static int chm_decompress_stream(int fd, chm_metadata_t *metadata, const char *dirname, cli_ctx *ctx)
{
lzx_content_t lzx_content;
lzx_reset_table_t lzx_reset_table;
lzx_control_t lzx_control;
int window_bits, length, tmpfd, retval=-1;
struct lzx_stream * stream;
char filename[1024];
struct cab_file file;
snprintf(filename, 1024, "%s"PATHSEP"clamav-unchm.bin", dirname);
tmpfd = open(filename, O_RDWR|O_CREAT|O_TRUNC|O_BINARY, S_IRWXU);
if (tmpfd<0) {
cli_dbgmsg("open failed for %s\n", filename);
return -1;
}
if (!metadata->sys_control.length || !metadata->sys_content.length ||!metadata->sys_reset.length) {
cli_dbgmsg("Control file missing\n");
goto abort;
}
if (!read_sys_control(metadata, &lzx_control)) {
goto abort;
}
if (!read_sys_content(metadata, &lzx_content)) {
goto abort;
}
if (!read_sys_reset_table(metadata, &lzx_reset_table)) {
goto abort;
}
switch (lzx_control.window_size) {
case 0x008000:
window_bits = 15;
break;
case 0x010000:
window_bits = 16;
break;
case 0x020000:
window_bits = 17;
break;
case 0x040000:
window_bits = 18;
break;
case 0x080000:
window_bits = 19;
break;
case 0x100000:
window_bits = 20;
break;
case 0x200000:
window_bits = 21;
break;
default:
cli_dbgmsg("bad control window size: 0x%x\n", lzx_control.window_size);
goto abort;
}
if (lzx_control.reset_interval % LZX_FRAME_SIZE) {
cli_dbgmsg("bad reset_interval: 0x%x\n", lzx_control.window_size);
goto abort;
}
length = lzx_reset_table.uncom_len;
length += lzx_control.reset_interval;
length &= -lzx_control.reset_interval;
cli_dbgmsg("Compressed offset: %lu\n", (unsigned long int) lzx_content.offset);
if ((uint64_t) lseek(fd, lzx_content.offset, SEEK_SET) != lzx_content.offset) {
goto abort;
}
memset(&file, 0, sizeof(struct cab_file));
file.max_size = ctx->engine->maxfilesize;
stream = lzx_init(fd, tmpfd, window_bits,
lzx_control.reset_interval / LZX_FRAME_SIZE,
4096, length, &file, NULL);
if (!stream) {
cli_dbgmsg("lzx_init failed\n");
goto abort;
}
lzx_decompress(stream, length);
lzx_free(stream);
#ifndef _WIN32
/* Delete the file */
if(cli_unlink(filename))
retval = -1;
else
#endif
retval = tmpfd;
abort:
if ((retval == -1) && (tmpfd >= 0)) {
close(tmpfd);
}
return retval;
}
int cab_extract(struct cab_file *file, const char *name)
{
int ret;
if(!file || !name) {
cli_errmsg("cab_extract: !file || !name\n");
return CL_ENULLARG;
}
if(!file->folder) {
cli_errmsg("cab_extract: file->folder == NULL\n");
return CL_ENULLARG;
}
file->ofd = open(name, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, S_IRWXU);
if(file->ofd == -1) {
cli_errmsg("cab_extract: Can't open file %s in write mode\n", name);
return CL_ECREAT;
}
switch(file->folder->cmethod & 0x000f) {
case 0x0000: /* STORE */
cli_dbgmsg("CAB: Compression method: STORED\n");
CAB_CHGFOLDER;
if(file->length > file->cab->length) {
cli_dbgmsg("cab_extract: Stored file larger than archive itself, trimming down\n");
file->length = file->cab->length;
}
ret = cab_unstore(file, file->length);
break;
case 0x0001: /* MSZIP */
cli_dbgmsg("CAB: Compression method: MSZIP\n");
CAB_CHGFOLDER;
ret = mszip_decompress(file->cab->state->stream, file->length);
break;
case 0x0002: /* QUANTUM */
cli_dbgmsg("CAB: Compression method: QUANTUM\n");
CAB_CHGFOLDER;
ret = qtm_decompress(file->cab->state->stream, file->length);
break;
case 0x0003: /* LZX */
cli_dbgmsg("CAB: Compression method: LZX\n");
CAB_CHGFOLDER;
ret = lzx_decompress(file->cab->state->stream, file->length);
break;
default:
cli_dbgmsg("CAB: Not supported compression method: 0x%x\n", file->folder->cmethod & 0x000f);
ret = CL_EFORMAT;
}
close(file->ofd);
if(ret == CL_BREAK)
ret = CL_SUCCESS;
return ret;
}
