crypto/libressl/apps/nc/compat/readpassphrase.c

   1 /*      $OpenBSD: readpassphrase.c,v 1.22 2010/01/13 10:20:54 dtucker Exp $     */
   2
   3 /*
   4  * Copyright (c) 2000-2002, 2007 Todd C. Miller <Todd.Miller@courtesan.com>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  * Sponsored in part by the Defense Advanced Research Projects
  19  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  20  * Materiel Command, USAF, under agreement number F39502-99-1-0512.
  21  */
  22
  23 /* OPENBSD ORIGINAL: lib/libc/gen/readpassphrase.c */
  24
  25 #include <termios.h>
  26 #include <signal.h>
  27 #include <ctype.h>
  28 #include <fcntl.h>
  29 #include <errno.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32
  33 #include <readpassphrase.h>
  34
  35 #ifndef _PATH_TTY
  36 # define _PATH_TTY "/dev/tty"
  37 #endif
  38
  39 #ifdef TCSASOFT
  40 # define _T_FLUSH       (TCSAFLUSH|TCSASOFT)
  41 #else
  42 # define _T_FLUSH       (TCSAFLUSH)
  43 #endif
  44
  45 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
  46 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
  47 #  define _POSIX_VDISABLE       VDISABLE
  48 #endif
  49
  50 #ifndef _NSIG
  51 # ifdef NSIG
  52 #  define _NSIG NSIG
  53 # else
  54 #  define _NSIG 128
  55 # endif
  56 #endif
  57
  58 static volatile sig_atomic_t signo[_NSIG];
  59
  60 static void handler(int);
  61
  62 char *
  63 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
  64 {
  65         ssize_t bytes_written = 0;
  66         ssize_t nr;
  67         int input, output, save_errno, i, need_restart;
  68         char ch, *p, *end;
  69         struct termios term, oterm;
  70         struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
  71         struct sigaction savetstp, savettin, savettou, savepipe;
  72
  73         /* I suppose we could alloc on demand in this case (XXX). */
  74         if (bufsiz == 0) {
  75                 errno = EINVAL;
  76                 return(NULL);
  77         }
  78
  79 restart:
  80         for (i = 0; i < _NSIG; i++)
  81                 signo[i] = 0;
  82         nr = -1;
  83         save_errno = 0;
  84         need_restart = 0;
  85         /*
  86          * Read and write to /dev/tty if available.  If not, read from
  87          * stdin and write to stderr unless a tty is required.
  88          */
  89         if ((flags & RPP_STDIN) ||
  90             (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
  91                 if (flags & RPP_REQUIRE_TTY) {
  92                         errno = ENOTTY;
  93                         return(NULL);
  94                 }
  95                 input = STDIN_FILENO;
  96                 output = STDERR_FILENO;
  97         }
  98
  99         /*
 100          * Catch signals that would otherwise cause the user to end
 101          * up with echo turned off in the shell.  Don't worry about
 102          * things like SIGXCPU and SIGVTALRM for now.
 103          */
 104         sigemptyset(&sa.sa_mask);
 105         sa.sa_flags = 0;                /* don't restart system calls */
 106         sa.sa_handler = handler;
 107         (void)sigaction(SIGALRM, &sa, &savealrm);
 108         (void)sigaction(SIGHUP, &sa, &savehup);
 109         (void)sigaction(SIGINT, &sa, &saveint);
 110         (void)sigaction(SIGPIPE, &sa, &savepipe);
 111         (void)sigaction(SIGQUIT, &sa, &savequit);
 112         (void)sigaction(SIGTERM, &sa, &saveterm);
 113         (void)sigaction(SIGTSTP, &sa, &savetstp);
 114         (void)sigaction(SIGTTIN, &sa, &savettin);
 115         (void)sigaction(SIGTTOU, &sa, &savettou);
 116
 117         /* Turn off echo if possible. */
 118         if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
 119                 memcpy(&term, &oterm, sizeof(term));
 120                 if (!(flags & RPP_ECHO_ON))
 121                         term.c_lflag &= ~(ECHO | ECHONL);
 122 #ifdef VSTATUS
 123                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
 124                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
 125 #endif
 126                 (void)tcsetattr(input, _T_FLUSH, &term);
 127         } else {
 128                 memset(&term, 0, sizeof(term));
 129                 term.c_lflag |= ECHO;
 130                 memset(&oterm, 0, sizeof(oterm));
 131                 oterm.c_lflag |= ECHO;
 132         }
 133
 134         /* No I/O if we are already backgrounded. */
 135         if (signo[SIGTTOU] != 1 && signo[SIGTTIN] != 1) {
 136                 if (!(flags & RPP_STDIN))
 137                         bytes_written = write(output, prompt, strlen(prompt));
 138                 end = buf + bufsiz - 1;
 139                 p = buf;
 140                 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
 141                         if (p < end) {
 142                                 if ((flags & RPP_SEVENBIT))
 143                                         ch &= 0x7f;
 144                                 if (isalpha((unsigned char)ch)) {
 145                                         if ((flags & RPP_FORCELOWER))
 146                                                 ch = (char)tolower((unsigned char)ch);
 147                                         if ((flags & RPP_FORCEUPPER))
 148                                                 ch = (char)toupper((unsigned char)ch);
 149                                 }
 150                                 *p++ = ch;
 151                         }
 152                 }
 153                 *p = '\0';
 154                 save_errno = errno;
 155                 if (!(term.c_lflag & ECHO))
 156                         bytes_written = write(output, "\n", 1);
 157         }
 158
 159         (void) bytes_written;
 160
 161         /* Restore old terminal settings and signals. */
 162         if (memcmp(&term, &oterm, sizeof(term)) != 0) {
 163                 while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
 164                     errno == EINTR)
 165                         continue;
 166         }
 167         (void)sigaction(SIGALRM, &savealrm, NULL);
 168         (void)sigaction(SIGHUP, &savehup, NULL);
 169         (void)sigaction(SIGINT, &saveint, NULL);
 170         (void)sigaction(SIGQUIT, &savequit, NULL);
 171         (void)sigaction(SIGPIPE, &savepipe, NULL);
 172         (void)sigaction(SIGTERM, &saveterm, NULL);
 173         (void)sigaction(SIGTSTP, &savetstp, NULL);
 174         (void)sigaction(SIGTTIN, &savettin, NULL);
 175         (void)sigaction(SIGTTOU, &savettou, NULL);
 176         if (input != STDIN_FILENO)
 177                 (void)close(input);
 178
 179         /*
 180          * If we were interrupted by a signal, resend it to ourselves
 181          * now that we have restored the signal handlers.
 182          */
 183         for (i = 0; i < _NSIG; i++) {
 184                 if (signo[i]) {
 185                         kill(getpid(), i);
 186                         switch (i) {
 187                         case SIGTSTP:
 188                         case SIGTTIN:
 189                         case SIGTTOU:
 190                                 need_restart = 1;
 191                         }
 192                 }
 193         }
 194         if (need_restart)
 195                 goto restart;
 196
 197         if (save_errno)
 198                 errno = save_errno;
 199         return(nr == -1 ? NULL : buf);
 200 }
 201
 202 static void handler(int s)
 203 {
 204         signo[s] = 1;
 205 }