openbsd-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 "includes.h"
  26
  27 #ifndef HAVE_READPASSPHRASE
  28
  29 #include <termios.h>
  30 #include <signal.h>
  31 #include <ctype.h>
  32 #include <fcntl.h>
  33 #include <readpassphrase.h>
  34 #include <errno.h>
  35 #include <string.h>
  36 #include <unistd.h>
  37
  38 #ifdef TCSASOFT
  39 # define _T_FLUSH       (TCSAFLUSH|TCSASOFT)
  40 #else
  41 # define _T_FLUSH       (TCSAFLUSH)
  42 #endif
  43
  44 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
  45 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
  46 #  define _POSIX_VDISABLE       VDISABLE
  47 #endif
  48
  49 static volatile sig_atomic_t signo[_NSIG];
  50
  51 static void handler(int);
  52
  53 char *
  54 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
  55 {
  56         ssize_t nr;
  57         int input, output, save_errno, i, need_restart;
  58         char ch, *p, *end;
  59         struct termios term, oterm;
  60         struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
  61         struct sigaction savetstp, savettin, savettou, savepipe;
  62
  63         /* I suppose we could alloc on demand in this case (XXX). */
  64         if (bufsiz == 0) {
  65                 errno = EINVAL;
  66                 return(NULL);
  67         }
  68
  69 restart:
  70         for (i = 0; i < _NSIG; i++)
  71                 signo[i] = 0;
  72         nr = -1;
  73         save_errno = 0;
  74         need_restart = 0;
  75         /*
  76          * Read and write to /dev/tty if available.  If not, read from
  77          * stdin and write to stderr unless a tty is required.
  78          */
  79         if ((flags & RPP_STDIN) ||
  80             (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
  81                 if (flags & RPP_REQUIRE_TTY) {
  82                         errno = ENOTTY;
  83                         return(NULL);
  84                 }
  85                 input = STDIN_FILENO;
  86                 output = STDERR_FILENO;
  87         }
  88
  89         /*
  90          * Catch signals that would otherwise cause the user to end
  91          * up with echo turned off in the shell.  Don't worry about
  92          * things like SIGXCPU and SIGVTALRM for now.
  93          */
  94         sigemptyset(&sa.sa_mask);
  95         sa.sa_flags = 0;                /* don't restart system calls */
  96         sa.sa_handler = handler;
  97         (void)sigaction(SIGALRM, &sa, &savealrm);
  98         (void)sigaction(SIGHUP, &sa, &savehup);
  99         (void)sigaction(SIGINT, &sa, &saveint);
 100         (void)sigaction(SIGPIPE, &sa, &savepipe);
 101         (void)sigaction(SIGQUIT, &sa, &savequit);
 102         (void)sigaction(SIGTERM, &sa, &saveterm);
 103         (void)sigaction(SIGTSTP, &sa, &savetstp);
 104         (void)sigaction(SIGTTIN, &sa, &savettin);
 105         (void)sigaction(SIGTTOU, &sa, &savettou);
 106
 107         /* Turn off echo if possible. */
 108         if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
 109                 memcpy(&term, &oterm, sizeof(term));
 110                 if (!(flags & RPP_ECHO_ON))
 111                         term.c_lflag &= ~(ECHO | ECHONL);
 112 #ifdef VSTATUS
 113                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
 114                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
 115 #endif
 116                 (void)tcsetattr(input, _T_FLUSH, &term);
 117         } else {
 118                 memset(&term, 0, sizeof(term));
 119                 term.c_lflag |= ECHO;
 120                 memset(&oterm, 0, sizeof(oterm));
 121                 oterm.c_lflag |= ECHO;
 122         }
 123
 124         /* No I/O if we are already backgrounded. */
 125         if (signo[SIGTTOU] != 1 && signo[SIGTTIN] != 1) {
 126                 if (!(flags & RPP_STDIN))
 127                         (void)write(output, prompt, strlen(prompt));
 128                 end = buf + bufsiz - 1;
 129                 p = buf;
 130                 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
 131                         if (p < end) {
 132                                 if ((flags & RPP_SEVENBIT))
 133                                         ch &= 0x7f;
 134                                 if (isalpha(ch)) {
 135                                         if ((flags & RPP_FORCELOWER))
 136                                                 ch = (char)tolower(ch);
 137                                         if ((flags & RPP_FORCEUPPER))
 138                                                 ch = (char)toupper(ch);
 139                                 }
 140                                 *p++ = ch;
 141                         }
 142                 }
 143                 *p = '\0';
 144                 save_errno = errno;
 145                 if (!(term.c_lflag & ECHO))
 146                         (void)write(output, "\n", 1);
 147         }
 148
 149         /* Restore old terminal settings and signals. */
 150         if (memcmp(&term, &oterm, sizeof(term)) != 0) {
 151                 while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
 152                     errno == EINTR)
 153                         continue;
 154         }
 155         (void)sigaction(SIGALRM, &savealrm, NULL);
 156         (void)sigaction(SIGHUP, &savehup, NULL);
 157         (void)sigaction(SIGINT, &saveint, NULL);
 158         (void)sigaction(SIGQUIT, &savequit, NULL);
 159         (void)sigaction(SIGPIPE, &savepipe, NULL);
 160         (void)sigaction(SIGTERM, &saveterm, NULL);
 161         (void)sigaction(SIGTSTP, &savetstp, NULL);
 162         (void)sigaction(SIGTTIN, &savettin, NULL);
 163         (void)sigaction(SIGTTOU, &savettou, NULL);
 164         if (input != STDIN_FILENO)
 165                 (void)close(input);
 166
 167         /*
 168          * If we were interrupted by a signal, resend it to ourselves
 169          * now that we have restored the signal handlers.
 170          */
 171         for (i = 0; i < _NSIG; i++) {
 172                 if (signo[i]) {
 173                         kill(getpid(), i);
 174                         switch (i) {
 175                         case SIGTSTP:
 176                         case SIGTTIN:
 177                         case SIGTTOU:
 178                                 need_restart = 1;
 179                         }
 180                 }
 181         }
 182         if (need_restart)
 183                 goto restart;
 184
 185         if (save_errno)
 186                 errno = save_errno;
 187         return(nr == -1 ? NULL : buf);
 188 }
 189
 190 #if 0
 191 char *
 192 getpass(const char *prompt)
 193 {
 194         static char buf[_PASSWORD_LEN + 1];
 195
 196         return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
 197 }
 198 #endif
 199
 200 static void handler(int s)
 201 {
 202
 203         signo[s] = 1;
 204 }
 205 #endif /* HAVE_READPASSPHRASE */