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mirror of git://git.gnupg.org/gnupg.git synced 2024-12-23 10:29:58 +01:00
gnupg/g10/compress.c
Werner Koch 5dfd5a6dac * pkclist.c (do_we_trust_pre): Changed the wording of a warning.
* encode.c (encode_simple,encode_crypt): Use new style CTB for
compressssed packets when using MDC.  We need to do this so that
concatenated messages are properly decrypted.  Old style
compression assumes that it is the last packet; given that we
can't determine the length in advance, the uncompressor does not
know where to start.  Actually we should use the new CTB always
but this would break PGP 2 compatibility.
* parse-packet.c (parse): Special treatment for new style CTB
compressed packets.

* build-packet.c (do_mdc): Removed. Was not used.
(do_encrypted_mdc): Count the version number and the MDC packet.
2002-08-30 16:34:13 +00:00

311 lines
8.3 KiB
C

/* compress.c - compress filter
* Copyright (C) 1998, 1999, 2000, 2001, 2002 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <zlib.h>
#include "util.h"
#include "memory.h"
#include "packet.h"
#include "filter.h"
#include "main.h"
#include "options.h"
static void
init_compress( compress_filter_context_t *zfx, z_stream *zs )
{
int rc;
int level;
if( opt.compress >= 0 && opt.compress <= 9 )
level = opt.compress;
else if( opt.compress == -1 )
level = Z_DEFAULT_COMPRESSION;
else if( opt.compress == 10 ) /* remove this ! */
level = 0;
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_fatal("zlib problem: %s\n", zs->msg? zs->msg :
rc == Z_MEM_ERROR ? "out of core" :
rc == Z_VERSION_ERROR ? "invalid lib version" :
"unknown error" );
}
zfx->outbufsize = 8192;
zfx->outbuf = m_alloc( zfx->outbufsize );
}
static int
do_compress( compress_filter_context_t *zfx, z_stream *zs, int flush, IOBUF a )
{
int zrc;
unsigned n;
do {
#ifndef __riscos__
zs->next_out = zfx->outbuf;
#else /* __riscos__ */
zs->next_out = (Bytef *) zfx->outbuf;
#endif /* __riscos__ */
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_fatal("zlib deflate problem: %s\n", zs->msg );
else
log_fatal("zlib deflate problem: rc=%d\n", zrc );
}
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( iobuf_write( a, zfx->outbuf, n ) ) {
log_debug("deflate: iobuf_write failed\n");
return G10ERR_WRITE_FILE;
}
} 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.
*/
if( (rc = zfx->algo == 1? inflateInit2( zs, -13)
: inflateInit( zs )) != Z_OK ) {
log_fatal("zlib problem: %s\n", zs->msg? zs->msg :
rc == Z_MEM_ERROR ? "out of core" :
rc == Z_VERSION_ERROR ? "invalid lib version" :
"unknown error" );
}
zfx->inbufsize = 2048;
zfx->inbuf = m_alloc( 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;
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 )
#ifndef __riscos__
zs->next_in = zfx->inbuf;
#else /* __riscos__ */
zs->next_in = (Bytef *) zfx->inbuf;
#endif /* __riscos__ */
count = zfx->inbufsize - n;
nread = iobuf_read( a, zfx->inbuf + n, count );
if( nread == -1 ) nread = 0;
n += nread;
/* If we use the undocumented feature to suppress
* the zlib header, we have to give inflate an
* extra dummy byte to read */
if( nread < count && zfx->algo == 1 ) {
*(zfx->inbuf + n) = 0xFF; /* is it really needed ? */
zfx->algo1hack = 1;
n++;
}
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);
#ifdef Z_SYNC_FLUSH
zrc = inflate( zs, Z_SYNC_FLUSH );
#else
zrc = inflate( zs, Z_PARTIAL_FLUSH );
#endif
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_fatal("zlib inflate problem: %s\n", zs->msg );
else
log_fatal("zlib inflate problem: rc=%d\n", zrc );
}
} while( zs->avail_out && zrc != Z_STREAM_END && zrc != Z_BUF_ERROR );
*ret_len = zfx->outbufsize - zs->avail_out;
if( DBG_FILTER )
log_debug("do_uncompress: returning %u bytes\n", (unsigned)*ret_len );
return rc;
}
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 = m_alloc_clear( sizeof *zs );
init_uncompress( zfx, zs );
zfx->status = 1;
}
#ifndef __riscos__
zs->next_out = buf;
#else /* __riscos__ */
zs->next_out = (Bytef *) buf;
#endif /* __riscos__ */
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 )
zfx->algo = DEFAULT_COMPRESS_ALGO;
if( zfx->algo != 1 && zfx->algo != 2 )
BUG();
memset( &cd, 0, sizeof cd );
cd.len = 0;
cd.algorithm = zfx->algo;
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 = m_alloc_clear( sizeof *zs );
init_compress( zfx, zs );
zfx->status = 2;
}
#ifndef __riscos__
zs->next_in = buf;
#else /* __riscos__ */
zs->next_in = (Bytef *) buf;
#endif /* __riscos__ */
zs->avail_in = size;
rc = do_compress( zfx, zs, Z_NO_FLUSH, a );
}
else if( control == IOBUFCTRL_FREE ) {
if( zfx->status == 1 ) {
inflateEnd(zs);
m_free(zs);
zfx->opaque = NULL;
m_free(zfx->outbuf); zfx->outbuf = NULL;
}
else if( zfx->status == 2 ) {
#ifndef __riscos__
zs->next_in = buf;
#else /* __riscos__ */
zs->next_in = (Bytef *) buf;
#endif /* __riscos__ */
zs->avail_in = 0;
do_compress( zfx, zs, Z_FINISH, a );
deflateEnd(zs);
m_free(zs);
zfx->opaque = NULL;
m_free(zfx->outbuf); zfx->outbuf = NULL;
}
if (zfx->release)
zfx->release (zfx);
}
else if( control == IOBUFCTRL_DESC )
*(char**)buf = "compress_filter";
return rc;
}
static void
release_context (compress_filter_context_t *ctx)
{
m_free (ctx);
}
/****************
* Handle a compressed packet
*/
int
handle_compressed( void *procctx, PKT_compressed *cd,
int (*callback)(IOBUF, void *), void *passthru )
{
compress_filter_context_t *cfx;
int rc;
if( cd->algorithm < 1 || cd->algorithm > 2 )
return G10ERR_COMPR_ALGO;
cfx = m_alloc_clear (sizeof *cfx);
cfx->algo = cd->algorithm;
cfx->release = release_context;
iobuf_push_filter( cd->buf, compress_filter, cfx );
if( callback )
rc = callback(cd->buf, passthru );
else
rc = proc_packets(procctx, cd->buf);
cd->buf = NULL;
return rc;
}