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

   1 /* getpass.c -- read a password without echo.
   2  *
   3  * Portions of this code are Copyright (c) 1988, 1993
   4  *      The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "h/mh.h"
  36 #include "getpass.h"
  37 #include <termios.h>
  38
  39 /* We don't use MAX_PASS here because the maximum password length on a remote
  40    POP daemon will have nothing to do with the length on our OS.  256 is
  41    arbitrary but hopefully big enough to accommodate everyone. */
  42 #define MAX_PASSWORD_LEN 256
  43
  44 #ifndef TCSANOW
  45 #define TCSANOW 0
  46 #endif
  47
  48 char *
  49 nmh_getpass(const char *prompt)
  50 {
  51   struct termios oterm, term;
  52   int ch;
  53   char *p;
  54   FILE *fout, *fin;
  55   static char  buf[MAX_PASSWORD_LEN + 1];
  56   int istty = isatty(fileno(stdin));
  57
  58   /* Find if stdin is connect to a terminal. If so, read directly from
  59    * the terminal, and turn off echo. Otherwise read from stdin.
  60    */
  61
  62   if (!istty || !(fout = fin = fopen("/dev/tty", "w+"))) {
  63     fout = stderr;
  64     fin = stdin;
  65   }
  66   else /* Reading directly from terminal here */
  67     {
  68       (void)tcgetattr(fileno(fin), &oterm);
  69       term = oterm; /* Save original info */
  70       term.c_lflag &= ~ECHO;
  71       (void)fputs(prompt, fout);
  72       rewind(fout);                     /* implied flush */
  73       (void)tcsetattr(fileno(fin), TCSANOW, &term);
  74     }
  75
  76   for (p = buf; (ch = getc(fin)) != EOF &&
  77                  ch != '\n' &&
  78                  p < buf + MAX_PASSWORD_LEN;)
  79     *p++ = ch;
  80   *p = '\0';
  81
  82   if (istty && fin != stdin) {
  83     (void)tcsetattr(fileno(fin), TCSANOW, &oterm);
  84     rewind(fout);
  85     (void)fputc('\n', fout);
  86     (void)fclose(fin);
  87   }
  88   return buf;
  89 }