/*
* Copyright (C) 2003 - 2004 Tomasz Kojm <tkojm@clamav.net>
*
* untgz() is based on public domain minitar utility by Charles G. Waldman
*
* 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.
*
* This program 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <zlib.h>
#include "clamav.h"
#include "others.h"
#include "dsig.h"
#include "str.h"
#define TAR_BLOCKSIZE 512
int cli_untgz(int fd, const char *destdir)
{
char *fullname, osize[13], name[101], type;
char block[TAR_BLOCKSIZE];
int nbytes, nread, nwritten, in_block = 0;
unsigned int size;
FILE *outfile = NULL;
gzFile *infile;
cli_dbgmsg("in cli_untgz()\n");
if((infile = gzdopen(fd, "rb")) == NULL) {
cli_errmsg("Can't gzdopen() descriptor %d\n", fd);
return -1;
}
fullname = (char *) calloc(sizeof(char), strlen(destdir) + 100 + 5);
while(1) {
nread = gzread(infile, block, TAR_BLOCKSIZE);
if(!in_block && nread == 0)
break;
if(nread != TAR_BLOCKSIZE) {
cli_errmsg("Incomplete block read.\n");
free(fullname);
gzclose(infile);
return -1;
}
if(!in_block) {
if (block[0] == '\0') /* We're done */
break;
strncpy(name, block, 100);
name[100] = '\0';
strcpy(fullname, destdir);
strcat(fullname, "/");
strcat(fullname, name);
cli_dbgmsg("Unpacking %s\n",fullname);
type = block[156];
switch(type) {
case '0':
case '\0':
break;
case '5':
cli_errmsg("Directories in CVD are not supported.\n");
free(fullname);
gzclose(infile);
return -1;
default:
cli_errmsg("Unknown type flag %c.\n",type);
free(fullname);
gzclose(infile);
return -1;
}
in_block = 1;
if(outfile) {
if(fclose(outfile)) {
cli_errmsg("Cannot close file %s.\n", fullname);
free(fullname);
gzclose(infile);
return -1;
}
outfile = NULL;
}
if(!(outfile = fopen(fullname, "wb"))) {
cli_errmsg("Cannot create file %s.\n", fullname);
free(fullname);
gzclose(infile);
return -1;
}
strncpy(osize, block + 124, 12);
osize[12] = '\0';
if((sscanf(osize, "%o", &size)) == 0) {
cli_errmsg("Invalid size in header.\n");
free(fullname);
gzclose(infile);
return -1;
}
} else { /* write or continue writing file contents */
nbytes = size > TAR_BLOCKSIZE ? TAR_BLOCKSIZE : size;
nwritten = fwrite(block, 1, nbytes, outfile);
if(nwritten != nbytes) {
cli_errmsg("Wrote %d instead of %d (%s).\n", nwritten, nbytes, fullname);
free(fullname);
gzclose(infile);
return -1;
}
size -= nbytes;
if(size == 0)
in_block = 0;
}
}
if(outfile)
fclose(outfile);
gzclose(infile);
free(fullname);
return 0;
}
struct cl_cvd *cl_cvdparse(const char *head)
{
char *pt;
struct cl_cvd *cvd;
if(strncmp(head, "ClamAV-VDB:", 11)) {
cli_dbgmsg("Not a CVD head.\n");
return NULL;
}
cvd = (struct cl_cvd *) cli_calloc(1, sizeof(struct cl_cvd));
if(!(cvd->time = cli_strtok(head, 1, ":"))) {
cli_errmsg("CVD -> Can't extract time from header.\n");
free(cvd);
return NULL;
}
if(!(pt = cli_strtok(head, 2, ":"))) {
cli_errmsg("CVD -> Can't extract version from header.\n");
free(cvd->time);
free(cvd);
return NULL;
}
cvd->version = atoi(pt);
free(pt);
if(!(pt = cli_strtok(head, 3, ":"))) {
cli_errmsg("CVD -> Can't extract signature number from header.\n");
free(cvd->time);
free(cvd);
return NULL;
}
cvd->sigs = atoi(pt);
free(pt);
if(!(pt = cli_strtok(head, 4, ":"))) {
cli_errmsg("CVD -> Can't extract functionality level from header.\n");
free(cvd->time);
free(cvd);
return NULL;
}
cvd->fl = (short int) atoi(pt);
free(pt);
if(!(cvd->md5 = cli_strtok(head, 5, ":"))) {
cli_errmsg("CVD -> Can't extract MD5 checksum from header.\n");
free(cvd->time);
free(cvd);
return NULL;
}
if(!(cvd->dsig = cli_strtok(head, 6, ":"))) {
cli_errmsg("CVD -> Can't extract digital signature from header.\n");
free(cvd->time);
free(cvd->md5);
free(cvd);
return NULL;
}
if(!(cvd->builder = cli_strtok(head, 7, ":"))) {
cli_errmsg("CVD -> Can't extract builder name from header.\n");
free(cvd->time);
free(cvd->md5);
free(cvd->dsig);
free(cvd);
return NULL;
}
return cvd;
}
struct cl_cvd *cl_cvdhead(const char *file)
{
FILE *fd;
char head[513];
int i;
if((fd = fopen(file, "rb")) == NULL) {
cli_dbgmsg("Can't open CVD file %s\n", file);
return NULL;
}
if((i=fread(head, 1, 512, fd)) != 512) {
cli_dbgmsg("Short read (%d) while reading CVD head from %s\n", i, file);
fclose(fd);
return NULL;
}
fclose(fd);
head[512] = 0;
for(i = 511; i > 0 && (head[i] == ' ' || head[i] == 10); head[i] = 0, i--);
return cl_cvdparse(head);
}
void cl_cvdfree(struct cl_cvd *cvd)
{
free(cvd->time);
free(cvd->md5);
free(cvd->dsig);
free(cvd->builder);
free(cvd);
}
int cli_cvdverify(FILE *fd)
{
struct cl_cvd *cvd;
char *md5, head[513];
int i;
fseek(fd, 0, SEEK_SET);
if(fread(head, 1, 512, fd) != 512) {
cli_dbgmsg("Can't read CVD head from stream\n");
return CL_ECVD;
}
head[512] = 0;
for(i = 511; i > 0 && (head[i] == ' ' || head[i] == 10); head[i] = 0, i--);
if((cvd = cl_cvdparse(head)) == NULL)
return CL_ECVD;
md5 = cli_md5stream(fd);
cli_dbgmsg("MD5(.tar.gz) = %s\n", md5);
if(strncmp(md5, cvd->md5, 32)) {
cli_dbgmsg("MD5 verification error.\n");
free(md5);
cl_cvdfree(cvd);
return CL_EMD5;
}
#ifdef HAVE_GMP
if(cli_versig(md5, cvd->dsig)) {
cli_dbgmsg("Digital signature verification error.\n");
free(md5);
cl_cvdfree(cvd);
return CL_EDSIG;
}
#endif
free(md5);
cl_cvdfree(cvd);
return 0;
}
int cl_cvdverify(const char *file)
{
FILE *fd;
int ret;
if((fd = fopen(file, "rb")) == NULL) {
cli_errmsg("Can't open CVD file %s\n", file);
return CL_EOPEN;
}
ret = cli_cvdverify(fd);
fclose(fd);
return ret;
}
int cli_cvdload(FILE *fd, struct cl_node **root, int *virnum)
{
char *dir, *tmp, *buffer;
int bytes, ret;
const char *tmpdir;
FILE *tmpd;
cli_dbgmsg("in cli_cvdload()\n");
/* verify */
if((ret = cli_cvdverify(fd)))
return ret;
fseek(fd, 512, SEEK_SET);
tmpdir = getenv("TMPDIR");
if(tmpdir == NULL)
#ifdef P_tmpdir
tmpdir = P_tmpdir;
#else
tmpdir = "/tmp";
#endif
dir = cl_gentemp(tmpdir);
if(mkdir(dir, 0700)) {
cli_errmsg("cli_cvdload(): Can't create temporary directory %s\n", dir);
return CL_ETMPDIR;
}
/*
if(cli_untgz(fileno(fd), dir)) {
cli_errmsg("cli_cvdload(): Can't unpack CVD file.\n");
return CL_ECVDEXTR;
}
*/
/* FIXME: it seems there is some problem with current position indicator
* after gzdopen() call in cli_untgz(). Temporarily we need this wrapper:
*/
/* start */
tmp = cl_gentemp(tmpdir);
if((tmpd = fopen(tmp, "wb+")) == NULL) {
cli_errmsg("Can't create temporary file %s\n", tmp);
free(dir);
free(tmp);
return CL_ETMPFILE;
}
if(!(buffer = (char *) cli_malloc(FILEBUFF)))
return CL_EMEM;
while((bytes = fread(buffer, 1, FILEBUFF, fd)) > 0)
fwrite(buffer, 1, bytes, tmpd);
free(buffer);
fflush(tmpd);
fseek(tmpd, 0L, SEEK_SET);
if(cli_untgz(fileno(tmpd), dir)) {
cli_errmsg("cli_cvdload(): Can't unpack CVD file.\n");
cli_rmdirs(dir);
free(dir);
unlink(tmp);
free(tmp);
return CL_ECVDEXTR;
}
fclose(tmpd);
unlink(tmp);
free(tmp);
/* end */
/* load extracted directory */
cl_loaddbdir(dir, root, virnum);
cli_rmdirs(dir);
free(dir);
return 0;
}