/**
* libpassphrase – Personalisable library for TTY passphrase reading
*
* Copyright © 2013, 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <termios.h>
#include <unistd.h>
#include "passphrase.h"
#define START_PASSPHRASE_LIMIT 32
#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
/**
* The original TTY settings
*/
static struct termios saved_stty;
#endif
#ifndef PASSPHRASE_REALLOC
static char* xrealloc(char* array, size_t cur_size, size_t new_size)
{
char* rc = malloc(new_size * sizeof(char));
size_t i;
if (rc)
for (i = 0; i < cur_size; i++)
*(rc + i) = *(array + i);
for (i = 0; i < cur_size; i++)
*(array + i) = 0;
free(array);
return rc;
}
#else
#define xrealloc(array, _cur_size, new_size) realloc(array, (new_size) * sizeof(char))
#endif
#if defined(PASSPHRASE_MOVE) && !defined(PASSPHRASE_STAR) && !defined(PASSPHRASE_ECHO)
# define xprintf(...) /* do nothing */
# define xflush() /* do nothing */
#elif defined(PASSPHRASE_MOVE) || defined(PASSPHRASE_STAR)
# define xprintf(...) fprintf(stderr, __VA_ARGS__)
# define xflush() fflush(stderr)
#else
# define xflush() fflush(stderr)
#endif
#ifdef PASSPHRASE_MOVE
# if defined(PASSPHRASE_STAR)
# define xputchar(C) ({ if ((C & 0xC0) != 0x80) fputc('*', stderr); })
# elif defined(PASSPHRASE_ECHO)
# define xputchar(C) fputc(C, stderr)
# else
# define xputchar(C) ({ /* be silent */ })
# endif
#endif
/**
* Reads the passphrase from stdin
*
* @return The passphrase, should be wiped `free`:ed, `NULL` on error
*/
char* passphrase_read(void)
{
char* rc = malloc(START_PASSPHRASE_LIMIT * sizeof(char));
long size = START_PASSPHRASE_LIMIT;
long len = 0;
#ifdef PASSPHRASE_MOVE
long point = 0;
long i = 0;
# ifdef PASSPHRASE_OVERRIDE
# if defined(PASSPHRASE_INSERT) && defined(DEFAULT_INSERT)
char insert = 1;
# elif defined(PASSPHRASE_INSERT)
char insert = 0;
# endif
# endif
#endif
int c;
if (rc == NULL)
return NULL;
/* Read password until EOF or Enter, skip all \0 as that
is probably not a part of the passphrase (good luck typing
that in X.org) and can be echoed into stdin by the kernel. */
for (;;)
{
c = getchar();
if ((c < 0) || (c == '\n'))
break;
if (c != 0)
{
#if defined(PASSPHRASE_MOVE)
/* \e[1~ \eOH ^A -1 home */
/* \e[2~ -2 insert */
/* \e[3~ ^D -3 delete */
/* \e[4~ \eOF ^E -4 end */
/* \8 \127 -5 erase */
/* \e[C ^F -6 right */
/* \e[D ^B -7 left */
int cc = 0;
#ifdef PASSPHRASE_DEDICATED
if (c == '\033')
{
c = getchar();
if (c == 'O')
{
c = getchar();
if (c == 'H') cc = -1;
else if (c == 'F') cc = -4;
}
else if (c == '[')
{
c = getchar();
if (c == 'C') cc = -6;
else if (c == 'D') cc = -7;
else if (('1' <= c) && (c <= '4') && (getchar() == '~'))
cc = -(c - '0');
}
}
else
#endif
if ((c == 8) || (c == 127))
cc = -5;
else if ((c < 0) || (c >= ' '))
cc = ((int)c) & 255;
#ifdef PASSPHRASE_CONTROL
else if (c == 'A' - '@') cc = -1;
else if (c == 'B' - '@') cc = -7;
else if (c == 'D' - '@') cc = -3;
else if (c == 'E' - '@') cc = -4;
else if (c == 'F' - '@') cc = -6;
#endif
if (cc > 0)
{
c = (char)cc;
if (point == len)
{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
xputchar(c);
#pragma GCC diagnostic pop
*(rc + len++) = c;
point++;
}
#ifdef PASSPHRASE_INSERT
else
#ifdef PASSPHRASE_OVERRIDE
if (insert)
#endif
{
if ((c & 0xC0) != 0x80)
{ xprintf("\033[@"); }
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
xputchar(c);
#pragma GCC diagnostic pop
for (i = len; i > point; i--)
*(rc + i) = *(rc + i - 1);
len++;
*(rc + point++) = c;
}
#endif
#ifdef PASSPHRASE_OVERRIDE
else
{
long n = 1;
char cn = c;
while ((*(rc + point + n) & 0xC0) == 0x80)
n++;
for (i = point + n; i < len; i++)
*(rc + i - n) = *(rc + i);
for (i = len - n; i < len; i++)
*(rc + i) = 0;
len -= n;
n = 0;
while (cn & 0x80)
{
cn <<= 1;
n++;
}
n = n ? n : 1;
if (len + n > size)
{
if ((rc = xrealloc(rc, (size_t)size, (size_t)size << 1L)) == NULL)
return NULL;
size <<= 1L;
}
len += n;
for (i = len - 1; i >= point + n; i--)
*(rc + i) = *(rc + i - n);
for (i = 0; i < n; i++)
{
if (i)
c = getchar();
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
xputchar(c);
#pragma GCC diagnostic pop
*(rc + point++) = c;
}
}
#endif
}
else if ((cc == -1) && point) /* home */
{
long n = 0;
for (i = 0; i < point; i++)
if ((*(rc + i) & 0xC0) != 0x80)
n++;
xprintf("\033[%liD", n);
point = 0;
}
#if defined(PASSPHRASE_INSERT) && defined(PASSPHRASE_OVERRIDE)
else if (cc == -2) /* insert */
insert ^= 1;
#endif
#ifdef PASSPHRASE_DELETE
else if ((cc == -3) && (len != point)) /* delete */
{
xprintf("\033[P");
#ifdef PASSPHRASE_INVALID
*(rc + len) = 0;
#endif
do
{
for (i = point; i < len; i++)
*(rc + i) = *(rc + i + 1);
len--;
}
while ((len != point) && ((*(rc + point) & 0xC0) == 0x80));
}
#endif
else if ((cc == -4) && (len != point)) /* end */
{
long n = 0;
for (i = point; i < len; i++)
if ((*(rc + i) & 0xC0) != 0x80)
n++;
xprintf("\033[%liC", n);
point = len;
}
else if ((cc == -5) && point) /* erase */
{
char redo = 1;
xprintf("\033[D\033[P");
#ifdef PASSPHRASE_INVALID
*(rc + len) = 0;
#endif
while (redo)
{
redo = (*(rc + point - 1) & 0xC0) == 0x80;
for (i = point; i <= len; i++)
*(rc + i - 1) = *(rc + i);
point--;
len--;
}
}
else if ((cc == -6) && (len != point)) /* right */
{
xprintf("\033[C");
do
point++;
while ((len != point) && ((*(rc + point) & 0xC0) == 0x80));
}
else if ((cc == -7) && point) /* left */
{
xprintf("\033[D");
point--;
while (point && ((*(rc + point) & 0xC0) == 0x80))
point--;
}
#elif defined(PASSPHRASE_STAR)
if ((c == 8) || (c == 127))
{
if (len == 0)
continue;
xprintf("\033[D \033[D");
xflush();
*(rc + --len) = 0;
#ifdef DEBUG
goto debug;
#else
continue;
#endif
}
if ((c & 0xC0) != 0x80)
fputc('*', stderr);
*(rc + len++) = (char)c;
#else
*(rc + len++) = (char)c;
#endif
xflush();
if (len == size)
{
if ((rc = xrealloc(rc, (size_t)size, (size_t)size << 1)) == NULL)
return NULL;
size <<= 1L;
}
#ifdef DEBUG
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-label"
debug:
{
long n = 0;
for (i = point; i < len; i++)
if ((*(rc + i) & 0xC0) != 0x80)
n++;
*(rc + len) = 0;
if (n)
fprintf(stderr, "\033[s\033[H\033[K%s\033[%liD\033[01;34m%s\033[00m\033[u", rc, n, rc + point);
else
fprintf(stderr, "\033[s\033[H\033[K%s\033[01;34m%s\033[00m\033[u", rc, rc + point);
fflush(stderr);
}
#endif
}
}
/* NUL-terminate passphrase */
*(rc + len) = 0;
#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
fprintf(stderr, "\n");
#endif
return rc;
}
/**
* Disable echoing and do anything else to the terminal settnings `passphrase_read` requires
*/
void passphrase_disable_echo(void)
{
#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
struct termios stty;
tcgetattr(STDIN_FILENO, &stty);
saved_stty = stty;
stty.c_lflag &= (tcflag_t)~ECHO;
#if defined(PASSPHRASE_STAR) || defined(PASSPHRASE_MOVE)
stty.c_lflag &= (tcflag_t)~ICANON;
#endif
tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty);
#endif
}
/**
* Undo the actions of `passphrase_disable_echo`
*/
void passphrase_reenable_echo(void)
{
#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty);
#endif
}
