blob: c2580b9ebe6914e3fe778914f20f32fad3f04ca7
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 */ |
13 | static void askpass_timeout(int UNUSED_PARAM ignore) |
14 | { |
15 | } |
16 | |
17 | char* FAST_FUNC bb_ask_stdin(const char *prompt) |
18 | { |
19 | return bb_ask(STDIN_FILENO, 0, prompt); |
20 | } |
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 |