1 /* vi: set sw=4 ts=4: */
2 /*
3 * Ask for a password
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9
10 #include "libbb.h"
11
12 /* do nothing signal handler */
askpass_timeout(int UNUSED_PARAM ignore)13 static void askpass_timeout(int UNUSED_PARAM ignore)
14 {
15 }
16
bb_ask_stdin(const char * prompt)17 char* FAST_FUNC bb_ask_stdin(const char *prompt)
18 {
19 return bb_ask(STDIN_FILENO, 0, prompt);
20 }
bb_ask(const int fd,int timeout,const char * prompt)21 char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt)
22 {
23 /* Was static char[BIGNUM] */
24 enum { sizeof_passwd = 128 };
25
26 char *passwd;
27 char *ret;
28 int i;
29 struct sigaction sa, oldsa;
30 struct termios tio, oldtio;
31
32 tcflush(fd, TCIFLUSH);
33 /* Was buggy: was printing prompt *before* flushing input,
34 * which was upsetting "expect" based scripts of some users.
35 */
36 fputs(prompt, stdout);
37 fflush_all();
38
39 tcgetattr(fd, &oldtio);
40 tio = oldtio;
41 #if 0
42 /* Switch off UPPERCASE->lowercase conversion (never used since 198x)
43 * and XON/XOFF (why we want to mess with this??)
44 */
45 # ifndef IUCLC
46 # define IUCLC 0
47 # endif
48 tio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
49 #endif
50 /* Switch off echo */
51 tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL);
52 tcsetattr(fd, TCSANOW, &tio);
53
54 memset(&sa, 0, sizeof(sa));
55 /* sa.sa_flags = 0; - no SA_RESTART! */
56 /* SIGINT and SIGALRM will interrupt reads below */
57 sa.sa_handler = askpass_timeout;
58 sigaction(SIGINT, &sa, &oldsa);
59 if (timeout) {
60 sigaction_set(SIGALRM, &sa);
61 alarm(timeout);
62 }
63
64 passwd = auto_string(xmalloc(sizeof_passwd));
65 ret = passwd;
66 i = 0;
67 while (1) {
68 int r = read(fd, &ret[i], 1);
69 if ((i == 0 && r == 0) /* EOF (^D) with no password */
70 || r < 0
71 ) {
72 /* read is interrupted by timeout or ^C */
73 ret = NULL;
74 break;
75 }
76 if (r == 0 /* EOF */
77 || ret[i] == '\r' || ret[i] == '\n' /* EOL */
78 || ++i == sizeof_passwd-1 /* line limit */
79 ) {
80 ret[i] = '\0';
81 break;
82 }
83 }
84
85 if (timeout) {
86 alarm(0);
87 }
88 sigaction_set(SIGINT, &oldsa);
89 tcsetattr(fd, TCSANOW, &oldtio);
90 bb_putchar('\n');
91 fflush_all();
92 return ret;
93 }
94