int cli_rebuildpe(char *buffer, struct cli_exe_section *sections, int sects, uint32_t base, uint32_t ep, uint32_t ResRva, uint32_t ResSize, int file)
{
uint32_t datasize=0, rawbase=PESALIGN(0x148+0x80+0x28*sects, 0x200);
char *pefile=NULL, *curpe;
struct IMAGE_PE_HEADER *fakepe;
int i, gotghost=(sections[0].rva > PESALIGN(rawbase, 0x1000));
if (gotghost) rawbase=PESALIGN(0x148+0x80+0x28*(sects+1), 0x200);
if(sects+gotghost > 96)
return 0;
for (i=0; i < sects; i++)
datasize+=PESALIGN(sections[i].rsz, 0x200);
if(datasize > CLI_MAX_ALLOCATION)
return 0;
if((pefile = (char *) cli_calloc(rawbase+datasize, 1))) {
memcpy(pefile, HEADERS, 0x148);
datasize = PESALIGN(rawbase, 0x1000);
fakepe = (struct IMAGE_PE_HEADER *)(pefile+0xd0);
fakepe->NumberOfSections = EC16(sects+gotghost);
fakepe->AddressOfEntryPoint = EC32(ep);
fakepe->ImageBase = EC32(base);
fakepe->SizeOfHeaders = EC32(rawbase);
memset(pefile+0x148, 0, 0x80);
cli_writeint32(pefile+0x148+0x10, ResRva);
cli_writeint32(pefile+0x148+0x14, ResSize);
curpe = pefile+0x148+0x80;
if (gotghost) {
snprintf(curpe, 8, "empty");
cli_writeint32(curpe+8, sections[0].rva-datasize); /* vsize */
cli_writeint32(curpe+12, datasize); /* rva */
cli_writeint32(curpe+0x24, 0xffffffff);
curpe+=40;
datasize+=PESALIGN(sections[0].rva-datasize, 0x1000);
}
for (i=0; i < sects; i++) {
snprintf(curpe, 8, ".clam%.2d", i+1);
cli_writeint32(curpe+8, sections[i].vsz);
cli_writeint32(curpe+12, sections[i].rva);
cli_writeint32(curpe+16, sections[i].rsz);
cli_writeint32(curpe+20, rawbase);
/* already zeroed
cli_writeint32(curpe+24, 0);
cli_writeint32(curpe+28, 0);
cli_writeint32(curpe+32, 0);
*/
cli_writeint32(curpe+0x24, 0xffffffff);
memcpy(pefile+rawbase, buffer+sections[i].raw, sections[i].rsz);
rawbase+=PESALIGN(sections[i].rsz, 0x200);
curpe+=40;
datasize+=PESALIGN(sections[i].vsz, 0x1000);
}
fakepe->SizeOfImage = EC32(datasize);
} else {
return 0;
}
i = (cli_writen(file, pefile, rawbase)!=-1);
free(pefile);
return i;
}
static int pefromupx (const char *src, uint32_t ssize, char *dst, uint32_t *dsize, uint32_t ep, uint32_t upx0, uint32_t upx1, uint32_t *magic, uint32_t dend)
{
char *imports, *sections=NULL, *pehdr=NULL, *newbuf;
unsigned int sectcnt=0, upd=1;
uint32_t realstuffsz=0, valign=0;
uint32_t foffset=0xd0+0xf8;
if((dst == NULL) || (src == NULL))
return 0;
while ((valign=magic[sectcnt++])) {
if ( ep - upx1 + valign <= ssize-5 && /* Wondering how we got so far?! */
src[ep - upx1 + valign - 2] == '\x8d' && /* lea edi, ... */
src[ep - upx1 + valign - 1] == '\xbe' ) /* ... [esi + offset] */
break;
}
if (!valign && ep - upx1 + 0x80 < ssize-8) {
const char *pt = &src[ep - upx1 + 0x80];
cli_dbgmsg("UPX: bad magic - scanning for imports\n");
while ((pt=cli_memstr(pt, ssize - (pt-src) - 8, "\x8d\xbe", 2))) {
if (pt[6] == '\x8b' && pt[7] == '\x07') { /* lea edi, [esi+imports] / mov eax, [edi] */
valign=pt-src+2-ep+upx1;
break;
}
pt++;
}
}
if (valign && CLI_ISCONTAINED(src, ssize, src + ep - upx1 + valign, 4)) {
imports = dst + cli_readint32(src + ep - upx1 + valign);
realstuffsz = imports-dst;
if (realstuffsz >= *dsize ) {
cli_dbgmsg("UPX: wrong realstuff size\n");
/* fallback and eventually craft */
} else {
pehdr = imports;
while (CLI_ISCONTAINED(dst, *dsize, pehdr, 8) && cli_readint32(pehdr)) {
pehdr+=8;
while(CLI_ISCONTAINED(dst, *dsize, pehdr, 2) && *pehdr) {
pehdr++;
while (CLI_ISCONTAINED(dst, *dsize, pehdr, 2) && *pehdr)
pehdr++;
pehdr++;
}
pehdr++;
}
pehdr+=4;
if (!(sections=checkpe(dst, *dsize, pehdr, &valign, §cnt))) pehdr=NULL;
}
}
if (!pehdr && dend>0xf8+0x28) {
cli_dbgmsg("UPX: no luck - scanning for PE\n");
pehdr = &dst[dend-0xf8-0x28];
while (pehdr>dst) {
if ((sections=checkpe(dst, *dsize, pehdr, &valign, §cnt)))
break;
pehdr--;
}
if (!(realstuffsz = pehdr-dst)) pehdr=NULL;
}
if (!pehdr) {
uint32_t rebsz = PESALIGN(dend, 0x1000);
cli_dbgmsg("UPX: no luck - brutally crafing a reasonable PE\n");
if (!(newbuf = (char *)cli_calloc(rebsz+0x200, sizeof(char)))) {
cli_dbgmsg("UPX: malloc failed - giving up rebuild\n");
return 0;
}
memcpy(newbuf, HEADERS, 0xd0);
memcpy(newbuf+0xd0, FAKEPE, 0x120);
memcpy(newbuf+0x200, dst, dend);
memcpy(dst, newbuf, dend+0x200);
free(newbuf);
cli_writeint32(dst+0xd0+0x50, rebsz+0x1000);
cli_writeint32(dst+0xd0+0x100, rebsz);
cli_writeint32(dst+0xd0+0x108, rebsz);
*dsize=rebsz+0x200;
cli_dbgmsg("UPX: PE structure added to uncompressed data\n");
return 1;
}
if (!sections)
sectcnt = 0;
foffset = PESALIGN(foffset+0x28*sectcnt, valign);
for (upd = 0; upd <sectcnt ; upd++) {
uint32_t vsize=PESALIGN((uint32_t)cli_readint32(sections+8), valign);
uint32_t urva=PEALIGN((uint32_t)cli_readint32(sections+12), valign);
/* Within bounds ? */
if (!CLI_ISCONTAINED(upx0, realstuffsz, urva, vsize)) {
cli_dbgmsg("UPX: Sect %d out of bounds - giving up rebuild\n", upd);
return 0;
}
cli_writeint32(sections+8, vsize);
cli_writeint32(sections+12, urva);
cli_writeint32(sections+16, vsize);
cli_writeint32(sections+20, foffset);
if (foffset + vsize < foffset) {
/* Integer overflow */
return 0;
}
foffset+=vsize;
sections+=0x28;
}
cli_writeint32(pehdr+8, 0x4d414c43);
cli_writeint32(pehdr+0x3c, valign);
if (!(newbuf = (char *) cli_calloc(foffset, sizeof(char)))) {
cli_dbgmsg("UPX: malloc failed - giving up rebuild\n");
return 0;
}
memcpy(newbuf, HEADERS, 0xd0);
memcpy(newbuf+0xd0, pehdr,0xf8+0x28*sectcnt);
sections = pehdr+0xf8;
for (upd = 0; upd <sectcnt ; upd++) {
uint32_t offset1, offset2, offset3;
offset1 = (uint32_t)cli_readint32(sections+20);
offset2 = (uint32_t)cli_readint32(sections+16);
if (offset1 > foffset || offset2 > foffset || offset1 + offset2 > foffset) {
free(newbuf);
return 1;
}
offset3 = (uint32_t)cli_readint32(sections+12);
if (offset3-upx0 > *dsize) {
free(newbuf);
return 1;
}
memcpy(newbuf+offset1, dst+offset3-upx0, offset2);
sections+=0x28;
}
/* CBA restoring the imports they'll look different from the originals anyway... */
/* ...and yeap i miss the icon too :P */
if (foffset > *dsize + 8192) {
cli_dbgmsg("UPX: wrong raw size - giving up rebuild\n");
free(newbuf);
return 0;
}
memcpy(dst, newbuf, foffset);
*dsize = foffset;
free(newbuf);
cli_dbgmsg("UPX: PE structure rebuilt from compressed file\n");
return 1;
}
