gen/FreeBSD/readpassphrase.c

   1 /*      $OpenBSD: readpassphrase.c,v 1.24 2013/11/24 23:51:29 deraadt Exp $     */
   2
   3 /*
   4  * Copyright (c) 2000-2002, 2007, 2010
   5  *      Todd C. Miller <Todd.Miller@courtesan.com>
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  *
  19  * Sponsored in part by the Defense Advanced Research Projects
  20  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  21  * Materiel Command, USAF, under agreement number F39502-99-1-0512.
  22  */
  23
  24 #include <sys/cdefs.h>
  25
  26 #include "xlocale_private.h"
  27
  28 #include "namespace.h"
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #include <fcntl.h>
  32 #include <paths.h>
  33 #include <pwd.h>
  34 #include <signal.h>
  35 #include <string.h>
  36 #include <termios.h>
  37 #include <unistd.h>
  38 #include <readpassphrase.h>
  39 #include "un-namespace.h"
  40 #include "libc_private.h"
  41
  42 static volatile int signo[NSIG];
  43
  44 static void handler(int);
  45
  46 char *
  47 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
  48 {
  49         ssize_t nr;
  50         int input, output, save_errno, i, need_restart, input_is_tty;
  51         char ch, *p, *end;
  52         struct termios term, oterm;
  53         struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
  54         struct sigaction savetstp, savettin, savettou, savepipe;
  55         locale_t loc = __current_locale();
  56
  57         /* I suppose we could alloc on demand in this case (XXX). */
  58         if (bufsiz == 0) {
  59                 errno = EINVAL;
  60                 return(NULL);
  61         }
  62
  63 restart:
  64         for (i = 0; i < NSIG; i++)
  65                 signo[i] = 0;
  66         nr = -1;
  67         save_errno = 0;
  68         need_restart = 0;
  69         /*
  70          * Read and write to /dev/tty if available.  If not, read from
  71          * stdin and write to stderr unless a tty is required.
  72          */
  73         input_is_tty = 0;
  74         if (!(flags & RPP_STDIN)) {
  75                 input = output = _open(_PATH_TTY, O_RDWR | O_CLOEXEC);
  76                 if (input == -1) {
  77                         if (flags & RPP_REQUIRE_TTY) {
  78                                 errno = ENOTTY;
  79                                 return(NULL);
  80                         }
  81                         input = STDIN_FILENO;
  82                         output = STDERR_FILENO;
  83                 } else {
  84                         input_is_tty = 1;
  85                 }
  86         } else {
  87                 input = STDIN_FILENO;
  88                 output = STDERR_FILENO;
  89         }
  90
  91         /*
  92          * Turn off echo if possible.
  93          * If we are using a tty but are not the foreground pgrp this will
  94          * generate SIGTTOU, so do it *before* installing the signal handlers.
  95          */
  96         if (input_is_tty && tcgetattr(input, &oterm) == 0) {
  97                 memcpy(&term, &oterm, sizeof(term));
  98                 if (!(flags & RPP_ECHO_ON))
  99                         term.c_lflag &= ~(ECHO | ECHONL);
 100                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
 101                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
 102                 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
 103         } else {
 104                 memset(&term, 0, sizeof(term));
 105                 term.c_lflag |= ECHO;
 106                 memset(&oterm, 0, sizeof(oterm));
 107                 oterm.c_lflag |= ECHO;
 108         }
 109
 110         /*
 111          * Catch signals that would otherwise cause the user to end
 112          * up with echo turned off in the shell.  Don't worry about
 113          * things like SIGXCPU and SIGVTALRM for now.
 114          */
 115         sigemptyset(&sa.sa_mask);
 116         sa.sa_flags = 0;                /* don't restart system calls */
 117         sa.sa_handler = handler;
 118         (void)_sigaction(SIGALRM, &sa, &savealrm);
 119         (void)_sigaction(SIGHUP, &sa, &savehup);
 120         (void)_sigaction(SIGINT, &sa, &saveint);
 121         (void)_sigaction(SIGPIPE, &sa, &savepipe);
 122         (void)_sigaction(SIGQUIT, &sa, &savequit);
 123         (void)_sigaction(SIGTERM, &sa, &saveterm);
 124         (void)_sigaction(SIGTSTP, &sa, &savetstp);
 125         (void)_sigaction(SIGTTIN, &sa, &savettin);
 126         (void)_sigaction(SIGTTOU, &sa, &savettou);
 127
 128         if (!(flags & RPP_STDIN))
 129                 (void)_write(output, prompt, strlen(prompt));
 130         end = buf + bufsiz - 1;
 131         p = buf;
 132         while ((nr = _read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
 133                 if (p < end) {
 134                         if ((flags & RPP_SEVENBIT))
 135                                 ch &= 0x7f;
 136                         if (isalpha_l(ch, loc)) {
 137                                 if ((flags & RPP_FORCELOWER))
 138                                         ch = (char)tolower_l(ch, loc);
 139                                 if ((flags & RPP_FORCEUPPER))
 140                                         ch = (char)toupper_l(ch, loc);
 141                         }
 142                         *p++ = ch;
 143                 }
 144         }
 145         *p = '\0';
 146         save_errno = errno;
 147         if (!(term.c_lflag & ECHO))
 148                 (void)_write(output, "\n", 1);
 149
 150         /* Restore old terminal settings and signals. */
 151         if (memcmp(&term, &oterm, sizeof(term)) != 0) {
 152                 while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 &&
 153                     errno == EINTR && !signo[SIGTTOU])
 154                         continue;
 155         }
 156         (void)_sigaction(SIGALRM, &savealrm, NULL);
 157         (void)_sigaction(SIGHUP, &savehup, NULL);
 158         (void)_sigaction(SIGINT, &saveint, NULL);
 159         (void)_sigaction(SIGQUIT, &savequit, NULL);
 160         (void)_sigaction(SIGPIPE, &savepipe, NULL);
 161         (void)_sigaction(SIGTERM, &saveterm, NULL);
 162         (void)_sigaction(SIGTSTP, &savetstp, NULL);
 163         (void)_sigaction(SIGTTIN, &savettin, NULL);
 164         (void)_sigaction(SIGTTOU, &savettou, NULL);
 165         if (input_is_tty)
 166                 (void)_close(input);
 167
 168         /*
 169          * If we were interrupted by a signal, resend it to ourselves
 170          * now that we have restored the signal handlers.
 171          */
 172         for (i = 0; i < NSIG; i++) {
 173                 if (signo[i]) {
 174                         kill(getpid(), i);
 175                         switch (i) {
 176                         case SIGTSTP:
 177                         case SIGTTIN:
 178                         case SIGTTOU:
 179                                 need_restart = 1;
 180                         }
 181                 }
 182         }
 183         if (need_restart)
 184                 goto restart;
 185
 186         if (save_errno)
 187                 errno = save_errno;
 188         return(nr == -1 ? NULL : buf);
 189 }
 190
 191 char *
 192 getpass(const char *prompt)
 193 {
 194         const size_t bufsiz = _PASSWORD_LEN + 1;
 195         static char *buf = NULL;
 196
 197         if (buf == NULL) {
 198                 buf = malloc(bufsiz);
 199                 if (buf == NULL) {
 200                         return NULL;
 201                 }
 202         }
 203
 204         if (readpassphrase(prompt, buf, bufsiz, RPP_ECHO_OFF) == NULL) {
 205                 buf[0] = '\0';
 206         }
 207         return buf;
 208 }
 209
 210 static void handler(int s)
 211 {
 212         signo[s] = 1;
 213 }