From 28282a3f352f1be7a4ff956fbeb0bca37bb8bc64 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Mon, 13 Jun 2016 11:45:15 -0400 Subject: ./move.sh --- src/libshared/ask-password-api.c | 736 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 736 insertions(+) create mode 100644 src/libshared/ask-password-api.c (limited to 'src/libshared/ask-password-api.c') diff --git a/src/libshared/ask-password-api.c b/src/libshared/ask-password-api.c new file mode 100644 index 0000000000..4a4bd8d3b8 --- /dev/null +++ b/src/libshared/ask-password-api.c @@ -0,0 +1,736 @@ +/*** + 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 . +***/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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, 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, 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; +} -- cgit v1.2.3-54-g00ecf