minix/lib/libc/gen/getpass.c

   1 /*      getpass() - read a password             Author: Kees J. Bot
   2  *                                                      Feb 16 1993
   3  */
   4 #include <sys/cdefs.h>
   5 #include "namespace.h"
   6
   7 #include <sys/types.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include <signal.h>
  11 #include <termios.h>
  12 #include <string.h>
  13
  14 #ifdef __weak_alias
  15 __weak_alias(getpass, _getpass)
  16 #endif
  17
  18 static int intr;
  19
  20 static void catch(int sig)
  21 {
  22         intr= 1;
  23 }
  24
  25 char *getpass(const char *prompt)
  26 {
  27         struct sigaction osa, sa;
  28         struct termios cooked, raw;
  29         static char password[32+1];
  30         int fd, n= 0;
  31
  32         /* Try to open the controlling terminal. */
  33         if ((fd= open("/dev/tty", O_RDONLY)) < 0) return NULL;
  34
  35         /* Trap interrupts unless ignored. */
  36         intr= 0;
  37         sigaction(SIGINT, NULL, &osa);
  38         if (osa.sa_handler != SIG_IGN) {
  39                 sigemptyset(&sa.sa_mask);
  40                 sa.sa_flags= 0;
  41                 sa.sa_handler= catch;
  42                 sigaction(SIGINT, &sa, &osa);
  43         }
  44
  45         /* Set the terminal to non-echo mode. */
  46         tcgetattr(fd, &cooked);
  47         raw= cooked;
  48         raw.c_iflag|= ICRNL;
  49         raw.c_lflag&= ~ECHO;
  50         raw.c_lflag|= ECHONL;
  51         raw.c_oflag|= OPOST | ONLCR;
  52         tcsetattr(fd, TCSANOW, &raw);
  53
  54         /* Print the prompt.  (After setting non-echo!) */
  55         write(2, prompt, strlen(prompt));
  56
  57         /* Read the password, 32 characters max. */
  58         while (read(fd, password+n, 1) > 0) {
  59                 if (password[n] == '\n') break;
  60                 if (n < 32) n++;
  61         }
  62         password[n]= 0;
  63
  64         /* Terminal back to cooked mode. */
  65         tcsetattr(fd, TCSANOW, &cooked);
  66
  67         close(fd);
  68
  69         /* Interrupt? */
  70         sigaction(SIGINT, &osa, NULL);
  71         if (intr) raise(SIGINT);
  72
  73         return password;
  74 }