g10/compress.c

   1 /* compress.c - compress filter
   2  * Copyright (C) 1998, 1999, 2000, 2001, 2002,
   3  *               2003, 2006 Free Software Foundation, Inc.
   4  *
   5  * This file is part of GnuPG.
   6  *
   7  * GnuPG is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * GnuPG is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /* Note that the code in compress-bz2.c is nearly identical to the
  22    code here, so if you fix a bug here, look there to see if a
  23    matching bug needs to be fixed.  I tried to have one set of
  24    functions that could do ZIP, ZLIB, and BZIP2, but it became
  25    dangerously unreadable with #ifdefs and if(algo) -dshaw */
  26
  27 #include <config.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <assert.h>
  33 #include <errno.h>
  34 #include <zlib.h>
  35 #if defined(__riscos__) && defined(USE_ZLIBRISCOS)
  36 # include "zlib-riscos.h"
  37 #endif
  38
  39 #include "gpg.h"
  40 #include "util.h"
  41 #include "packet.h"
  42 #include "filter.h"
  43 #include "main.h"
  44 #include "options.h"
  45
  46
  47 #ifdef __riscos__
  48 #define BYTEF_CAST(a) ((Bytef *)(a))
  49 #else
  50 #define BYTEF_CAST(a) (a)
  51 #endif
  52
  53
  54
  55 int compress_filter_bz2( void *opaque, int control,
  56                          IOBUF a, byte *buf, size_t *ret_len);
  57
  58 static void
  59 init_compress( compress_filter_context_t *zfx, z_stream *zs )
  60 {
  61     int rc;
  62     int level;
  63
  64 #if defined(__riscos__) && defined(USE_ZLIBRISCOS)
  65     static int zlib_initialized = 0;
  66
  67     if (!zlib_initialized)
  68         zlib_initialized = riscos_load_module("ZLib", zlib_path, 1);
  69 #endif
  70
  71     if( opt.compress_level >= 1 && opt.compress_level <= 9 )
  72         level = opt.compress_level;
  73     else if( opt.compress_level == -1 )
  74         level = Z_DEFAULT_COMPRESSION;
  75     else {
  76         log_error("invalid compression level; using default level\n");
  77         level = Z_DEFAULT_COMPRESSION;
  78     }
  79
  80     if( (rc = zfx->algo == 1? deflateInit2( zs, level, Z_DEFLATED,
  81                                             -13, 8, Z_DEFAULT_STRATEGY)
  82                             : deflateInit( zs, level )
  83                             ) != Z_OK ) {
  84         log_fatal("zlib problem: %s\n", zs->msg? zs->msg :
  85                                rc == Z_MEM_ERROR ? "out of core" :
  86                                rc == Z_VERSION_ERROR ? "invalid lib version" :
  87                                                        "unknown error" );
  88     }
  89
  90     zfx->outbufsize = 8192;
  91     zfx->outbuf = xmalloc( zfx->outbufsize );
  92 }
  93
  94 static int
  95 do_compress( compress_filter_context_t *zfx, z_stream *zs, int flush, IOBUF a )
  96 {
  97     int rc;
  98     int zrc;
  99     unsigned n;
 100
 101     do {
 102         zs->next_out = BYTEF_CAST (zfx->outbuf);
 103         zs->avail_out = zfx->outbufsize;
 104         if( DBG_FILTER )
 105             log_debug("enter deflate: avail_in=%u, avail_out=%u, flush=%d\n",
 106                     (unsigned)zs->avail_in, (unsigned)zs->avail_out, flush );
 107         zrc = deflate( zs, flush );
 108         if( zrc == Z_STREAM_END && flush == Z_FINISH )
 109             ;
 110         else if( zrc != Z_OK ) {
 111             if( zs->msg )
 112                 log_fatal("zlib deflate problem: %s\n", zs->msg );
 113             else
 114                 log_fatal("zlib deflate problem: rc=%d\n", zrc );
 115         }
 116         n = zfx->outbufsize - zs->avail_out;
 117         if( DBG_FILTER )
 118             log_debug("leave deflate: "
 119                       "avail_in=%u, avail_out=%u, n=%u, zrc=%d\n",
 120                 (unsigned)zs->avail_in, (unsigned)zs->avail_out,
 121                                                (unsigned)n, zrc );
 122
 123         if( (rc=iobuf_write( a, zfx->outbuf, n )) ) {
 124             log_debug("deflate: iobuf_write failed\n");
 125             return rc;
 126         }
 127     } while( zs->avail_in || (flush == Z_FINISH && zrc != Z_STREAM_END) );
 128     return 0;
 129 }
 130
 131 static void
 132 init_uncompress( compress_filter_context_t *zfx, z_stream *zs )
 133 {
 134     int rc;
 135
 136     /****************
 137      * PGP uses a windowsize of 13 bits. Using a negative value for
 138      * it forces zlib not to expect a zlib header.  This is a
 139      * undocumented feature Peter Gutmann told me about.
 140      *
 141      * We must use 15 bits for the inflator because CryptoEx uses 15
 142      * bits thus the output would get scrambled w/o error indication
 143      * if we would use 13 bits.  For the uncompressing this does not
 144      * matter at all.
 145      */
 146     if( (rc = zfx->algo == 1? inflateInit2( zs, -15)
 147                             : inflateInit( zs )) != Z_OK ) {
 148         log_fatal("zlib problem: %s\n", zs->msg? zs->msg :
 149                                rc == Z_MEM_ERROR ? "out of core" :
 150                                rc == Z_VERSION_ERROR ? "invalid lib version" :
 151                                                        "unknown error" );
 152     }
 153
 154     zfx->inbufsize = 2048;
 155     zfx->inbuf = xmalloc( zfx->inbufsize );
 156     zs->avail_in = 0;
 157 }
 158
 159 static int
 160 do_uncompress( compress_filter_context_t *zfx, z_stream *zs,
 161                IOBUF a, size_t *ret_len )
 162 {
 163     int zrc;
 164     int rc=0;
 165     size_t n;
 166     int nread, count;
 167     int refill = !zs->avail_in;
 168
 169     if( DBG_FILTER )
 170         log_debug("begin inflate: avail_in=%u, avail_out=%u, inbuf=%u\n",
 171                 (unsigned)zs->avail_in, (unsigned)zs->avail_out,
 172                 (unsigned)zfx->inbufsize );
 173     do {
 174         if( zs->avail_in < zfx->inbufsize && refill ) {
 175             n = zs->avail_in;
 176             if( !n )
 177             zs->next_in = BYTEF_CAST (zfx->inbuf);
 178             count = zfx->inbufsize - n;
 179             nread = iobuf_read( a, zfx->inbuf + n, count );
 180             if( nread == -1 ) nread = 0;
 181             n += nread;
 182             /* If we use the undocumented feature to suppress
 183              * the zlib header, we have to give inflate an
 184              * extra dummy byte to read */
 185             if( nread < count && zfx->algo == 1 ) {
 186                 *(zfx->inbuf + n) = 0xFF; /* is it really needed ? */
 187                 zfx->algo1hack = 1;
 188                 n++;
 189             }
 190             zs->avail_in = n;
 191         }
 192         refill = 1;
 193         if( DBG_FILTER )
 194             log_debug("enter inflate: avail_in=%u, avail_out=%u\n",
 195                     (unsigned)zs->avail_in, (unsigned)zs->avail_out);
 196         zrc = inflate ( zs, Z_SYNC_FLUSH );
 197         if( DBG_FILTER )
 198             log_debug("leave inflate: avail_in=%u, avail_out=%u, zrc=%d\n",
 199                    (unsigned)zs->avail_in, (unsigned)zs->avail_out, zrc);
 200         if( zrc == Z_STREAM_END )
 201             rc = -1; /* eof */
 202         else if( zrc != Z_OK && zrc != Z_BUF_ERROR ) {
 203             if( zs->msg )
 204                 log_fatal("zlib inflate problem: %s\n", zs->msg );
 205             else
 206                 log_fatal("zlib inflate problem: rc=%d\n", zrc );
 207         }
 208     } while( zs->avail_out && zrc != Z_STREAM_END && zrc != Z_BUF_ERROR );
 209
 210     *ret_len = zfx->outbufsize - zs->avail_out;
 211     if( DBG_FILTER )
 212         log_debug("do_uncompress: returning %u bytes (%u ignored)\n",
 213                   (unsigned int)*ret_len, (unsigned int)zs->avail_in );
 214     return rc;
 215 }
 216
 217 static int
 218 compress_filter( void *opaque, int control,
 219                  IOBUF a, byte *buf, size_t *ret_len)
 220 {
 221     size_t size = *ret_len;
 222     compress_filter_context_t *zfx = opaque;
 223     z_stream *zs = zfx->opaque;
 224     int rc=0;
 225
 226     if( control == IOBUFCTRL_UNDERFLOW ) {
 227         if( !zfx->status ) {
 228             zs = zfx->opaque = xmalloc_clear( sizeof *zs );
 229             init_uncompress( zfx, zs );
 230             zfx->status = 1;
 231         }
 232
 233         zs->next_out = BYTEF_CAST (buf);
 234         zs->avail_out = size;
 235         zfx->outbufsize = size; /* needed only for calculation */
 236         rc = do_uncompress( zfx, zs, a, ret_len );
 237     }
 238     else if( control == IOBUFCTRL_FLUSH ) {
 239         if( !zfx->status ) {
 240             PACKET pkt;
 241             PKT_compressed cd;
 242             if(zfx->algo != COMPRESS_ALGO_ZIP
 243                && zfx->algo != COMPRESS_ALGO_ZLIB)
 244               BUG();
 245             memset( &cd, 0, sizeof cd );
 246             cd.len = 0;
 247             cd.algorithm = zfx->algo;
 248             init_packet( &pkt );
 249             pkt.pkttype = PKT_COMPRESSED;
 250             pkt.pkt.compressed = &cd;
 251             if( build_packet( a, &pkt ))
 252                 log_bug("build_packet(PKT_COMPRESSED) failed\n");
 253             zs = zfx->opaque = xmalloc_clear( sizeof *zs );
 254             init_compress( zfx, zs );
 255             zfx->status = 2;
 256         }
 257
 258         zs->next_in = BYTEF_CAST (buf);
 259         zs->avail_in = size;
 260         rc = do_compress( zfx, zs, Z_NO_FLUSH, a );
 261     }
 262     else if( control == IOBUFCTRL_FREE ) {
 263         if( zfx->status == 1 ) {
 264             inflateEnd(zs);
 265             xfree(zs);
 266             zfx->opaque = NULL;
 267             xfree(zfx->outbuf); zfx->outbuf = NULL;
 268         }
 269         else if( zfx->status == 2 ) {
 270             zs->next_in = BYTEF_CAST (buf);
 271             zs->avail_in = 0;
 272             do_compress( zfx, zs, Z_FINISH, a );
 273             deflateEnd(zs);
 274             xfree(zs);
 275             zfx->opaque = NULL;
 276             xfree(zfx->outbuf); zfx->outbuf = NULL;
 277         }
 278         if (zfx->release)
 279           zfx->release (zfx);
 280     }
 281     else if( control == IOBUFCTRL_DESC )
 282         *(char**)buf = "compress_filter";
 283     return rc;
 284 }
 285
 286
 287 static void
 288 release_context (compress_filter_context_t *ctx)
 289 {
 290   xfree (ctx);
 291 }
 292
 293 /****************
 294  * Handle a compressed packet
 295  */
 296 int
 297 handle_compressed( void *procctx, PKT_compressed *cd,
 298                    int (*callback)(IOBUF, void *), void *passthru )
 299 {
 300     compress_filter_context_t *cfx;
 301     int rc;
 302
 303     if(check_compress_algo(cd->algorithm))
 304       return G10ERR_COMPR_ALGO;
 305     cfx = xmalloc_clear (sizeof *cfx);
 306     cfx->release = release_context;
 307     cfx->algo = cd->algorithm;
 308     push_compress_filter(cd->buf,cfx,cd->algorithm);
 309     if( callback )
 310         rc = callback(cd->buf, passthru );
 311     else
 312         rc = proc_packets(procctx, cd->buf);
 313     cd->buf = NULL;
 314     return rc;
 315 }
 316
 317 void
 318 push_compress_filter(IOBUF out,compress_filter_context_t *zfx,int algo)
 319 {
 320   push_compress_filter2(out,zfx,algo,0);
 321 }
 322
 323 void
 324 push_compress_filter2(IOBUF out,compress_filter_context_t *zfx,
 325                       int algo,int rel)
 326 {
 327   if(algo>=0)
 328     zfx->algo=algo;
 329   else
 330     zfx->algo=DEFAULT_COMPRESS_ALGO;
 331
 332   switch(zfx->algo)
 333     {
 334     case COMPRESS_ALGO_NONE:
 335       break;
 336
 337     case COMPRESS_ALGO_ZIP:
 338     case COMPRESS_ALGO_ZLIB:
 339       iobuf_push_filter2(out,compress_filter,zfx,rel);
 340       break;
 341
 342 #ifdef HAVE_BZIP2
 343     case COMPRESS_ALGO_BZIP2:
 344       iobuf_push_filter2(out,compress_filter_bz2,zfx,rel);
 345       break;
 346 #endif
 347
 348     default:
 349       BUG();
 350     }
 351 }