| /*** |
| 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 (IN_SET(errno, EINTR, 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 (IN_SET(c, '\b', 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 (IN_SET(errno, EAGAIN, 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; |
| } |