busybox/libbb/bb_askpass.c

/* vi: set sw=4 ts=4: */
/*
 * Ask for a password
 * I use a static buffer in this function.  Plan accordingly.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

/* do nothing signal handler */
static void askpass_timeout(int UNUSED_PARAM ignore)
{
}

char* FAST_FUNC bb_ask_stdin(const char *prompt)
{
	return bb_ask(STDIN_FILENO, 0, prompt);
}
char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt)
{
	/* Was static char[BIGNUM] */
	enum { sizeof_passwd = 128 };
	static char *passwd;

	char *ret;
	int i;
	struct sigaction sa, oldsa;
	struct termios tio, oldtio;

	if (!passwd)
		passwd = xmalloc(sizeof_passwd);
	memset(passwd, 0, sizeof_passwd);

	tcgetattr(fd, &oldtio);
	tcflush(fd, TCIFLUSH);
	tio = oldtio;
#ifndef IUCLC
# define IUCLC 0
#endif
	tio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
	tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
	tcsetattr_stdin_TCSANOW(&tio);

	memset(&sa, 0, sizeof(sa));
	/* sa.sa_flags = 0; - no SA_RESTART! */
	/* SIGINT and SIGALRM will interrupt read below */
	sa.sa_handler = askpass_timeout;
	sigaction(SIGINT, &sa, &oldsa);
	if (timeout) {
		sigaction_set(SIGALRM, &sa);
		alarm(timeout);
	}

	fputs(prompt, stdout);
	fflush_all();
	ret = NULL;
	/* On timeout or Ctrl-C, read will hopefully be interrupted,
	 * and we return NULL */
	if (read(fd, passwd, sizeof_passwd - 1) > 0) {
		ret = passwd;
		i = 0;
		/* Last byte is guaranteed to be 0
		   (read did not overwrite it) */
		do {
			if (passwd[i] == '\r' || passwd[i] == '\n')
				passwd[i] = '\0';
		} while (passwd[i++]);
	}

	if (timeout) {
		alarm(0);
	}
	sigaction_set(SIGINT, &oldsa);

	tcsetattr_stdin_TCSANOW(&oldtio);
	bb_putchar('\n');
	fflush_all();
	return ret;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Ask for a password
4	* I use a static buffer in this function. Plan accordingly.
5	*
6	* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7	*
8	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9	*/
10
11	#include "libbb.h"
12
13	/* do nothing signal handler */
14	static void askpass_timeout(int UNUSED_PARAM ignore)
15	{
16	}
17
18	char* FAST_FUNC bb_ask_stdin(const char *prompt)
19	{
20	return bb_ask(STDIN_FILENO, 0, prompt);
21	}
22	char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt)
23	{
24	/* Was static char[BIGNUM] */
25	enum { sizeof_passwd = 128 };
26	static char *passwd;
27
28	char *ret;
29	int i;
30	struct sigaction sa, oldsa;
31	struct termios tio, oldtio;
32
33	if (!passwd)
34	passwd = xmalloc(sizeof_passwd);
35	memset(passwd, 0, sizeof_passwd);
36
37	tcgetattr(fd, &oldtio);
38	tcflush(fd, TCIFLUSH);
39	tio = oldtio;
40	#ifndef IUCLC
41	# define IUCLC 0
42	#endif
43	tio.c_iflag &= ~(IUCLC\|IXON\|IXOFF\|IXANY);
44	tio.c_lflag &= ~(ECHO\|ECHOE\|ECHOK\|ECHONL\|TOSTOP);
45	tcsetattr_stdin_TCSANOW(&tio);
46
47	memset(&sa, 0, sizeof(sa));
48	/* sa.sa_flags = 0; - no SA_RESTART! */
49	/* SIGINT and SIGALRM will interrupt read below */
50	sa.sa_handler = askpass_timeout;
51	sigaction(SIGINT, &sa, &oldsa);
52	if (timeout) {
53	sigaction_set(SIGALRM, &sa);
54	alarm(timeout);
55	}
56
57	fputs(prompt, stdout);
58	fflush_all();
59	ret = NULL;
60	/* On timeout or Ctrl-C, read will hopefully be interrupted,
61	* and we return NULL */
62	if (read(fd, passwd, sizeof_passwd - 1) > 0) {
63	ret = passwd;
64	i = 0;
65	/* Last byte is guaranteed to be 0
66	(read did not overwrite it) */
67	do {
68	if (passwd[i] == '\r' \|\| passwd[i] == '\n')
69	passwd[i] = '\0';
70	} while (passwd[i++]);
71	}
72
73	if (timeout) {
74	alarm(0);
75	}
76	sigaction_set(SIGINT, &oldsa);
77
78	tcsetattr_stdin_TCSANOW(&oldtio);
79	bb_putchar('\n');
80	fflush_all();
81	return ret;
82	}