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gnupg/g10/plaintext.c

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/* plaintext.c - process plaintext packets
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
* 2006, 2009, 2010 Free Software Foundation, Inc.
*
* 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 <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/types.h>
#ifdef HAVE_DOSISH_SYSTEM
# include <fcntl.h> /* for setmode() */
#endif
#include "gpg.h"
#include "util.h"
#include "options.h"
#include "packet.h"
#include "ttyio.h"
#include "filter.h"
#include "main.h"
#include "status.h"
#include "i18n.h"
/* Handle a plaintext packet. If MFX is not NULL, update the MDs
* Note: We should have used the filter stuff here, but we have to add
* some easy mimic to set a read limit, so we calculate only the bytes
* from the plaintext. */
int
handle_plaintext (PKT_plaintext * pt, md_filter_context_t * mfx,
int nooutput, int clearsig)
{
char *fname = NULL;
FILE *fp = NULL;
static off_t count = 0;
int rc = 0;
int c;
int convert = (pt->mode == 't' || pt->mode == 'u');
#ifdef __riscos__
int filetype = 0xfff;
#endif
/* Let people know what the plaintext info is. This allows the
receiving program to try and do something different based on the
format code (say, recode UTF-8 to local). */
if (!nooutput && is_status_enabled ())
{
char status[50];
/* Better make sure that stdout has been flushed in case the
output will be written to it. This is to make sure that no
not-yet-flushed stuff will be written after the plaintext
status message. */
fflush (stdout);
snprintf (status, sizeof status,
"%X %lu ", (byte) pt->mode, (ulong) pt->timestamp);
write_status_text_and_buffer (STATUS_PLAINTEXT,
status, pt->name, pt->namelen, 0);
if (!pt->is_partial)
{
sprintf (status, "%lu", (ulong) pt->len);
write_status_text (STATUS_PLAINTEXT_LENGTH, status);
}
}
/* Create the filename as C string. */
if (nooutput)
;
else if (opt.outfp)
{
fname = xstrdup ("[FP]");
}
else if (opt.outfile)
{
fname = xstrdup (opt.outfile);
}
else if (pt->namelen == 8 && !memcmp (pt->name, "_CONSOLE", 8))
{
log_info (_("data not saved; use option \"--output\" to save it\n"));
nooutput = 1;
}
else if (!opt.flags.use_embedded_filename)
{
fname = make_outfile_name (iobuf_get_real_fname (pt->buf));
if (!fname)
fname = ask_outfile_name (pt->name, pt->namelen);
if (!fname)
{
rc = gpg_error (GPG_ERR_GENERAL); /* Can't create file. */
goto leave;
}
}
else
fname = utf8_to_native (pt->name, pt->namelen, 0);
if (nooutput)
;
else if (opt.outfp)
{
fp = opt.outfp;
#ifdef HAVE_DOSISH_SYSTEM
setmode (fileno (fp), O_BINARY);
#endif
}
else if (iobuf_is_pipe_filename (fname) || !*fname)
{
/* No filename or "-" given; write to stdout. */
fp = stdout;
#ifdef HAVE_DOSISH_SYSTEM
setmode (fileno (fp), O_BINARY);
#endif
}
else
{
while (!overwrite_filep (fname))
{
char *tmp = ask_outfile_name (NULL, 0);
if (!tmp || !*tmp)
{
xfree (tmp);
/* FIXME: Below used to be G10ERR_CREATE_FILE */
rc = gpg_error (GPG_ERR_GENERAL);
goto leave;
}
xfree (fname);
fname = tmp;
}
}
#ifndef __riscos__
if (opt.outfp && is_secured_file (fileno (opt.outfp)))
{
rc = gpg_error (GPG_ERR_EPERM);
log_error (_("error creating `%s': %s\n"), fname, gpg_strerror (rc));
goto leave;
}
else if (fp || nooutput)
;
else if (is_secured_filename (fname))
{
gpg_err_set_errno (EPERM);
rc = gpg_error_from_syserror ();
log_error (_("error creating `%s': %s\n"), fname, strerror (errno));
goto leave;
}
else if (!(fp = fopen (fname, "wb")))
{
rc = gpg_error_from_syserror ();
log_error (_("error creating `%s': %s\n"), fname, strerror (errno));
goto leave;
}
#else /* __riscos__ */
/* If no output filename was given, i.e. we constructed it, convert
all '.' in fname to '/' but not vice versa as we don't create
directories! */
if (!opt.outfile)
for (c = 0; fname[c]; ++c)
if (fname[c] == '.')
fname[c] = '/';
if (fp || nooutput)
;
else
{
fp = fopen (fname, "wb");
if (!fp)
{
log_error (_("error creating `%s': %s\n"), fname, strerror (errno));
rc = G10ERR_CREATE_FILE;
if (errno == 106)
log_info ("Do output file and input file have the same name?\n");
goto leave;
}
/* If there's a ,xxx extension in the embedded filename,
use that, else check whether the user input (in fname)
has a ,xxx appended, then use that in preference */
if ((c = riscos_get_filetype_from_string (pt->name, pt->namelen)) != -1)
filetype = c;
if ((c = riscos_get_filetype_from_string (fname, strlen (fname))) != -1)
filetype = c;
riscos_set_filetype_by_number (fname, filetype);
}
#endif /* __riscos__ */
if (!pt->is_partial)
{
/* We have an actual length (which might be zero). */
if (clearsig)
{
log_error ("clearsig encountered while not expected\n");
rc = G10ERR_UNEXPECTED;
goto leave;
}
if (convert) /* Text mode. */
{
for (; pt->len; pt->len--)
{
if ((c = iobuf_get (pt->buf)) == -1)
{
rc = gpg_error_from_syserror ();
log_error ("problem reading source (%u bytes remaining)\n",
(unsigned) pt->len);
goto leave;
}
if (mfx->md)
gcry_md_putc (mfx->md, c);
#ifndef HAVE_DOSISH_SYSTEM
if (c == '\r') /* convert to native line ending */
continue; /* fixme: this hack might be too simple */
#endif
if (fp)
{
if (opt.max_output && (++count) > opt.max_output)
{
log_error ("error writing to `%s': %s\n",
fname, "exceeded --max-output limit\n");
rc = gpg_error (GPG_ERR_TOO_LARGE);
goto leave;
}
else if (putc (c, fp) == EOF)
{
if (ferror (fp))
rc = gpg_error_from_syserror ();
else
rc = gpg_error (GPG_ERR_EOF);
log_error ("error writing to `%s': %s\n",
fname, strerror (errno));
goto leave;
}
}
}
}
else /* Binary mode. */
{
byte *buffer = xmalloc (32768);
while (pt->len)
{
int len = pt->len > 32768 ? 32768 : pt->len;
len = iobuf_read (pt->buf, buffer, len);
if (len == -1)
{
rc = gpg_error_from_syserror ();
log_error ("problem reading source (%u bytes remaining)\n",
(unsigned) pt->len);
xfree (buffer);
goto leave;
}
if (mfx->md)
gcry_md_write (mfx->md, buffer, len);
if (fp)
{
if (opt.max_output && (count += len) > opt.max_output)
{
log_error ("error writing to `%s': %s\n",
fname, "exceeded --max-output limit\n");
rc = gpg_error (GPG_ERR_TOO_LARGE);
xfree (buffer);
goto leave;
}
else if (fwrite (buffer, 1, len, fp) != len)
{
rc = gpg_error_from_syserror ();
log_error ("error writing to `%s': %s\n",
fname, strerror (errno));
xfree (buffer);
goto leave;
}
}
pt->len -= len;
}
xfree (buffer);
}
}
else if (!clearsig)
{
if (convert)
{ /* text mode */
while ((c = iobuf_get (pt->buf)) != -1)
{
if (mfx->md)
gcry_md_putc (mfx->md, c);
#ifndef HAVE_DOSISH_SYSTEM
if (convert && c == '\r')
continue; /* fixme: this hack might be too simple */
#endif
if (fp)
{
if (opt.max_output && (++count) > opt.max_output)
{
log_error ("Error writing to `%s': %s\n",
fname, "exceeded --max-output limit\n");
rc = gpg_error (GPG_ERR_TOO_LARGE);
goto leave;
}
else if (putc (c, fp) == EOF)
{
if (ferror (fp))
rc = gpg_error_from_syserror ();
else
rc = gpg_error (GPG_ERR_EOF);
log_error ("error writing to `%s': %s\n",
fname, strerror (errno));
goto leave;
}
}
}
}
else
{ /* binary mode */
byte *buffer = xmalloc (32768);
int eof_seen = 0;
while (!eof_seen)
{
/* Why do we check for len < 32768:
* If we won't, we would practically read 2 EOFs but
* the first one has already popped the block_filter
* off and therefore we don't catch the boundary.
* So, always assume EOF if iobuf_read returns less bytes
* then requested */
int len = iobuf_read (pt->buf, buffer, 32768);
if (len == -1)
break;
if (len < 32768)
eof_seen = 1;
if (mfx->md)
gcry_md_write (mfx->md, buffer, len);
if (fp)
{
if (opt.max_output && (count += len) > opt.max_output)
{
log_error ("error writing to `%s': %s\n",
fname, "exceeded --max-output limit\n");
rc = gpg_error (GPG_ERR_TOO_LARGE);
xfree (buffer);
goto leave;
}
else if (fwrite (buffer, 1, len, fp) != len)
{
rc = (errno ? gpg_error_from_syserror ()
: gpg_error (GPG_ERR_INTERNAL));
log_error ("error writing to `%s': %s\n",
fname, strerror (errno));
xfree (buffer);
goto leave;
}
}
}
xfree (buffer);
}
pt->buf = NULL;
}
else /* Clear text signature - don't hash the last CR,LF. */
{
int state = 0;
while ((c = iobuf_get (pt->buf)) != -1)
{
if (fp)
{
if (opt.max_output && (++count) > opt.max_output)
{
log_error ("error writing to `%s': %s\n",
fname, "exceeded --max-output limit\n");
rc = gpg_error (GPG_ERR_TOO_LARGE);
goto leave;
}
else if (putc (c, fp) == EOF)
{
rc = (errno ? gpg_error_from_syserror ()
: gpg_error (GPG_ERR_INTERNAL));
log_error ("error writing to `%s': %s\n",
fname, strerror (errno));
goto leave;
}
}
if (!mfx->md)
continue;
if (state == 2)
{
gcry_md_putc (mfx->md, '\r');
gcry_md_putc (mfx->md, '\n');
state = 0;
}
if (!state)
{
if (c == '\r')
state = 1;
else if (c == '\n')
state = 2;
else
gcry_md_putc (mfx->md, c);
}
else if (state == 1)
{
if (c == '\n')
state = 2;
else
{
gcry_md_putc (mfx->md, '\r');
if (c == '\r')
state = 1;
else
{
state = 0;
gcry_md_putc (mfx->md, c);
}
}
}
}
pt->buf = NULL;
}
if (fp && fp != stdout && fp != opt.outfp && fclose (fp))
{
rc = (errno ? gpg_error_from_syserror ()
: gpg_error (GPG_ERR_INTERNAL));
log_error ("error closing `%s': %s\n", fname, strerror (errno));
fp = NULL;
goto leave;
}
fp = NULL;
leave:
/* Make sure that stdout gets flushed after the plaintext has been
handled. This is for extra security as we do a flush anyway
before checking the signature. */
if (fflush (stdout))
{
/* We need to check the return code to detect errors like disk
full for short plaintexts. See bug#1207. Checking return
values is a good idea in any case. */
if (!rc)
rc = gpg_error_from_syserror ();
log_error ("error flushing `%s': %s\n", "[stdout]", strerror (errno));
}
if (fp && fp != stdout && fp != opt.outfp)
fclose (fp);
xfree (fname);
return rc;
}
static void
do_hash (gcry_md_hd_t md, gcry_md_hd_t md2, IOBUF fp, int textmode)
{
text_filter_context_t tfx;
int c;
if (textmode)
{
memset (&tfx, 0, sizeof tfx);
iobuf_push_filter (fp, text_filter, &tfx);
}
if (md2)
{ /* work around a strange behaviour in pgp2 */
/* It seems that at least PGP5 converts a single CR to a CR,LF too */
int lc = -1;
while ((c = iobuf_get (fp)) != -1)
{
if (c == '\n' && lc == '\r')
gcry_md_putc (md2, c);
else if (c == '\n')
{
gcry_md_putc (md2, '\r');
gcry_md_putc (md2, c);
}
else if (c != '\n' && lc == '\r')
{
gcry_md_putc (md2, '\n');
gcry_md_putc (md2, c);
}
else
gcry_md_putc (md2, c);
if (md)
gcry_md_putc (md, c);
lc = c;
}
}
else
{
while ((c = iobuf_get (fp)) != -1)
{
if (md)
gcry_md_putc (md, c);
}
}
}
/****************
* Ask for the detached datafile and calculate the digest from it.
* INFILE is the name of the input file.
*/
int
ask_for_detached_datafile (gcry_md_hd_t md, gcry_md_hd_t md2,
const char *inname, int textmode)
{
progress_filter_context_t *pfx;
char *answer = NULL;
IOBUF fp;
int rc = 0;
pfx = new_progress_context ();
fp = open_sigfile (inname, pfx); /* Open default file. */
if (!fp && !opt.batch)
{
int any = 0;
tty_printf (_("Detached signature.\n"));
do
{
char *name;
xfree (answer);
tty_enable_completion (NULL);
name = cpr_get ("detached_signature.filename",
_("Please enter name of data file: "));
tty_disable_completion ();
cpr_kill_prompt ();
answer = make_filename (name, (void *) NULL);
xfree (name);
if (any && !*answer)
{
rc = gpg_error (GPG_ERR_GENERAL); /*G10ERR_READ_FILE */
goto leave;
}
fp = iobuf_open (answer);
if (fp && is_secured_file (iobuf_get_fd (fp)))
{
iobuf_close (fp);
fp = NULL;
gpg_err_set_errno (EPERM);
}
if (!fp && errno == ENOENT)
{
tty_printf ("No such file, try again or hit enter to quit.\n");
any++;
}
else if (!fp)
{
rc = gpg_error_from_syserror ();
log_error (_("can't open `%s': %s\n"), answer,
strerror (errno));
goto leave;
}
}
while (!fp);
}
if (!fp)
{
if (opt.verbose)
log_info (_("reading stdin ...\n"));
fp = iobuf_open (NULL);
assert (fp);
}
do_hash (md, md2, fp, textmode);
iobuf_close (fp);
leave:
xfree (answer);
release_progress_context (pfx);
return rc;
}
/****************
* Hash the given files and append the hash to hash context md.
* If FILES is NULL, hash stdin.
*/
int
hash_datafiles (gcry_md_hd_t md, gcry_md_hd_t md2, strlist_t files,
const char *sigfilename, int textmode)
{
progress_filter_context_t *pfx;
IOBUF fp;
strlist_t sl;
pfx = new_progress_context ();
if (!files)
{
/* check whether we can open the signed material */
fp = open_sigfile (sigfilename, pfx);
if (fp)
{
do_hash (md, md2, fp, textmode);
iobuf_close (fp);
release_progress_context (pfx);
return 0;
}
log_error (_("no signed data\n"));
release_progress_context (pfx);
return gpg_error (GPG_ERR_NO_DATA);
}
for (sl = files; sl; sl = sl->next)
{
fp = iobuf_open (sl->d);
if (fp && is_secured_file (iobuf_get_fd (fp)))
{
iobuf_close (fp);
fp = NULL;
gpg_err_set_errno (EPERM);
}
if (!fp)
{
int rc = gpg_error_from_syserror ();
log_error (_("can't open signed data `%s'\n"),
print_fname_stdin (sl->d));
release_progress_context (pfx);
return rc;
}
handle_progress (pfx, fp, sl->d);
do_hash (md, md2, fp, textmode);
iobuf_close (fp);
}
release_progress_context (pfx);
return 0;
}
/* Hash the data from file descriptor DATA_FD and append the hash to hash
contexts MD and MD2. */
int
hash_datafile_by_fd (gcry_md_hd_t md, gcry_md_hd_t md2, int data_fd,
int textmode)
{
progress_filter_context_t *pfx = new_progress_context ();
iobuf_t fp;
if (is_secured_file (data_fd))
{
fp = NULL;
gpg_err_set_errno (EPERM);
}
else
fp = iobuf_fdopen_nc (data_fd, "rb");
if (!fp)
{
int rc = gpg_error_from_syserror ();
log_error (_("can't open signed data fd=%d: %s\n"),
data_fd, strerror (errno));
release_progress_context (pfx);
return rc;
}
handle_progress (pfx, fp, NULL);
do_hash (md, md2, fp, textmode);
iobuf_close (fp);
release_progress_context (pfx);
return 0;
}
/* Set up a plaintext packet with the appropriate filename. If there
is a --set-filename, use it (it's already UTF8). If there is a
regular filename, UTF8-ize it if necessary. If there is no
filenames at all, set the field empty. */
PKT_plaintext *
setup_plaintext_name (const char *filename, IOBUF iobuf)
{
PKT_plaintext *pt;
if ((filename && !iobuf_is_pipe_filename (filename))
|| (opt.set_filename && !iobuf_is_pipe_filename (opt.set_filename)))
{
char *s;
if (opt.set_filename)
s = make_basename (opt.set_filename, iobuf_get_real_fname (iobuf));
else if (filename && !opt.flags.utf8_filename)
{
char *tmp = native_to_utf8 (filename);
s = make_basename (tmp, iobuf_get_real_fname (iobuf));
xfree (tmp);
}
else
s = make_basename (filename, iobuf_get_real_fname (iobuf));
pt = xmalloc (sizeof *pt + strlen (s) - 1);
pt->namelen = strlen (s);
memcpy (pt->name, s, pt->namelen);
xfree (s);
}
else
{
/* no filename */
pt = xmalloc (sizeof *pt - 1);
pt->namelen = 0;
}
return pt;
}
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