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
  36 #ifdef TCSASOFT
  37 # define _T_FLUSH       (TCSAFLUSH|TCSASOFT)
  38 #else
  39 # define _T_FLUSH       (TCSAFLUSH)
  40 #endif
  41
  42 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
  43 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
  44 #  define _POSIX_VDISABLE       VDISABLE
  45 #endif
  46
  47 static volatile sig_atomic_t signo;
  48
  49 static void handler(int);
  50
  51 char *
  52 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
  53 {
  54         ssize_t nr;
  55         int input, output, save_errno;
  56         char ch, *p, *end;
  57         struct termios term, oterm;
  58         struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
  59         struct sigaction savetstp, savettin, savettou, savepipe;
  60
  61         /* I suppose we could alloc on demand in this case (XXX). */
  62         if (bufsiz == 0) {
  63                 errno = EINVAL;
  64                 return(NULL);
  65         }
  66
  67 restart:
  68         signo = 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         if ((flags & RPP_STDIN) ||
  74             (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
  75                 if (flags & RPP_REQUIRE_TTY) {
  76                         errno = ENOTTY;
  77                         return(NULL);
  78                 }
  79                 input = STDIN_FILENO;
  80                 output = STDERR_FILENO;
  81         }
  82
  83         /*
  84          * Catch signals that would otherwise cause the user to end
  85          * up with echo turned off in the shell.  Don't worry about
  86          * things like SIGXCPU and SIGVTALRM for now.
  87          */
  88         sigemptyset(&sa.sa_mask);
  89         sa.sa_flags = 0;                /* don't restart system calls */
  90         sa.sa_handler = handler;
  91         (void)sigaction(SIGALRM, &sa, &savealrm);
  92         (void)sigaction(SIGHUP, &sa, &savehup);
  93         (void)sigaction(SIGINT, &sa, &saveint);
  94         (void)sigaction(SIGPIPE, &sa, &savepipe);
  95         (void)sigaction(SIGQUIT, &sa, &savequit);
  96         (void)sigaction(SIGTERM, &sa, &saveterm);
  97         (void)sigaction(SIGTSTP, &sa, &savetstp);
  98         (void)sigaction(SIGTTIN, &sa, &savettin);
  99         (void)sigaction(SIGTTOU, &sa, &savettou);
 100
 101         /* Turn off echo if possible. */
 102         if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
 103                 memcpy(&term, &oterm, sizeof(term));
 104                 if (!(flags & RPP_ECHO_ON))
 105                         term.c_lflag &= ~(ECHO | ECHONL);
 106 #ifdef VSTATUS
 107                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
 108                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
 109 #endif
 110                 (void)tcsetattr(input, _T_FLUSH, &term);
 111         } else {
 112                 memset(&term, 0, sizeof(term));
 113                 term.c_lflag |= ECHO;
 114                 memset(&oterm, 0, sizeof(oterm));
 115                 oterm.c_lflag |= ECHO;
 116         }
 117
 118         if (!(flags & RPP_STDIN))
 119                 (void)write(output, prompt, strlen(prompt));
 120         end = buf + bufsiz - 1;
 121         for (p = buf; (nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) {
 122                 if (p < end) {
 123                         if ((flags & RPP_SEVENBIT))
 124                                 ch &= 0x7f;
 125                         if (isalpha(ch)) {
 126                                 if ((flags & RPP_FORCELOWER))
 127                                         ch = tolower(ch);
 128                                 if ((flags & RPP_FORCEUPPER))
 129                                         ch = toupper(ch);
 130                         }
 131                         *p++ = ch;
 132                 }
 133         }
 134         *p = '\0';
 135         save_errno = errno;
 136         if (!(term.c_lflag & ECHO))
 137                 (void)write(output, "\n", 1);
 138
 139         /* Restore old terminal settings and signals. */
 140         if (memcmp(&term, &oterm, sizeof(term)) != 0) {
 141                 while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
 142                     errno == EINTR)
 143                         continue;
 144         }
 145         (void)sigaction(SIGALRM, &savealrm, NULL);
 146         (void)sigaction(SIGHUP, &savehup, NULL);
 147         (void)sigaction(SIGINT, &saveint, NULL);
 148         (void)sigaction(SIGQUIT, &savequit, NULL);
 149         (void)sigaction(SIGPIPE, &savepipe, NULL);
 150         (void)sigaction(SIGTERM, &saveterm, NULL);
 151         (void)sigaction(SIGTSTP, &savetstp, NULL);
 152         (void)sigaction(SIGTTIN, &savettin, NULL);
 153         if (input != STDIN_FILENO)
 154                 (void)close(input);
 155
 156         /*
 157          * If we were interrupted by a signal, resend it to ourselves
 158          * now that we have restored the signal handlers.
 159          */
 160         if (signo) {
 161                 kill(getpid(), signo);
 162                 switch (signo) {
 163                 case SIGTSTP:
 164                 case SIGTTIN:
 165                 case SIGTTOU:
 166                         goto restart;
 167                 }
 168         }
 169
 170         errno = save_errno;
 171         return(nr == -1 ? NULL : buf);
 172 }
 173
 174 #if 0
 175 char *
 176 getpass(const char *prompt)
 177 {
 178         static char buf[_PASSWORD_LEN + 1];
 179
 180         return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
 181 }
 182 #endif
 183
 184 static void handler(int s)
 185 {
 186
 187         signo = s;
 188 }
 189 #endif /* HAVE_READPASSPHRASE */