mirror of
https://github.com/sheumann/hush.git
synced 2024-12-27 01:32:08 +00:00
299 lines
7.1 KiB
C
299 lines
7.1 KiB
C
#include "config.h"
|
|
#include "libbb.h"
|
|
|
|
#if defined CONFIG_UNCOMPRESS || defined CONFIG_FEATURE_GUNZIP_UNCOMPRESS
|
|
|
|
/* uncompress for busybox -- (c) 2002 Robert Griebl
|
|
*
|
|
* based on the original compress42.c source
|
|
* (see disclaimer below)
|
|
*/
|
|
|
|
|
|
/* (N)compress42.c - File compression ala IEEE Computer, Mar 1992.
|
|
*
|
|
* Authors:
|
|
* Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
|
|
* Jim McKie (decvax!mcvax!jim)
|
|
* Steve Davies (decvax!vax135!petsd!peora!srd)
|
|
* Ken Turkowski (decvax!decwrl!turtlevax!ken)
|
|
* James A. Woods (decvax!ihnp4!ames!jaw)
|
|
* Joe Orost (decvax!vax135!petsd!joe)
|
|
* Dave Mack (csu@alembic.acs.com)
|
|
* Peter Jannesen, Network Communication Systems
|
|
* (peter@ncs.nl)
|
|
*
|
|
* marc@suse.de : a small security fix for a buffer overflow
|
|
*
|
|
* [... History snipped ...]
|
|
*
|
|
*/
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
/* Defailt input buffer size */
|
|
#define IBUFSIZ 2048
|
|
|
|
/* Default output buffer size */
|
|
#define OBUFSIZ 2048
|
|
|
|
/* Defines for third byte of header */
|
|
#define MAGIC_1 (char_type)'\037' /* First byte of compressed file */
|
|
#define MAGIC_2 (char_type)'\235' /* Second byte of compressed file */
|
|
#define BIT_MASK 0x1f /* Mask for 'number of compresssion bits' */
|
|
/* Masks 0x20 and 0x40 are free. */
|
|
/* I think 0x20 should mean that there is */
|
|
/* a fourth header byte (for expansion). */
|
|
#define BLOCK_MODE 0x80 /* Block compresssion if table is full and */
|
|
/* compression rate is dropping flush tables */
|
|
/* the next two codes should not be changed lightly, as they must not */
|
|
/* lie within the contiguous general code space. */
|
|
#define FIRST 257 /* first free entry */
|
|
#define CLEAR 256 /* table clear output code */
|
|
|
|
#define INIT_BITS 9 /* initial number of bits/code */
|
|
|
|
|
|
/* machine variants which require cc -Dmachine: pdp11, z8000, DOS */
|
|
#define FAST
|
|
|
|
#define HBITS 17 /* 50% occupancy */
|
|
#define HSIZE (1<<HBITS)
|
|
#define HMASK (HSIZE-1)
|
|
#define HPRIME 9941
|
|
#define BITS 16
|
|
#undef MAXSEG_64K
|
|
#define MAXCODE(n) (1L << (n))
|
|
|
|
/* Block compress mode -C compatible with 2.0 */
|
|
int block_mode = BLOCK_MODE;
|
|
|
|
/* user settable max # bits/code */
|
|
int maxbits = BITS;
|
|
|
|
/* Exitcode of compress (-1 no file compressed) */
|
|
int exit_code = -1;
|
|
|
|
/* Input buffer */
|
|
unsigned char inbuf[IBUFSIZ + 64];
|
|
|
|
/* Output buffer */
|
|
unsigned char outbuf[OBUFSIZ + 2048];
|
|
|
|
|
|
long int htab[HSIZE];
|
|
unsigned short codetab[HSIZE];
|
|
|
|
#define htabof(i) htab[i]
|
|
#define codetabof(i) codetab[i]
|
|
#define tab_prefixof(i) codetabof(i)
|
|
#define tab_suffixof(i) ((unsigned char *)(htab))[i]
|
|
#define de_stack ((unsigned char *)&(htab[HSIZE-1]))
|
|
#define clear_htab() memset(htab, -1, sizeof(htab))
|
|
#define clear_tab_prefixof() memset(codetab, 0, 256);
|
|
|
|
|
|
/*
|
|
* Decompress stdin to stdout. This routine adapts to the codes in the
|
|
* file building the "string" table on-the-fly; requiring no table to
|
|
* be stored in the compressed file. The tables used herein are shared
|
|
* with those of the compress() routine. See the definitions above.
|
|
*/
|
|
|
|
extern int uncompress(int fd_in, int fd_out)
|
|
{
|
|
unsigned char *stackp;
|
|
long int code;
|
|
int finchar;
|
|
long int oldcode;
|
|
long int incode;
|
|
int inbits;
|
|
int posbits;
|
|
int outpos;
|
|
int insize;
|
|
int bitmask;
|
|
long int free_ent;
|
|
long int maxcode;
|
|
long int maxmaxcode;
|
|
int n_bits;
|
|
int rsize = 0;
|
|
|
|
insize = 0;
|
|
|
|
inbuf[0] = bb_xread_char(fd_in);
|
|
|
|
maxbits = inbuf[0] & BIT_MASK;
|
|
block_mode = inbuf[0] & BLOCK_MODE;
|
|
maxmaxcode = MAXCODE(maxbits);
|
|
|
|
if (maxbits > BITS) {
|
|
bb_error_msg("compressed with %d bits, can only handle %d bits", maxbits,
|
|
BITS);
|
|
return -1;
|
|
}
|
|
|
|
maxcode = MAXCODE(n_bits = INIT_BITS) - 1;
|
|
bitmask = (1 << n_bits) - 1;
|
|
oldcode = -1;
|
|
finchar = 0;
|
|
outpos = 0;
|
|
posbits = 0 << 3;
|
|
|
|
free_ent = ((block_mode) ? FIRST : 256);
|
|
|
|
/* As above, initialize the first 256 entries in the table. */
|
|
clear_tab_prefixof();
|
|
|
|
for (code = 255; code >= 0; --code) {
|
|
tab_suffixof(code) = (unsigned char) code;
|
|
}
|
|
|
|
do {
|
|
resetbuf:;
|
|
{
|
|
int i;
|
|
int e;
|
|
int o;
|
|
|
|
e = insize - (o = (posbits >> 3));
|
|
|
|
for (i = 0; i < e; ++i)
|
|
inbuf[i] = inbuf[i + o];
|
|
|
|
insize = e;
|
|
posbits = 0;
|
|
}
|
|
|
|
if (insize < (int) sizeof(inbuf) - IBUFSIZ) {
|
|
rsize = read(fd_in, inbuf + insize, IBUFSIZ);
|
|
insize += rsize;
|
|
}
|
|
|
|
inbits = ((rsize > 0) ? (insize - insize % n_bits) << 3 :
|
|
(insize << 3) - (n_bits - 1));
|
|
|
|
while (inbits > posbits) {
|
|
if (free_ent > maxcode) {
|
|
posbits =
|
|
((posbits - 1) +
|
|
((n_bits << 3) -
|
|
(posbits - 1 + (n_bits << 3)) % (n_bits << 3)));
|
|
++n_bits;
|
|
if (n_bits == maxbits) {
|
|
maxcode = maxmaxcode;
|
|
} else {
|
|
maxcode = MAXCODE(n_bits) - 1;
|
|
}
|
|
bitmask = (1 << n_bits) - 1;
|
|
goto resetbuf;
|
|
}
|
|
{
|
|
unsigned char *p = &inbuf[posbits >> 3];
|
|
|
|
code =
|
|
((((long) (p[0])) | ((long) (p[1]) << 8) |
|
|
((long) (p[2]) << 16)) >> (posbits & 0x7)) & bitmask;
|
|
}
|
|
posbits += n_bits;
|
|
|
|
|
|
if (oldcode == -1) {
|
|
outbuf[outpos++] = (unsigned char) (finchar =
|
|
(int) (oldcode = code));
|
|
continue;
|
|
}
|
|
|
|
if (code == CLEAR && block_mode) {
|
|
clear_tab_prefixof();
|
|
free_ent = FIRST - 1;
|
|
posbits =
|
|
((posbits - 1) +
|
|
((n_bits << 3) -
|
|
(posbits - 1 + (n_bits << 3)) % (n_bits << 3)));
|
|
maxcode = MAXCODE(n_bits = INIT_BITS) - 1;
|
|
bitmask = (1 << n_bits) - 1;
|
|
goto resetbuf;
|
|
}
|
|
|
|
incode = code;
|
|
stackp = de_stack;
|
|
|
|
/* Special case for KwKwK string. */
|
|
if (code >= free_ent) {
|
|
if (code > free_ent) {
|
|
unsigned char *p;
|
|
|
|
posbits -= n_bits;
|
|
p = &inbuf[posbits >> 3];
|
|
|
|
bb_error_msg
|
|
("insize:%d posbits:%d inbuf:%02X %02X %02X %02X %02X (%d)",
|
|
insize, posbits, p[-1], p[0], p[1], p[2], p[3],
|
|
(posbits & 07));
|
|
bb_error_msg("uncompress: corrupt input");
|
|
return -1;
|
|
}
|
|
|
|
*--stackp = (unsigned char) finchar;
|
|
code = oldcode;
|
|
}
|
|
|
|
/* Generate output characters in reverse order */
|
|
while ((long int) code >= (long int) 256) {
|
|
*--stackp = tab_suffixof(code);
|
|
code = tab_prefixof(code);
|
|
}
|
|
|
|
*--stackp = (unsigned char) (finchar = tab_suffixof(code));
|
|
|
|
/* And put them out in forward order */
|
|
{
|
|
int i;
|
|
|
|
if (outpos + (i = (de_stack - stackp)) >= OBUFSIZ) {
|
|
do {
|
|
if (i > OBUFSIZ - outpos) {
|
|
i = OBUFSIZ - outpos;
|
|
}
|
|
|
|
if (i > 0) {
|
|
memcpy(outbuf + outpos, stackp, i);
|
|
outpos += i;
|
|
}
|
|
|
|
if (outpos >= OBUFSIZ) {
|
|
write(fd_out, outbuf, outpos);
|
|
outpos = 0;
|
|
}
|
|
stackp += i;
|
|
} while ((i = (de_stack - stackp)) > 0);
|
|
} else {
|
|
memcpy(outbuf + outpos, stackp, i);
|
|
outpos += i;
|
|
}
|
|
}
|
|
|
|
/* Generate the new entry. */
|
|
if ((code = free_ent) < maxmaxcode) {
|
|
tab_prefixof(code) = (unsigned short) oldcode;
|
|
tab_suffixof(code) = (unsigned char) finchar;
|
|
free_ent = code + 1;
|
|
}
|
|
|
|
/* Remember previous code. */
|
|
oldcode = incode;
|
|
}
|
|
|
|
} while (rsize > 0);
|
|
|
|
if (outpos > 0) {
|
|
write(fd_out, outbuf, outpos);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
#endif
|