crypto/external/bsd/openssh/dist/readpassphrase.c

   1 /*      $NetBSD: readpassphrase.c,v 1.14 2009/02/16 20:55:22 christos Exp $     */
   2 /*
   3  * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  19  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  20  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  23  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "includes.h"
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.7 2001/08/07 19:34:11 millert Exp $";
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include <ctype.h>
  35 #include <errno.h>
  36 #include <fcntl.h>
  37 #include <paths.h>
  38 #include <pwd.h>
  39 #include <signal.h>
  40 #include <string.h>
  41 #include <termios.h>
  42 #include <unistd.h>
  43 #include <readpassphrase.h>
  44
  45 char *
  46 readpassphrase(prompt, buf, bufsiz, flags)
  47         const char *prompt;
  48         char *buf;
  49         size_t bufsiz;
  50         int flags;
  51 {
  52         struct termios term, oterm;
  53         char ch, *p, *end;
  54         int input, output;
  55         sigset_t oset, nset;
  56
  57         /* I suppose we could alloc on demand in this case (XXX). */
  58         if (bufsiz == 0) {
  59                 errno = EINVAL;
  60                 return(NULL);
  61         }
  62
  63         /*
  64          * Read and write to /dev/tty if available.  If not, read from
  65          * stdin and write to stderr unless a tty is required.
  66          */
  67         if ((input = output = open(_PATH_TTY, O_RDWR)) == -1) {
  68                 if (flags & RPP_REQUIRE_TTY) {
  69                         errno = ENOTTY;
  70                         return(NULL);
  71                 }
  72                 input = STDIN_FILENO;
  73                 output = STDERR_FILENO;
  74         }
  75
  76         /*
  77          * We block SIGINT and SIGTSTP so the terminal is not left
  78          * in an inconsistent state (ie: no echo).  It would probably
  79          * be better to simply catch these though.
  80          */
  81         sigemptyset(&nset);
  82         sigaddset(&nset, SIGINT);
  83         sigaddset(&nset, SIGTSTP);
  84         (void)sigprocmask(SIG_BLOCK, &nset, &oset);
  85
  86         /* Turn off echo if possible. */
  87         if (tcgetattr(input, &oterm) == 0) {
  88                 memcpy(&term, &oterm, sizeof(term));
  89                 if (!(flags & RPP_ECHO_ON) && (term.c_lflag & ECHO))
  90                         term.c_lflag &= ~ECHO;
  91                 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
  92                         term.c_cc[VSTATUS] = _POSIX_VDISABLE;
  93                 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
  94         } else {
  95                 memset(&term, 0, sizeof(term));
  96                 memset(&oterm, 0, sizeof(oterm));
  97         }
  98
  99         (void)write(output, prompt, strlen(prompt));
 100         end = buf + bufsiz - 1;
 101         for (p = buf; read(input, &ch, 1) == 1 && ch != '\n' && ch != '\r';) {
 102                 if (p < end) {
 103                         if ((flags & RPP_SEVENBIT))
 104                                 ch &= 0x7f;
 105                         if (isalpha((unsigned char)ch)) {
 106                                 if ((flags & RPP_FORCELOWER))
 107                                         ch = tolower((unsigned char)ch);
 108                                 if ((flags & RPP_FORCEUPPER))
 109                                         ch = toupper((unsigned char)ch);
 110                         }
 111                         *p++ = ch;
 112                 }
 113         }
 114         *p = '\0';
 115         if (!(term.c_lflag & ECHO))
 116                 (void)write(output, "\n", 1);
 117
 118         /* Restore old terminal settings and signal mask. */
 119         if (memcmp(&term, &oterm, sizeof(term)) != 0)
 120                 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm);
 121         (void)sigprocmask(SIG_SETMASK, &oset, NULL);
 122         if (input != STDIN_FILENO)
 123                 (void)close(input);
 124         return(buf);
 125 }
 126
 127 char *
 128 getpass(prompt)
 129         const char *prompt;
 130 {
 131         static char buf[_PASSWORD_LEN + 1];
 132
 133         return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
 134 }