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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
commit55944e5e40b1be2afc4855d8d2baf4b73d1876b5 (patch)
tree33f869f55a1b149e9b7c2b7e201867ca5dd52992 /src/shared/ask-password-api.c
parentInitial commit. (diff)
downloadsystemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.tar.xz
systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.zip
Adding upstream version 255.4.upstream/255.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/shared/ask-password-api.c')
-rw-r--r--src/shared/ask-password-api.c1002
1 files changed, 1002 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..0e323f4
--- /dev/null
+++ b/src/shared/ask-password-api.c
@@ -0,0 +1,1002 @@
+/* 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 "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "fs-util.h"
+#include "glyph-util.h"
+#include "io-util.h"
+#include "iovec-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 "nulstr-util.h"
+#include "plymouth-util.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;
+
+ /* chop off the final NUL byte. We do this because we want to use the separator NUL bytes only if we
+ * have multiple passwords. */
+ n = LESS_BY(n, (size_t) 1);
+
+ 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 (ERRNO_IS_NEG_NOT_SUPPORTED(r) || r == -EPERM)
+ /* 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. */
+ return -ENOKEY;
+ if (r < 0)
+ 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);
+}
+
+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 a 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) {
+
+ _cleanup_close_ int fd = -EBADF, notify = -EBADF;
+ _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;
+
+ if (inotify_add_watch(notify, flag_file, IN_ATTRIB) < 0) /* for the link count */
+ return -errno;
+ }
+
+ fd = plymouth_connect(SOCK_NONBLOCK);
+ if (fd < 0)
+ return fd;
+
+ 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_full(fd, packet, n + 1, USEC_INFINITY);
+ if (r < 0)
+ return r;
+
+ CLEANUP_ERASE(buffer);
+
+ 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)
+ return -errno;
+
+ r = ppoll_usec(pollfd, notify >= 0 ? 2 : 1, timeout);
+ if (r == -EINTR)
+ continue;
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -ETIME;
+
+ 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;
+
+ return -errno;
+ }
+ if (k == 0)
+ return -EIO;
+
+ 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)
+ return -ENOMEM;
+
+ r = loop_write_full(fd, packet, n + 1, USEC_INFINITY);
+ if (r < 0)
+ return r;
+
+ flags &= ~ASK_PASSWORD_ACCEPT_CACHED;
+ p = 0;
+ continue;
+ }
+
+ /* No password, because UI not shown */
+ return -ENOENT;
+
+ } 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))
+ return -EIO;
+
+ if (p-5 < size)
+ continue;
+
+ l = strv_parse_nulstr(buffer + 5, size);
+ if (!l)
+ return -ENOMEM;
+
+ *ret = l;
+ break;
+
+ } else
+ /* Unknown packet */
+ return -EIO;
+ }
+
+ return 0;
+}
+
+#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 = -EBADF, notify = -EBADF;
+ 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;
+ }
+
+ CLEANUP_ERASE(passphrase);
+
+ /* 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, SIZE_MAX);
+
+ (void) loop_write(ttyfd, message, SIZE_MAX);
+ (void) loop_write(ttyfd, " ", 1);
+
+ if (!FLAGS_SET(flags, ASK_PASSWORD_SILENT) && !FLAGS_SET(flags, ASK_PASSWORD_ECHO)) {
+ if (use_color)
+ (void) loop_write(ttyfd, ansi_grey(), SIZE_MAX);
+
+ (void) loop_write(ttyfd, PRESS_TAB, SIZE_MAX);
+ press_tab_visible = true;
+ }
+
+ if (use_color)
+ (void) loop_write(ttyfd, ANSI_NORMAL, SIZE_MAX);
+
+ new_termios = old_termios;
+ new_termios.c_lflag &= ~(ICANON|ECHO);
+ new_termios.c_cc[VMIN] = 1;
+ new_termios.c_cc[VTIME] = 0;
+
+ r = RET_NERRNO(tcsetattr(ttyfd, TCSADRAIN, &new_termios));
+ if (r < 0)
+ 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) {
+ r = RET_NERRNO(access(flag_file, F_OK));
+ if (r < 0)
+ 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, SIZE_MAX);
+
+ 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, SIZE_MAX);
+
+ } else if (ttyfd >= 0)
+ (void) loop_write(ttyfd, "\a", 1);
+
+ } 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, SIZE_MAX);
+
+ } else if (p >= sizeof(passphrase)-1) {
+
+ /* Reached the size limit */
+ if (ttyfd >= 0)
+ (void) loop_write(ttyfd, "\a", 1);
+
+ } 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);
+ else
+ (void) loop_write(ttyfd,
+ special_glyph(SPECIAL_GLYPH_BULLET),
+ SIZE_MAX);
+ codepoint = p;
+ }
+ }
+
+ dirty = true;
+ }
+ }
+
+ x = strndup(passphrase, p);
+ 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);
+ (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 = -EBADF;
+ 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;
+
+ 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 = -EBADF, signal_fd = -EBADF, notify = -EBADF, fd = -EBADF;
+ 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;
+ }
+
+ r = RET_NERRNO(inotify_add_watch(notify, "/run/systemd/ask-password", IN_ATTRIB /* for mtime */));
+ if (r < 0)
+ 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';
+
+ r = RET_NERRNO(rename(temp, final));
+ if (r < 0)
+ 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 (ERRNO_IS_NEG_TRANSIENT(n))
+ continue;
+ else if (n == -EXFULL) {
+ log_debug("Got message with truncated control data, ignoring.");
+ continue;
+ } else if (n < 0) {
+ r = (int) n;
+ goto finish;
+ }
+
+ CLEANUP_ERASE(passphrase);
+
+ 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);
+ 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;
+}