/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2016 OpenVPN Technologies, Inc. <sales@openvpn.net>
* Copyright (C) 2014-2015 David Sommerseth <davids@redhat.com>
* Copyright (C) 2016 David Sommerseth <davids@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* These functions covers handing user input/output using the default consoles
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif
#include "syshead.h"
#include "console.h"
#include "error.h"
#include "buffer.h"
#include "misc.h"
#ifdef _WIN32
#include "win32.h"
/**
* Get input from a Windows console.
*
* @param prompt Prompt to display to the user
* @param echo Should the user input be displayed in the console
* @param input Pointer to the buffer the user input will be saved
* @param capacity Size of the buffer for the user input
*
* @return Return false on input error, or if service
* exit event is signaled.
*/
static bool get_console_input_win32 (const char *prompt, const bool echo, char *input, const int capacity)
{
HANDLE in = INVALID_HANDLE_VALUE;
HANDLE err = INVALID_HANDLE_VALUE;
DWORD len = 0;
ASSERT (prompt);
ASSERT (input);
ASSERT (capacity > 0);
input[0] = '\0';
in = GetStdHandle (STD_INPUT_HANDLE);
err = get_orig_stderr ();
if (in != INVALID_HANDLE_VALUE
&& err != INVALID_HANDLE_VALUE
&& !win32_service_interrupt (&win32_signal)
&& WriteFile (err, prompt, strlen (prompt), &len, NULL))
{
bool is_console = (GetFileType (in) == FILE_TYPE_CHAR);
DWORD flags_save = 0;
int status = 0;
WCHAR *winput;
if (is_console)
{
if (GetConsoleMode (in, &flags_save))
{
DWORD flags = ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
if (echo)
flags |= ENABLE_ECHO_INPUT;
SetConsoleMode (in, flags);
} else
is_console = 0;
}
if (is_console)
{
winput = malloc (capacity * sizeof (WCHAR));
if (winput == NULL)
return false;
status = ReadConsoleW (in, winput, capacity, &len, NULL);
WideCharToMultiByte (CP_UTF8, 0, winput, len, input, capacity, NULL, NULL);
free (winput);
} else
status = ReadFile (in, input, capacity, &len, NULL);
string_null_terminate (input, (int)len, capacity);
chomp (input);
if (!echo)
WriteFile (err, "\r\n", 2, &len, NULL);
if (is_console)
SetConsoleMode (in, flags_save);
if (status && !win32_service_interrupt (&win32_signal))
return true;
}
return false;
}
#endif /* _WIN32 */
#ifdef HAVE_GETPASS
/**
* Open the current console TTY for read/write operations
*
* @params write If true, the user wants to write to the console
* otherwise read from the console
*
* @returns Returns a FILE pointer to either the TTY in read or write mode
* or stdin/stderr, depending on the write flag
*
*/
static FILE * open_tty (const bool write)
{
FILE *ret;
ret = fopen ("/dev/tty", write ? "w" : "r");
if (!ret)
ret = write ? stderr : stdin;
return ret;
}
/**
* Closes the TTY FILE pointer, but only if it is not a stdin/stderr FILE object.
*
* @params fp FILE pointer to close
*
*/
static void close_tty (FILE *fp)
{
if (fp != stderr && fp != stdin)
fclose (fp);
}
#endif /* HAVE_GETPASS */
/**
* Core function for getting input from console
*
* @params prompt The prompt to present to the user
* @params echo Should the user see what is being typed
* @params input Pointer to the buffer used to save the user input
* @params capacity Size of the input buffer
*
* @returns Returns True if user input was gathered
*/
static bool get_console_input (const char *prompt, const bool echo, char *input, const int capacity)
{
bool ret = false;
ASSERT (prompt);
ASSERT (input);
ASSERT (capacity > 0);
input[0] = '\0';
#if defined(_WIN32)
return get_console_input_win32 (prompt, echo, input, capacity);
#elif defined(HAVE_GETPASS)
/* did we --daemon'ize before asking for passwords?
* (in which case neither stdin or stderr are connected to a tty and
* /dev/tty can not be open()ed anymore)
*/
if ( !isatty(0) && !isatty(2) )
{
int fd = open( "/dev/tty", O_RDWR );
if ( fd < 0 )
{
msg(M_FATAL, "neither stdin nor stderr are a tty device and you have neither a "
"controlling tty nor systemd - can't ask for '%s'. If you used --daemon, "
"you need to use --askpass to make passphrase-protected keys work, and you "
"can not use --auth-nocache.", prompt );
}
close(fd);
}
if (echo)
{
FILE *fp;
fp = open_tty (true);
fprintf (fp, "%s", prompt);
fflush (fp);
close_tty (fp);
fp = open_tty (false);
if (fgets (input, capacity, fp) != NULL)
{
chomp (input);
ret = true;
}
close_tty (fp);
} else {
char *gp = getpass (prompt);
if (gp)
{
strncpynt (input, gp, capacity);
memset (gp, 0, strlen (gp));
ret = true;
}
}
#else
msg (M_FATAL, "Sorry, but I can't get console input on this OS (%s)", prompt);
#endif
return ret;
}
/**
* @copydoc query_user_exec()
*
* Default method for querying user using default stdin/stdout on a console.
* This needs to be available as a backup interface for the alternative
* implementations in case they cannot query through their implementation
* specific methods.
*
* If no alternative implementation is declared, a wrapper in console.h will ensure
* query_user_exec() will call this function instead.
*
*/
bool query_user_exec_builtin()
{
bool ret = true; /* Presume everything goes okay */
int i;
/* Loop through configured query_user slots */
for (i = 0; i < QUERY_USER_NUMSLOTS && query_user[i].response != NULL; i++)
{
if (!get_console_input(query_user[i].prompt, query_user[i].echo,
query_user[i].response, query_user[i].response_len) )
{
/* Force the final result state to failed on failure */
ret = false;
}
}
return ret;
}