[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 "formats-util.h"
#include "io-util.h"
#include "log.h"
#include "macro.h"
#include "missing.h"
#include "mkdir.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;

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

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

        memory_erase(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;

        /* Truncate trailing NUL */
        assert(n > 0);
        assert(p[n-1] == 0);

        serial = add_key("user", keyname, p, n-1, KEY_SPEC_USER_KEYRING);
        memory_erase(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;
                }

                loop_write(ttyfd, ANSI_HIGHLIGHT, strlen(ANSI_HIGHLIGHT), false);
                loop_write(ttyfd, message, strlen(message), false);
                loop_write(ttyfd, " ", 1, false);
                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);
        memory_erase(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, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 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, O_WRONLY|O_CLOEXEC);
        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(),
                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);
                        memory_erase(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
663996b3 MS	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
	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.
	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
	14	Lesser General Public License for more details.
	15
	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/>.
	18	***/
6300502b	19
663996b3 MS	20	#include <errno.h>
663996b3 MS	21	#include <fcntl.h>
4c89c718 MP	22	#include <inttypes.h>
4c89c718 MP	23	#include <limits.h>
6300502b	24	#include <poll.h>
4c89c718	25	#include <signal.h>
6300502b	26	#include <stdbool.h>
663996b3	27	#include <stddef.h>
4c89c718 MP	28	#include <stdint.h>
	29	#include <stdio.h>
	30	#include <stdlib.h>
6300502b MP	31	#include <string.h>
6300502b MP	32	#include <sys/inotify.h>
663996b3	33	#include <sys/signalfd.h>
6300502b	34	#include <sys/socket.h>
4c89c718 MP	35	#include <sys/stat.h>
	36	#include <sys/time.h>
	37	#include <sys/uio.h>
6300502b MP	38	#include <sys/un.h>
	39	#include <termios.h>
	40	#include <unistd.h>
663996b3	41
db2df898 MP	42	#include "alloc-util.h"
	43	#include "ask-password-api.h"
	44	#include "fd-util.h"
	45	#include "fileio.h"
e3bff60a	46	#include "formats-util.h"
db2df898	47	#include "io-util.h"
4c89c718 MP	48	#include "log.h"
4c89c718 MP	49	#include "macro.h"
6300502b	50	#include "missing.h"
663996b3	51	#include "mkdir.h"
e3bff60a	52	#include "random-util.h"
86f210e9	53	#include "signal-util.h"
6300502b	54	#include "socket-util.h"
db2df898	55	#include "string-util.h"
6300502b MP	56	#include "strv.h"
6300502b MP	57	#include "terminal-util.h"
4c89c718	58	#include "time-util.h"
db2df898	59	#include "umask-util.h"
4c89c718	60	#include "utf8.h"
6300502b	61	#include "util.h"
663996b3	62
6300502b MP	63	#define KEYRING_TIMEOUT_USEC ((5 * USEC_PER_MINUTE) / 2)
	64
	65	static int lookup_key(const char keyname, key_serial_t ret) {
	66	key_serial_t serial;
	67
	68	assert(keyname);
	69	assert(ret);
	70
	71	serial = request_key("user", keyname, NULL, 0);
	72	if (serial == -1)
4c89c718	73	return negative_errno();
6300502b MP	74
	75	*ret = serial;
	76	return 0;
	77	}
	78
	79	static int retrieve_key(key_serial_t serial, char ***ret) {
	80	_cleanup_free_ char *p = NULL;
	81	long m = 100, n;
	82	char **l;
	83
	84	assert(ret);
	85
	86	for (;;) {
	87	p = new(char, m);
	88	if (!p)
	89	return -ENOMEM;
	90
	91	n = keyctl(KEYCTL_READ, (unsigned long) serial, (unsigned long) p, (unsigned long) m, 0);
	92	if (n < 0)
	93	return -errno;
	94
	95	if (n < m)
	96	break;
	97
db2df898	98	memory_erase(p, n);
6300502b MP	99	free(p);
	100	m *= 2;
	101	}
	102
	103	l = strv_parse_nulstr(p, n);
	104	if (!l)
	105	return -ENOMEM;
	106
db2df898 MP	107	memory_erase(p, n);
db2df898 MP	108
6300502b MP	109	*ret = l;
	110	return 0;
	111	}
	112
	113	static int add_to_keyring(const char keyname, AskPasswordFlags flags, char *passwords) {
db2df898	114	_cleanup_strv_free_erase_ char **l = NULL;
6300502b MP	115	_cleanup_free_ char *p = NULL;
	116	key_serial_t serial;
	117	size_t n;
	118	int r;
	119
	120	assert(keyname);
	121	assert(passwords);
	122
	123	if (!(flags & ASK_PASSWORD_PUSH_CACHE))
	124	return 0;
	125
	126	r = lookup_key(keyname, &serial);
	127	if (r >= 0) {
	128	r = retrieve_key(serial, &l);
	129	if (r < 0)
	130	return r;
	131	} else if (r != -ENOKEY)
	132	return r;
	133
	134	r = strv_extend_strv(&l, passwords, true);
	135	if (r <= 0)
	136	return r;
	137
	138	r = strv_make_nulstr(l, &p, &n);
	139	if (r < 0)
	140	return r;
	141
	142	/* Truncate trailing NUL */
	143	assert(n > 0);
	144	assert(p[n-1] == 0);
	145
	146	serial = add_key("user", keyname, p, n-1, KEY_SPEC_USER_KEYRING);
db2df898	147	memory_erase(p, n);
6300502b MP	148	if (serial == -1)
	149	return -errno;
	150
	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");
	155
	156	log_debug("Added key to keyring as %" PRIi32 ".", serial);
	157
	158	return 1;
	159	}
	160
	161	static int add_to_keyring_and_log(const char keyname, AskPasswordFlags flags, char *passwords) {
	162	int r;
	163
	164	assert(keyname);
	165	assert(passwords);
	166
	167	r = add_to_keyring(keyname, flags, passwords);
	168	if (r < 0)
	169	return log_debug_errno(r, "Failed to add password to keyring: %m");
	170
	171	return 0;
	172	}
	173
	174	int ask_password_keyring(const char keyname, AskPasswordFlags flags, char **ret) {
	175
	176	key_serial_t serial;
	177	int r;
	178
	179	assert(keyname);
	180	assert(ret);
	181
	182	if (!(flags & ASK_PASSWORD_ACCEPT_CACHED))
	183	return -EUNATCH;
	184
	185	r = lookup_key(keyname, &serial);
	186	if (r == -ENOSYS) /* when retrieving the distinction doesn't matter */
	187	return -ENOKEY;
	188	if (r < 0)
	189	return r;
	190
	191	return retrieve_key(serial, ret);
	192	}
	193
663996b3 MS	194	static void backspace_chars(int ttyfd, size_t p) {
	195
	196	if (ttyfd < 0)
	197	return;
	198
	199	while (p > 0) {
	200	p--;
	201
	202	loop_write(ttyfd, "\b \b", 3, false);
	203	}
	204	}
	205
	206	int ask_password_tty(
	207	const char *message,
6300502b	208	const char *keyname,
663996b3	209	usec_t until,
6300502b	210	AskPasswordFlags flags,
663996b3	211	const char *flag_file,
6300502b	212	char **ret) {
663996b3 MS	213
663996b3 MS	214	struct termios old_termios, new_termios;
4c89c718 MP	215	char passphrase[LINE_MAX + 1] = {}, *x;
4c89c718 MP	216	size_t p = 0, codepoint = 0;
60f067b4 JS	217	int r;
60f067b4 JS	218	_cleanup_close_ int ttyfd = -1, notify = -1;
663996b3 MS	219	struct pollfd pollfd[2];
663996b3 MS	220	bool reset_tty = false;
663996b3 MS	221	bool dirty = false;
	222	enum {
	223	POLL_TTY,
	224	POLL_INOTIFY
	225	};
	226
6300502b MP	227	assert(ret);
	228
	229	if (flags & ASK_PASSWORD_NO_TTY)
	230	return -EUNATCH;
	231
	232	if (!message)
	233	message = "Password:";
663996b3 MS	234
663996b3 MS	235	if (flag_file) {
60f067b4 JS	236	notify = inotify_init1(IN_CLOEXEC\|IN_NONBLOCK);
60f067b4 JS	237	if (notify < 0) {
663996b3 MS	238	r = -errno;
	239	goto finish;
	240	}
	241
	242	if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) {
	243	r = -errno;
	244	goto finish;
	245	}
	246	}
	247
60f067b4 JS	248	ttyfd = open("/dev/tty", O_RDWR\|O_NOCTTY\|O_CLOEXEC);
60f067b4 JS	249	if (ttyfd >= 0) {
663996b3 MS	250
	251	if (tcgetattr(ttyfd, &old_termios) < 0) {
	252	r = -errno;
	253	goto finish;
	254	}
	255
6300502b	256	loop_write(ttyfd, ANSI_HIGHLIGHT, strlen(ANSI_HIGHLIGHT), false);
663996b3 MS	257	loop_write(ttyfd, message, strlen(message), false);
663996b3 MS	258	loop_write(ttyfd, " ", 1, false);
6300502b	259	loop_write(ttyfd, ANSI_NORMAL, strlen(ANSI_NORMAL), false);
663996b3 MS	260
	261	new_termios = old_termios;
	262	new_termios.c_lflag &= ~(ICANON\|ECHO);
	263	new_termios.c_cc[VMIN] = 1;
	264	new_termios.c_cc[VTIME] = 0;
	265
	266	if (tcsetattr(ttyfd, TCSADRAIN, &new_termios) < 0) {
	267	r = -errno;
	268	goto finish;
	269	}
	270
	271	reset_tty = true;
	272	}
	273
	274	zero(pollfd);
	275	pollfd[POLL_TTY].fd = ttyfd >= 0 ? ttyfd : STDIN_FILENO;
	276	pollfd[POLL_TTY].events = POLLIN;
	277	pollfd[POLL_INOTIFY].fd = notify;
	278	pollfd[POLL_INOTIFY].events = POLLIN;
	279
	280	for (;;) {
	281	char c;
	282	int sleep_for = -1, k;
	283	ssize_t n;
	284
	285	if (until > 0) {
	286	usec_t y;
	287
	288	y = now(CLOCK_MONOTONIC);
	289
	290	if (y > until) {
	291	r = -ETIME;
	292	goto finish;
	293	}
	294
	295	sleep_for = (int) ((until - y) / USEC_PER_MSEC);
	296	}
	297
	298	if (flag_file)
	299	if (access(flag_file, F_OK) < 0) {
	300	r = -errno;
	301	goto finish;
	302	}
	303
6300502b	304	k = poll(pollfd, notify >= 0 ? 2 : 1, sleep_for);
60f067b4	305	if (k < 0) {
663996b3 MS	306	if (errno == EINTR)
	307	continue;
	308
	309	r = -errno;
	310	goto finish;
	311	} else if (k == 0) {
	312	r = -ETIME;
	313	goto finish;
	314	}
	315
6300502b	316	if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0)
663996b3 MS	317	flush_fd(notify);
	318
	319	if (pollfd[POLL_TTY].revents == 0)
	320	continue;
	321
60f067b4 JS	322	n = read(ttyfd >= 0 ? ttyfd : STDIN_FILENO, &c, 1);
60f067b4 JS	323	if (n < 0) {
663996b3 MS	324	if (errno == EINTR \|\| errno == EAGAIN)
	325	continue;
	326
	327	r = -errno;
	328	goto finish;
	329
	330	} else if (n == 0)
	331	break;
	332
	333	if (c == '\n')
	334	break;
	335	else if (c == 21) { /* C-u */
	336
6300502b	337	if (!(flags & ASK_PASSWORD_SILENT))
663996b3 MS	338	backspace_chars(ttyfd, p);
	339	p = 0;
	340
	341	} else if (c == '\b' \|\| c == 127) {
	342
	343	if (p > 0) {
	344
6300502b	345	if (!(flags & ASK_PASSWORD_SILENT))
663996b3 MS	346	backspace_chars(ttyfd, 1);
	347
	348	p--;
6300502b	349	} else if (!dirty && !(flags & ASK_PASSWORD_SILENT)) {
663996b3	350
6300502b	351	flags \|= ASK_PASSWORD_SILENT;
663996b3 MS	352
	353	/* There are two ways to enter silent
	354	* mode. Either by pressing backspace
6300502b MP	355	* as first key (and only as first
6300502b MP	356	* key), or ... */
663996b3 MS	357	if (ttyfd >= 0)
	358	loop_write(ttyfd, "(no echo) ", 10, false);
	359
	360	} else if (ttyfd >= 0)
	361	loop_write(ttyfd, "\a", 1, false);
	362
6300502b	363	} else if (c == '\t' && !(flags & ASK_PASSWORD_SILENT)) {
663996b3 MS	364
663996b3 MS	365	backspace_chars(ttyfd, p);
6300502b	366	flags \|= ASK_PASSWORD_SILENT;
663996b3 MS	367
	368	/* ... or by pressing TAB at any time. */
	369
	370	if (ttyfd >= 0)
	371	loop_write(ttyfd, "(no echo) ", 10, false);
	372	} else {
60f067b4 JS	373	if (p >= sizeof(passphrase)-1) {
	374	loop_write(ttyfd, "\a", 1, false);
	375	continue;
	376	}
	377
663996b3 MS	378	passphrase[p++] = c;
663996b3 MS	379
4c89c718 MP	380	if (!(flags & ASK_PASSWORD_SILENT) && ttyfd >= 0) {
	381	n = utf8_encoded_valid_unichar(passphrase + codepoint);
	382	if (n >= 0) {
	383	codepoint = p;
	384	loop_write(ttyfd, (flags & ASK_PASSWORD_ECHO) ? &c : "*", 1, false);
	385	}
	386	}
663996b3 MS	387
	388	dirty = true;
	389	}
db2df898 MP	390
db2df898 MP	391	c = 'x';
663996b3 MS	392	}
663996b3 MS	393
60f067b4	394	x = strndup(passphrase, p);
db2df898	395	memory_erase(passphrase, p);
60f067b4	396	if (!x) {
663996b3 MS	397	r = -ENOMEM;
	398	goto finish;
	399	}
	400
6300502b MP	401	if (keyname)
	402	(void) add_to_keyring_and_log(keyname, flags, STRV_MAKE(x));
	403
	404	*ret = x;
663996b3 MS	405	r = 0;
	406
	407	finish:
60f067b4 JS	408	if (ttyfd >= 0 && reset_tty) {
	409	loop_write(ttyfd, "\n", 1, false);
	410	tcsetattr(ttyfd, TCSADRAIN, &old_termios);
663996b3 MS	411	}
	412
	413	return r;
	414	}
	415
	416	static int create_socket(char **name) {
6300502b	417	union sockaddr_union sa = {
663996b3 MS	418	.un.sun_family = AF_UNIX,
663996b3 MS	419	};
6300502b MP	420	_cleanup_close_ int fd = -1;
6300502b MP	421	static const int one = 1;
663996b3	422	char *c;
6300502b	423	int r;
663996b3 MS	424
	425	assert(name);
	426
	427	fd = socket(AF_UNIX, SOCK_DGRAM\|SOCK_CLOEXEC\|SOCK_NONBLOCK, 0);
f47781d8	428	if (fd < 0)
6300502b	429	return -errno;
663996b3	430
60f067b4	431	snprintf(sa.un.sun_path, sizeof(sa.un.sun_path)-1, "/run/systemd/ask-password/sck.%" PRIx64, random_u64());
663996b3 MS	432
663996b3 MS	433	RUN_WITH_UMASK(0177) {
6300502b MP	434	if (bind(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0)
6300502b MP	435	return -errno;
663996b3 MS	436	}
663996b3 MS	437
6300502b MP	438	if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
6300502b MP	439	return -errno;
663996b3 MS	440
663996b3 MS	441	c = strdup(sa.un.sun_path);
6300502b MP	442	if (!c)
6300502b MP	443	return -ENOMEM;
663996b3 MS	444
663996b3 MS	445	*name = c;
663996b3	446
6300502b MP	447	r = fd;
6300502b MP	448	fd = -1;
663996b3 MS	449
	450	return r;
	451	}
	452
	453	int ask_password_agent(
	454	const char *message,
	455	const char *icon,
60f067b4	456	const char *id,
6300502b	457	const char *keyname,
663996b3	458	usec_t until,
6300502b MP	459	AskPasswordFlags flags,
6300502b MP	460	char ***ret) {
663996b3 MS	461
	462	enum {
	463	FD_SOCKET,
	464	FD_SIGNAL,
	465	_FD_MAX
	466	};
	467
6300502b	468	_cleanup_close_ int socket_fd = -1, signal_fd = -1, fd = -1;
663996b3 MS	469	char temp[] = "/run/systemd/ask-password/tmp.XXXXXX";
663996b3 MS	470	char final[sizeof(temp)] = "";
60f067b4	471	_cleanup_free_ char *socket_name = NULL;
6300502b MP	472	_cleanup_strv_free_ char **l = NULL;
6300502b MP	473	_cleanup_fclose_ FILE *f = NULL;
663996b3	474	struct pollfd pollfd[_FD_MAX];
6300502b	475	sigset_t mask, oldmask;
60f067b4	476	int r;
663996b3	477
6300502b MP	478	assert(ret);
	479
	480	if (flags & ASK_PASSWORD_NO_AGENT)
	481	return -EUNATCH;
663996b3	482
86f210e9 MP	483	assert_se(sigemptyset(&mask) >= 0);
	484	assert_se(sigset_add_many(&mask, SIGINT, SIGTERM, -1) >= 0);
	485	assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) >= 0);
663996b3	486
6300502b	487	(void) mkdir_p_label("/run/systemd/ask-password", 0755);
663996b3	488
60f067b4	489	fd = mkostemp_safe(temp, O_WRONLY\|O_CLOEXEC);
663996b3	490	if (fd < 0) {
db2df898	491	r = fd;
663996b3 MS	492	goto finish;
	493	}
	494
6300502b	495	(void) fchmod(fd, 0644);
663996b3	496
60f067b4 JS	497	f = fdopen(fd, "w");
60f067b4 JS	498	if (!f) {
663996b3 MS	499	r = -errno;
	500	goto finish;
	501	}
	502
	503	fd = -1;
	504
60f067b4 JS	505	signal_fd = signalfd(-1, &mask, SFD_NONBLOCK\|SFD_CLOEXEC);
60f067b4 JS	506	if (signal_fd < 0) {
663996b3 MS	507	r = -errno;
	508	goto finish;
	509	}
	510
60f067b4 JS	511	socket_fd = create_socket(&socket_name);
60f067b4 JS	512	if (socket_fd < 0) {
663996b3 MS	513	r = socket_fd;
	514	goto finish;
	515	}
	516
	517	fprintf(f,
	518	"[Ask]\n"
60f067b4	519	"PID="PID_FMT"\n"
663996b3 MS	520	"Socket=%s\n"
663996b3 MS	521	"AcceptCached=%i\n"
5eef597e	522	"Echo=%i\n"
60f067b4 JS	523	"NotAfter="USEC_FMT"\n",
60f067b4 JS	524	getpid(),
663996b3	525	socket_name,
6300502b MP	526	(flags & ASK_PASSWORD_ACCEPT_CACHED) ? 1 : 0,
6300502b MP	527	(flags & ASK_PASSWORD_ECHO) ? 1 : 0,
60f067b4	528	until);
663996b3 MS	529
	530	if (message)
	531	fprintf(f, "Message=%s\n", message);
	532
	533	if (icon)
	534	fprintf(f, "Icon=%s\n", icon);
	535
60f067b4 JS	536	if (id)
	537	fprintf(f, "Id=%s\n", id);
	538
5fd56512	539	r = fflush_and_check(f);
6300502b	540	if (r < 0)
663996b3	541	goto finish;
663996b3 MS	542
	543	memcpy(final, temp, sizeof(temp));
	544
	545	final[sizeof(final)-11] = 'a';
	546	final[sizeof(final)-10] = 's';
	547	final[sizeof(final)-9] = 'k';
	548
	549	if (rename(temp, final) < 0) {
663996b3 MS	550	r = -errno;
	551	goto finish;
	552	}
	553
	554	zero(pollfd);
	555	pollfd[FD_SOCKET].fd = socket_fd;
	556	pollfd[FD_SOCKET].events = POLLIN;
	557	pollfd[FD_SIGNAL].fd = signal_fd;
	558	pollfd[FD_SIGNAL].events = POLLIN;
	559
	560	for (;;) {
	561	char passphrase[LINE_MAX+1];
	562	struct msghdr msghdr;
	563	struct iovec iovec;
	564	struct ucred *ucred;
	565	union {
	566	struct cmsghdr cmsghdr;
	567	uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
	568	} control;
	569	ssize_t n;
	570	int k;
	571	usec_t t;
	572
	573	t = now(CLOCK_MONOTONIC);
	574
	575	if (until > 0 && until <= t) {
663996b3 MS	576	r = -ETIME;
	577	goto finish;
	578	}
	579
60f067b4 JS	580	k = poll(pollfd, _FD_MAX, until > 0 ? (int) ((until-t)/USEC_PER_MSEC) : -1);
60f067b4 JS	581	if (k < 0) {
663996b3 MS	582	if (errno == EINTR)
	583	continue;
	584
663996b3 MS	585	r = -errno;
	586	goto finish;
	587	}
	588
	589	if (k <= 0) {
663996b3 MS	590	r = -ETIME;
	591	goto finish;
	592	}
	593
	594	if (pollfd[FD_SIGNAL].revents & POLLIN) {
	595	r = -EINTR;
	596	goto finish;
	597	}
	598
	599	if (pollfd[FD_SOCKET].revents != POLLIN) {
663996b3 MS	600	r = -EIO;
	601	goto finish;
	602	}
	603
	604	zero(iovec);
	605	iovec.iov_base = passphrase;
	606	iovec.iov_len = sizeof(passphrase);
	607
	608	zero(control);
	609	zero(msghdr);
	610	msghdr.msg_iov = &iovec;
	611	msghdr.msg_iovlen = 1;
	612	msghdr.msg_control = &control;
	613	msghdr.msg_controllen = sizeof(control);
	614
60f067b4 JS	615	n = recvmsg(socket_fd, &msghdr, 0);
60f067b4 JS	616	if (n < 0) {
663996b3 MS	617	if (errno == EAGAIN \|\|
	618	errno == EINTR)
	619	continue;
	620
663996b3 MS	621	r = -errno;
	622	goto finish;
	623	}
	624
e3bff60a MP	625	cmsg_close_all(&msghdr);
e3bff60a MP	626
663996b3	627	if (n <= 0) {
6300502b	628	log_debug("Message too short");
663996b3 MS	629	continue;
	630	}
	631
	632	if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) \|\|
	633	control.cmsghdr.cmsg_level != SOL_SOCKET \|\|
	634	control.cmsghdr.cmsg_type != SCM_CREDENTIALS \|\|
	635	control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
6300502b	636	log_debug("Received message without credentials. Ignoring.");
663996b3 MS	637	continue;
	638	}
	639
	640	ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
	641	if (ucred->uid != 0) {
6300502b	642	log_debug("Got request from unprivileged user. Ignoring.");
663996b3 MS	643	continue;
	644	}
	645
	646	if (passphrase[0] == '+') {
6300502b	647	/* An empty message refers to the empty password */
663996b3 MS	648	if (n == 1)
	649	l = strv_new("", NULL);
	650	else
	651	l = strv_parse_nulstr(passphrase+1, n-1);
db2df898	652	memory_erase(passphrase, n);
663996b3 MS	653	if (!l) {
	654	r = -ENOMEM;
	655	goto finish;
	656	}
	657
	658	if (strv_length(l) <= 0) {
6300502b MP	659	l = strv_free(l);
6300502b MP	660	log_debug("Invalid packet");
663996b3 MS	661	continue;
	662	}
	663
6300502b MP	664	break;
6300502b MP	665	}
663996b3	666
6300502b	667	if (passphrase[0] == '-') {
663996b3 MS	668	r = -ECANCELED;
663996b3 MS	669	goto finish;
663996b3 MS	670	}
663996b3 MS	671
6300502b	672	log_debug("Invalid packet");
663996b3 MS	673	}
663996b3 MS	674
6300502b MP	675	if (keyname)
	676	(void) add_to_keyring_and_log(keyname, flags, l);
	677
	678	*ret = l;
	679	l = NULL;
663996b3 MS	680	r = 0;
	681
	682	finish:
60f067b4	683	if (socket_name)
6300502b	684	(void) unlink(socket_name);
663996b3	685
6300502b	686	(void) unlink(temp);
663996b3 MS	687
663996b3 MS	688	if (final[0])
6300502b	689	(void) unlink(final);
663996b3 MS	690
663996b3 MS	691	assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);
663996b3 MS	692	return r;
	693	}
	694
6300502b MP	695	int ask_password_auto(
	696	const char *message,
	697	const char *icon,
	698	const char *id,
	699	const char *keyname,
	700	usec_t until,
	701	AskPasswordFlags flags,
	702	char ***ret) {
	703
	704	int r;
	705
	706	assert(ret);
	707
	708	if ((flags & ASK_PASSWORD_ACCEPT_CACHED) && keyname) {
	709	r = ask_password_keyring(keyname, flags, ret);
	710	if (r != -ENOKEY)
	711	return r;
	712	}
663996b3	713
6300502b	714	if (!(flags & ASK_PASSWORD_NO_TTY) && isatty(STDIN_FILENO)) {
663996b3 MS	715	char s = NULL, *l = NULL;
663996b3 MS	716
6300502b	717	r = ask_password_tty(message, keyname, until, flags, NULL, &s);
60f067b4	718	if (r < 0)
663996b3 MS	719	return r;
663996b3 MS	720
db2df898 MP	721	r = strv_push(&l, s);
	722	if (r < 0) {
	723	string_erase(s);
	724	free(s);
6300502b	725	return -ENOMEM;
db2df898	726	}
663996b3	727
6300502b MP	728	*ret = l;
	729	return 0;
	730	}
	731
	732	if (!(flags & ASK_PASSWORD_NO_AGENT))
	733	return ask_password_agent(message, icon, id, keyname, until, flags, ret);
	734
	735	return -EUNATCH;
663996b3	736	}