diplodocus.org Git - nmh/blob - sbr/getpass.c

   1 /*
   2  * Portions of this code are Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <h/mh.h>
  35 #include <termios.h>
  36
  37 /* We don't use MAX_PASS here because the maximum password length on a remote
  38    POP daemon will have nothing to do with the length on our OS.  256 is
  39    arbitrary but hopefully big enough to accommodate everyone. */
  40 #define MAX_PASSWORD_LEN 256
  41
  42 #ifndef TCSANOW
  43 #define TCSANOW 0
  44 #endif
  45
  46 char *
  47 nmh_getpass(const char *prompt)
  48 {
  49   struct termios oterm, term;
  50   int ch;
  51   char *p;
  52   FILE *fout, *fin;
  53   static char  buf[MAX_PASSWORD_LEN + 1];
  54   int istty = isatty(fileno(stdin));
  55
  56   /* Find if stdin is connect to a terminal. If so, read directly from
  57    * the terminal, and turn off echo. Otherwise read from stdin.
  58    */
  59
  60   if (!istty || !(fout = fin = fopen("/dev/tty", "w+"))) {
  61     fout = stderr;
  62     fin = stdin;
  63   }
  64   else /* Reading directly from terminal here */
  65     {
  66       (void)tcgetattr(fileno(fin), &oterm);
  67       term = oterm; /* Save original info */
  68       term.c_lflag &= ~ECHO;
  69       (void)fputs(prompt, fout);
  70       rewind(fout);                     /* implied flush */
  71       (void)tcsetattr(fileno(fin), TCSANOW, &term);
  72     }
  73
  74   for (p = buf; (ch = getc(fin)) != EOF &&
  75                  ch != '\n' &&
  76                  p < buf + MAX_PASSWORD_LEN;)
  77     *p++ = ch;
  78   *p = '\0';
  79
  80   if (istty) {
  81     (void)tcsetattr(fileno(fin), TCSANOW, &oterm);
  82     rewind(fout);
  83     (void)fputc('\n', fout);
  84     (void)fclose(fin);
  85   }
  86   return buf;
  87 }