Mercurial > libpst
diff lzfu.c @ 0:6b1b602514db libpst_0_5
Initial revision
author | carl |
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date | Fri, 09 Jul 2004 07:26:16 -0700 |
parents | |
children | 43e8802f08c5 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lzfu.c Fri Jul 09 07:26:16 2004 -0700 @@ -0,0 +1,125 @@ + /* + This program 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. + + 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 "define.h" +#include "libpst.h" +#include <sys/types.h> +#include <string.h> +#include <stdio.h> + +#ifndef _MSC_VER +#include <stdint.h> +#endif + +#ifdef _MSC_VER +#define uint32_t unsigned int +#endif + +#define LZFU_COMPRESSED 0x75465a4c +#define LZFU_UNCOMPRESSED 0x414c454d + +// initital dictionary +#define LZFU_INITDICT "{\\rtf1\\ansi\\mac\\deff0\\deftab720{\\fonttbl;}" \ + "{\\f0\\fnil \\froman \\fswiss \\fmodern \\fscrip" \ + "t \\fdecor MS Sans SerifSymbolArialTimes Ne" \ + "w RomanCourier{\\colortbl\\red0\\green0\\blue0" \ + "\r\n\\par \\pard\\plain\\f0\\fs20\\b\\i\\u\\tab" \ + "\\tx" +// initial length of dictionary +#define LZFU_INITLENGTH 207 + +// header for compressed rtf +typedef struct _lzfuheader { + uint32_t cbSize; + uint32_t cbRawSize; + uint32_t dwMagic; + uint32_t dwCRC; +} lzfuheader; + + +/** + We always need to add 0x10 to the buffer offset because we need to skip past the header info +*/ + +unsigned char* lzfu_decompress (unsigned char* rtfcomp) { + // the dictionary buffer + unsigned char dict[4096]; + // the dictionary pointer + unsigned int dict_length=0; + // the header of the lzfu block + lzfuheader lzfuhdr; + // container for the data blocks + unsigned char flags; + // temp value for determining the bits in the flag + unsigned char flag_mask; + unsigned int i, in_size; + unsigned char *out_buf; + unsigned int out_ptr = 0; + + memcpy(dict, LZFU_INITDICT, LZFU_INITLENGTH); + dict_length = LZFU_INITLENGTH; + memcpy(&lzfuhdr, rtfcomp, sizeof(lzfuhdr)); + LE32_CPU(lzfuhdr.cbSize); LE32_CPU(lzfuhdr.cbRawSize); + LE32_CPU(lzfuhdr.dwMagic); LE32_CPU(lzfuhdr.dwCRC); + /* printf("total size: %d\n", lzfuhdr.cbSize+4); + printf("raw size : %d\n", lzfuhdr.cbRawSize); + printf("compressed: %s\n", (lzfuhdr.dwMagic == LZFU_COMPRESSED ? "yes" : "no")); + printf("CRC : %#x\n", lzfuhdr.dwCRC); + printf("\n");*/ + out_buf = (unsigned char*)xmalloc(lzfuhdr.cbRawSize+20); //plus 4 cause we have 2x'}' and a \0 + in_size = 0; + // we add plus one here cause when referencing an array, the index is always one less + // (ie, when accessing 2 element array, highest index is [1]) + while (in_size+0x11 < lzfuhdr.cbSize) { + memcpy(&flags, &(rtfcomp[in_size+0x10]), 1); + in_size += 1; + + flag_mask = 1; + while (flag_mask != 0 && in_size+0x11 < lzfuhdr.cbSize) { + if (flag_mask & flags) { + // read 2 bytes from input + unsigned short int blkhdr, offset, length; + memcpy(&blkhdr, &(rtfcomp[in_size+0x10]), 2); + LE16_CPU(blkhdr); + in_size += 2; + /* swap the upper and lower bytes of blkhdr */ + blkhdr = (((blkhdr&0xFF00)>>8)+ + ((blkhdr&0x00FF)<<8)); + /* the offset is the first 24 bits of the 32 bit value */ + offset = (blkhdr&0xFFF0)>>4; + /* the length of the dict entry are the last 8 bits */ + length = (blkhdr&0x000F)+2; + // add the value we are about to print to the dictionary + for (i=0; i < length; i++) { + unsigned char c1; + c1 = dict[(offset+i)%4096]; + dict[dict_length]=c1; + dict_length = (dict_length+1) % 4096; + out_buf[out_ptr++] = c1; + } + } else { + // uncompressed chunk (single byte) + char c1 = rtfcomp[in_size+0x10]; + in_size ++; + dict[dict_length] = c1; + dict_length = (dict_length+1)%4096; + out_buf[out_ptr++] = c1; + } + flag_mask <<= 1; + } + } + // the compressed version doesn't appear to drop the closing braces onto the doc. + // we should do that + out_buf[out_ptr++] = '}'; + out_buf[out_ptr++] = '}'; + out_buf[out_ptr++] = '\0'; + return out_buf; +}