#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
static char const rcsid[] = "$Id: tnef.c,v 1.31 2006/03/14 11:39:43 nigelhorne Exp $";
#include <stdio.h>
#include <fcntl.h>
#include "cltypes.h"
#include "clamav.h"
#include "others.h"
#include "tnef.h"
#if CL_DEBUG
#include "mbox.h"
#endif
#include "blob.h"
static int tnef_message(FILE *fp, uint16_t type, uint16_t tag, int32_t length, off_t fsize);
static int tnef_attachment(FILE *fp, uint16_t type, uint16_t tag, int32_t length, const char *dir, fileblob **fbref, off_t fsize);
static int tnef_header(FILE *fp, uint8_t *part, uint16_t *type, uint16_t *tag, int32_t *length);
#define TNEF_SIGNATURE 0x223E9f78
#define LVL_MESSAGE 0x01
#define LVL_ATTACHMENT 0x02
#define attMSGCLASS 0x8008
#define attBODY 0x800c
#define attATTACHDATA 0x800f
#define attATTACHTITLE 0x8010
#define attDATEMODIFIED 0x8020
#define attTNEFVERSION 0x9006
#define attOEMCODEPAGE 0x9007
#if WORDS_BIGENDIAN == 0
#define host16(v) (v)
#define host32(v) (v)
#else
#define host16(v) ((v >> 8) | (v << 8))
#define host32(v) ((v >> 24) | ((v & 0x00FF0000) >> 8) | \
((v & 0x0000FF00) << 8) | (v << 24))
#endif
extern short cli_debug_flag;
int
cli_tnef(const char *dir, int desc)
{
uint32_t i32;
uint16_t i16;
fileblob *fb;
int i, ret, alldone;
FILE *fp;
off_t fsize;
struct stat statb;
lseek(desc, 0L, SEEK_SET);
if(fstat(desc, &statb) < 0) {
cli_errmsg("Can't fstat descriptor %d\n", desc);
return CL_EIO;
}
fsize = statb.st_size;
i = dup(desc);
if((fp = fdopen(i, "rb")) == NULL) {
cli_errmsg("Can't open descriptor %d\n", desc);
close(i);
return CL_EOPEN;
}
if(fread(&i32, sizeof(uint32_t), 1, fp) != 1) {
fclose(fp);
return CL_EIO;
}
if(host32(i32) != TNEF_SIGNATURE) {
fclose(fp);
return CL_EFORMAT;
}
if(fread(&i16, sizeof(uint16_t), 1, fp) != 1) {
fclose(fp);
return CL_EIO;
}
fb = NULL;
ret = CL_CLEAN;
alldone = 0;
do {
uint8_t part = 0;
uint16_t type = 0, tag = 0;
int32_t length = 0;
switch(tnef_header(fp, &part, &type, &tag, &length)) {
case 0:
if(ferror(fp)) {
perror("read");
ret = CL_EIO;
}
alldone = 1;
break;
case 1:
break;
default:
ret = CL_EIO;
alldone = 1;
break;
}
if(length == 0)
continue;
if(length < 0) {
cli_warnmsg("Corrupt TNEF header detected - length %d\n", length);
ret = CL_EFORMAT;
break;
}
if(alldone)
break;
switch(part) {
case LVL_MESSAGE:
cli_dbgmsg("TNEF - found message\n");
if(fb != NULL) {
fileblobDestroy(fb);
fb = NULL;
}
fb = fileblobCreate();
if(tnef_message(fp, type, tag, length, fsize) != 0) {
cli_errmsg("Error reading TNEF message\n");
ret = CL_EFORMAT;
alldone = 1;
}
break;
case LVL_ATTACHMENT:
cli_dbgmsg("TNEF - found attachment\n");
if(tnef_attachment(fp, type, tag, length, dir, &fb, fsize) != 0) {
cli_errmsg("Error reading TNEF message\n");
ret = CL_EFORMAT;
alldone = 1;
}
break;
case 0:
break;
default:
cli_warnmsg("TNEF - unknown level %d tag 0x%x\n", (int)part, (int)tag);
if(cli_debug_flag) {
int fout;
char *filename = cli_gentemp(NULL);
char buffer[BUFSIZ];
#ifdef O_BINARY
fout = open(filename, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC|O_BINARY, 0600);
#else
fout = open(filename, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600);
#endif
if(fout >= 0) {
int count;
cli_warnmsg("Saving dump to %s - send to bugs@clamav.net\n", filename);
lseek(desc, 0L, SEEK_SET);
while((count = cli_readn(desc, buffer, sizeof(buffer))) > 0)
cli_writen(fout, buffer, count);
close(fout);
}
free(filename);
}
ret = CL_EFORMAT;
alldone = 1;
break;
}
} while(!alldone);
fclose(fp);
if(fb) {
cli_dbgmsg("cli_tnef: flushing final data\n");
if(fileblobGetFilename(fb) == NULL) {
cli_dbgmsg("Saving TNEF portion with an unknown name\n");
fileblobSetFilename(fb, dir, "tnef");
}
fileblobDestroy(fb);
fb = NULL;
}
cli_dbgmsg("cli_tnef: returning %d\n", ret);
return ret;
}
static int
tnef_message(FILE *fp, uint16_t type, uint16_t tag, int32_t length, off_t fsize)
{
uint16_t i16;
off_t offset;
#if CL_DEBUG
uint32_t i32;
char *string;
#endif
cli_dbgmsg("message tag 0x%x, type 0x%x, length %d\n", tag, type, length);
offset = ftell(fp);
switch(tag) {
case attBODY:
cli_warnmsg("TNEF body not being scanned - if you believe this file contains a virus, submit it to www.clamav.net\n");
break;
#if CL_DEBUG
case attTNEFVERSION:
if(fread(&i32, sizeof(uint32_t), 1, fp) != 1)
return -1;
i32 = host32(i32);
cli_dbgmsg("TNEF version %d\n", i32);
break;
case attOEMCODEPAGE:
if(fread(&i32, sizeof(uint32_t), 1, fp) != 1)
return -1;
i32 = host32(i32);
cli_dbgmsg("TNEF codepage %d\n", i32);
break;
case attDATEMODIFIED:
break;
case attMSGCLASS:
if(length <= 0)
return -1;
string = cli_malloc(length + 1);
if(string == NULL)
return -1;
if(fread(string, 1, (uint32_t)length, fp) != (uint32_t)length) {
free(string);
return -1;
}
string[length] = '\0';
cli_dbgmsg("TNEF class %s\n", string);
free(string);
break;
default:
cli_dbgmsg("TNEF - unsupported message tag 0x%x type 0x%d length %d\n", tag, type, length);
break;
#endif
}
if(!CLI_ISCONTAINED2(0, fsize, (off_t)offset, (off_t)length)) {
cli_errmsg("TNEF: Incorrect length field\n");
return -1;
}
if(fseek(fp, offset + length, SEEK_SET) < 0)
return -1;
if(fread(&i16, sizeof(uint16_t), 1, fp) != 1)
return -1;
return 0;
}
static int
tnef_attachment(FILE *fp, uint16_t type, uint16_t tag, int32_t length, const char *dir, fileblob **fbref, off_t fsize)
{
uint32_t todo;
uint16_t i16;
off_t offset;
char *string;
cli_dbgmsg("attachment tag 0x%x, type 0x%x, length %d\n", tag, type, length);
offset = ftell(fp);
switch(tag) {
case attATTACHTITLE:
if(length <= 0)
return -1;
string = cli_malloc(length + 1);
if(string == NULL)
return -1;
if(fread(string, 1, (uint32_t)length, fp) != (uint32_t)length) {
free(string);
return -1;
}
string[length] = '\0';
cli_dbgmsg("TNEF filename %s\n", string);
if(*fbref == NULL) {
*fbref = fileblobCreate();
if(*fbref == NULL) {
free(string);
return -1;
}
}
fileblobSetFilename(*fbref, dir, string);
free(string);
break;
case attATTACHDATA:
if(*fbref == NULL) {
*fbref = fileblobCreate();
if(*fbref == NULL)
return -1;
}
for(todo = length; todo; todo--) {
#if WORDS_BIGENDIAN == 1
int c;
unsigned char c2;
if((c = fgetc(fp)) == EOF)
break;
c2 = (unsigned char)c;
fileblobAddData(*fbref, (const unsigned char *)&c2, 1);
#else
int c;
if((c = fgetc(fp)) == EOF)
break;
fileblobAddData(*fbref, (const unsigned char *)&c, 1);
#endif
}
break;
default:
cli_dbgmsg("TNEF - unsupported attachment tag 0x%x type 0x%d length %d\n", tag, type, length);
break;
}
if(!CLI_ISCONTAINED2(0, fsize, (off_t)offset, (off_t)length)) {
cli_errmsg("TNEF: Incorrect length field\n");
return -1;
}
if(fseek(fp, (long)(offset + length), SEEK_SET) < 0)
return -1;
if(fread(&i16, sizeof(uint16_t), 1, fp) != 1)
return -1;
return 0;
}
static int
tnef_header(FILE *fp, uint8_t *part, uint16_t *type, uint16_t *tag, int32_t *length)
{
uint32_t i32;
if(fread(part, sizeof(uint8_t), 1, fp) != 1)
return 0;
if(*part == (uint8_t)0)
return 0;
if(fread(&i32, sizeof(uint32_t), 1, fp) != 1)
return -1;
i32 = host32(i32);
*tag = (uint16_t)(i32 & 0xFFFF);
*type = (uint16_t)((i32 & 0xFFFF0000) >> 16);
if(fread(&i32, sizeof(uint32_t), 1, fp) != 1)
return -1;
*length = (int32_t)host32(i32);
cli_dbgmsg("message tag 0x%x, type 0x%x, length %d\n", *tag, *type, *length);
return 1;
}