[thirdparty/systemd.git] / src / shared / ask-password-api.c

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <poll.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/inotify.h>
#include <sys/signalfd.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <termios.h>
#include <unistd.h>

#include "alloc-util.h"
#include "ask-password-api.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
#include "io-util.h"
#include "log.h"
#include "macro.h"
#include "missing.h"
#include "mkdir.h"
#include "process-util.h"
#include "random-util.h"
#include "signal-util.h"
#include "socket-util.h"
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"
#include "time-util.h"
#include "umask-util.h"
#include "utf8.h"
#include "util.h"

#define KEYRING_TIMEOUT_USEC ((5 * USEC_PER_MINUTE) / 2)

static int lookup_key(const char *keyname, key_serial_t *ret) {
        key_serial_t serial;

        assert(keyname);
        assert(ret);

        serial = request_key("user", keyname, NULL, 0);
        if (serial == -1)
                return negative_errno();

        *ret = serial;
        return 0;
}

static int retrieve_key(key_serial_t serial, char ***ret) {
        _cleanup_free_ char *p = NULL;
        long m = 100, n;
        char **l;

        assert(ret);

        for (;;) {
                p = new(char, m);
                if (!p)
                        return -ENOMEM;

                n = keyctl(KEYCTL_READ, (unsigned long) serial, (unsigned long) p, (unsigned long) m, 0);
                if (n < 0)
                        return -errno;

                if (n < m)
                        break;

                explicit_bzero(p, n);
                free(p);
                m *= 2;
        }

        l = strv_parse_nulstr(p, n);
        if (!l)
                return -ENOMEM;

        explicit_bzero(p, n);

        *ret = l;
        return 0;
}

static int add_to_keyring(const char *keyname, AskPasswordFlags flags, char **passwords) {
        _cleanup_strv_free_erase_ char **l = NULL;
        _cleanup_free_ char *p = NULL;
        key_serial_t serial;
        size_t n;
        int r;

        assert(keyname);
        assert(passwords);

        if (!(flags & ASK_PASSWORD_PUSH_CACHE))
                return 0;

        r = lookup_key(keyname, &serial);
        if (r >= 0) {
                r = retrieve_key(serial, &l);
                if (r < 0)
                        return r;
        } else if (r != -ENOKEY)
                return r;

        r = strv_extend_strv(&l, passwords, true);
        if (r <= 0)
                return r;

        r = strv_make_nulstr(l, &p, &n);
        if (r < 0)
                return r;

        serial = add_key("user", keyname, p, n, KEY_SPEC_USER_KEYRING);
        explicit_bzero(p, n);
        if (serial == -1)
                return -errno;

        if (keyctl(KEYCTL_SET_TIMEOUT,
                   (unsigned long) serial,
                   (unsigned long) DIV_ROUND_UP(KEYRING_TIMEOUT_USEC, USEC_PER_SEC), 0, 0) < 0)
                log_debug_errno(errno, "Failed to adjust timeout: %m");

        log_debug("Added key to keyring as %" PRIi32 ".", serial);

        return 1;
}

static int add_to_keyring_and_log(const char *keyname, AskPasswordFlags flags, char **passwords) {
        int r;

        assert(keyname);
        assert(passwords);

        r = add_to_keyring(keyname, flags, passwords);
        if (r < 0)
                return log_debug_errno(r, "Failed to add password to keyring: %m");

        return 0;
}

int ask_password_keyring(const char *keyname, AskPasswordFlags flags, char ***ret) {

        key_serial_t serial;
        int r;

        assert(keyname);
        assert(ret);

        if (!(flags & ASK_PASSWORD_ACCEPT_CACHED))
                return -EUNATCH;

        r = lookup_key(keyname, &serial);
        if (r == -ENOSYS) /* when retrieving the distinction doesn't matter */
                return -ENOKEY;
        if (r < 0)
                return r;

        return retrieve_key(serial, ret);
}

static void backspace_chars(int ttyfd, size_t p) {

        if (ttyfd < 0)
                return;

        while (p > 0) {
                p--;

                loop_write(ttyfd, "\b \b", 3, false);
        }
}

int ask_password_tty(
                const char *message,
                const char *keyname,
                usec_t until,
                AskPasswordFlags flags,
                const char *flag_file,
                char **ret) {

        struct termios old_termios, new_termios;
        char passphrase[LINE_MAX + 1] = {}, *x;
        size_t p = 0, codepoint = 0;
        int r;
        _cleanup_close_ int ttyfd = -1, notify = -1;
        struct pollfd pollfd[2];
        bool reset_tty = false;
        bool dirty = false;
        enum {
                POLL_TTY,
                POLL_INOTIFY
        };

        assert(ret);

        if (flags & ASK_PASSWORD_NO_TTY)
                return -EUNATCH;

        if (!message)
                message = "Password:";

        if (flag_file) {
                notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK);
                if (notify < 0) {
                        r = -errno;
                        goto finish;
                }

                if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) {
                        r = -errno;
                        goto finish;
                }
        }

        ttyfd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC);
        if (ttyfd >= 0) {

                if (tcgetattr(ttyfd, &old_termios) < 0) {
                        r = -errno;
                        goto finish;
                }

                if (colors_enabled())
                        loop_write(ttyfd, ANSI_HIGHLIGHT, strlen(ANSI_HIGHLIGHT), false);
                loop_write(ttyfd, message, strlen(message), false);
                loop_write(ttyfd, " ", 1, false);
                if (colors_enabled())
                        loop_write(ttyfd, ANSI_NORMAL, strlen(ANSI_NORMAL), false);

                new_termios = old_termios;
                new_termios.c_lflag &= ~(ICANON|ECHO);
                new_termios.c_cc[VMIN] = 1;
                new_termios.c_cc[VTIME] = 0;

                if (tcsetattr(ttyfd, TCSADRAIN, &new_termios) < 0) {
                        r = -errno;
                        goto finish;
                }

                reset_tty = true;
        }

        zero(pollfd);
        pollfd[POLL_TTY].fd = ttyfd >= 0 ? ttyfd : STDIN_FILENO;
        pollfd[POLL_TTY].events = POLLIN;
        pollfd[POLL_INOTIFY].fd = notify;
        pollfd[POLL_INOTIFY].events = POLLIN;

        for (;;) {
                char c;
                int sleep_for = -1, k;
                ssize_t n;

                if (until > 0) {
                        usec_t y;

                        y = now(CLOCK_MONOTONIC);

                        if (y > until) {
                                r = -ETIME;
                                goto finish;
                        }

                        sleep_for = (int) ((until - y) / USEC_PER_MSEC);
                }

                if (flag_file)
                        if (access(flag_file, F_OK) < 0) {
                                r = -errno;
                                goto finish;
                        }

                k = poll(pollfd, notify >= 0 ? 2 : 1, sleep_for);
                if (k < 0) {
                        if (errno == EINTR)
                                continue;

                        r = -errno;
                        goto finish;
                } else if (k == 0) {
                        r = -ETIME;
                        goto finish;
                }

                if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0)
                        flush_fd(notify);

                if (pollfd[POLL_TTY].revents == 0)
                        continue;

                n = read(ttyfd >= 0 ? ttyfd : STDIN_FILENO, &c, 1);
                if (n < 0) {
                        if (errno == EINTR || errno == EAGAIN)
                                continue;

                        r = -errno;
                        goto finish;

                } else if (n == 0)
                        break;

                if (c == '\n')
                        break;
                else if (c == 21) { /* C-u */

                        if (!(flags & ASK_PASSWORD_SILENT))
                                backspace_chars(ttyfd, p);
                        p = 0;

                } else if (c == '\b' || c == 127) {

                        if (p > 0) {

                                if (!(flags & ASK_PASSWORD_SILENT))
                                        backspace_chars(ttyfd, 1);

                                p--;
                        } else if (!dirty && !(flags & ASK_PASSWORD_SILENT)) {

                                flags |= ASK_PASSWORD_SILENT;

                                /* There are two ways to enter silent
                                 * mode. Either by pressing backspace
                                 * as first key (and only as first
                                 * key), or ... */
                                if (ttyfd >= 0)
                                        loop_write(ttyfd, "(no echo) ", 10, false);

                        } else if (ttyfd >= 0)
                                loop_write(ttyfd, "\a", 1, false);

                } else if (c == '\t' && !(flags & ASK_PASSWORD_SILENT)) {

                        backspace_chars(ttyfd, p);
                        flags |= ASK_PASSWORD_SILENT;

                        /* ... or by pressing TAB at any time. */

                        if (ttyfd >= 0)
                                loop_write(ttyfd, "(no echo) ", 10, false);
                } else {
                        if (p >= sizeof(passphrase)-1) {
                                loop_write(ttyfd, "\a", 1, false);
                                continue;
                        }

                        passphrase[p++] = c;

                        if (!(flags & ASK_PASSWORD_SILENT) && ttyfd >= 0) {
                                n = utf8_encoded_valid_unichar(passphrase + codepoint);
                                if (n >= 0) {
                                        codepoint = p;
                                        loop_write(ttyfd, (flags & ASK_PASSWORD_ECHO) ? &c : "*", 1, false);
                                }
                        }

                        dirty = true;
                }

                c = 'x';
        }

        x = strndup(passphrase, p);
        explicit_bzero(passphrase, p);
        if (!x) {
                r = -ENOMEM;
                goto finish;
        }

        if (keyname)
                (void) add_to_keyring_and_log(keyname, flags, STRV_MAKE(x));

        *ret = x;
        r = 0;

finish:
        if (ttyfd >= 0 && reset_tty) {
                loop_write(ttyfd, "\n", 1, false);
                tcsetattr(ttyfd, TCSADRAIN, &old_termios);
        }

        return r;
}

static int create_socket(char **name) {
        union sockaddr_union sa = {
                .un.sun_family = AF_UNIX,
        };
        _cleanup_close_ int fd = -1;
        static const int one = 1;
        char *c;
        int r;

        assert(name);

        fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
        if (fd < 0)
                return -errno;

        snprintf(sa.un.sun_path, sizeof(sa.un.sun_path)-1, "/run/systemd/ask-password/sck.%" PRIx64, random_u64());

        RUN_WITH_UMASK(0177) {
                if (bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
                        return -errno;
        }

        if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
                return -errno;

        c = strdup(sa.un.sun_path);
        if (!c)
                return -ENOMEM;

        *name = c;

        r = fd;
        fd = -1;

        return r;
}

int ask_password_agent(
                const char *message,
                const char *icon,
                const char *id,
                const char *keyname,
                usec_t until,
                AskPasswordFlags flags,
                char ***ret) {

        enum {
                FD_SOCKET,
                FD_SIGNAL,
                _FD_MAX
        };

        _cleanup_close_ int socket_fd = -1, signal_fd = -1, fd = -1;
        char temp[] = "/run/systemd/ask-password/tmp.XXXXXX";
        char final[sizeof(temp)] = "";
        _cleanup_free_ char *socket_name = NULL;
        _cleanup_strv_free_ char **l = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        struct pollfd pollfd[_FD_MAX];
        sigset_t mask, oldmask;
        int r;

        assert(ret);

        if (flags & ASK_PASSWORD_NO_AGENT)
                return -EUNATCH;

        assert_se(sigemptyset(&mask) >= 0);
        assert_se(sigset_add_many(&mask, SIGINT, SIGTERM, -1) >= 0);
        assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) >= 0);

        (void) mkdir_p_label("/run/systemd/ask-password", 0755);

        fd = mkostemp_safe(temp);
        if (fd < 0) {
                r = fd;
                goto finish;
        }

        (void) fchmod(fd, 0644);

        f = fdopen(fd, "w");
        if (!f) {
                r = -errno;
                goto finish;
        }

        fd = -1;

        signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
        if (signal_fd < 0) {
                r = -errno;
                goto finish;
        }

        socket_fd = create_socket(&socket_name);
        if (socket_fd < 0) {
                r = socket_fd;
                goto finish;
        }

        fprintf(f,
                "[Ask]\n"
                "PID="PID_FMT"\n"
                "Socket=%s\n"
                "AcceptCached=%i\n"
                "Echo=%i\n"
                "NotAfter="USEC_FMT"\n",
                getpid_cached(),
                socket_name,
                (flags & ASK_PASSWORD_ACCEPT_CACHED) ? 1 : 0,
                (flags & ASK_PASSWORD_ECHO) ? 1 : 0,
                until);

        if (message)
                fprintf(f, "Message=%s\n", message);

        if (icon)
                fprintf(f, "Icon=%s\n", icon);

        if (id)
                fprintf(f, "Id=%s\n", id);

        r = fflush_and_check(f);
        if (r < 0)
                goto finish;

        memcpy(final, temp, sizeof(temp));

        final[sizeof(final)-11] = 'a';
        final[sizeof(final)-10] = 's';
        final[sizeof(final)-9] = 'k';

        if (rename(temp, final) < 0) {
                r = -errno;
                goto finish;
        }

        zero(pollfd);
        pollfd[FD_SOCKET].fd = socket_fd;
        pollfd[FD_SOCKET].events = POLLIN;
        pollfd[FD_SIGNAL].fd = signal_fd;
        pollfd[FD_SIGNAL].events = POLLIN;

        for (;;) {
                char passphrase[LINE_MAX+1];
                struct msghdr msghdr;
                struct iovec iovec;
                struct ucred *ucred;
                union {
                        struct cmsghdr cmsghdr;
                        uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
                } control;
                ssize_t n;
                int k;
                usec_t t;

                t = now(CLOCK_MONOTONIC);

                if (until > 0 && until <= t) {
                        r = -ETIME;
                        goto finish;
                }

                k = poll(pollfd, _FD_MAX, until > 0 ? (int) ((until-t)/USEC_PER_MSEC) : -1);
                if (k < 0) {
                        if (errno == EINTR)
                                continue;

                        r = -errno;
                        goto finish;
                }

                if (k <= 0) {
                        r = -ETIME;
                        goto finish;
                }

                if (pollfd[FD_SIGNAL].revents & POLLIN) {
                        r = -EINTR;
                        goto finish;
                }

                if (pollfd[FD_SOCKET].revents != POLLIN) {
                        r = -EIO;
                        goto finish;
                }

                zero(iovec);
                iovec.iov_base = passphrase;
                iovec.iov_len = sizeof(passphrase);

                zero(control);
                zero(msghdr);
                msghdr.msg_iov = &iovec;
                msghdr.msg_iovlen = 1;
                msghdr.msg_control = &control;
                msghdr.msg_controllen = sizeof(control);

                n = recvmsg(socket_fd, &msghdr, 0);
                if (n < 0) {
                        if (errno == EAGAIN ||
                            errno == EINTR)
                                continue;

                        r = -errno;
                        goto finish;
                }

                cmsg_close_all(&msghdr);

                if (n <= 0) {
                        log_debug("Message too short");
                        continue;
                }

                if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
                    control.cmsghdr.cmsg_level != SOL_SOCKET ||
                    control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
                    control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
                        log_debug("Received message without credentials. Ignoring.");
                        continue;
                }

                ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
                if (ucred->uid != 0) {
                        log_debug("Got request from unprivileged user. Ignoring.");
                        continue;
                }

                if (passphrase[0] == '+') {
                        /* An empty message refers to the empty password */
                        if (n == 1)
                                l = strv_new("", NULL);
                        else
                                l = strv_parse_nulstr(passphrase+1, n-1);
                        explicit_bzero(passphrase, n);
                        if (!l) {
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (strv_length(l) <= 0) {
                                l = strv_free(l);
                                log_debug("Invalid packet");
                                continue;
                        }

                        break;
                }

                if (passphrase[0] == '-') {
                        r = -ECANCELED;
                        goto finish;
                }

                log_debug("Invalid packet");
        }

        if (keyname)
                (void) add_to_keyring_and_log(keyname, flags, l);

        *ret = l;
        l = NULL;
        r = 0;

finish:
        if (socket_name)
                (void) unlink(socket_name);

        (void) unlink(temp);

        if (final[0])
                (void) unlink(final);

        assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);
        return r;
}

int ask_password_auto(
                const char *message,
                const char *icon,
                const char *id,
                const char *keyname,
                usec_t until,
                AskPasswordFlags flags,
                char ***ret) {

        int r;

        assert(ret);

        if ((flags & ASK_PASSWORD_ACCEPT_CACHED) && keyname) {
                r = ask_password_keyring(keyname, flags, ret);
                if (r != -ENOKEY)
                        return r;
        }

        if (!(flags & ASK_PASSWORD_NO_TTY) && isatty(STDIN_FILENO)) {
                char *s = NULL, **l = NULL;

                r = ask_password_tty(message, keyname, until, flags, NULL, &s);
                if (r < 0)
                        return r;

                r = strv_push(&l, s);
                if (r < 0) {
                        string_erase(s);
                        free(s);
                        return -ENOMEM;
                }

                *ret = l;
                return 0;
        }

        if (!(flags & ASK_PASSWORD_NO_AGENT))
                return ask_password_agent(message, icon, id, keyname, until, flags, ret);

        return -EUNATCH;
}
Commit	Line	Data
7f4e0805 LP	1	/***
	2	This file is part of systemd.
	3
	4	Copyright 2010 Lennart Poettering
	5
	6	systemd is free software; you can redistribute it and/or modify it
5430f7f2 LP	7	under the terms of the GNU Lesser General Public License as published by
5430f7f2 LP	8	the Free Software Foundation; either version 2.1 of the License, or
7f4e0805 LP	9	(at your option) any later version.
	10
	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
5430f7f2	14	Lesser General Public License for more details.
7f4e0805	15
5430f7f2	16	You should have received a copy of the GNU Lesser General Public License
7f4e0805 LP	17	along with systemd; If not, see <http://www.gnu.org/licenses/>.
7f4e0805 LP	18	***/
00843602	19
7f4e0805 LP	20	#include <errno.h>
7f4e0805 LP	21	#include <fcntl.h>
a8fbdf54 TA	22	#include <inttypes.h>
a8fbdf54 TA	23	#include <limits.h>
00843602	24	#include <poll.h>
a8fbdf54	25	#include <signal.h>
00843602	26	#include <stdbool.h>
7f4e0805	27	#include <stddef.h>
a8fbdf54 TA	28	#include <stdint.h>
	29	#include <stdio.h>
	30	#include <stdlib.h>
00843602 LP	31	#include <string.h>
00843602 LP	32	#include <sys/inotify.h>
7f4e0805	33	#include <sys/signalfd.h>
00843602	34	#include <sys/socket.h>
a8fbdf54 TA	35	#include <sys/stat.h>
	36	#include <sys/time.h>
	37	#include <sys/uio.h>
00843602 LP	38	#include <sys/un.h>
	39	#include <termios.h>
	40	#include <unistd.h>
7f4e0805	41
b5efdb8a	42	#include "alloc-util.h"
3ffd4af2 LP	43	#include "ask-password-api.h"
3ffd4af2 LP	44	#include "fd-util.h"
0d39fa9c	45	#include "fileio.h"
f97b34a6	46	#include "format-util.h"
c004493c	47	#include "io-util.h"
a8fbdf54 TA	48	#include "log.h"
a8fbdf54 TA	49	#include "macro.h"
e287086b	50	#include "missing.h"
49e942b2	51	#include "mkdir.h"
df0ff127	52	#include "process-util.h"
3df3e884	53	#include "random-util.h"
24882e06	54	#include "signal-util.h"
00843602	55	#include "socket-util.h"
07630cea	56	#include "string-util.h"
00843602 LP	57	#include "strv.h"
00843602 LP	58	#include "terminal-util.h"
a8fbdf54	59	#include "time-util.h"
affb60b1	60	#include "umask-util.h"
f3149d57	61	#include "utf8.h"
00843602	62	#include "util.h"
7f4e0805	63
e287086b LP	64	#define KEYRING_TIMEOUT_USEC ((5 * USEC_PER_MINUTE) / 2)
	65
	66	static int lookup_key(const char keyname, key_serial_t ret) {
	67	key_serial_t serial;
	68
	69	assert(keyname);
	70	assert(ret);
	71
	72	serial = request_key("user", keyname, NULL, 0);
	73	if (serial == -1)
9c4615fb	74	return negative_errno();
e287086b LP	75
	76	*ret = serial;
	77	return 0;
	78	}
	79
	80	static int retrieve_key(key_serial_t serial, char ***ret) {
	81	_cleanup_free_ char *p = NULL;
	82	long m = 100, n;
	83	char **l;
	84
	85	assert(ret);
	86
	87	for (;;) {
	88	p = new(char, m);
	89	if (!p)
	90	return -ENOMEM;
	91
	92	n = keyctl(KEYCTL_READ, (unsigned long) serial, (unsigned long) p, (unsigned long) m, 0);
	93	if (n < 0)
	94	return -errno;
	95
	96	if (n < m)
	97	break;
	98
2d26d8e0	99	explicit_bzero(p, n);
e287086b LP	100	free(p);
	101	m *= 2;
	102	}
	103
	104	l = strv_parse_nulstr(p, n);
	105	if (!l)
	106	return -ENOMEM;
	107
2d26d8e0	108	explicit_bzero(p, n);
1602b008	109
e287086b LP	110	*ret = l;
	111	return 0;
	112	}
	113
	114	static int add_to_keyring(const char keyname, AskPasswordFlags flags, char *passwords) {
ab84f5b9	115	_cleanup_strv_free_erase_ char **l = NULL;
e287086b LP	116	_cleanup_free_ char *p = NULL;
	117	key_serial_t serial;
	118	size_t n;
	119	int r;
	120
	121	assert(keyname);
	122	assert(passwords);
	123
	124	if (!(flags & ASK_PASSWORD_PUSH_CACHE))
	125	return 0;
	126
	127	r = lookup_key(keyname, &serial);
	128	if (r >= 0) {
	129	r = retrieve_key(serial, &l);
	130	if (r < 0)
	131	return r;
	132	} else if (r != -ENOKEY)
	133	return r;
	134
	135	r = strv_extend_strv(&l, passwords, true);
	136	if (r <= 0)
	137	return r;
	138
	139	r = strv_make_nulstr(l, &p, &n);
	140	if (r < 0)
	141	return r;
	142
b60df13b	143	serial = add_key("user", keyname, p, n, KEY_SPEC_USER_KEYRING);
2d26d8e0	144	explicit_bzero(p, n);
e287086b LP	145	if (serial == -1)
	146	return -errno;
	147
	148	if (keyctl(KEYCTL_SET_TIMEOUT,
	149	(unsigned long) serial,
	150	(unsigned long) DIV_ROUND_UP(KEYRING_TIMEOUT_USEC, USEC_PER_SEC), 0, 0) < 0)
	151	log_debug_errno(errno, "Failed to adjust timeout: %m");
	152
	153	log_debug("Added key to keyring as %" PRIi32 ".", serial);
	154
	155	return 1;
	156	}
	157
	158	static int add_to_keyring_and_log(const char keyname, AskPasswordFlags flags, char *passwords) {
	159	int r;
	160
	161	assert(keyname);
	162	assert(passwords);
	163
	164	r = add_to_keyring(keyname, flags, passwords);
	165	if (r < 0)
	166	return log_debug_errno(r, "Failed to add password to keyring: %m");
	167
	168	return 0;
	169	}
	170
	171	int ask_password_keyring(const char keyname, AskPasswordFlags flags, char **ret) {
	172
	173	key_serial_t serial;
	174	int r;
	175
	176	assert(keyname);
	177	assert(ret);
	178
	179	if (!(flags & ASK_PASSWORD_ACCEPT_CACHED))
	180	return -EUNATCH;
	181
	182	r = lookup_key(keyname, &serial);
	183	if (r == -ENOSYS) /* when retrieving the distinction doesn't matter */
	184	return -ENOKEY;
	185	if (r < 0)
	186	return r;
	187
	188	return retrieve_key(serial, ret);
	189	}
	190
58fc840b LP	191	static void backspace_chars(int ttyfd, size_t p) {
	192
	193	if (ttyfd < 0)
	194	return;
	195
	196	while (p > 0) {
	197	p--;
	198
	199	loop_write(ttyfd, "\b \b", 3, false);
	200	}
	201	}
	202
7f4e0805 LP	203	int ask_password_tty(
7f4e0805 LP	204	const char *message,
e287086b	205	const char *keyname,
7f4e0805	206	usec_t until,
e287086b	207	AskPasswordFlags flags,
7f4e0805	208	const char *flag_file,
e287086b	209	char **ret) {
7f4e0805 LP	210
7f4e0805 LP	211	struct termios old_termios, new_termios;
f3149d57 ZJS	212	char passphrase[LINE_MAX + 1] = {}, *x;
f3149d57 ZJS	213	size_t p = 0, codepoint = 0;
981e4cd3 LP	214	int r;
981e4cd3 LP	215	_cleanup_close_ int ttyfd = -1, notify = -1;
7f4e0805 LP	216	struct pollfd pollfd[2];
7f4e0805 LP	217	bool reset_tty = false;
441dfe09	218	bool dirty = false;
7f4e0805 LP	219	enum {
	220	POLL_TTY,
	221	POLL_INOTIFY
	222	};
	223
e287086b LP	224	assert(ret);
	225
	226	if (flags & ASK_PASSWORD_NO_TTY)
	227	return -EUNATCH;
	228
	229	if (!message)
	230	message = "Password:";
7f4e0805 LP	231
7f4e0805 LP	232	if (flag_file) {
981e4cd3 LP	233	notify = inotify_init1(IN_CLOEXEC\|IN_NONBLOCK);
981e4cd3 LP	234	if (notify < 0) {
7f4e0805 LP	235	r = -errno;
	236	goto finish;
	237	}
	238
	239	if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) {
	240	r = -errno;
	241	goto finish;
	242	}
	243	}
	244
981e4cd3 LP	245	ttyfd = open("/dev/tty", O_RDWR\|O_NOCTTY\|O_CLOEXEC);
981e4cd3 LP	246	if (ttyfd >= 0) {
7f4e0805 LP	247
	248	if (tcgetattr(ttyfd, &old_termios) < 0) {
	249	r = -errno;
	250	goto finish;
	251	}
	252
7565bb98 LP	253	if (colors_enabled())
7565bb98 LP	254	loop_write(ttyfd, ANSI_HIGHLIGHT, strlen(ANSI_HIGHLIGHT), false);
7f4e0805	255	loop_write(ttyfd, message, strlen(message), false);
bd1db33f	256	loop_write(ttyfd, " ", 1, false);
7565bb98 LP	257	if (colors_enabled())
7565bb98 LP	258	loop_write(ttyfd, ANSI_NORMAL, strlen(ANSI_NORMAL), false);
7f4e0805 LP	259
	260	new_termios = old_termios;
	261	new_termios.c_lflag &= ~(ICANON\|ECHO);
	262	new_termios.c_cc[VMIN] = 1;
	263	new_termios.c_cc[VTIME] = 0;
	264
	265	if (tcsetattr(ttyfd, TCSADRAIN, &new_termios) < 0) {
	266	r = -errno;
	267	goto finish;
	268	}
	269
	270	reset_tty = true;
	271	}
	272
	273	zero(pollfd);
7f4e0805 LP	274	pollfd[POLL_TTY].fd = ttyfd >= 0 ? ttyfd : STDIN_FILENO;
	275	pollfd[POLL_TTY].events = POLLIN;
	276	pollfd[POLL_INOTIFY].fd = notify;
	277	pollfd[POLL_INOTIFY].events = POLLIN;
	278
	279	for (;;) {
	280	char c;
	281	int sleep_for = -1, k;
	282	ssize_t n;
	283
	284	if (until > 0) {
	285	usec_t y;
	286
	287	y = now(CLOCK_MONOTONIC);
	288
	289	if (y > until) {
7ded2e28	290	r = -ETIME;
7f4e0805 LP	291	goto finish;
	292	}
	293
	294	sleep_for = (int) ((until - y) / USEC_PER_MSEC);
	295	}
	296
	297	if (flag_file)
	298	if (access(flag_file, F_OK) < 0) {
	299	r = -errno;
	300	goto finish;
	301	}
	302
e287086b	303	k = poll(pollfd, notify >= 0 ? 2 : 1, sleep_for);
981e4cd3	304	if (k < 0) {
7f4e0805 LP	305	if (errno == EINTR)
	306	continue;
	307
	308	r = -errno;
	309	goto finish;
	310	} else if (k == 0) {
ccc80078	311	r = -ETIME;
7f4e0805 LP	312	goto finish;
	313	}
	314
e287086b	315	if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0)
7f4e0805 LP	316	flush_fd(notify);
	317
	318	if (pollfd[POLL_TTY].revents == 0)
	319	continue;
	320
981e4cd3 LP	321	n = read(ttyfd >= 0 ? ttyfd : STDIN_FILENO, &c, 1);
981e4cd3 LP	322	if (n < 0) {
7f4e0805 LP	323	if (errno == EINTR \|\| errno == EAGAIN)
	324	continue;
	325
	326	r = -errno;
	327	goto finish;
	328
	329	} else if (n == 0)
	330	break;
	331
	332	if (c == '\n')
	333	break;
58fc840b	334	else if (c == 21) { /* C-u */
7f4e0805	335
e287086b	336	if (!(flags & ASK_PASSWORD_SILENT))
58fc840b LP	337	backspace_chars(ttyfd, p);
58fc840b LP	338	p = 0;
7f4e0805 LP	339
7f4e0805 LP	340	} else if (c == '\b' \|\| c == 127) {
58fc840b LP	341
	342	if (p > 0) {
	343
e287086b	344	if (!(flags & ASK_PASSWORD_SILENT))
58fc840b LP	345	backspace_chars(ttyfd, 1);
58fc840b LP	346
7f4e0805	347	p--;
e287086b	348	} else if (!dirty && !(flags & ASK_PASSWORD_SILENT)) {
441dfe09	349
e287086b	350	flags \|= ASK_PASSWORD_SILENT;
441dfe09 LP	351
	352	/* There are two ways to enter silent
	353	* mode. Either by pressing backspace
e287086b LP	354	* as first key (and only as first
e287086b LP	355	* key), or ... */
441dfe09 LP	356	if (ttyfd >= 0)
	357	loop_write(ttyfd, "(no echo) ", 10, false);
	358
58fc840b LP	359	} else if (ttyfd >= 0)
58fc840b LP	360	loop_write(ttyfd, "\a", 1, false);
7f4e0805	361
e287086b	362	} else if (c == '\t' && !(flags & ASK_PASSWORD_SILENT)) {
58fc840b LP	363
58fc840b LP	364	backspace_chars(ttyfd, p);
e287086b	365	flags \|= ASK_PASSWORD_SILENT;
58fc840b	366
441dfe09 LP	367	/* ... or by pressing TAB at any time. */
441dfe09 LP	368
58fc840b LP	369	if (ttyfd >= 0)
58fc840b LP	370	loop_write(ttyfd, "(no echo) ", 10, false);
7f4e0805	371	} else {
036eeac5 LP	372	if (p >= sizeof(passphrase)-1) {
	373	loop_write(ttyfd, "\a", 1, false);
	374	continue;
	375	}
	376
7f4e0805 LP	377	passphrase[p++] = c;
7f4e0805 LP	378
f3149d57 ZJS	379	if (!(flags & ASK_PASSWORD_SILENT) && ttyfd >= 0) {
	380	n = utf8_encoded_valid_unichar(passphrase + codepoint);
	381	if (n >= 0) {
	382	codepoint = p;
	383	loop_write(ttyfd, (flags & ASK_PASSWORD_ECHO) ? &c : "*", 1, false);
	384	}
	385	}
441dfe09 LP	386
441dfe09 LP	387	dirty = true;
7f4e0805	388	}
1602b008 LP	389
1602b008 LP	390	c = 'x';
7f4e0805 LP	391	}
7f4e0805 LP	392
981e4cd3	393	x = strndup(passphrase, p);
2d26d8e0	394	explicit_bzero(passphrase, p);
981e4cd3	395	if (!x) {
7f4e0805 LP	396	r = -ENOMEM;
	397	goto finish;
	398	}
	399
e287086b LP	400	if (keyname)
	401	(void) add_to_keyring_and_log(keyname, flags, STRV_MAKE(x));
	402
	403	*ret = x;
7f4e0805 LP	404	r = 0;
	405
	406	finish:
981e4cd3 LP	407	if (ttyfd >= 0 && reset_tty) {
	408	loop_write(ttyfd, "\n", 1, false);
	409	tcsetattr(ttyfd, TCSADRAIN, &old_termios);
7f4e0805 LP	410	}
	411
	412	return r;
	413	}
	414
	415	static int create_socket(char **name) {
00843602	416	union sockaddr_union sa = {
b92bea5d ZJS	417	.un.sun_family = AF_UNIX,
b92bea5d ZJS	418	};
00843602 LP	419	_cleanup_close_ int fd = -1;
00843602 LP	420	static const int one = 1;
7f4e0805	421	char *c;
00843602	422	int r;
7f4e0805 LP	423
	424	assert(name);
	425
e62d8c39	426	fd = socket(AF_UNIX, SOCK_DGRAM\|SOCK_CLOEXEC\|SOCK_NONBLOCK, 0);
4a62c710	427	if (fd < 0)
00843602	428	return -errno;
7f4e0805	429
9bf3b535	430	snprintf(sa.un.sun_path, sizeof(sa.un.sun_path)-1, "/run/systemd/ask-password/sck.%" PRIx64, random_u64());
7f4e0805	431
5c0d398d	432	RUN_WITH_UMASK(0177) {
fc2fffe7	433	if (bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
00843602	434	return -errno;
5c0d398d	435	}
1d6702e8	436
00843602 LP	437	if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
00843602 LP	438	return -errno;
7f4e0805	439
e62d8c39	440	c = strdup(sa.un.sun_path);
00843602 LP	441	if (!c)
00843602 LP	442	return -ENOMEM;
7f4e0805 LP	443
7f4e0805 LP	444	*name = c;
7f4e0805	445
00843602 LP	446	r = fd;
00843602 LP	447	fd = -1;
7f4e0805 LP	448
	449	return r;
	450	}
	451
7f4e0805 LP	452	int ask_password_agent(
	453	const char *message,
	454	const char *icon,
9fa1de96	455	const char *id,
e287086b	456	const char *keyname,
7f4e0805	457	usec_t until,
e287086b LP	458	AskPasswordFlags flags,
e287086b LP	459	char ***ret) {
7f4e0805 LP	460
	461	enum {
	462	FD_SOCKET,
	463	FD_SIGNAL,
	464	_FD_MAX
	465	};
	466
e287086b	467	_cleanup_close_ int socket_fd = -1, signal_fd = -1, fd = -1;
2b583ce6	468	char temp[] = "/run/systemd/ask-password/tmp.XXXXXX";
7f4e0805	469	char final[sizeof(temp)] = "";
981e4cd3	470	_cleanup_free_ char *socket_name = NULL;
e287086b LP	471	_cleanup_strv_free_ char **l = NULL;
e287086b LP	472	_cleanup_fclose_ FILE *f = NULL;
7f4e0805	473	struct pollfd pollfd[_FD_MAX];
e287086b	474	sigset_t mask, oldmask;
981e4cd3	475	int r;
7f4e0805	476
e287086b	477	assert(ret);
21bc923a	478
e287086b LP	479	if (flags & ASK_PASSWORD_NO_AGENT)
e287086b LP	480	return -EUNATCH;
00843602	481
72c0a2c2 LP	482	assert_se(sigemptyset(&mask) >= 0);
	483	assert_se(sigset_add_many(&mask, SIGINT, SIGTERM, -1) >= 0);
	484	assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) >= 0);
f9b72cd8	485
00843602	486	(void) mkdir_p_label("/run/systemd/ask-password", 0755);
7f4e0805	487
646853bd	488	fd = mkostemp_safe(temp);
1d6702e8	489	if (fd < 0) {
709f6e46	490	r = fd;
7f4e0805 LP	491	goto finish;
	492	}
	493
00843602	494	(void) fchmod(fd, 0644);
7f4e0805	495
981e4cd3 LP	496	f = fdopen(fd, "w");
981e4cd3 LP	497	if (!f) {
00843602	498	r = -errno;
7f4e0805 LP	499	goto finish;
	500	}
	501
	502	fd = -1;
	503
981e4cd3 LP	504	signal_fd = signalfd(-1, &mask, SFD_NONBLOCK\|SFD_CLOEXEC);
981e4cd3 LP	505	if (signal_fd < 0) {
00843602	506	r = -errno;
7f4e0805 LP	507	goto finish;
	508	}
	509
981e4cd3 LP	510	socket_fd = create_socket(&socket_name);
981e4cd3 LP	511	if (socket_fd < 0) {
7f4e0805 LP	512	r = socket_fd;
	513	goto finish;
	514	}
	515
	516	fprintf(f,
	517	"[Ask]\n"
de0671ee	518	"PID="PID_FMT"\n"
7f4e0805	519	"Socket=%s\n"
21bc923a	520	"AcceptCached=%i\n"
64845bdc	521	"Echo=%i\n"
de0671ee	522	"NotAfter="USEC_FMT"\n",
df0ff127	523	getpid_cached(),
7f4e0805	524	socket_name,
e287086b LP	525	(flags & ASK_PASSWORD_ACCEPT_CACHED) ? 1 : 0,
e287086b LP	526	(flags & ASK_PASSWORD_ECHO) ? 1 : 0,
de0671ee	527	until);
7f4e0805 LP	528
	529	if (message)
	530	fprintf(f, "Message=%s\n", message);
	531
	532	if (icon)
	533	fprintf(f, "Icon=%s\n", icon);
	534
9fa1de96 DH	535	if (id)
	536	fprintf(f, "Id=%s\n", id);
	537
dacd6cee	538	r = fflush_and_check(f);
00843602	539	if (r < 0)
7f4e0805	540	goto finish;
7f4e0805 LP	541
	542	memcpy(final, temp, sizeof(temp));
	543
	544	final[sizeof(final)-11] = 'a';
	545	final[sizeof(final)-10] = 's';
	546	final[sizeof(final)-9] = 'k';
	547
	548	if (rename(temp, final) < 0) {
00843602	549	r = -errno;
7f4e0805 LP	550	goto finish;
	551	}
	552
	553	zero(pollfd);
	554	pollfd[FD_SOCKET].fd = socket_fd;
	555	pollfd[FD_SOCKET].events = POLLIN;
	556	pollfd[FD_SIGNAL].fd = signal_fd;
	557	pollfd[FD_SIGNAL].events = POLLIN;
	558
	559	for (;;) {
	560	char passphrase[LINE_MAX+1];
	561	struct msghdr msghdr;
	562	struct iovec iovec;
	563	struct ucred *ucred;
	564	union {
	565	struct cmsghdr cmsghdr;
	566	uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
	567	} control;
	568	ssize_t n;
	569	int k;
	570	usec_t t;
	571
	572	t = now(CLOCK_MONOTONIC);
	573
7dcda352	574	if (until > 0 && until <= t) {
7f4e0805 LP	575	r = -ETIME;
	576	goto finish;
	577	}
	578
981e4cd3 LP	579	k = poll(pollfd, _FD_MAX, until > 0 ? (int) ((until-t)/USEC_PER_MSEC) : -1);
981e4cd3 LP	580	if (k < 0) {
7f4e0805 LP	581	if (errno == EINTR)
	582	continue;
	583
00843602	584	r = -errno;
7f4e0805 LP	585	goto finish;
	586	}
	587
	588	if (k <= 0) {
7f4e0805 LP	589	r = -ETIME;
	590	goto finish;
	591	}
	592
21bc923a LP	593	if (pollfd[FD_SIGNAL].revents & POLLIN) {
	594	r = -EINTR;
	595	goto finish;
	596	}
7f4e0805 LP	597
7f4e0805 LP	598	if (pollfd[FD_SOCKET].revents != POLLIN) {
7f4e0805 LP	599	r = -EIO;
	600	goto finish;
	601	}
	602
	603	zero(iovec);
	604	iovec.iov_base = passphrase;
21bc923a	605	iovec.iov_len = sizeof(passphrase);
7f4e0805 LP	606
	607	zero(control);
	608	zero(msghdr);
	609	msghdr.msg_iov = &iovec;
	610	msghdr.msg_iovlen = 1;
	611	msghdr.msg_control = &control;
	612	msghdr.msg_controllen = sizeof(control);
	613
981e4cd3 LP	614	n = recvmsg(socket_fd, &msghdr, 0);
981e4cd3 LP	615	if (n < 0) {
7f4e0805 LP	616	if (errno == EAGAIN \|\|
	617	errno == EINTR)
	618	continue;
	619
00843602	620	r = -errno;
7f4e0805 LP	621	goto finish;
	622	}
	623
1c8da044 LP	624	cmsg_close_all(&msghdr);
1c8da044 LP	625
7f4e0805	626	if (n <= 0) {
00843602	627	log_debug("Message too short");
7f4e0805 LP	628	continue;
	629	}
	630
	631	if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) \|\|
	632	control.cmsghdr.cmsg_level != SOL_SOCKET \|\|
	633	control.cmsghdr.cmsg_type != SCM_CREDENTIALS \|\|
	634	control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
00843602	635	log_debug("Received message without credentials. Ignoring.");
7f4e0805 LP	636	continue;
	637	}
	638
	639	ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
	640	if (ucred->uid != 0) {
00843602	641	log_debug("Got request from unprivileged user. Ignoring.");
7f4e0805 LP	642	continue;
	643	}
	644
	645	if (passphrase[0] == '+') {
e287086b	646	/* An empty message refers to the empty password */
8254a475 LP	647	if (n == 1)
	648	l = strv_new("", NULL);
	649	else
	650	l = strv_parse_nulstr(passphrase+1, n-1);
2d26d8e0	651	explicit_bzero(passphrase, n);
8254a475	652	if (!l) {
7f4e0805 LP	653	r = -ENOMEM;
	654	goto finish;
	655	}
	656
21bc923a	657	if (strv_length(l) <= 0) {
e287086b	658	l = strv_free(l);
00843602	659	log_debug("Invalid packet");
21bc923a LP	660	continue;
	661	}
	662
e287086b LP	663	break;
e287086b LP	664	}
21bc923a	665
e287086b	666	if (passphrase[0] == '-') {
7f4e0805 LP	667	r = -ECANCELED;
7f4e0805 LP	668	goto finish;
7f4e0805 LP	669	}
7f4e0805 LP	670
e287086b	671	log_debug("Invalid packet");
7f4e0805 LP	672	}
7f4e0805 LP	673
e287086b LP	674	if (keyname)
	675	(void) add_to_keyring_and_log(keyname, flags, l);
	676
	677	*ret = l;
	678	l = NULL;
7f4e0805 LP	679	r = 0;
	680
	681	finish:
981e4cd3	682	if (socket_name)
00843602	683	(void) unlink(socket_name);
7f4e0805	684
00843602	685	(void) unlink(temp);
7f4e0805 LP	686
7f4e0805 LP	687	if (final[0])
00843602	688	(void) unlink(final);
7f4e0805	689
f9b72cd8	690	assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);
7f4e0805 LP	691	return r;
7f4e0805 LP	692	}
260ab287	693
00843602 LP	694	int ask_password_auto(
	695	const char *message,
	696	const char *icon,
	697	const char *id,
e287086b	698	const char *keyname,
00843602	699	usec_t until,
e287086b LP	700	AskPasswordFlags flags,
e287086b LP	701	char ***ret) {
00843602 LP	702
	703	int r;
	704
e287086b	705	assert(ret);
21bc923a	706
e287086b LP	707	if ((flags & ASK_PASSWORD_ACCEPT_CACHED) && keyname) {
	708	r = ask_password_keyring(keyname, flags, ret);
	709	if (r != -ENOKEY)
	710	return r;
	711	}
	712
	713	if (!(flags & ASK_PASSWORD_NO_TTY) && isatty(STDIN_FILENO)) {
21bc923a LP	714	char s = NULL, *l = NULL;
21bc923a LP	715
e287086b	716	r = ask_password_tty(message, keyname, until, flags, NULL, &s);
981e4cd3	717	if (r < 0)
21bc923a LP	718	return r;
21bc923a LP	719
1602b008 LP	720	r = strv_push(&l, s);
	721	if (r < 0) {
	722	string_erase(s);
	723	free(s);
00843602	724	return -ENOMEM;
1602b008	725	}
21bc923a	726
e287086b	727	*ret = l;
00843602 LP	728	return 0;
	729	}
	730
e287086b LP	731	if (!(flags & ASK_PASSWORD_NO_AGENT))
	732	return ask_password_agent(message, icon, id, keyname, until, flags, ret);
	733
	734	return -EUNATCH;
260ab287	735	}