gen/FreeBSD/readpassphrase.c

   1 /*      $OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $     */
   2
   3 /*
   4  * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/readpassphrase.c,v 1.6 2002/03/09 03:16:41 green Exp $");
  35
  36 #include "namespace.h"
  37 #include <ctype.h>
  38 #include <errno.h>
  39 #include <fcntl.h>
  40 #include <paths.h>
  41 #include <pwd.h>
  42 #include <signal.h>
  43 #include <string.h>
  44 #include <termios.h>
  45 #include <unistd.h>
  46 #include <readpassphrase.h>
  47 #include "un-namespace.h"
  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, saveint, savehup, savequit, saveterm;
  61         struct sigaction savetstp, savettin, savettou;
  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         /*
  71          * Read and write to /dev/tty if available.  If not, read from
  72          * stdin and write to stderr unless a tty is required.
  73          */
  74         if ((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 SIGALRM and SIGPIPE 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(SIGINT, &sa, &saveint);
  92         (void)_sigaction(SIGHUP, &sa, &savehup);
  93         (void)_sigaction(SIGQUIT, &sa, &savequit);
  94         (void)_sigaction(SIGTERM, &sa, &saveterm);
  95         (void)_sigaction(SIGTSTP, &sa, &savetstp);
  96         (void)_sigaction(SIGTTIN, &sa, &savettin);
  97         (void)_sigaction(SIGTTOU, &sa, &savettou);
  98
  99         /* Turn off echo if possible. */
 100         if (tcgetattr(input, &oterm) == 0) {
 101                 memcpy(&term, &oterm, sizeof(term));
 102                 if (!(flags & RPP_ECHO_ON))
 103                         term.c_lflag &= ~(ECHO | ECHONL);
 104                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
 105                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
 106                 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
 107         } else {
 108                 memset(&term, 0, sizeof(term));
 109                 memset(&oterm, 0, sizeof(oterm));
 110         }
 111
 112         (void)_write(output, prompt, strlen(prompt));
 113         end = buf + bufsiz - 1;
 114         for (p = buf; (nr = _read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) {
 115                 if (p < end) {
 116                         if ((flags & RPP_SEVENBIT))
 117                                 ch &= 0x7f;
 118                         if (isalpha(ch)) {
 119                                 if ((flags & RPP_FORCELOWER))
 120                                         ch = tolower(ch);
 121                                 if ((flags & RPP_FORCEUPPER))
 122                                         ch = toupper(ch);
 123                         }
 124                         *p++ = ch;
 125                 }
 126         }
 127         *p = '\0';
 128         save_errno = errno;
 129         if (!(term.c_lflag & ECHO))
 130                 (void)_write(output, "\n", 1);
 131
 132         /* Restore old terminal settings and signals. */
 133         if (memcmp(&term, &oterm, sizeof(term)) != 0)
 134                 (void)tcsetattr(input, TCSANOW|TCSASOFT, &oterm);
 135         (void)_sigaction(SIGINT, &saveint, NULL);
 136         (void)_sigaction(SIGHUP, &savehup, NULL);
 137         (void)_sigaction(SIGQUIT, &savequit, NULL);
 138         (void)_sigaction(SIGTERM, &saveterm, NULL);
 139         (void)_sigaction(SIGTSTP, &savetstp, NULL);
 140         (void)_sigaction(SIGTTIN, &savettin, NULL);
 141         (void)_sigaction(SIGTTOU, &savettou, NULL);
 142         if (input != STDIN_FILENO)
 143                 (void)_close(input);
 144
 145         /*
 146          * If we were interrupted by a signal, resend it to ourselves
 147          * now that we have restored the signal handlers.
 148          */
 149         if (signo) {
 150                 kill(getpid(), signo);
 151                 switch (signo) {
 152                 case SIGTSTP:
 153                 case SIGTTIN:
 154                 case SIGTTOU:
 155                         signo = 0;
 156                         goto restart;
 157                 }
 158         }
 159
 160         errno = save_errno;
 161         return(nr == -1 ? NULL : buf);
 162 }
 163
 164 char *
 165 getpass(const char *prompt)
 166 {
 167         static char buf[_PASSWORD_LEN + 1];
 168
 169         if (readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF) == NULL)
 170                 buf[0] = '\0';
 171         return(buf);
 172 }
 173
 174 static void handler(int s)
 175 {
 176
 177         signo = s;
 178 }