diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
commit | b750101eb236130cf056c675997decbac904cc49 (patch) | |
tree | a5df1a06754bdd014cb975c051c83b01c9a97532 /src/shared/ask-password-api.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/shared/ask-password-api.c | 1021 |
1 files changed, 1021 insertions, 0 deletions
diff --git a/src/shared/ask-password-api.c b/src/shared/ask-password-api.c new file mode 100644 index 0000000..17474fe --- /dev/null +++ b/src/shared/ask-password-api.c @@ -0,0 +1,1021 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <inttypes.h> +#include <limits.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/inotify.h> +#include <sys/signalfd.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 "creds-util.h" +#include "def.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "fs-util.h" +#include "glyph-util.h" +#include "io-util.h" +#include "keyring-util.h" +#include "log.h" +#include "macro.h" +#include "memory-util.h" +#include "missing_syscall.h" +#include "mkdir-label.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 "tmpfile-util.h" +#include "umask-util.h" +#include "utf8.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_(erase_and_freep) void *p = NULL; + char **l; + size_t n; + int r; + + assert(ret); + + r = keyring_read(serial, &p, &n); + if (r < 0) + return r; + + l = strv_parse_nulstr(p, n); + if (!l) + return -ENOMEM; + + *ret = l; + return 0; +} + +static int add_to_keyring(const char *keyname, AskPasswordFlags flags, char **passwords) { + _cleanup_strv_free_erase_ char **l = NULL; + _cleanup_(erase_and_freep) char *p = NULL; + key_serial_t serial; + size_t n; + int r; + + assert(keyname); + + if (!FLAGS_SET(flags, ASK_PASSWORD_PUSH_CACHE)) + return 0; + if (strv_isempty(passwords)) + 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); + 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 kernel keyring key timeout: %m"); + + /* Tell everyone to check the keyring */ + (void) touch("/run/systemd/ask-password"); + + log_debug("Added key to kernel keyring as %" PRIi32 ".", serial); + + return 1; +} + +static int add_to_keyring_and_log(const char *keyname, AskPasswordFlags flags, char **passwords) { + int r; + + assert(keyname); + + r = add_to_keyring(keyname, flags, passwords); + if (r < 0) + return log_debug_errno(r, "Failed to add password to kernel keyring: %m"); + + return 0; +} + +static int ask_password_keyring(const char *keyname, AskPasswordFlags flags, char ***ret) { + + key_serial_t serial; + int r; + + assert(keyname); + assert(ret); + + if (!FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED)) + return -EUNATCH; + + r = lookup_key(keyname, &serial); + if (r < 0) { + /* when retrieving the distinction between "kernel or container manager don't support + * or allow this" and "no matching key known" doesn't matter. Note that we propagate + * EACCESS here (even if EPERM not) since that is used if the keyring is available but + * we lack access to the key. */ + if (ERRNO_IS_NOT_SUPPORTED(r) || r == -EPERM) + return -ENOKEY; + + return r; + } + + return retrieve_key(serial, ret); +} + +static int backspace_chars(int ttyfd, size_t p) { + if (ttyfd < 0) + return 0; + + _cleanup_free_ char *buf = malloc_multiply(3, p); + if (!buf) + return log_oom(); + + for (size_t i = 0; i < p; i++) + memcpy(buf + 3 * i, "\b \b", 3); + + return loop_write(ttyfd, buf, 3*p, false); +} + +static int backspace_string(int ttyfd, const char *str) { + assert(str); + + /* Backspaces through enough characters to entirely undo printing of the specified string. */ + + if (ttyfd < 0) + return 0; + + size_t m = utf8_n_codepoints(str); + if (m == SIZE_MAX) + m = strlen(str); /* Not a valid UTF-8 string? If so, let's backspace the number of bytes + * output. Most likely this happened because we are not in an UTF-8 locale, + * and in that case that is the correct thing to do. And even if it's not, + * terminals tend to stop backspacing at the leftmost column, hence + * backspacing too much should be mostly OK. */ + + return backspace_chars(ttyfd, m); +} + +int ask_password_plymouth( + const char *message, + usec_t until, + AskPasswordFlags flags, + const char *flag_file, + char ***ret) { + + static const union sockaddr_union sa = PLYMOUTH_SOCKET; + _cleanup_close_ int fd = -1, notify = -1; + _cleanup_free_ char *packet = NULL; + ssize_t k; + int r, n; + struct pollfd pollfd[2] = {}; + char buffer[LINE_MAX]; + size_t p = 0; + enum { + POLL_SOCKET, + POLL_INOTIFY + }; + + assert(ret); + + if (!message) + message = "Password:"; + + if (flag_file) { + notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK); + if (notify < 0) + return -errno; + + r = inotify_add_watch(notify, flag_file, IN_ATTRIB); /* for the link count */ + if (r < 0) + return -errno; + } + + fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return -errno; + + r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)); + if (r < 0) + return -errno; + + if (FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED)) { + packet = strdup("c"); + n = 1; + } else if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0) + packet = NULL; + if (!packet) + return -ENOMEM; + + r = loop_write(fd, packet, n + 1, true); + if (r < 0) + return r; + + pollfd[POLL_SOCKET].fd = fd; + pollfd[POLL_SOCKET].events = POLLIN; + pollfd[POLL_INOTIFY].fd = notify; + pollfd[POLL_INOTIFY].events = POLLIN; + + for (;;) { + usec_t timeout; + + if (until > 0) + timeout = usec_sub_unsigned(until, now(CLOCK_MONOTONIC)); + else + timeout = USEC_INFINITY; + + if (flag_file && access(flag_file, F_OK) < 0) { + r = -errno; + goto finish; + } + + r = ppoll_usec(pollfd, notify >= 0 ? 2 : 1, timeout); + if (r == -EINTR) + continue; + if (r < 0) + goto finish; + if (r == 0) { + r = -ETIME; + goto finish; + } + + if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0) + (void) flush_fd(notify); + + if (pollfd[POLL_SOCKET].revents == 0) + continue; + + k = read(fd, buffer + p, sizeof(buffer) - p); + if (k < 0) { + if (ERRNO_IS_TRANSIENT(errno)) + continue; + + r = -errno; + goto finish; + } + if (k == 0) { + r = -EIO; + goto finish; + } + + p += k; + + if (buffer[0] == 5) { + + if (FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED)) { + /* Hmm, first try with cached + * passwords failed, so let's retry + * with a normal password request */ + packet = mfree(packet); + + if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0) { + r = -ENOMEM; + goto finish; + } + + r = loop_write(fd, packet, n+1, true); + if (r < 0) + goto finish; + + flags &= ~ASK_PASSWORD_ACCEPT_CACHED; + p = 0; + continue; + } + + /* No password, because UI not shown */ + r = -ENOENT; + goto finish; + + } else if (IN_SET(buffer[0], 2, 9)) { + uint32_t size; + char **l; + + /* One or more answers */ + if (p < 5) + continue; + + memcpy(&size, buffer+1, sizeof(size)); + size = le32toh(size); + if (size + 5 > sizeof(buffer)) { + r = -EIO; + goto finish; + } + + if (p-5 < size) + continue; + + l = strv_parse_nulstr(buffer + 5, size); + if (!l) { + r = -ENOMEM; + goto finish; + } + + *ret = l; + break; + + } else { + /* Unknown packet */ + r = -EIO; + goto finish; + } + } + + r = 0; + +finish: + explicit_bzero_safe(buffer, sizeof(buffer)); + return r; +} + +#define NO_ECHO "(no echo) " +#define PRESS_TAB "(press TAB for no echo) " +#define SKIPPED "(skipped)" + +int ask_password_tty( + int ttyfd, + const char *message, + const char *keyname, + usec_t until, + AskPasswordFlags flags, + const char *flag_file, + char ***ret) { + + enum { + POLL_TTY, + POLL_INOTIFY, + _POLL_MAX, + }; + + bool reset_tty = false, dirty = false, use_color = false, press_tab_visible = false; + _cleanup_close_ int cttyfd = -1, notify = -1; + struct termios old_termios, new_termios; + char passphrase[LINE_MAX + 1] = {}, *x; + _cleanup_strv_free_erase_ char **l = NULL; + struct pollfd pollfd[_POLL_MAX]; + size_t p = 0, codepoint = 0; + int r; + + assert(ret); + + if (FLAGS_SET(flags, ASK_PASSWORD_NO_TTY)) + return -EUNATCH; + + if (!message) + message = "Password:"; + + if (!FLAGS_SET(flags, ASK_PASSWORD_HIDE_EMOJI) && emoji_enabled()) + message = strjoina(special_glyph(SPECIAL_GLYPH_LOCK_AND_KEY), " ", message); + + if (flag_file || (FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED) && keyname)) { + notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK); + if (notify < 0) + return -errno; + } + if (flag_file) { + if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) + return -errno; + } + if (FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED) && keyname) { + r = ask_password_keyring(keyname, flags, ret); + if (r >= 0) + return 0; + else if (r != -ENOKEY) + return r; + + if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_ATTRIB /* for mtime */) < 0) + return -errno; + } + + /* If the caller didn't specify a TTY, then use the controlling tty, if we can. */ + if (ttyfd < 0) + ttyfd = cttyfd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC); + + if (ttyfd >= 0) { + if (tcgetattr(ttyfd, &old_termios) < 0) + return -errno; + + if (FLAGS_SET(flags, ASK_PASSWORD_CONSOLE_COLOR)) + use_color = dev_console_colors_enabled(); + else + use_color = colors_enabled(); + + if (use_color) + (void) loop_write(ttyfd, ANSI_HIGHLIGHT, STRLEN(ANSI_HIGHLIGHT), false); + + (void) loop_write(ttyfd, message, strlen(message), false); + (void) loop_write(ttyfd, " ", 1, false); + + if (!FLAGS_SET(flags, ASK_PASSWORD_SILENT) && !FLAGS_SET(flags, ASK_PASSWORD_ECHO)) { + if (use_color) + (void) loop_write(ttyfd, ansi_grey(), strlen(ansi_grey()), false); + (void) loop_write(ttyfd, PRESS_TAB, strlen(PRESS_TAB), false); + press_tab_visible = true; + } + + if (use_color) + (void) 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; + } + + pollfd[POLL_TTY] = (struct pollfd) { + .fd = ttyfd >= 0 ? ttyfd : STDIN_FILENO, + .events = POLLIN, + }; + pollfd[POLL_INOTIFY] = (struct pollfd) { + .fd = notify, + .events = POLLIN, + }; + + for (;;) { + _cleanup_(erase_char) char c; + usec_t timeout; + ssize_t n; + + if (until > 0) + timeout = usec_sub_unsigned(until, now(CLOCK_MONOTONIC)); + else + timeout = USEC_INFINITY; + + if (flag_file) + if (access(flag_file, F_OK) < 0) { + r = -errno; + goto finish; + } + + r = ppoll_usec(pollfd, notify >= 0 ? 2 : 1, timeout); + if (r == -EINTR) + continue; + if (r < 0) + goto finish; + if (r == 0) { + r = -ETIME; + goto finish; + } + + if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0 && keyname) { + (void) flush_fd(notify); + + r = ask_password_keyring(keyname, flags, ret); + if (r >= 0) { + r = 0; + goto finish; + } else if (r != -ENOKEY) + goto finish; + } + + if (pollfd[POLL_TTY].revents == 0) + continue; + + n = read(ttyfd >= 0 ? ttyfd : STDIN_FILENO, &c, 1); + if (n < 0) { + if (ERRNO_IS_TRANSIENT(errno)) + continue; + + r = -errno; + goto finish; + + } + + if (press_tab_visible) { + assert(ttyfd >= 0); + backspace_chars(ttyfd, strlen(PRESS_TAB)); + press_tab_visible = false; + } + + /* We treat EOF, newline and NUL byte all as valid end markers */ + if (n == 0 || c == '\n' || c == 0) + break; + + if (c == 4) { /* C-d also known as EOT */ + if (ttyfd >= 0) + (void) loop_write(ttyfd, SKIPPED, strlen(SKIPPED), false); + + goto skipped; + } + + if (c == 21) { /* C-u */ + + if (!FLAGS_SET(flags, ASK_PASSWORD_SILENT)) + (void) backspace_string(ttyfd, passphrase); + + explicit_bzero_safe(passphrase, sizeof(passphrase)); + p = codepoint = 0; + + } else if (IN_SET(c, '\b', 127)) { + + if (p > 0) { + size_t q; + + if (!FLAGS_SET(flags, ASK_PASSWORD_SILENT)) + (void) backspace_chars(ttyfd, 1); + + /* Remove a full UTF-8 codepoint from the end. For that, figure out where the + * last one begins */ + q = 0; + for (;;) { + int z; + + z = utf8_encoded_valid_unichar(passphrase + q, SIZE_MAX); + if (z <= 0) { + q = SIZE_MAX; /* Invalid UTF8! */ + break; + } + + if (q + z >= p) /* This one brings us over the edge */ + break; + + q += z; + } + + p = codepoint = q == SIZE_MAX ? p - 1 : q; + explicit_bzero_safe(passphrase + p, sizeof(passphrase) - p); + + } else if (!dirty && !FLAGS_SET(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) + (void) loop_write(ttyfd, NO_ECHO, strlen(NO_ECHO), false); + + } else if (ttyfd >= 0) + (void) loop_write(ttyfd, "\a", 1, false); + + } else if (c == '\t' && !FLAGS_SET(flags, ASK_PASSWORD_SILENT)) { + + (void) backspace_string(ttyfd, passphrase); + flags |= ASK_PASSWORD_SILENT; + + /* ... or by pressing TAB at any time. */ + + if (ttyfd >= 0) + (void) loop_write(ttyfd, NO_ECHO, strlen(NO_ECHO), false); + + } else if (p >= sizeof(passphrase)-1) { + + /* Reached the size limit */ + if (ttyfd >= 0) + (void) loop_write(ttyfd, "\a", 1, false); + + } else { + passphrase[p++] = c; + + if (!FLAGS_SET(flags, ASK_PASSWORD_SILENT) && ttyfd >= 0) { + /* Check if we got a complete UTF-8 character now. If so, let's output one '*'. */ + n = utf8_encoded_valid_unichar(passphrase + codepoint, SIZE_MAX); + if (n >= 0) { + if (FLAGS_SET(flags, ASK_PASSWORD_ECHO)) + (void) loop_write(ttyfd, passphrase + codepoint, n, false); + else + (void) loop_write(ttyfd, "*", 1, false); + codepoint = p; + } + } + + dirty = true; + } + } + + x = strndup(passphrase, p); + explicit_bzero_safe(passphrase, sizeof(passphrase)); + if (!x) { + r = -ENOMEM; + goto finish; + } + + r = strv_consume(&l, x); + if (r < 0) + goto finish; + +skipped: + if (strv_isempty(l)) + r = log_debug_errno(SYNTHETIC_ERRNO(ECANCELED), "Password query was cancelled."); + else { + if (keyname) + (void) add_to_keyring_and_log(keyname, flags, l); + + *ret = TAKE_PTR(l); + r = 0; + } + +finish: + if (ttyfd >= 0 && reset_tty) { + (void) loop_write(ttyfd, "\n", 1, false); + (void) tcsetattr(ttyfd, TCSADRAIN, &old_termios); + } + + return r; +} + +static int create_socket(char **ret) { + _cleanup_free_ char *path = NULL; + union sockaddr_union sa; + socklen_t sa_len; + _cleanup_close_ int fd = -1; + int r; + + assert(ret); + + fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return -errno; + + if (asprintf(&path, "/run/systemd/ask-password/sck.%" PRIx64, random_u64()) < 0) + return -ENOMEM; + + r = sockaddr_un_set_path(&sa.un, path); + if (r < 0) + return r; + sa_len = r; + + RUN_WITH_UMASK(0177) + if (bind(fd, &sa.sa, sa_len) < 0) + return -errno; + + r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true); + if (r < 0) + return r; + + *ret = TAKE_PTR(path); + return TAKE_FD(fd); +} + +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_INOTIFY, + _FD_MAX + }; + + _cleanup_close_ int socket_fd = -1, signal_fd = -1, notify = -1, fd = -1; + char temp[] = "/run/systemd/ask-password/tmp.XXXXXX"; + char final[sizeof(temp)] = ""; + _cleanup_free_ char *socket_name = NULL; + _cleanup_strv_free_erase_ char **l = NULL; + _cleanup_fclose_ FILE *f = NULL; + struct pollfd pollfd[_FD_MAX]; + sigset_t mask, oldmask; + int r; + + assert(ret); + + if (FLAGS_SET(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); + + if (FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED) && keyname) { + r = ask_password_keyring(keyname, flags, ret); + if (r >= 0) { + r = 0; + goto finish; + } else if (r != -ENOKEY) + goto finish; + + notify = inotify_init1(IN_CLOEXEC | IN_NONBLOCK); + if (notify < 0) { + r = -errno; + goto finish; + } + if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_ATTRIB /* for mtime */) < 0) { + r = -errno; + goto finish; + } + } + + fd = mkostemp_safe(temp); + if (fd < 0) { + r = fd; + goto finish; + } + + (void) fchmod(fd, 0644); + + f = take_fdopen(&fd, "w"); + if (!f) { + r = -errno; + goto finish; + } + + 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" + "Silent=%i\n", + getpid_cached(), + socket_name, + FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED), + FLAGS_SET(flags, ASK_PASSWORD_ECHO), + until, + FLAGS_SET(flags, ASK_PASSWORD_SILENT)); + + 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; + pollfd[FD_INOTIFY].fd = notify; + pollfd[FD_INOTIFY].events = POLLIN; + + for (;;) { + CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control; + char passphrase[LINE_MAX+1]; + struct iovec iovec; + struct ucred *ucred; + usec_t timeout; + ssize_t n; + + if (until > 0) + timeout = usec_sub_unsigned(until, now(CLOCK_MONOTONIC)); + else + timeout = USEC_INFINITY; + + r = ppoll_usec(pollfd, notify >= 0 ? _FD_MAX : _FD_MAX - 1, timeout); + if (r == -EINTR) + continue; + if (r < 0) + goto finish; + if (r == 0) { + r = -ETIME; + goto finish; + } + + if (pollfd[FD_SIGNAL].revents & POLLIN) { + r = -EINTR; + goto finish; + } + + if (notify >= 0 && pollfd[FD_INOTIFY].revents != 0) { + (void) flush_fd(notify); + + r = ask_password_keyring(keyname, flags, ret); + if (r >= 0) { + r = 0; + goto finish; + } else if (r != -ENOKEY) + goto finish; + } + + if (pollfd[FD_SOCKET].revents == 0) + continue; + + if (pollfd[FD_SOCKET].revents != POLLIN) { + r = -EIO; + goto finish; + } + + iovec = IOVEC_MAKE(passphrase, sizeof(passphrase)); + + struct msghdr msghdr = { + .msg_iov = &iovec, + .msg_iovlen = 1, + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + + n = recvmsg_safe(socket_fd, &msghdr, 0); + if (n < 0) { + if (ERRNO_IS_TRANSIENT(n)) + continue; + if (n == -EXFULL) { + log_debug("Got message with truncated control data, ignoring."); + continue; + } + + r = (int) n; + goto finish; + } + + cmsg_close_all(&msghdr); + + if (n == 0) { + log_debug("Message too short"); + continue; + } + + ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred); + if (!ucred) { + log_debug("Received message without credentials. Ignoring."); + continue; + } + + 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(""); + else + l = strv_parse_nulstr(passphrase+1, n-1); + explicit_bzero_safe(passphrase, n); + if (!l) { + r = -ENOMEM; + goto finish; + } + + if (strv_isempty(l)) { + 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 = TAKE_PTR(l); + 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; +} + +static int ask_password_credential(const char *credential_name, AskPasswordFlags flags, char ***ret) { + _cleanup_(erase_and_freep) char *buffer = NULL; + size_t size; + char **l; + int r; + + assert(credential_name); + assert(ret); + + r = read_credential(credential_name, (void**) &buffer, &size); + if (IN_SET(r, -ENXIO, -ENOENT)) /* No credentials passed or this credential not defined? */ + return -ENOKEY; + + l = strv_parse_nulstr(buffer, size); + if (!l) + return -ENOMEM; + + *ret = l; + return 0; +} + +int ask_password_auto( + const char *message, + const char *icon, + const char *id, /* id in "ask-password" protocol */ + const char *key_name, /* name in kernel keyring */ + const char *credential_name, /* name in $CREDENTIALS_DIRECTORY directory */ + usec_t until, + AskPasswordFlags flags, + char ***ret) { + + int r; + + assert(ret); + + if (!FLAGS_SET(flags, ASK_PASSWORD_NO_CREDENTIAL) && credential_name) { + r = ask_password_credential(credential_name, flags, ret); + if (r != -ENOKEY) + return r; + } + + if (FLAGS_SET(flags, ASK_PASSWORD_ACCEPT_CACHED) && + key_name && + (FLAGS_SET(flags, ASK_PASSWORD_NO_TTY) || !isatty(STDIN_FILENO)) && + FLAGS_SET(flags, ASK_PASSWORD_NO_AGENT)) { + r = ask_password_keyring(key_name, flags, ret); + if (r != -ENOKEY) + return r; + } + + if (!FLAGS_SET(flags, ASK_PASSWORD_NO_TTY) && isatty(STDIN_FILENO)) + return ask_password_tty(-1, message, key_name, until, flags, NULL, ret); + + if (!FLAGS_SET(flags, ASK_PASSWORD_NO_AGENT)) + return ask_password_agent(message, icon, id, key_name, until, flags, ret); + + return -EUNATCH; +} |