accepted/total): %u/%u/%u\n"
398 "current loglevel: %s\n"
399 "supported audio formats: %s\n",
403 mmd->active_connections,
406 ENUM_STRING_VAL(LOGLEVEL),
407 AUDIO_FORMAT_HANDLERS
409 mutex_unlock(mmd_mutex);
411 return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
413 EXPORT_SERVER_CMD_HANDLER(si);
415 static int com_version(struct command_context *cc, struct lls_parse_result *lpr)
420 if (SERVER_CMD_OPT_GIVEN(VERSION, VERBOSE, lpr))
421 len = xasprintf(&msg, "%s", version_text("server"));
423 len = xasprintf(&msg, "%s\n", version_single_line("server"));
424 return send_sb(&cc->scc, msg, len, SBD_OUTPUT, false);
426 EXPORT_SERVER_CMD_HANDLER(version);
428 /** These status items are cleared if no audio file is currently open. */
429 #define EMPTY_STATUS_ITEMS \
434 ITEM(attributes_bitmap) \
435 ITEM(attributes_txt) \
446 ITEM(seconds_total) \
459 ITEM(amplification) \
463 * Create a set of audio-file related status items with empty values. These are
464 * written to stat clients when no audio file is open.
466 static unsigned empty_status_items(bool parser_friendly, char **result)
472 len = xasprintf(&esi,
473 #define ITEM(x) "0004 %02x:\n"
476 #define ITEM(x) , (unsigned) SI_ ## x
481 len = xasprintf(&esi,
482 #define ITEM(x) "%s:\n"
485 #define ITEM(x) ,status_item_list[SI_ ## x]
492 #undef EMPTY_STATUS_ITEMS
494 static int com_stat(struct command_context *cc, struct lls_parse_result *lpr)
497 struct misc_meta_data tmp, *nmmd = &tmp;
499 bool parser_friendly = SERVER_CMD_OPT_GIVEN(STAT, PARSER_FRIENDLY,
501 uint32_t num = SERVER_CMD_UINT32_VAL(STAT, NUM, lpr);
502 const struct timespec ts = {.tv_sec = 50, .tv_nsec = 0};
504 para_sigaction(SIGINT, SIG_IGN);
505 para_sigaction(SIGUSR1, command_handler_sighandler);
506 para_sigaction(SIGTERM, command_handler_sighandler);
508 * Simply checking subcmd_should_die is racy because a signal may
509 * arrive after the check but before the subsequent call to sleep(3).
510 * If this happens, sleep(3) would not be interrupted by the signal.
511 * To avoid this we block SIGTERM here and allow it to arrive only
514 para_block_signal(SIGTERM);
518 * Copy the mmd structure to minimize the time we hold the mmd
521 mutex_lock(mmd_mutex);
523 mutex_unlock(mmd_mutex);
524 ret = get_status(nmmd, parser_friendly, &s);
525 ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
528 if (nmmd->vss_status_flags & VSS_NEXT) {
530 ret = empty_status_items(parser_friendly, &esi);
531 ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT, false);
535 send_afs_status(cc, parser_friendly);
537 if (num > 0 && !--num)
539 sigemptyset(&set); /* empty set means: unblock all signals */
541 * pselect(2) allows to atomically unblock signals, then go to
542 * sleep. Calling sigprocmask(2) followed by sleep(3) would
543 * open a race window similar to the one described above.
545 pselect(1, NULL, NULL, NULL, &ts, &set);
546 if (subcmd_should_die)
548 ret = -E_SERVER_CRASH;
555 EXPORT_SERVER_CMD_HANDLER(stat);
557 const char *aux_info_cb(unsigned cmd_num, bool verbose)
559 static char result[80];
560 unsigned perms = server_command_perms[cmd_num];
563 /* permissions: VSS_READ | VSS_WRITE */
564 sprintf(result, "permissions: %s",
565 server_command_perms_txt[cmd_num]);
567 result[0] = perms & AFS_READ? 'a' : '-';
568 result[1] = perms & AFS_WRITE? 'A' : '-';
569 result[2] = perms & VSS_READ? 'v' : '-';
570 result[3] = perms & VSS_WRITE? 'V' : '-';
576 static int com_help(struct command_context *cc, struct lls_parse_result *lpr)
581 bool long_help = SERVER_CMD_OPT_GIVEN(HELP, LONG, lpr);
583 lsu_com_help(long_help, lpr, server_cmd_suite, aux_info_cb, &buf, &n);
584 ret = send_sb(&cc->scc, buf, n, SBD_OUTPUT, false);
587 EXPORT_SERVER_CMD_HANDLER(help);
589 static int com_hup(__a_unused struct command_context *cc,
590 __a_unused struct lls_parse_result *lpr)
592 kill(getppid(), SIGHUP);
595 EXPORT_SERVER_CMD_HANDLER(hup);
597 static int com_term(__a_unused struct command_context *cc,
598 __a_unused struct lls_parse_result *lpr)
600 kill(getppid(), SIGTERM);
603 EXPORT_SERVER_CMD_HANDLER(term);
605 static int com_play(__a_unused struct command_context *cc,
606 __a_unused struct lls_parse_result *lpr)
608 mutex_lock(mmd_mutex);
609 mmd->new_vss_status_flags |= VSS_PLAYING;
610 mmd->new_vss_status_flags &= ~VSS_NOMORE;
611 mutex_unlock(mmd_mutex);
614 EXPORT_SERVER_CMD_HANDLER(play);
616 static int com_stop(__a_unused struct command_context *cc,
617 __a_unused struct lls_parse_result *lpr)
619 mutex_lock(mmd_mutex);
620 mmd->new_vss_status_flags &= ~VSS_PLAYING;
621 mmd->new_vss_status_flags &= ~VSS_REPOS;
622 mmd->new_vss_status_flags |= VSS_NEXT;
623 mutex_unlock(mmd_mutex);
626 EXPORT_SERVER_CMD_HANDLER(stop);
628 static int com_pause(__a_unused struct command_context *cc,
629 __a_unused struct lls_parse_result *lpr)
631 mutex_lock(mmd_mutex);
632 if (!vss_paused() && !vss_stopped()) {
634 mmd->new_vss_status_flags &= ~VSS_PLAYING;
635 mmd->new_vss_status_flags &= ~VSS_NEXT;
637 mutex_unlock(mmd_mutex);
640 EXPORT_SERVER_CMD_HANDLER(pause);
642 static int com_next(__a_unused struct command_context *cc,
643 __a_unused struct lls_parse_result *lpr)
645 mutex_lock(mmd_mutex);
647 mmd->new_vss_status_flags |= VSS_NEXT;
648 mutex_unlock(mmd_mutex);
651 EXPORT_SERVER_CMD_HANDLER(next);
653 static int com_nomore(__a_unused struct command_context *cc,
654 __a_unused struct lls_parse_result *lpr)
656 mutex_lock(mmd_mutex);
657 if (vss_playing() || vss_paused())
658 mmd->new_vss_status_flags |= VSS_NOMORE;
659 mutex_unlock(mmd_mutex);
662 EXPORT_SERVER_CMD_HANDLER(nomore);
664 static int com_ff(struct command_context *cc, struct lls_parse_result *lpr)
670 ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
672 send_errctx(cc, errctx);
675 ret = para_atoi32(lls_input(0, lpr), &i);
677 if (ret != -E_ATOI_JUNK_AT_END)
680 * Compatibility code to keep the historic syntax (ff 30-)
681 * working. This can be removed after 0.7.0.
683 ret = sscanf(lls_input(0, lpr), "%i%c", &i, &c);
685 return -E_COMMAND_SYNTAX;
686 if (ret > 1 && c == '-') {
687 PARA_WARNING_LOG("use of obsolete syntax\n");
691 mutex_lock(mmd_mutex);
692 ret = -E_NO_AUDIO_FILE;
693 if (!mmd->afd.afhi.chunks_total || !mmd->afd.afhi.seconds_total)
696 promille = (1000 * mmd->current_chunk) / mmd->afd.afhi.chunks_total;
698 * We need this cast because without it the expression on the right
699 * hand side is of unsigned type.
701 promille += 1000 * i / (int)mmd->afd.afhi.seconds_total;
704 if (promille > 1000) {
705 mmd->new_vss_status_flags |= VSS_NEXT;
708 mmd->repos_request = (mmd->afd.afhi.chunks_total * promille) / 1000;
709 mmd->new_vss_status_flags |= VSS_REPOS;
710 mmd->new_vss_status_flags &= ~VSS_NEXT;
713 mutex_unlock(mmd_mutex);
716 EXPORT_SERVER_CMD_HANDLER(ff);
718 static int com_jmp(struct command_context *cc, struct lls_parse_result *lpr)
723 ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
725 send_errctx(cc, errctx);
728 if (sscanf(lls_input(0, lpr), "%d", &i) <= 0)
729 return -ERRNO_TO_PARA_ERROR(EINVAL);
730 if (i < 0 || i > 100)
731 return -ERRNO_TO_PARA_ERROR(EINVAL);
732 mutex_lock(mmd_mutex);
733 ret = -E_NO_AUDIO_FILE;
734 if (!mmd->afd.afhi.chunks_total)
736 PARA_INFO_LOG("jumping to %d%%\n", i);
737 mmd->repos_request = (mmd->afd.afhi.chunks_total * i + 50) / 100;
738 mmd->new_vss_status_flags |= VSS_REPOS;
739 mmd->new_vss_status_flags &= ~VSS_NEXT;
743 mutex_unlock(mmd_mutex);
746 EXPORT_SERVER_CMD_HANDLER(jmp);
748 /* deprecated, does nothing */
749 static int com_tasks(__a_unused struct command_context *cc,
750 __a_unused struct lls_parse_result *lpr)
754 EXPORT_SERVER_CMD_HANDLER(tasks);
756 static void reset_signals(void)
758 para_sigaction(SIGCHLD, SIG_IGN);
759 para_sigaction(SIGINT, SIG_DFL);
760 para_sigaction(SIGTERM, SIG_DFL);
761 para_sigaction(SIGHUP, SIG_DFL);
764 struct connection_features {
765 int dummy; /* none at the moment */
768 static int parse_auth_request(char *buf, int len, const struct user **u,
769 struct connection_features *cf)
772 char *p, *username, **features = NULL;
773 size_t auth_rq_len = strlen(AUTH_REQUEST_MSG);
776 memset(cf, 0, sizeof(*cf));
777 if (len < auth_rq_len + 2)
778 return -E_AUTH_REQUEST;
779 if (strncmp(buf, AUTH_REQUEST_MSG, auth_rq_len) != 0)
780 return -E_AUTH_REQUEST;
781 username = buf + auth_rq_len;
782 p = strchr(username, ' ');
786 return -E_AUTH_REQUEST;
789 create_argv(p, ",", &features);
791 * Still accept sideband and AES feature requests (as a no-op)
792 * because some 0.6.x clients request them. The two checks
793 * below may be removed after 0.7.1.
795 for (i = 0; features[i]; i++) {
796 if (strcmp(features[i], "sideband") == 0)
798 if (strcmp(features[i], "aes_ctr128") == 0)
801 ret = -E_BAD_FEATURE;
806 PARA_DEBUG_LOG("received auth request for user %s\n", username);
807 *u = user_list_lookup(username);
814 #define HANDSHAKE_BUFSIZE 4096
816 static int run_command(struct command_context *cc, struct iovec *iov)
819 char *p, *end, **argv;
820 const struct lls_command *lcmd = NULL;
822 struct lls_parse_result *lpr;
825 if (iov->iov_base == NULL || iov->iov_len == 0)
826 return -ERRNO_TO_PARA_ERROR(EINVAL);
828 p[iov->iov_len - 1] = '\0'; /* just to be sure */
830 ret = lls(lls_lookup_subcmd(p, server_cmd_suite, &errctx));
832 send_errctx(cc, errctx);
835 perms = server_command_perms[ret];
836 if ((perms & cc->u->perms) != perms)
838 lcmd = lls_cmd(ret, server_cmd_suite);
839 end = iov->iov_base + iov->iov_len;
840 for (i = 0; p < end; i++)
843 argv = para_malloc((argc + 1) * sizeof(char *));
844 for (i = 0, p = iov->iov_base; p < end; i++) {
845 argv[i] = para_strdup(p);
849 PARA_NOTICE_LOG("calling com_%s() for user %s\n",
850 lls_command_name(lcmd), cc->u->name);
851 ret = lls(lls_parse(argc, argv, lcmd, &lpr, &errctx));
853 const struct server_cmd_user_data *ud = lls_user_data(lcmd);
854 ret = ud->handler(cc, lpr);
855 lls_free_parse_result(lpr, lcmd);
857 send_errctx(cc, errctx);
859 mutex_lock(mmd_mutex);
861 if (ret >= 0 && (perms & AFS_WRITE))
863 mutex_unlock(mmd_mutex);
868 * Perform user authentication and execute a command.
870 * \param fd The file descriptor to send output to.
872 * Whenever para_server accepts an incoming tcp connection on the port it
873 * listens on, it forks and the resulting child calls this function.
875 * An RSA-based challenge/response is used to authenticate the peer. If the
876 * authentication succeeds, a random session key is generated and sent back to
877 * the peer, encrypted with its RSA public key. From this point on, all
878 * transfers are encrypted with this session key using a stream cipher.
880 * Next it is checked if the peer supplied a valid server command or a command
881 * for the audio file selector. If yes, and if the user has sufficient
882 * permissions to execute this command, the function calls the corresponding
883 * command handler which performs argument checking and further processing.
885 * To cope with DOS attacks, a timer is set up right after the fork. If the
886 * connection was still not authenticated when the timeout expires, the child
887 * process is terminated.
891 * \sa alarm(2), \ref openssl.c, \ref crypt.h.
893 int handle_connect(int fd)
896 unsigned char rand_buf[APC_CHALLENGE_SIZE + 2 * SESSION_KEY_LEN];
897 unsigned char challenge_hash[HASH_SIZE];
898 char *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */;
900 struct command_context cc_struct = {.u = NULL}, *cc = &cc_struct;
902 struct connection_features cf;
906 /* we need a blocking fd here as recv() might return EAGAIN otherwise. */
907 ret = mark_fd_blocking(fd);
910 /* send Welcome message */
911 ret = write_va_buffer(fd, "This is para_server, version "
912 PACKAGE_VERSION ".\n"
917 /* recv auth request line */
918 ret = recv_buffer(fd, buf, HANDSHAKE_BUFSIZE);
921 ret = parse_auth_request(buf, ret, &cc->u, &cf);
925 get_random_bytes_or_die(rand_buf, sizeof(rand_buf));
926 ret = apc_pub_encrypt(cc->u->pubkey, rand_buf, sizeof(rand_buf),
927 (unsigned char *)buf);
933 * We don't want to reveal our user names, so we send a
934 * challenge to the client even if the user does not exist, and
935 * fail the authentication later.
938 get_random_bytes_or_die((unsigned char *)buf, numbytes);
940 PARA_DEBUG_LOG("sending %d byte challenge + session key (%zu bytes)\n",
941 APC_CHALLENGE_SIZE, numbytes);
942 ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
946 ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
947 HANDSHAKE_BUFSIZE, &iov);
951 numbytes = iov.iov_len;
952 PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes);
957 * The correct response is the hash of the first APC_CHALLENGE_SIZE bytes
958 * of the random data.
961 if (numbytes != HASH_SIZE)
963 hash_function((char *)rand_buf, APC_CHALLENGE_SIZE, challenge_hash);
964 if (memcmp(challenge_hash, buf, HASH_SIZE))
966 /* auth successful */
968 PARA_INFO_LOG("good auth for %s\n", cc->u->name);
969 /* init stream cipher keys with the second part of the random buffer */
970 cc->scc.recv = sc_new(rand_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
971 cc->scc.send = sc_new(rand_buf + APC_CHALLENGE_SIZE + SESSION_KEY_LEN,
973 ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
976 ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
979 ret = run_command(cc, &iov);
986 if (send_strerror(cc, -ret) >= 0)
987 send_sb(&cc->scc, NULL, 0, SBD_EXIT__FAILURE, true);
989 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
993 mutex_lock(mmd_mutex);
994 mmd->active_connections--;
995 mutex_unlock(mmd_mutex);
997 ret = send_sb(&cc->scc, NULL, 0, SBD_EXIT__SUCCESS, true);
999 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1001 sc_free(cc->scc.recv);
1002 sc_free(cc->scc.send);