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
__weak_alias(getpass,_getpass)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
getpass(const char * prompt)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 }
75