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/*
* Copyright (C) 2000 Nikos Mavroyanopoulos
*
* This file is part of GNUTLS.
*
* GNUTLS 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.
*
* GNUTLS 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 <defines.h>
#include "gnutls_int.h"
#include "gnutls_compress.h"
#include "gnutls_errors.h"
#include "gnutls_compress_int.h"
#include <zlib.h>
#define MAX_COMP_SIZE 17408 /* 2^14+1024 */
int gnutls_compress( CompressionMethod algorithm, char* plain, int plain_size, char** compressed) {
int compressed_size;
uLongf size;
int err;
switch (algorithm) {
case GNUTLS_COMPRESSION_NULL:
*compressed = gnutls_malloc(plain_size);
memmove(*compressed, plain, plain_size);
compressed_size = plain_size;
break;
#ifdef HAVE_LIBZ
case GNUTLS_ZLIB:
size = (plain_size*1.2)+12;
*compressed=NULL;
do {
size += size;
if (*compressed!=NULL) gnutls_free(*compressed);
*compressed = gnutls_malloc(size);
err = compress( *compressed, &size, plain, plain_size);
} while(err==Z_BUF_ERROR && size <= MAX_COMP_SIZE);
if (err!=Z_OK) {
gnutls_free(*compressed);
return GNUTLS_E_COMPRESSION_FAILED;
}
compressed_size = size;
break;
#endif
default:
*compressed=NULL;
return GNUTLS_E_UNKNOWN_COMPRESSION_ALGORITHM;
}
if (compressed_size > MAX_COMP_SIZE) {
gnutls_free(*compressed);
return GNUTLS_E_COMPRESSION_FAILED;
}
return compressed_size;
}
int gnutls_decompress( CompressionMethod algorithm, char* compressed, int compressed_size, char** plain) {
int plain_size, err;
uLongf size;
if (compressed_size > MAX_COMP_SIZE) return GNUTLS_E_DECOMPRESSION_FAILED;
switch (algorithm) {
case GNUTLS_COMPRESSION_NULL:
*plain = gnutls_malloc(compressed_size);
memmove(*plain, compressed, compressed_size);
plain_size = compressed_size;
break;
#ifdef HAVE_LIBZ
case GNUTLS_ZLIB:
*plain = NULL;
size = compressed_size;
do {
size += compressed_size;
*plain = gnutls_realloc(*plain, size);
err = uncompress( *plain, &size, compressed, compressed_size);
} while( err==Z_BUF_ERROR && size <= MAX_COMP_SIZE);
if (err!=Z_OK) {
gnutls_free(*plain);
return GNUTLS_E_DECOMPRESSION_FAILED;
}
plain_size = size;
break;
#endif
default:
*plain=NULL;
return GNUTLS_E_UNKNOWN_COMPRESSION_ALGORITHM;
}
return plain_size;
}
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