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/* Copyright (C) 1992-2001, 2003-2007, 2009-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#ifndef _LIBC
/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc
warns for the null checks on 'prompt' below. */
# define _GL_ARG_NONNULL(params)
# include <config.h>
#endif
#include "getpass.h"
#include <stdio.h>
#if !(defined _WIN32 && !defined __CYGWIN__)
# if HAVE_DECL___FSETLOCKING && HAVE___FSETLOCKING
# if HAVE_STDIO_EXT_H
# include <stdio_ext.h>
# endif
# else
# define __fsetlocking(stream, type) /* empty */
# endif
# if HAVE_TERMIOS_H
# include <termios.h>
# endif
# if USE_UNLOCKED_IO
# include "unlocked-io.h"
# else
# if !HAVE_DECL_FFLUSH_UNLOCKED
# undef fflush_unlocked
# define fflush_unlocked(x) fflush (x)
# endif
# if !HAVE_DECL_FLOCKFILE
# undef flockfile
# define flockfile(x) ((void) 0)
# endif
# if !HAVE_DECL_FUNLOCKFILE
# undef funlockfile
# define funlockfile(x) ((void) 0)
# endif
# if !HAVE_DECL_FPUTS_UNLOCKED
# undef fputs_unlocked
# define fputs_unlocked(str,stream) fputs (str, stream)
# endif
# if !HAVE_DECL_PUTC_UNLOCKED
# undef putc_unlocked
# define putc_unlocked(c,stream) putc (c, stream)
# endif
# endif
/* It is desirable to use this bit on systems that have it.
The only bit of terminal state we want to twiddle is echoing, which is
done in software; there is no need to change the state of the terminal
hardware. */
# ifndef TCSASOFT
# define TCSASOFT 0
# endif
static void
call_fclose (void *arg)
{
if (arg != NULL)
fclose (arg);
}
char *
getpass (const char *prompt)
{
FILE *tty;
FILE *in, *out;
# if HAVE_TCGETATTR
struct termios s, t;
# endif
bool tty_changed = false;
static char *buf;
static size_t bufsize;
ssize_t nread;
/* Try to write to and read from the terminal if we can.
If we can't open the terminal, use stderr and stdin. */
tty = fopen ("/dev/tty", "w+e");
if (tty == NULL)
{
in = stdin;
out = stderr;
}
else
{
/* We do the locking ourselves. */
__fsetlocking (tty, FSETLOCKING_BYCALLER);
out = in = tty;
}
flockfile (out);
/* Turn echoing off if it is on now. */
# if HAVE_TCGETATTR
if (tcgetattr (fileno (in), &t) == 0)
{
/* Save the old one. */
s = t;
/* Tricky, tricky. */
t.c_lflag &= ~(ECHO | ISIG);
tty_changed = (tcsetattr (fileno (in), TCSAFLUSH | TCSASOFT, &t) == 0);
}
# endif
if (prompt)
{
/* Write the prompt. */
fputs_unlocked (prompt, out);
fflush_unlocked (out);
}
/* Read the password. */
nread = getline (&buf, &bufsize, in);
/* According to the C standard, input may not be followed by output
on the same stream without an intervening call to a file
positioning function. Suppose in == out; then without this fseek
call, on Solaris, HP-UX, AIX, OSF/1, the previous input gets
echoed, whereas on IRIX, the following newline is not output as
it should be. POSIX imposes similar restrictions if fileno (in)
== fileno (out). The POSIX restrictions are tricky and change
from POSIX version to POSIX version, so play it safe and invoke
fseek even if in != out. */
fseeko (out, 0, SEEK_CUR);
if (buf != NULL)
{
if (nread < 0)
buf[0] = '\0';
else if (buf[nread - 1] == '\n')
{
/* Remove the newline. */
buf[nread - 1] = '\0';
if (tty_changed)
{
/* Write the newline that was not echoed. */
putc_unlocked ('\n', out);
}
}
}
/* Restore the original setting. */
# if HAVE_TCSETATTR
if (tty_changed)
tcsetattr (fileno (in), TCSAFLUSH | TCSASOFT, &s);
# endif
funlockfile (out);
call_fclose (tty);
return buf;
}
#else /* W32 native */
/* Windows implementation by Martin Lambers <marlam@marlam.de>,
improved by Simon Josefsson. */
/* For PASS_MAX. */
# include <limits.h>
/* For _getch(). */
# include <conio.h>
/* For strdup(). */
# include <string.h>
# ifndef PASS_MAX
# define PASS_MAX 512
# endif
char *
getpass (const char *prompt)
{
char getpassbuf[PASS_MAX + 1];
size_t i = 0;
int c;
if (prompt)
{
fputs (prompt, stderr);
fflush (stderr);
}
for (;;)
{
c = _getch ();
if (c == '\r')
{
getpassbuf[i] = '\0';
break;
}
else if (i < PASS_MAX)
{
getpassbuf[i++] = c;
}
if (i >= PASS_MAX)
{
getpassbuf[i] = '\0';
break;
}
}
if (prompt)
{
fputs ("\r\n", stderr);
fflush (stderr);
}
return strdup (getpassbuf);
}
#endif
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