2 This file is part of systemd.
4 Copyright 2010 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
32 #include <sys/inotify.h>
33 #include <sys/signalfd.h>
34 #include <sys/socket.h>
42 #include "alloc-util.h"
43 #include "ask-password-api.h"
46 #include "formats-util.h"
52 #include "random-util.h"
53 #include "signal-util.h"
54 #include "socket-util.h"
55 #include "string-util.h"
57 #include "terminal-util.h"
58 #include "time-util.h"
59 #include "umask-util.h"
63 #define KEYRING_TIMEOUT_USEC ((5 * USEC_PER_MINUTE) / 2)
65 static int lookup_key(const char *keyname
, key_serial_t
*ret
) {
71 serial
= request_key("user", keyname
, NULL
, 0);
73 return negative_errno();
79 static int retrieve_key(key_serial_t serial
, char ***ret
) {
80 _cleanup_free_
char *p
= NULL
;
91 n
= keyctl(KEYCTL_READ
, (unsigned long) serial
, (unsigned long) p
, (unsigned long) m
, 0);
103 l
= strv_parse_nulstr(p
, n
);
113 static int add_to_keyring(const char *keyname
, AskPasswordFlags flags
, char **passwords
) {
114 _cleanup_strv_free_erase_
char **l
= NULL
;
115 _cleanup_free_
char *p
= NULL
;
123 if (!(flags
& ASK_PASSWORD_PUSH_CACHE
))
126 r
= lookup_key(keyname
, &serial
);
128 r
= retrieve_key(serial
, &l
);
131 } else if (r
!= -ENOKEY
)
134 r
= strv_extend_strv(&l
, passwords
, true);
138 r
= strv_make_nulstr(l
, &p
, &n
);
142 /* Truncate trailing NUL */
146 serial
= add_key("user", keyname
, p
, n
-1, KEY_SPEC_USER_KEYRING
);
151 if (keyctl(KEYCTL_SET_TIMEOUT
,
152 (unsigned long) serial
,
153 (unsigned long) DIV_ROUND_UP(KEYRING_TIMEOUT_USEC
, USEC_PER_SEC
), 0, 0) < 0)
154 log_debug_errno(errno
, "Failed to adjust timeout: %m");
156 log_debug("Added key to keyring as %" PRIi32
".", serial
);
161 static int add_to_keyring_and_log(const char *keyname
, AskPasswordFlags flags
, char **passwords
) {
167 r
= add_to_keyring(keyname
, flags
, passwords
);
169 return log_debug_errno(r
, "Failed to add password to keyring: %m");
174 int ask_password_keyring(const char *keyname
, AskPasswordFlags flags
, char ***ret
) {
182 if (!(flags
& ASK_PASSWORD_ACCEPT_CACHED
))
185 r
= lookup_key(keyname
, &serial
);
186 if (r
== -ENOSYS
) /* when retrieving the distinction doesn't matter */
191 return retrieve_key(serial
, ret
);
194 static void backspace_chars(int ttyfd
, size_t p
) {
202 loop_write(ttyfd
, "\b \b", 3, false);
206 int ask_password_tty(
210 AskPasswordFlags flags
,
211 const char *flag_file
,
214 struct termios old_termios
, new_termios
;
215 char passphrase
[LINE_MAX
+ 1] = {}, *x
;
216 size_t p
= 0, codepoint
= 0;
218 _cleanup_close_
int ttyfd
= -1, notify
= -1;
219 struct pollfd pollfd
[2];
220 bool reset_tty
= false;
229 if (flags
& ASK_PASSWORD_NO_TTY
)
233 message
= "Password:";
236 notify
= inotify_init1(IN_CLOEXEC
|IN_NONBLOCK
);
242 if (inotify_add_watch(notify
, flag_file
, IN_ATTRIB
/* for the link count */) < 0) {
248 ttyfd
= open("/dev/tty", O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
251 if (tcgetattr(ttyfd
, &old_termios
) < 0) {
256 if (colors_enabled())
257 loop_write(ttyfd
, ANSI_HIGHLIGHT
, strlen(ANSI_HIGHLIGHT
), false);
258 loop_write(ttyfd
, message
, strlen(message
), false);
259 loop_write(ttyfd
, " ", 1, false);
260 if (colors_enabled())
261 loop_write(ttyfd
, ANSI_NORMAL
, strlen(ANSI_NORMAL
), false);
263 new_termios
= old_termios
;
264 new_termios
.c_lflag
&= ~(ICANON
|ECHO
);
265 new_termios
.c_cc
[VMIN
] = 1;
266 new_termios
.c_cc
[VTIME
] = 0;
268 if (tcsetattr(ttyfd
, TCSADRAIN
, &new_termios
) < 0) {
277 pollfd
[POLL_TTY
].fd
= ttyfd
>= 0 ? ttyfd
: STDIN_FILENO
;
278 pollfd
[POLL_TTY
].events
= POLLIN
;
279 pollfd
[POLL_INOTIFY
].fd
= notify
;
280 pollfd
[POLL_INOTIFY
].events
= POLLIN
;
284 int sleep_for
= -1, k
;
290 y
= now(CLOCK_MONOTONIC
);
297 sleep_for
= (int) ((until
- y
) / USEC_PER_MSEC
);
301 if (access(flag_file
, F_OK
) < 0) {
306 k
= poll(pollfd
, notify
>= 0 ? 2 : 1, sleep_for
);
318 if (notify
>= 0 && pollfd
[POLL_INOTIFY
].revents
!= 0)
321 if (pollfd
[POLL_TTY
].revents
== 0)
324 n
= read(ttyfd
>= 0 ? ttyfd
: STDIN_FILENO
, &c
, 1);
326 if (errno
== EINTR
|| errno
== EAGAIN
)
337 else if (c
== 21) { /* C-u */
339 if (!(flags
& ASK_PASSWORD_SILENT
))
340 backspace_chars(ttyfd
, p
);
343 } else if (c
== '\b' || c
== 127) {
347 if (!(flags
& ASK_PASSWORD_SILENT
))
348 backspace_chars(ttyfd
, 1);
351 } else if (!dirty
&& !(flags
& ASK_PASSWORD_SILENT
)) {
353 flags
|= ASK_PASSWORD_SILENT
;
355 /* There are two ways to enter silent
356 * mode. Either by pressing backspace
357 * as first key (and only as first
360 loop_write(ttyfd
, "(no echo) ", 10, false);
362 } else if (ttyfd
>= 0)
363 loop_write(ttyfd
, "\a", 1, false);
365 } else if (c
== '\t' && !(flags
& ASK_PASSWORD_SILENT
)) {
367 backspace_chars(ttyfd
, p
);
368 flags
|= ASK_PASSWORD_SILENT
;
370 /* ... or by pressing TAB at any time. */
373 loop_write(ttyfd
, "(no echo) ", 10, false);
375 if (p
>= sizeof(passphrase
)-1) {
376 loop_write(ttyfd
, "\a", 1, false);
382 if (!(flags
& ASK_PASSWORD_SILENT
) && ttyfd
>= 0) {
383 n
= utf8_encoded_valid_unichar(passphrase
+ codepoint
);
386 loop_write(ttyfd
, (flags
& ASK_PASSWORD_ECHO
) ? &c
: "*", 1, false);
396 x
= strndup(passphrase
, p
);
397 memory_erase(passphrase
, p
);
404 (void) add_to_keyring_and_log(keyname
, flags
, STRV_MAKE(x
));
410 if (ttyfd
>= 0 && reset_tty
) {
411 loop_write(ttyfd
, "\n", 1, false);
412 tcsetattr(ttyfd
, TCSADRAIN
, &old_termios
);
418 static int create_socket(char **name
) {
419 union sockaddr_union sa
= {
420 .un
.sun_family
= AF_UNIX
,
422 _cleanup_close_
int fd
= -1;
423 static const int one
= 1;
429 fd
= socket(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
|SOCK_NONBLOCK
, 0);
433 snprintf(sa
.un
.sun_path
, sizeof(sa
.un
.sun_path
)-1, "/run/systemd/ask-password/sck.%" PRIx64
, random_u64());
435 RUN_WITH_UMASK(0177) {
436 if (bind(fd
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
)) < 0)
440 if (setsockopt(fd
, SOL_SOCKET
, SO_PASSCRED
, &one
, sizeof(one
)) < 0)
443 c
= strdup(sa
.un
.sun_path
);
455 int ask_password_agent(
461 AskPasswordFlags flags
,
470 _cleanup_close_
int socket_fd
= -1, signal_fd
= -1, fd
= -1;
471 char temp
[] = "/run/systemd/ask-password/tmp.XXXXXX";
472 char final
[sizeof(temp
)] = "";
473 _cleanup_free_
char *socket_name
= NULL
;
474 _cleanup_strv_free_
char **l
= NULL
;
475 _cleanup_fclose_
FILE *f
= NULL
;
476 struct pollfd pollfd
[_FD_MAX
];
477 sigset_t mask
, oldmask
;
482 if (flags
& ASK_PASSWORD_NO_AGENT
)
485 assert_se(sigemptyset(&mask
) >= 0);
486 assert_se(sigset_add_many(&mask
, SIGINT
, SIGTERM
, -1) >= 0);
487 assert_se(sigprocmask(SIG_BLOCK
, &mask
, &oldmask
) >= 0);
489 (void) mkdir_p_label("/run/systemd/ask-password", 0755);
491 fd
= mkostemp_safe(temp
, O_WRONLY
|O_CLOEXEC
);
497 (void) fchmod(fd
, 0644);
507 signal_fd
= signalfd(-1, &mask
, SFD_NONBLOCK
|SFD_CLOEXEC
);
513 socket_fd
= create_socket(&socket_name
);
525 "NotAfter="USEC_FMT
"\n",
528 (flags
& ASK_PASSWORD_ACCEPT_CACHED
) ? 1 : 0,
529 (flags
& ASK_PASSWORD_ECHO
) ? 1 : 0,
533 fprintf(f
, "Message=%s\n", message
);
536 fprintf(f
, "Icon=%s\n", icon
);
539 fprintf(f
, "Id=%s\n", id
);
541 r
= fflush_and_check(f
);
545 memcpy(final
, temp
, sizeof(temp
));
547 final
[sizeof(final
)-11] = 'a';
548 final
[sizeof(final
)-10] = 's';
549 final
[sizeof(final
)-9] = 'k';
551 if (rename(temp
, final
) < 0) {
557 pollfd
[FD_SOCKET
].fd
= socket_fd
;
558 pollfd
[FD_SOCKET
].events
= POLLIN
;
559 pollfd
[FD_SIGNAL
].fd
= signal_fd
;
560 pollfd
[FD_SIGNAL
].events
= POLLIN
;
563 char passphrase
[LINE_MAX
+1];
564 struct msghdr msghdr
;
568 struct cmsghdr cmsghdr
;
569 uint8_t buf
[CMSG_SPACE(sizeof(struct ucred
))];
575 t
= now(CLOCK_MONOTONIC
);
577 if (until
> 0 && until
<= t
) {
582 k
= poll(pollfd
, _FD_MAX
, until
> 0 ? (int) ((until
-t
)/USEC_PER_MSEC
) : -1);
596 if (pollfd
[FD_SIGNAL
].revents
& POLLIN
) {
601 if (pollfd
[FD_SOCKET
].revents
!= POLLIN
) {
607 iovec
.iov_base
= passphrase
;
608 iovec
.iov_len
= sizeof(passphrase
);
612 msghdr
.msg_iov
= &iovec
;
613 msghdr
.msg_iovlen
= 1;
614 msghdr
.msg_control
= &control
;
615 msghdr
.msg_controllen
= sizeof(control
);
617 n
= recvmsg(socket_fd
, &msghdr
, 0);
619 if (errno
== EAGAIN
||
627 cmsg_close_all(&msghdr
);
630 log_debug("Message too short");
634 if (msghdr
.msg_controllen
< CMSG_LEN(sizeof(struct ucred
)) ||
635 control
.cmsghdr
.cmsg_level
!= SOL_SOCKET
||
636 control
.cmsghdr
.cmsg_type
!= SCM_CREDENTIALS
||
637 control
.cmsghdr
.cmsg_len
!= CMSG_LEN(sizeof(struct ucred
))) {
638 log_debug("Received message without credentials. Ignoring.");
642 ucred
= (struct ucred
*) CMSG_DATA(&control
.cmsghdr
);
643 if (ucred
->uid
!= 0) {
644 log_debug("Got request from unprivileged user. Ignoring.");
648 if (passphrase
[0] == '+') {
649 /* An empty message refers to the empty password */
651 l
= strv_new("", NULL
);
653 l
= strv_parse_nulstr(passphrase
+1, n
-1);
654 memory_erase(passphrase
, n
);
660 if (strv_length(l
) <= 0) {
662 log_debug("Invalid packet");
669 if (passphrase
[0] == '-') {
674 log_debug("Invalid packet");
678 (void) add_to_keyring_and_log(keyname
, flags
, l
);
686 (void) unlink(socket_name
);
691 (void) unlink(final
);
693 assert_se(sigprocmask(SIG_SETMASK
, &oldmask
, NULL
) == 0);
697 int ask_password_auto(
703 AskPasswordFlags flags
,
710 if ((flags
& ASK_PASSWORD_ACCEPT_CACHED
) && keyname
) {
711 r
= ask_password_keyring(keyname
, flags
, ret
);
716 if (!(flags
& ASK_PASSWORD_NO_TTY
) && isatty(STDIN_FILENO
)) {
717 char *s
= NULL
, **l
= NULL
;
719 r
= ask_password_tty(message
, keyname
, until
, flags
, NULL
, &s
);
723 r
= strv_push(&l
, s
);
734 if (!(flags
& ASK_PASSWORD_NO_AGENT
))
735 return ask_password_agent(message
, icon
, id
, keyname
, until
, flags
, ret
);