busybox/libbb/bb_askpass.c
Denis Vlasenko ab24e18c7a passwd: rework:
* do not make backup copy by copying (just retain old file)
* correctly fall back to /etc/passwd if user is not in shadow
* fix bug with overlong passwd entries
* be permissive on some kinds of failures
* reduce stack usage
* code size: -500 bytes
2006-11-30 16:41:15 +00:00

76 lines
1.5 KiB
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 <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
#include <sys/ioctl.h>
#include "libbb.h"
/* do nothing signal handler */
static void askpass_timeout(int ATTRIBUTE_UNUSED ignore)
{
}
char *bb_askpass(int timeout, const char * prompt)
{
static char passwd[64];
char *ret;
int i;
struct sigaction sa;
struct termios old, new;
tcgetattr(STDIN_FILENO, &old);
tcflush(STDIN_FILENO, TCIFLUSH);
memset(passwd, 0, sizeof(passwd));
fputs(prompt, stdout);
fflush(stdout);
tcgetattr(STDIN_FILENO, &new);
new.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
new.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
tcsetattr(STDIN_FILENO, TCSANOW, &new);
if (timeout) {
sa.sa_flags = 0;
sa.sa_handler = askpass_timeout;
sigaction(SIGALRM, &sa, NULL);
alarm(timeout);
}
ret = NULL;
if (read(STDIN_FILENO, 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);
}
tcsetattr(STDIN_FILENO, TCSANOW, &old);
puts("");
fflush(stdout);
return ret;
}