1 /*
2 This program is free software; you can redistribute it and/or modify
3 it under the terms of the GNU General Public License as published by
4 the Free Software Foundation; either version 2 of the License, or
5 (at your option) any later version.
6
7 You should have received a copy of the GNU General Public License
8 along with this program; if not, write to the Free Software Foundation,
9 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
10 */
11
12 #include "define.h"
13 #include "lzfu.h"
14
15
16 #define LZFU_COMPRESSED 0x75465a4c
17 #define LZFU_UNCOMPRESSED 0x414c454d
18
19 // initital dictionary
20 #define LZFU_INITDICT "{\\rtf1\\ansi\\mac\\deff0\\deftab720{\\fonttbl;}" \
21 "{\\f0\\fnil \\froman \\fswiss \\fmodern \\fscrip" \
22 "t \\fdecor MS Sans SerifSymbolArialTimes Ne" \
23 "w RomanCourier{\\colortbl\\red0\\green0\\blue0" \
24 "\r\n\\par \\pard\\plain\\f0\\fs20\\b\\i\\u\\tab" \
25 "\\tx"
26 // initial length of dictionary
27 #define LZFU_INITLENGTH 207
28
29 // header for compressed rtf
30 typedef struct _lzfuheader {
31 uint32_t cbSize;
32 uint32_t cbRawSize;
33 uint32_t dwMagic;
34 uint32_t dwCRC;
35 } lzfuheader;
36
37
pst_lzfu_decompress(char * rtfcomp,uint32_t compsize,size_t * size)38 char* pst_lzfu_decompress(char* rtfcomp, uint32_t compsize, size_t *size) {
39 unsigned char dict[4096]; // the dictionary buffer
40 unsigned int dict_length = 0; // the dictionary pointer
41 lzfuheader lzfuhdr; // the header of the lzfu block
42 unsigned char flags; // 8 bits of flags (1=2byte block pointer into the dict, 0=1 byte literal)
43 unsigned char flag_mask; // look at one flag bit each time through the loop
44 uint32_t i;
45 char *out_buf;
46 uint32_t out_ptr = 0;
47 uint32_t out_size;
48 uint32_t in_ptr;
49 uint32_t in_size;
50
51 memcpy(dict, LZFU_INITDICT, LZFU_INITLENGTH);
52 memset(dict + LZFU_INITLENGTH, 0, sizeof(dict) - LZFU_INITLENGTH);
53 dict_length = LZFU_INITLENGTH;
54
55 memcpy(&lzfuhdr, rtfcomp, sizeof(lzfuhdr));
56 LE32_CPU(lzfuhdr.cbSize);
57 LE32_CPU(lzfuhdr.cbRawSize);
58 LE32_CPU(lzfuhdr.dwMagic);
59 LE32_CPU(lzfuhdr.dwCRC);
60 //printf("total size: %d\n", lzfuhdr.cbSize+4);
61 //printf("raw size : %d\n", lzfuhdr.cbRawSize);
62 //printf("compressed: %s\n", (lzfuhdr.dwMagic == LZFU_COMPRESSED ? "yes" : "no"));
63 //printf("CRC : %#x\n", lzfuhdr.dwCRC);
64 //printf("\n");
65 out_size = lzfuhdr.cbRawSize;
66 out_buf = (char*)pst_malloc(out_size);
67 in_ptr = sizeof(lzfuhdr);
68 // Make sure to correct lzfuhdr.cbSize with 4 bytes before comparing
69 // to compsize
70 in_size = (lzfuhdr.cbSize + 4 < compsize) ? lzfuhdr.cbSize + 4 : compsize;
71 while (in_ptr < in_size) {
72 flags = (unsigned char)(rtfcomp[in_ptr++]);
73 flag_mask = 1;
74 while (flag_mask) {
75 if (flag_mask & flags) {
76 // two bytes available?
77 if (in_ptr+1 < in_size) {
78 // read 2 bytes from input
79 uint16_t blkhdr, offset, length;
80 memcpy(&blkhdr, rtfcomp+in_ptr, 2);
81 LE16_CPU(blkhdr);
82 in_ptr += 2;
83 /* swap the upper and lower bytes of blkhdr */
84 blkhdr = (((blkhdr&0xFF00)>>8)+
85 ((blkhdr&0x00FF)<<8));
86 /* the offset is the first 12 bits of the 16 bit value */
87 offset = (blkhdr&0xFFF0)>>4;
88 /* the length of the dict entry are the last 4 bits */
89 length = (blkhdr&0x000F)+2;
90 // add the value we are about to print to the dictionary
91 for (i=0; i < length; i++) {
92 unsigned char c1;
93 c1 = dict[(offset+i)%4096];
94 dict[dict_length] = c1;
95 dict_length = (dict_length+1) % 4096;
96 if (out_ptr < out_size) out_buf[out_ptr++] = (char)c1;
97 // required for dictionary wrap around
98 // otherwise 0 byte values are referenced incorrectly
99 dict[dict_length] = 0;
100 }
101 }
102 } else {
103 // one byte available?
104 if (in_ptr < in_size) {
105 // uncompressed chunk (single byte)
106 char c1 = rtfcomp[in_ptr++];
107 dict[dict_length] = c1;
108 dict_length = (dict_length+1)%4096;
109 if (out_ptr < out_size) out_buf[out_ptr++] = (char)c1;
110 // required for dictionary wrap around
111 // otherwise 0 byte values are referenced incorrect
112 dict[dict_length] = 0;
113 }
114 }
115 flag_mask <<= 1;
116 }
117 }
118 *size = out_ptr;
119 return out_buf;
120 }
121