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-rw-r--r--src/ask-password-api.c576
1 files changed, 576 insertions, 0 deletions
diff --git a/src/ask-password-api.c b/src/ask-password-api.c
new file mode 100644
index 000000000..ce2f3cbe7
--- /dev/null
+++ b/src/ask-password-api.c
@@ -0,0 +1,576 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ 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 General Public License as published by
+ the Free Software Foundation; either version 2 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+#include <stdbool.h>
+#include <termios.h>
+#include <unistd.h>
+#include <sys/poll.h>
+#include <sys/inotify.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <string.h>
+#include <sys/un.h>
+#include <stddef.h>
+#include <sys/signalfd.h>
+
+#include "util.h"
+#include "strv.h"
+
+#include "ask-password-api.h"
+
+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,
+ usec_t until,
+ const char *flag_file,
+ char **_passphrase) {
+
+ struct termios old_termios, new_termios;
+ char passphrase[LINE_MAX];
+ size_t p = 0;
+ int r, ttyfd = -1, notify = -1;
+ struct pollfd pollfd[2];
+ bool reset_tty = false;
+ bool silent_mode = false;
+ bool dirty = false;
+ enum {
+ POLL_TTY,
+ POLL_INOTIFY
+ };
+
+ assert(message);
+ assert(_passphrase);
+
+ if (flag_file) {
+ if ((notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) {
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ if ((ttyfd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC)) >= 0) {
+
+ if (tcgetattr(ttyfd, &old_termios) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ loop_write(ttyfd, ANSI_HIGHLIGHT_ON, sizeof(ANSI_HIGHLIGHT_ON)-1, false);
+ loop_write(ttyfd, message, strlen(message), false);
+ loop_write(ttyfd, " ", 1, false);
+ loop_write(ttyfd, ANSI_HIGHLIGHT_OFF, sizeof(ANSI_HIGHLIGHT_OFF)-1, 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;
+ }
+
+ if ((k = poll(pollfd, notify > 0 ? 2 : 1, sleep_for)) < 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;
+
+ if ((n = read(ttyfd >= 0 ? ttyfd : STDIN_FILENO, &c, 1)) < 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 (!silent_mode)
+ backspace_chars(ttyfd, p);
+ p = 0;
+
+ } else if (c == '\b' || c == 127) {
+
+ if (p > 0) {
+
+ if (!silent_mode)
+ backspace_chars(ttyfd, 1);
+
+ p--;
+ } else if (!dirty && !silent_mode) {
+
+ silent_mode = true;
+
+ /* 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' && !silent_mode) {
+
+ backspace_chars(ttyfd, p);
+ silent_mode = true;
+
+ /* ... or by pressing TAB at any time. */
+
+ if (ttyfd >= 0)
+ loop_write(ttyfd, "(no echo) ", 10, false);
+ } else {
+ passphrase[p++] = c;
+
+ if (!silent_mode && ttyfd >= 0)
+ loop_write(ttyfd, "*", 1, false);
+
+ dirty = true;
+ }
+ }
+
+ passphrase[p] = 0;
+
+ if (!(*_passphrase = strdup(passphrase))) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ if (notify >= 0)
+ close_nointr_nofail(notify);
+
+ if (ttyfd >= 0) {
+
+ if (reset_tty) {
+ loop_write(ttyfd, "\n", 1, false);
+ tcsetattr(ttyfd, TCSADRAIN, &old_termios);
+ }
+
+ close_nointr_nofail(ttyfd);
+ }
+
+ return r;
+}
+
+static int create_socket(char **name) {
+ int fd;
+ union {
+ struct sockaddr sa;
+ struct sockaddr_un un;
+ } sa;
+ int one = 1, r;
+ char *c;
+ mode_t u;
+
+ assert(name);
+
+ if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
+ log_error("socket() failed: %m");
+ return -errno;
+ }
+
+ zero(sa);
+ sa.un.sun_family = AF_UNIX;
+ snprintf(sa.un.sun_path, sizeof(sa.un.sun_path)-1, "/run/systemd/ask-password/sck.%llu", random_ull());
+
+ u = umask(0177);
+ r = bind(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
+ umask(u);
+
+ if (r < 0) {
+ r = -errno;
+ log_error("bind() failed: %m");
+ goto fail;
+ }
+
+ if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
+ r = -errno;
+ log_error("SO_PASSCRED failed: %m");
+ goto fail;
+ }
+
+ if (!(c = strdup(sa.un.sun_path))) {
+ r = -ENOMEM;
+ log_error("Out of memory");
+ goto fail;
+ }
+
+ *name = c;
+ return fd;
+
+fail:
+ close_nointr_nofail(fd);
+
+ return r;
+}
+
+int ask_password_agent(
+ const char *message,
+ const char *icon,
+ usec_t until,
+ bool accept_cached,
+ char ***_passphrases) {
+
+ enum {
+ FD_SOCKET,
+ FD_SIGNAL,
+ _FD_MAX
+ };
+
+ char temp[] = "/run/systemd/ask-password/tmp.XXXXXX";
+ char final[sizeof(temp)] = "";
+ int fd = -1, r;
+ FILE *f = NULL;
+ char *socket_name = NULL;
+ int socket_fd = -1, signal_fd = -1;
+ sigset_t mask, oldmask;
+ struct pollfd pollfd[_FD_MAX];
+ mode_t u;
+
+ assert(_passphrases);
+
+ assert_se(sigemptyset(&mask) == 0);
+ sigset_add_many(&mask, SIGINT, SIGTERM, -1);
+ assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
+
+ mkdir_p("/run/systemd/ask-password", 0755);
+
+ u = umask(0022);
+ fd = mkostemp(temp, O_CLOEXEC|O_CREAT|O_WRONLY);
+ umask(u);
+
+ if (fd < 0) {
+ log_error("Failed to create password file: %m");
+ r = -errno;
+ goto finish;
+ }
+
+ fchmod(fd, 0644);
+
+ if (!(f = fdopen(fd, "w"))) {
+ log_error("Failed to allocate FILE: %m");
+ r = -errno;
+ goto finish;
+ }
+
+ fd = -1;
+
+ if ((signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) {
+ log_error("signalfd(): %m");
+ r = -errno;
+ goto finish;
+ }
+
+ if ((socket_fd = create_socket(&socket_name)) < 0) {
+ r = socket_fd;
+ goto finish;
+ }
+
+ fprintf(f,
+ "[Ask]\n"
+ "PID=%lu\n"
+ "Socket=%s\n"
+ "AcceptCached=%i\n"
+ "NotAfter=%llu\n",
+ (unsigned long) getpid(),
+ socket_name,
+ accept_cached ? 1 : 0,
+ (unsigned long long) until);
+
+ if (message)
+ fprintf(f, "Message=%s\n", message);
+
+ if (icon)
+ fprintf(f, "Icon=%s\n", icon);
+
+ fflush(f);
+
+ if (ferror(f)) {
+ log_error("Failed to write query file: %m");
+ r = -errno;
+ 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) {
+ log_error("Failed to rename query file: %m");
+ 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) {
+ log_notice("Timed out");
+ r = -ETIME;
+ goto finish;
+ }
+
+ if ((k = poll(pollfd, _FD_MAX, until > 0 ? (int) ((until-t)/USEC_PER_MSEC) : -1)) < 0) {
+
+ if (errno == EINTR)
+ continue;
+
+ log_error("poll() failed: %m");
+ r = -errno;
+ goto finish;
+ }
+
+ if (k <= 0) {
+ log_notice("Timed out");
+ r = -ETIME;
+ goto finish;
+ }
+
+ if (pollfd[FD_SIGNAL].revents & POLLIN) {
+ r = -EINTR;
+ goto finish;
+ }
+
+ if (pollfd[FD_SOCKET].revents != POLLIN) {
+ log_error("Unexpected poll() event.");
+ 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);
+
+ if ((n = recvmsg(socket_fd, &msghdr, 0)) < 0) {
+
+ if (errno == EAGAIN ||
+ errno == EINTR)
+ continue;
+
+ log_error("recvmsg() failed: %m");
+ r = -errno;
+ goto finish;
+ }
+
+ if (n <= 0) {
+ log_error("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_warning("Received message without credentials. Ignoring.");
+ continue;
+ }
+
+ ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+ if (ucred->uid != 0) {
+ log_warning("Got request from unprivileged user. Ignoring.");
+ continue;
+ }
+
+ if (passphrase[0] == '+') {
+ char **l;
+
+ if (n == 1)
+ l = strv_new("", NULL);
+ else
+ l = strv_parse_nulstr(passphrase+1, n-1);
+ /* An empty message refers to the empty password */
+
+ if (!l) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (strv_length(l) <= 0) {
+ strv_free(l);
+ log_error("Invalid packet");
+ continue;
+ }
+
+ *_passphrases = l;
+
+ } else if (passphrase[0] == '-') {
+ r = -ECANCELED;
+ goto finish;
+ } else {
+ log_error("Invalid packet");
+ continue;
+ }
+
+ break;
+ }
+
+ r = 0;
+
+finish:
+ if (fd >= 0)
+ close_nointr_nofail(fd);
+
+ if (socket_name) {
+ unlink(socket_name);
+ free(socket_name);
+ }
+
+ if (socket_fd >= 0)
+ close_nointr_nofail(socket_fd);
+
+ if (signal_fd >= 0)
+ close_nointr_nofail(signal_fd);
+
+ if (f)
+ fclose(f);
+
+ unlink(temp);
+
+ if (final[0])
+ unlink(final);
+
+ assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);
+
+ return r;
+}
+
+int ask_password_auto(const char *message, const char *icon, usec_t until, bool accept_cached, char ***_passphrases) {
+ assert(message);
+ assert(_passphrases);
+
+ if (isatty(STDIN_FILENO)) {
+ int r;
+ char *s = NULL, **l = NULL;
+
+ if ((r = ask_password_tty(message, until, NULL, &s)) < 0)
+ return r;
+
+ l = strv_new(s, NULL);
+ free(s);
+
+ if (!l)
+ return -ENOMEM;
+
+ *_passphrases = l;
+ return r;
+
+ } else
+ return ask_password_agent(message, icon, until, accept_cached, _passphrases);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-27 00:56:22 +0000