openbsd-compat/readpassphrase.c

   1 /*      $OpenBSD: readpassphrase.c,v 1.18 2005/08/08 08:05:34 espie Exp $       */
   2
   3 /*
   4  * Copyright (c) 2000-2002 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;
  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;
  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         signo = 0;
  71         /*
  72          * Read and write to /dev/tty if available.  If not, read from
  73          * stdin and write to stderr unless a tty is required.
  74          */
  75         if ((flags & RPP_STDIN) ||
  76             (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
  77                 if (flags & RPP_REQUIRE_TTY) {
  78                         errno = ENOTTY;
  79                         return(NULL);
  80                 }
  81                 input = STDIN_FILENO;
  82                 output = STDERR_FILENO;
  83         }
  84
  85         /*
  86          * Catch signals that would otherwise cause the user to end
  87          * up with echo turned off in the shell.  Don't worry about
  88          * things like SIGXCPU and SIGVTALRM for now.
  89          */
  90         sigemptyset(&sa.sa_mask);
  91         sa.sa_flags = 0;                /* don't restart system calls */
  92         sa.sa_handler = handler;
  93         (void)sigaction(SIGALRM, &sa, &savealrm);
  94         (void)sigaction(SIGHUP, &sa, &savehup);
  95         (void)sigaction(SIGINT, &sa, &saveint);
  96         (void)sigaction(SIGPIPE, &sa, &savepipe);
  97         (void)sigaction(SIGQUIT, &sa, &savequit);
  98         (void)sigaction(SIGTERM, &sa, &saveterm);
  99         (void)sigaction(SIGTSTP, &sa, &savetstp);
 100         (void)sigaction(SIGTTIN, &sa, &savettin);
 101         (void)sigaction(SIGTTOU, &sa, &savettou);
 102
 103         /* Turn off echo if possible. */
 104         if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
 105                 memcpy(&term, &oterm, sizeof(term));
 106                 if (!(flags & RPP_ECHO_ON))
 107                         term.c_lflag &= ~(ECHO | ECHONL);
 108 #ifdef VSTATUS
 109                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
 110                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
 111 #endif
 112                 (void)tcsetattr(input, _T_FLUSH, &term);
 113         } else {
 114                 memset(&term, 0, sizeof(term));
 115                 term.c_lflag |= ECHO;
 116                 memset(&oterm, 0, sizeof(oterm));
 117                 oterm.c_lflag |= ECHO;
 118         }
 119
 120         if (!(flags & RPP_STDIN))
 121                 (void)write(output, prompt, strlen(prompt));
 122         end = buf + bufsiz - 1;
 123         for (p = buf; (nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) {
 124                 if (p < end) {
 125                         if ((flags & RPP_SEVENBIT))
 126                                 ch &= 0x7f;
 127                         if (isalpha(ch)) {
 128                                 if ((flags & RPP_FORCELOWER))
 129                                         ch = tolower(ch);
 130                                 if ((flags & RPP_FORCEUPPER))
 131                                         ch = toupper(ch);
 132                         }
 133                         *p++ = ch;
 134                 }
 135         }
 136         *p = '\0';
 137         save_errno = errno;
 138         if (!(term.c_lflag & ECHO))
 139                 (void)write(output, "\n", 1);
 140
 141         /* Restore old terminal settings and signals. */
 142         if (memcmp(&term, &oterm, sizeof(term)) != 0) {
 143                 while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
 144                     errno == EINTR)
 145                         continue;
 146         }
 147         (void)sigaction(SIGALRM, &savealrm, NULL);
 148         (void)sigaction(SIGHUP, &savehup, NULL);
 149         (void)sigaction(SIGINT, &saveint, NULL);
 150         (void)sigaction(SIGQUIT, &savequit, NULL);
 151         (void)sigaction(SIGPIPE, &savepipe, NULL);
 152         (void)sigaction(SIGTERM, &saveterm, NULL);
 153         (void)sigaction(SIGTSTP, &savetstp, NULL);
 154         (void)sigaction(SIGTTIN, &savettin, NULL);
 155         if (input != STDIN_FILENO)
 156                 (void)close(input);
 157
 158         /*
 159          * If we were interrupted by a signal, resend it to ourselves
 160          * now that we have restored the signal handlers.
 161          */
 162         if (signo) {
 163                 kill(getpid(), signo);
 164                 switch (signo) {
 165                 case SIGTSTP:
 166                 case SIGTTIN:
 167                 case SIGTTOU:
 168                         goto restart;
 169                 }
 170         }
 171
 172         errno = save_errno;
 173         return(nr == -1 ? NULL : buf);
 174 }
 175
 176 #if 0
 177 char *
 178 getpass(const char *prompt)
 179 {
 180         static char buf[_PASSWORD_LEN + 1];
 181
 182         return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
 183 }
 184 #endif
 185
 186 static void handler(int s)
 187 {
 188
 189         signo = s;
 190 }
 191 #endif /* HAVE_READPASSPHRASE */