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gnupg/g10/compress.c

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/* compress.c - compress filter
* Copyright (C) 1998, 1999, 2000, 2001, 2002,
* 2003, 2006, 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 <https://www.gnu.org/licenses/>.
*/
/* Note that the code in compress-bz2.c is nearly identical to the
code here, so if you fix a bug here, look there to see if a
matching bug needs to be fixed. I tried to have one set of
functions that could do ZIP, ZLIB, and BZIP2, but it became
dangerously unreadable with #ifdefs and if(algo) -dshaw */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#ifdef HAVE_ZIP
# include <zlib.h>
#endif
#include "gpg.h"
#include "../common/util.h"
#include "packet.h"
#include "filter.h"
#include "main.h"
#include "options.h"
#ifdef __riscos__
#define BYTEF_CAST(a) ((Bytef *)(a))
#else
#define BYTEF_CAST(a) (a)
#endif
int compress_filter_bz2( void *opaque, int control,
IOBUF a, byte *buf, size_t *ret_len);
#ifdef HAVE_ZIP
static void
init_compress( compress_filter_context_t *zfx, z_stream *zs )
{
int rc;
int level;
if( opt.compress_level >= 1 && opt.compress_level <= 9 )
level = opt.compress_level;
else if( opt.compress_level == -1 )
level = Z_DEFAULT_COMPRESSION;
else {
log_error("invalid compression level; using default level\n");
level = Z_DEFAULT_COMPRESSION;
}
if( (rc = zfx->algo == 1? deflateInit2( zs, level, Z_DEFLATED,
-13, 8, Z_DEFAULT_STRATEGY)
: deflateInit( zs, level )
) != Z_OK ) {
log_error ("zlib problem: %s\n", zs->msg? zs->msg :
rc == Z_MEM_ERROR ? "out of core" :
rc == Z_VERSION_ERROR ? "invalid lib version" :
"unknown error" );
write_status_error ("zlib.init", gpg_error (GPG_ERR_INTERNAL));
g10_exit (2);
}
zfx->outbufsize = 8192;
zfx->outbuf = xmalloc( zfx->outbufsize );
}
static int
do_compress( compress_filter_context_t *zfx, z_stream *zs, int flush, IOBUF a )
{
int rc;
int zrc;
unsigned n;
if (flush == Z_NO_FLUSH && zs->avail_in == 0)
return 0;
do {
zs->next_out = BYTEF_CAST (zfx->outbuf);
zs->avail_out = zfx->outbufsize;
if( DBG_FILTER )
log_debug("enter deflate: avail_in=%u, avail_out=%u, flush=%d\n",
(unsigned)zs->avail_in, (unsigned)zs->avail_out, flush );
zrc = deflate( zs, flush );
if( zrc == Z_STREAM_END && flush == Z_FINISH )
;
else if( zrc != Z_OK ) {
if( zs->msg )
log_error ("zlib deflate problem: %s\n", zs->msg );
else
log_error ("zlib deflate problem: rc=%d\n", zrc );
write_status_error ("zlib.deflate", gpg_error (GPG_ERR_INTERNAL));
g10_exit (2);
}
n = zfx->outbufsize - zs->avail_out;
if( DBG_FILTER )
log_debug("leave deflate: "
"avail_in=%u, avail_out=%u, n=%u, zrc=%d\n",
(unsigned)zs->avail_in, (unsigned)zs->avail_out,
(unsigned)n, zrc );
if( (rc=iobuf_write( a, zfx->outbuf, n )) ) {
log_error ("deflate: iobuf_write failed\n");
return rc;
}
} while( zs->avail_in || (flush == Z_FINISH && zrc != Z_STREAM_END) );
return 0;
}
static void
init_uncompress( compress_filter_context_t *zfx, z_stream *zs )
{
int rc;
/****************
* PGP uses a windowsize of 13 bits. Using a negative value for
* it forces zlib not to expect a zlib header. This is a
* undocumented feature Peter Gutmann told me about.
*
* We must use 15 bits for the inflator because CryptoEx uses 15
* bits thus the output would get scrambled w/o error indication
* if we would use 13 bits. For the uncompressing this does not
* matter at all.
*/
if( (rc = zfx->algo == 1? inflateInit2( zs, -15)
: inflateInit( zs )) != Z_OK ) {
log_error ("zlib problem: %s\n", zs->msg? zs->msg :
rc == Z_MEM_ERROR ? "out of core" :
rc == Z_VERSION_ERROR ? "invalid lib version" :
"unknown error" );
write_status_error ("zlib.init.un", gpg_error (GPG_ERR_INTERNAL));
g10_exit (2);
}
zfx->inbufsize = 2048;
zfx->inbuf = xmalloc( zfx->inbufsize );
zs->avail_in = 0;
}
static int
do_uncompress( compress_filter_context_t *zfx, z_stream *zs,
IOBUF a, size_t *ret_len )
{
int zrc;
int rc = 0;
int leave = 0;
size_t n;
int nread, count;
int refill = !zs->avail_in;
if( DBG_FILTER )
log_debug("begin inflate: avail_in=%u, avail_out=%u, inbuf=%u\n",
(unsigned)zs->avail_in, (unsigned)zs->avail_out,
(unsigned)zfx->inbufsize );
do {
if( zs->avail_in < zfx->inbufsize && refill ) {
n = zs->avail_in;
if( !n )
zs->next_in = BYTEF_CAST (zfx->inbuf);
count = zfx->inbufsize - n;
nread = iobuf_read( a, zfx->inbuf + n, count );
if( nread == -1 ) nread = 0;
n += nread;
/* Algo 1 has no zlib header which requires us to give
* inflate an extra dummy byte to read. To be on the safe
* side we allow for up to 4 ff bytes. */
if( nread < count && zfx->algo == 1 && zfx->algo1hack < 4) {
*(zfx->inbuf + n) = 0xFF;
zfx->algo1hack++;
n++;
leave = 1;
}
zs->avail_in = n;
}
refill = 1;
if( DBG_FILTER )
log_debug("enter inflate: avail_in=%u, avail_out=%u\n",
(unsigned)zs->avail_in, (unsigned)zs->avail_out);
zrc = inflate ( zs, Z_SYNC_FLUSH );
if( DBG_FILTER )
log_debug("leave inflate: avail_in=%u, avail_out=%u, zrc=%d\n",
(unsigned)zs->avail_in, (unsigned)zs->avail_out, zrc);
if( zrc == Z_STREAM_END )
rc = -1; /* eof */
else if( zrc != Z_OK && zrc != Z_BUF_ERROR ) {
if( zs->msg )
log_error ("zlib inflate problem: %s\n", zs->msg );
else
log_error ("zlib inflate problem: rc=%d\n", zrc );
write_status_error ("zlib.inflate", gpg_error (GPG_ERR_BAD_DATA));
g10_exit (2);
}
} while (zs->avail_out && zrc != Z_STREAM_END && zrc != Z_BUF_ERROR
&& !leave);
*ret_len = zfx->outbufsize - zs->avail_out;
if( DBG_FILTER )
log_debug("do_uncompress: returning %u bytes (%u ignored)\n",
(unsigned int)*ret_len, (unsigned int)zs->avail_in );
return rc;
}
static int
compress_filter( void *opaque, int control,
IOBUF a, byte *buf, size_t *ret_len)
{
size_t size = *ret_len;
compress_filter_context_t *zfx = opaque;
z_stream *zs = zfx->opaque;
int rc=0;
if( control == IOBUFCTRL_UNDERFLOW ) {
if( !zfx->status ) {
zs = zfx->opaque = xmalloc_clear( sizeof *zs );
init_uncompress( zfx, zs );
zfx->status = 1;
}
zs->next_out = BYTEF_CAST (buf);
zs->avail_out = size;
zfx->outbufsize = size; /* needed only for calculation */
rc = do_uncompress( zfx, zs, a, ret_len );
}
else if( control == IOBUFCTRL_FLUSH ) {
if( !zfx->status ) {
PACKET pkt;
PKT_compressed cd;
if(zfx->algo != COMPRESS_ALGO_ZIP
&& zfx->algo != COMPRESS_ALGO_ZLIB)
BUG();
memset( &cd, 0, sizeof cd );
cd.len = 0;
cd.algorithm = zfx->algo;
/* Fixme: We should force a new CTB here:
cd.new_ctb = zfx->new_ctb;
*/
init_packet( &pkt );
pkt.pkttype = PKT_COMPRESSED;
pkt.pkt.compressed = &cd;
if( build_packet( a, &pkt ))
log_bug("build_packet(PKT_COMPRESSED) failed\n");
zs = zfx->opaque = xmalloc_clear( sizeof *zs );
init_compress( zfx, zs );
zfx->status = 2;
}
zs->next_in = BYTEF_CAST (buf);
zs->avail_in = size;
rc = do_compress( zfx, zs, Z_NO_FLUSH, a );
}
else if( control == IOBUFCTRL_FREE ) {
if( zfx->status == 1 ) {
inflateEnd(zs);
xfree(zs);
zfx->opaque = NULL;
xfree(zfx->outbuf); zfx->outbuf = NULL;
}
else if( zfx->status == 2 ) {
zs->next_in = BYTEF_CAST (buf);
zs->avail_in = 0;
do_compress( zfx, zs, Z_FINISH, a );
deflateEnd(zs);
xfree(zs);
zfx->opaque = NULL;
xfree(zfx->outbuf); zfx->outbuf = NULL;
}
if (zfx->release)
zfx->release (zfx);
}
else if( control == IOBUFCTRL_DESC )
mem2str (buf, "compress_filter", *ret_len);
return rc;
}
#endif /*HAVE_ZIP*/
static void
release_context (compress_filter_context_t *ctx)
{
xfree(ctx->inbuf);
ctx->inbuf = NULL;
xfree(ctx->outbuf);
ctx->outbuf = NULL;
xfree (ctx);
}
/****************
* Handle a compressed packet
*/
int
handle_compressed (ctrl_t ctrl, void *procctx, PKT_compressed *cd,
int (*callback)(IOBUF, void *), void *passthru )
{
int rc;
if(check_compress_algo(cd->algorithm))
return GPG_ERR_COMPR_ALGO;
if(cd->algorithm) {
compress_filter_context_t *cfx;
cfx = xmalloc_clear (sizeof *cfx);
cfx->release = release_context;
cfx->algo = cd->algorithm;
if (push_compress_filter(cd->buf, cfx, cd->algorithm))
xfree (cfx);
}
if( callback )
rc = callback(cd->buf, passthru );
else
rc = proc_packets (ctrl,procctx, cd->buf);
cd->buf = NULL;
return rc;
}
gpg_error_t
push_compress_filter(IOBUF out,compress_filter_context_t *zfx,int algo)
{
return push_compress_filter2(out,zfx,algo,0);
}
/* Push a compress filter and return 0 if that succeeded. */
gpg_error_t
push_compress_filter2(IOBUF out,compress_filter_context_t *zfx,
int algo,int rel)
{
gpg_error_t err = gpg_error (GPG_ERR_FALSE);
if(algo>=0)
zfx->algo=algo;
else
zfx->algo=DEFAULT_COMPRESS_ALGO;
switch(zfx->algo)
{
case COMPRESS_ALGO_NONE:
break;
#ifdef HAVE_ZIP
case COMPRESS_ALGO_ZIP:
case COMPRESS_ALGO_ZLIB:
iobuf_push_filter2(out,compress_filter,zfx,rel);
err = 0;
break;
#endif
#ifdef HAVE_BZIP2
case COMPRESS_ALGO_BZIP2:
iobuf_push_filter2(out,compress_filter_bz2,zfx,rel);
err = 0;
break;
#endif
default:
BUG();
}
return err;
}
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