/* Fake pinentry program for the OpenPGP test suite.
*
* Copyright (C) 2016 g10 code GmbH
*
* This file is part of GnuPG.
*
* GnuPG 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.
*
* GnuPG 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 <https://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
static FILE *log_stream;
static int
reply (const char *fmt, ...)
{
int result;
va_list ap;
if (log_stream)
{
fprintf (log_stream, "> ");
va_start (ap, fmt);
vfprintf (log_stream, fmt, ap);
va_end (ap);
}
va_start (ap, fmt);
result = vprintf (fmt, ap);
va_end (ap);
fflush (stdout);
return result;
}
/* Return the first line from FNAME, removing it from the file. */
static char *
get_passphrase (const char *fname)
{
char *passphrase = NULL;
size_t fname_len;
char *fname_new;
FILE *source, *sink;
char linebuf[80];
fname_len = strlen (fname);
fname_new = malloc (fname_len + 5);
if (fname_new == NULL)
{
perror ("malloc");
exit (1);
}
snprintf (fname_new, fname_len + 5, "%s.new", fname);
source = fopen (fname, "r");
if (! source)
{
perror (fname);
exit (1);
}
sink = fopen (fname_new, "w");
if (! sink)
{
perror (fname_new);
exit (1);
}
while (fgets (linebuf, sizeof linebuf, source))
{
linebuf[sizeof linebuf - 1] = 0;
if (passphrase == NULL)
{
passphrase = strdup (linebuf);
if (passphrase == NULL)
{
perror ("strdup");
exit (1);
}
}
else
fputs (linebuf, sink);
}
if (ferror (source))
{
perror (fname);
exit (1);
}
if (ferror (sink))
{
perror (fname_new);
exit (1);
}
fclose (source);
fclose (sink);
if (remove (fname))
{
fprintf (stderr, "Failed to remove %s: %s",
fname, strerror (errno));
exit (1);
}
if (rename (fname_new, fname))
{
fprintf (stderr, "Failed to rename %s to %s: %s",
fname, fname_new, strerror (errno));
exit (1);
}
free (fname_new);
return passphrase;
}
#define whitespacep(p) (*(p) == ' ' || *(p) == '\t' \
|| *(p) == '\r' || *(p) == '\n')
/* rstrip line. */
static void
rstrip (char *buffer)
{
char *p;
if (!*buffer)
return; /* This is to avoid p = buffer - 1 */
for (p = buffer + strlen (buffer) - 1; p >= buffer; p--)
{
if (! whitespacep (p))
break;
*p = 0;
}
}
/* Skip over options in LINE.
Blanks after the options are also removed. Options are indicated
by two leading dashes followed by a string consisting of non-space
characters. The special option "--" indicates an explicit end of
options; all what follows will not be considered an option. The
first no-option string also indicates the end of option parsing. */
char *
skip_options (const char *line)
{
while (whitespacep (line))
line++;
while (*line == '-' && line[1] == '-')
{
while (*line && !whitespacep (line))
line++;
while (whitespacep (line))
line++;
}
return (char*) line;
}
/* Return a pointer to the argument of the option with NAME. If such
an option is not given, NULL is returned. */
char *
option_value (const char *line, const char *name)
{
char *s;
int n = strlen (name);
s = strstr (line, name);
if (s && s >= skip_options (line))
return NULL;
if (s && (s == line || whitespacep (s-1))
&& s[n] && (whitespacep (s+n) || s[n] == '='))
{
s += n + 1;
s += strspn (s, " ");
if (*s && !whitespacep(s))
return s;
}
return NULL;
}
int
main (int argc, char **argv)
{
char *args;
char *option_user_data = NULL;
int got_environment_user_data;
char *logfile;
char *passphrasefile;
char *passphrase;
/* We get our options via PINENTRY_USER_DATA. */
(void) argc, (void) argv;
setvbuf (stdin, NULL, _IOLBF, BUFSIZ);
setvbuf (stdout, NULL, _IOLBF, BUFSIZ);
args = getenv ("PINENTRY_USER_DATA");
got_environment_user_data = !!args;
if (! args)
args = "";
restart:
logfile = option_value (args, "--logfile");
if (logfile)
{
char *p = logfile, more;
while (*p && ! whitespacep (p))
p++;
more = !! *p;
*p = 0;
args = more ? p+1 : p;
log_stream = fopen (logfile, "a");
if (! log_stream)
{
perror (logfile);
return 1;
}
}
passphrasefile = option_value (args, "--passphrasefile");
if (passphrasefile)
{
char *p = passphrasefile, more;
while (*p && ! whitespacep (p))
p++;
more = !! *p;
*p = 0;
args = more ? p+1 : p;
passphrase = get_passphrase (passphrasefile);
if (! passphrase)
{
reply ("# Passphrasefile '%s' is empty. Terminating.\n",
passphrasefile);
return 1;
}
rstrip (passphrase);
}
else
{
passphrase = skip_options (args);
if (*passphrase == 0)
passphrase = "no PINENTRY_USER_DATA -- using default passphrase";
}
reply ("# fake-pinentry(%u) started. Passphrase='%s'.\n",
(unsigned int)getpid (), passphrase);
reply ("OK - what's up?\n");
while (! feof (stdin))
{
char buffer[1024];
if (fgets (buffer, sizeof buffer, stdin) == NULL)
break;
if (log_stream)
fprintf (log_stream, "< %s", buffer);
rstrip (buffer);
#define OPT_USER_DATA "OPTION pinentry-user-data="
if (strncmp (buffer, "GETPIN", 6) == 0)
reply ("D %s\n", passphrase);
else if (strncmp (buffer, "BYE", 3) == 0)
{
reply ("OK\n");
break;
}
else if (strncmp (buffer, OPT_USER_DATA, strlen (OPT_USER_DATA)) == 0)
{
if (got_environment_user_data)
{
reply ("OK - I already got the data from the environment.\n");
continue;
}
if (log_stream)
fclose (log_stream);
log_stream = NULL;
free (option_user_data);
option_user_data = args = strdup (buffer + strlen (OPT_USER_DATA));
goto restart;
}
reply ("OK\n");
}
#undef OPT_USER_DATA
reply ("# Connection terminated.\n");
if (log_stream)
fclose (log_stream);
free (option_user_data);
return 0;
}