2 * Copyright (C) 1997-2013 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file command.c Client authentication and server commands. */
12 #include <sys/types.h>
20 #include "server.cmdline.h"
33 #include "user_list.h"
34 #include "server_command_list.h"
35 #include "afs_command_list.h"
39 struct server_command afs_cmds
[] = {DEFINE_AFS_CMD_ARRAY
};
40 struct server_command server_cmds
[] = {DEFINE_SERVER_CMD_ARRAY
};
42 /** Commands including options must be shorter than this. */
43 #define MAX_COMMAND_LEN 32768
46 extern struct misc_meta_data
*mmd
;
47 extern struct sender senders
[];
48 int send_afs_status(struct command_context
*cc
, int parser_friendly
);
50 static void dummy(__a_unused
int s
)
54 static void mmd_dup(struct misc_meta_data
*new_mmd
)
56 mutex_lock(mmd_mutex
);
58 mutex_unlock(mmd_mutex
);
62 * Compute human readable string containing vss status for given integer value.
64 * We don't want to use vss_playing() and friends here because we take a
65 * snapshot of the mmd struct and use the copy for computing the state of the
66 * vss. If the real data were used, we would take the mmd lock for a rather
67 * long time or risk to get an inconsistent view.
69 static char *vss_status_tohuman(unsigned int flags
)
71 if (flags
& VSS_PLAYING
)
72 return para_strdup("playing");
74 return para_strdup("stopped");
75 return para_strdup("paused");
79 * return human readable permission string. Never returns NULL.
81 static char *cmd_perms_itohuman(unsigned int perms
)
83 char *msg
= para_malloc(5 * sizeof(char));
85 msg
[0] = perms
& AFS_READ
? 'a' : '-';
86 msg
[1] = perms
& AFS_WRITE
? 'A' : '-';
87 msg
[2] = perms
& VSS_READ
? 'v' : '-';
88 msg
[3] = perms
& VSS_WRITE
? 'V' : '-';
96 static char *vss_get_status_flags(unsigned int flags
)
98 char *msg
= para_malloc(5 * sizeof(char));
100 msg
[0] = (flags
& VSS_PLAYING
)? 'P' : '_';
101 msg
[1] = (flags
& VSS_NOMORE
)? 'O' : '_';
102 msg
[2] = (flags
& VSS_NEXT
)? 'N' : '_';
103 msg
[3] = (flags
& VSS_REPOS
)? 'R' : '_';
108 static unsigned get_status(struct misc_meta_data
*nmmd
, int parser_friendly
,
112 char *status
, *flags
; /* vss status info */
113 /* nobody updates our version of "now" */
114 char *ut
= get_server_uptime_str(NULL
);
115 long offset
= (nmmd
->offset
+ 500) / 1000;
116 struct timeval current_time
;
118 struct para_buffer b
= {.flags
= parser_friendly
? PBF_SIZE_PREFIX
: 0};
120 /* report real status */
121 status
= vss_status_tohuman(nmmd
->vss_status_flags
);
122 flags
= vss_get_status_flags(nmmd
->vss_status_flags
);
123 if (nmmd
->size
) { /* parent currently has an audio file open */
124 localtime_r(&nmmd
->mtime
, &mtime_tm
);
125 strftime(mtime
, 29, "%b %d %Y", &mtime_tm
);
127 gettimeofday(¤t_time
, NULL
);
129 * The calls to WRITE_STATUS_ITEM() below never fail because
130 * b->max_size is zero (unlimited), see para_printf(). However, clang
131 * is not smart enough to prove this and complains nevertheless.
132 * Casting the return value to void silences clang.
134 (void)WRITE_STATUS_ITEM(&b
, SI_FILE_SIZE
, "%zu\n", nmmd
->size
/ 1024);
135 (void)WRITE_STATUS_ITEM(&b
, SI_MTIME
, "%s\n", mtime
);
136 (void)WRITE_STATUS_ITEM(&b
, SI_STATUS
, "%s\n", status
);
137 (void)WRITE_STATUS_ITEM(&b
, SI_STATUS_FLAGS
, "%s\n", flags
);
138 (void)WRITE_STATUS_ITEM(&b
, SI_OFFSET
, "%li\n", offset
);
139 (void)WRITE_STATUS_ITEM(&b
, SI_AFS_MODE
, "%s\n", mmd
->afs_mode_string
);
140 (void)WRITE_STATUS_ITEM(&b
, SI_STREAM_START
, "%lu.%lu\n",
141 (long unsigned)nmmd
->stream_start
.tv_sec
,
142 (long unsigned)nmmd
->stream_start
.tv_usec
);
143 (void)WRITE_STATUS_ITEM(&b
, SI_CURRENT_TIME
, "%lu.%lu\n",
144 (long unsigned)current_time
.tv_sec
,
145 (long unsigned)current_time
.tv_usec
);
153 static int check_sender_args(int argc
, char * const * argv
, struct sender_command_data
*scd
)
156 /* this has to match sender.h */
157 const char *subcmds
[] = {"add", "delete", "allow", "deny", "on", "off", NULL
};
159 scd
->sender_num
= -1;
161 return -E_COMMAND_SYNTAX
;
162 for (i
= 0; senders
[i
].name
; i
++)
163 if (!strcmp(senders
[i
].name
, argv
[1]))
165 PARA_DEBUG_LOG("%d:%s\n", argc
, argv
[1]);
166 if (!senders
[i
].name
)
167 return -E_COMMAND_SYNTAX
;
169 for (i
= 0; subcmds
[i
]; i
++)
170 if (!strcmp(subcmds
[i
], argv
[2]))
173 return -E_COMMAND_SYNTAX
;
175 if (!senders
[scd
->sender_num
].client_cmds
[scd
->cmd_num
])
176 return -E_SENDER_CMD
;
177 switch (scd
->cmd_num
) {
181 return -E_COMMAND_SYNTAX
;
185 if (argc
!= 4 || parse_cidr(argv
[3], scd
->host
,
186 sizeof(scd
->host
), &scd
->netmask
) == NULL
)
187 return -E_COMMAND_SYNTAX
;
192 return -E_COMMAND_SYNTAX
;
193 return parse_fec_url(argv
[3], scd
);
195 return -E_COMMAND_SYNTAX
;
201 * Send a sideband packet through a blocking file descriptor.
203 * \param scc fd and crypto keys.
204 * \param buf The buffer to send.
205 * \param numbytes The size of \a buf.
206 * \param band The sideband designator of this packet.
207 * \param dont_free If true, never deallocate \a buf.
209 * The nonblock flag must be disabled for the file descriptor given by \a scc.
211 * Stream cipher encryption is automatically activated if neccessary via the
212 * sideband transformation, depending on the value of \a band.
216 * \sa \ref send_sb_va().
218 int send_sb(struct stream_cipher_context
*scc
, void *buf
, size_t numbytes
,
219 int band
, bool dont_free
)
222 struct sb_context
*sbc
;
224 struct sb_buffer sbb
= SBB_INIT(band
, buf
, numbytes
);
225 sb_transformation trafo
= band
< SBD_PROCEED
? NULL
: sc_trafo
;
227 sbc
= sb_new_send(&sbb
, dont_free
, trafo
, scc
->send
);
229 ret
= sb_get_send_buffers(sbc
, iov
);
230 ret
= xwritev(scc
->fd
, iov
, ret
);
233 } while (sb_sent(sbc
, ret
) == false);
241 * Create a variable sized buffer and send it as a sideband packet.
243 * \param scc Passed to \ref send_sb.
244 * \param band See \ref send_sb.
245 * \param fmt The format string.
247 * \return The return value of the underlying call to \ref send_sb.
249 __printf_3_4
int send_sb_va(struct stream_cipher_context
*scc
, int band
,
250 const char *fmt
, ...)
257 ret
= xvasprintf(&msg
, fmt
, ap
);
259 return send_sb(scc
, msg
, ret
, band
, false);
263 * Send an error message to a client.
265 * \param cc Client info.
266 * \param err The (positive) error code.
268 * \return The return value of the underlying call to send_sb_va().
270 int send_strerror(struct command_context
*cc
, int err
)
272 return send_sb_va(&cc
->scc
, SBD_ERROR_LOG
, "%s\n", para_strerror(err
));
276 * Send a sideband packet through a blocking file descriptor.
278 * \param scc fd and crypto keys.
279 * \param expected_band The expected band designator.
280 * \param max_size Passed to \ref sb_new_recv().
281 * \param result Body of the sideband packet is returned here.
283 * If \a expected_band is not \p SBD_ANY, the band designator of the received
284 * sideband packet is compared to \a expected_band and a mismatch is considered
289 int recv_sb(struct stream_cipher_context
*scc
,
290 enum sb_designator expected_band
,
291 size_t max_size
, struct iovec
*result
)
294 struct sb_context
*sbc
;
296 struct sb_buffer sbb
;
297 sb_transformation trafo
;
299 trafo
= expected_band
!= SBD_ANY
&& expected_band
< SBD_PROCEED
?
301 sbc
= sb_new_recv(max_size
, trafo
, scc
->recv
);
303 sb_get_recv_buffer(sbc
, &iov
);
304 ret
= recv_bin_buffer(scc
->fd
, iov
.iov_base
, iov
.iov_len
);
309 ret
= sb_received(sbc
, ret
, &sbb
);
316 if (expected_band
!= SBD_ANY
&& sbb
.band
!= expected_band
)
325 static int com_sender(struct command_context
*cc
)
329 struct sender_command_data scd
;
332 for (i
= 0; senders
[i
].name
; i
++) {
334 ret
= xasprintf(&tmp
, "%s%s\n", msg
? msg
: "",
339 return send_sb(&cc
->scc
, msg
, ret
, SBD_OUTPUT
, false);
341 ret
= check_sender_args(cc
->argc
, cc
->argv
, &scd
);
343 if (scd
.sender_num
< 0)
345 msg
= senders
[scd
.sender_num
].help();
346 return send_sb(&cc
->scc
, msg
, strlen(msg
), SBD_OUTPUT
, false);
349 switch (scd
.cmd_num
) {
352 assert(senders
[scd
.sender_num
].resolve_target
);
353 ret
= senders
[scd
.sender_num
].resolve_target(cc
->argv
[3], &scd
);
358 for (i
= 0; i
< 10; i
++) {
359 mutex_lock(mmd_mutex
);
360 if (mmd
->sender_cmd_data
.cmd_num
>= 0) {
361 mutex_unlock(mmd_mutex
);
365 memcpy(&mmd
->sender_cmd_data
, &scd
, sizeof(scd
));
366 mutex_unlock(mmd_mutex
);
369 return (i
< 10)? 1 : -E_LOCK
;
373 static int com_si(struct command_context
*cc
)
376 char *msg
, *ut
, *sender_info
= NULL
;
379 return -E_COMMAND_SYNTAX
;
380 mutex_lock(mmd_mutex
);
381 for (i
= 0; senders
[i
].name
; i
++) {
382 char *info
= senders
[i
].info();
383 sender_info
= para_strcat(sender_info
, info
);
386 ut
= get_server_uptime_str(now
);
387 ret
= xasprintf(&msg
, "version: " GIT_VERSION
"\n"
388 "up: %s\nplayed: %u\n"
391 "connections (active/accepted/total): %u/%u/%u\n"
392 "current loglevel: %s\n"
393 "supported audio formats: %s\n"
398 mmd
->active_connections
,
402 SERVER_AUDIO_FORMATS
,
405 mutex_unlock(mmd_mutex
);
408 return send_sb(&cc
->scc
, msg
, ret
, SBD_OUTPUT
, false);
412 static int com_version(struct command_context
*cc
)
418 return -E_COMMAND_SYNTAX
;
419 msg
= VERSION_TEXT("server") "built: " BUILD_DATE
"\n" UNAME_RS
420 ", " CC_VERSION
"\n";
422 return send_sb(&cc
->scc
, msg
, len
, SBD_OUTPUT
, true);
425 #define EMPTY_STATUS_ITEMS \
430 ITEM(ATTRIBUTES_BITMAP) \
431 ITEM(ATTRIBUTES_TXT) \
442 ITEM(SECONDS_TOTAL) \
454 * Write a list of audio-file related status items with empty values.
456 * This is used by vss when currently no audio file is open.
458 static unsigned empty_status_items(int parser_friendly
, char **result
)
467 len
= xasprintf(&esi
,
468 #define ITEM(x) "0004 %02x:\n"
471 #define ITEM(x) , SI_ ## x
476 len
= xasprintf(&esi
,
477 #define ITEM(x) "%s:\n"
480 #define ITEM(x) ,status_item_list[SI_ ## x]
488 #undef EMPTY_STATUS_ITEMS
491 static int com_stat(struct command_context
*cc
)
494 struct misc_meta_data tmp
, *nmmd
= &tmp
;
495 char *s
, *esi
= NULL
;
497 int parser_friendly
= 0;
499 para_sigaction(SIGUSR1
, dummy
);
501 for (i
= 1; i
< cc
->argc
; i
++) {
502 const char *arg
= cc
->argv
[i
];
505 if (!strcmp(arg
, "--")) {
509 if (!strncmp(arg
, "-n=", 3)) {
510 ret
= para_atoi32(arg
+ 3, &num
);
515 if (!strcmp(arg
, "-p")) {
519 return -E_COMMAND_SYNTAX
;
522 return -E_COMMAND_SYNTAX
;
525 ret
= get_status(nmmd
, parser_friendly
, &s
);
526 ret
= send_sb(&cc
->scc
, s
, ret
, SBD_OUTPUT
, false);
529 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
, true);
535 send_afs_status(cc
, parser_friendly
);
537 if (num
> 0 && !--num
)
540 ret
= -E_SERVER_CRASH
;
549 static int send_list_of_commands(struct command_context
*cc
, struct server_command
*cmd
,
554 for (; cmd
->name
; cmd
++) {
555 char *tmp
, *perms
= cmd_perms_itohuman(cmd
->perms
);
556 tmp
= make_message("%s\t%s\t%s\t%s\n", cmd
->name
, handler
,
557 perms
, cmd
->description
);
559 msg
= para_strcat(msg
, tmp
);
562 return send_sb(&cc
->scc
, msg
, strlen(msg
), SBD_OUTPUT
, false);
565 /* returns string that must be freed by the caller */
566 static struct server_command
*get_cmd_ptr(const char *name
, char **handler
)
568 struct server_command
*cmd
;
570 for (cmd
= server_cmds
; cmd
->name
; cmd
++)
571 if (!strcmp(cmd
->name
, name
)) {
573 *handler
= para_strdup("server"); /* server commands */
576 /* not found, look for commands supported by afs */
577 for (cmd
= afs_cmds
; cmd
->name
; cmd
++)
578 if (!strcmp(cmd
->name
, name
)) {
580 *handler
= para_strdup("afs");
587 static int com_help(struct command_context
*cc
)
589 struct server_command
*cmd
;
590 char *perms
, *handler
, *buf
;
594 /* no argument given, print list of commands */
595 if ((ret
= send_list_of_commands(cc
, server_cmds
, "server")) < 0)
597 return send_list_of_commands(cc
, afs_cmds
, "afs");
599 /* argument given for help */
600 cmd
= get_cmd_ptr(cc
->argv
[1], &handler
);
603 perms
= cmd_perms_itohuman(cmd
->perms
);
604 ret
= xasprintf(&buf
, "%s - %s\n\n"
618 return send_sb(&cc
->scc
, buf
, ret
, SBD_OUTPUT
, false);
622 static int com_hup(struct command_context
*cc
)
625 return -E_COMMAND_SYNTAX
;
626 kill(getppid(), SIGHUP
);
631 static int com_term(struct command_context
*cc
)
634 return -E_COMMAND_SYNTAX
;
635 kill(getppid(), SIGTERM
);
639 static int com_play(struct command_context
*cc
)
642 return -E_COMMAND_SYNTAX
;
643 mutex_lock(mmd_mutex
);
644 mmd
->new_vss_status_flags
|= VSS_PLAYING
;
645 mmd
->new_vss_status_flags
&= ~VSS_NOMORE
;
646 mutex_unlock(mmd_mutex
);
651 static int com_stop(struct command_context
*cc
)
654 return -E_COMMAND_SYNTAX
;
655 mutex_lock(mmd_mutex
);
656 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
657 mmd
->new_vss_status_flags
&= ~VSS_REPOS
;
658 mmd
->new_vss_status_flags
|= VSS_NEXT
;
659 mutex_unlock(mmd_mutex
);
664 static int com_pause(struct command_context
*cc
)
667 return -E_COMMAND_SYNTAX
;
668 mutex_lock(mmd_mutex
);
669 if (!vss_paused() && !vss_stopped()) {
671 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
672 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
674 mutex_unlock(mmd_mutex
);
679 static int com_next(struct command_context
*cc
)
682 return -E_COMMAND_SYNTAX
;
683 mutex_lock(mmd_mutex
);
685 mmd
->new_vss_status_flags
|= VSS_NEXT
;
686 mutex_unlock(mmd_mutex
);
691 static int com_nomore(struct command_context
*cc
)
694 return -E_COMMAND_SYNTAX
;
695 mutex_lock(mmd_mutex
);
696 if (vss_playing() || vss_paused())
697 mmd
->new_vss_status_flags
|= VSS_NOMORE
;
698 mutex_unlock(mmd_mutex
);
703 static int com_ff(struct command_context
*cc
)
706 int ret
, backwards
= 0;
711 return -E_COMMAND_SYNTAX
;
712 if (!(ret
= sscanf(cc
->argv
[1], "%u%c", &i
, &c
)))
713 return -E_COMMAND_SYNTAX
;
714 if (ret
> 1 && c
== '-')
715 backwards
= 1; /* jmp backwards */
716 mutex_lock(mmd_mutex
);
717 ret
= -E_NO_AUDIO_FILE
;
718 if (!mmd
->afd
.afhi
.chunks_total
|| !mmd
->afd
.afhi
.seconds_total
)
720 promille
= (1000 * mmd
->current_chunk
) / mmd
->afd
.afhi
.chunks_total
;
722 promille
-= 1000 * i
/ mmd
->afd
.afhi
.seconds_total
;
724 promille
+= 1000 * i
/ mmd
->afd
.afhi
.seconds_total
;
727 if (promille
> 1000) {
728 mmd
->new_vss_status_flags
|= VSS_NEXT
;
731 mmd
->repos_request
= (mmd
->afd
.afhi
.chunks_total
* promille
) / 1000;
732 mmd
->new_vss_status_flags
|= VSS_REPOS
;
733 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
737 mutex_unlock(mmd_mutex
);
742 static int com_jmp(struct command_context
*cc
)
748 return -E_COMMAND_SYNTAX
;
749 if (sscanf(cc
->argv
[1], "%lu", &i
) <= 0)
750 return -E_COMMAND_SYNTAX
;
751 mutex_lock(mmd_mutex
);
752 ret
= -E_NO_AUDIO_FILE
;
753 if (!mmd
->afd
.afhi
.chunks_total
)
757 PARA_INFO_LOG("jumping to %lu%%\n", i
);
758 mmd
->repos_request
= (mmd
->afd
.afhi
.chunks_total
* i
+ 50)/ 100;
759 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
760 mmd
->chunks_sent
, mmd
->offset
);
761 mmd
->new_vss_status_flags
|= VSS_REPOS
;
762 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
766 mutex_unlock(mmd_mutex
);
771 * check if perms are sufficient to exec a command having perms cmd_perms.
772 * Returns 0 if perms are sufficient, -E_PERM otherwise.
774 static int check_perms(unsigned int perms
, struct server_command
*cmd_ptr
)
776 PARA_DEBUG_LOG("checking permissions\n");
777 return (cmd_ptr
->perms
& perms
) < cmd_ptr
->perms
? -E_PERM
: 0;
780 static void reset_signals(void)
782 para_sigaction(SIGCHLD
, SIG_IGN
);
783 para_sigaction(SIGINT
, SIG_DFL
);
784 para_sigaction(SIGTERM
, SIG_DFL
);
785 para_sigaction(SIGHUP
, SIG_DFL
);
788 static int parse_auth_request(char *buf
, int len
, struct user
**u
)
791 char *p
, *username
, **features
= NULL
;
792 size_t auth_rq_len
= strlen(AUTH_REQUEST_MSG
);
793 bool sideband_requested
= false;
796 if (len
< auth_rq_len
+ 2)
797 return -E_AUTH_REQUEST
;
798 if (strncmp(buf
, AUTH_REQUEST_MSG
, auth_rq_len
) != 0)
799 return -E_AUTH_REQUEST
;
800 username
= buf
+ auth_rq_len
;
801 p
= strchr(username
, ' ');
805 return -E_AUTH_REQUEST
;
808 create_argv(p
, ",", &features
);
809 for (i
= 0; features
[i
]; i
++) {
810 if (strcmp(features
[i
], "sideband") == 0)
811 sideband_requested
= true;
813 ret
= -E_BAD_FEATURE
;
818 if (sideband_requested
== false) { /* sideband is mandatory */
819 PARA_ERROR_LOG("client did not request sideband\n");
820 ret
= -E_BAD_FEATURE
;
823 PARA_DEBUG_LOG("received auth request for user %s\n", username
);
824 *u
= lookup_user(username
);
831 #define HANDSHAKE_BUFSIZE 4096
833 static int parse_sb_command(struct command_context
*cc
, struct iovec
*iov
)
839 if (iov
->iov_base
== NULL
|| iov
->iov_len
== 0)
842 p
[iov
->iov_len
- 1] = '\0'; /* just to be sure */
843 cc
->cmd
= get_cmd_ptr(p
, NULL
);
846 ret
= check_perms(cc
->u
->perms
, cc
->cmd
);
849 end
= iov
->iov_base
+ iov
->iov_len
;
850 for (i
= 0, p
= iov
->iov_base
; p
< end
; i
++)
853 cc
->argv
= para_malloc((cc
->argc
+ 1) * sizeof(char *));
854 for (i
= 0, p
= iov
->iov_base
; p
< end
; i
++) {
855 cc
->argv
[i
] = para_strdup(p
);
858 cc
->argv
[cc
->argc
] = NULL
;
866 * Perform user authentication and execute a command.
868 * \param fd The file descriptor to send output to.
869 * \param peername Identifies the connecting peer.
871 * Whenever para_server accepts an incoming tcp connection on
872 * the port it listens on, it forks and the resulting child
873 * calls this function.
875 * An RSA-based challenge/response is used to authenticate
876 * the peer. It that authentication succeeds, a random
877 * session key is generated and sent back to the peer,
878 * encrypted with its RSA public key. From this point on,
879 * all transfers are crypted with this session key.
881 * Next it is checked if the peer supplied a valid server command or a command
882 * for the audio file selector. If yes, and if the user has sufficient
883 * permissions to execute that command, the function calls the corresponding
884 * command handler which does argument checking and further processing.
886 * In order to cope with a DOS attacks, a timeout is set up
887 * which terminates the function if the connection was not
888 * authenticated when the timeout expires.
890 * \sa alarm(2), crypt.c, crypt.h
892 __noreturn
void handle_connect(int fd
, const char *peername
)
895 unsigned char rand_buf
[CHALLENGE_SIZE
+ 2 * SESSION_KEY_LEN
];
896 unsigned char challenge_hash
[HASH_SIZE
];
897 char *p
, *command
= NULL
, *buf
= para_malloc(HANDSHAKE_BUFSIZE
) /* must be on the heap */;
899 struct command_context cc_struct
= {.peer
= peername
}, *cc
= &cc_struct
;
904 /* we need a blocking fd here as recv() might return EAGAIN otherwise. */
905 ret
= mark_fd_blocking(fd
);
908 /* send Welcome message */
909 ret
= write_va_buffer(fd
, "This is para_server, version "
910 PACKAGE_VERSION
".\n"
911 "Features: sideband\n"
915 /* recv auth request line */
916 ret
= recv_buffer(fd
, buf
, HANDSHAKE_BUFSIZE
);
919 ret
= parse_auth_request(buf
, ret
, &cc
->u
);
922 p
= buf
+ strlen(AUTH_REQUEST_MSG
);
923 PARA_DEBUG_LOG("received auth request for user %s\n", p
);
924 cc
->u
= lookup_user(p
);
926 get_random_bytes_or_die(rand_buf
, sizeof(rand_buf
));
927 ret
= pub_encrypt(cc
->u
->pubkey
, rand_buf
, sizeof(rand_buf
),
928 (unsigned char *)buf
);
934 * We don't want to reveal our user names, so we send a
935 * challenge to the client even if the user does not exist, and
936 * fail the authentication later.
939 get_random_bytes_or_die((unsigned char *)buf
, numbytes
);
941 PARA_DEBUG_LOG("sending %u byte challenge + rc4 keys (%zu bytes)\n",
942 CHALLENGE_SIZE
, numbytes
);
943 ret
= send_sb(&cc
->scc
, buf
, numbytes
, SBD_CHALLENGE
, false);
947 ret
= recv_sb(&cc
->scc
, SBD_CHALLENGE_RESPONSE
,
948 HANDSHAKE_BUFSIZE
, &iov
);
952 numbytes
= iov
.iov_len
;
953 PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes
);
958 * The correct response is the hash of the first CHALLENGE_SIZE bytes
959 * of the random data.
962 if (numbytes
!= HASH_SIZE
)
964 hash_function((char *)rand_buf
, CHALLENGE_SIZE
, challenge_hash
);
965 if (memcmp(challenge_hash
, buf
, HASH_SIZE
))
967 /* auth successful */
969 PARA_INFO_LOG("good auth for %s\n", cc
->u
->name
);
970 /* init stream cipher keys with the second part of the random buffer */
971 cc
->scc
.recv
= sc_new(rand_buf
+ CHALLENGE_SIZE
, SESSION_KEY_LEN
);
972 cc
->scc
.send
= sc_new(rand_buf
+ CHALLENGE_SIZE
+ SESSION_KEY_LEN
, 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
= parse_sb_command(cc
, &iov
);
983 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cc
->cmd
->name
,
984 cc
->u
->name
, peername
);
985 ret
= cc
->cmd
->handler(cc
);
987 mutex_lock(mmd_mutex
);
989 mutex_unlock(mmd_mutex
);
993 if (send_strerror(cc
, -ret
) >= 0)
994 send_sb(&cc
->scc
, NULL
, 0, SBD_EXIT__FAILURE
, true);
996 PARA_NOTICE_LOG("%s\n", para_strerror(-ret
));
1000 mutex_lock(mmd_mutex
);
1001 if (cc
->cmd
&& (cc
->cmd
->perms
& AFS_WRITE
) && ret
>= 0)
1003 mmd
->active_connections
--;
1004 mutex_unlock(mmd_mutex
);
1006 ret
= send_sb(&cc
->scc
, NULL
, 0, SBD_EXIT__SUCCESS
, true);
1008 PARA_NOTICE_LOG("%s\n", para_strerror(-ret
));
1010 sc_free(cc
->scc
.recv
);
1011 sc_free(cc
->scc
.send
);
1012 exit(ret
< 0? EXIT_FAILURE
: EXIT_SUCCESS
);