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Slightly improve fteqcc's handling of weird zips.

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This commit is contained in:
Shpoike 2023-04-23 06:21:46 +01:00
parent ff80b3bd59
commit ed7713e0e3
1 changed files with 96 additions and 14 deletions
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110
engine/qclib/qcd_main.c
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@ -256,6 +256,8 @@ int QC_EnumerateFilesFromBlob(const void *blob, size_t blobsize, void (*cb)(cons
{
unsigned int cdentries;
unsigned int cdlen;
unsigned int cdstart;
unsigned int zipoffset = 0;
const unsigned char *eocd;
const unsigned char *cd;
unsigned int ofs_le;
@ -263,7 +265,8 @@ int QC_EnumerateFilesFromBlob(const void *blob, size_t blobsize, void (*cb)(cons
int ret = 0;
const unsigned char *le;
unsigned int csize, usize, method;
unsigned int csize, usize;
int method; //negatives for errors.
unsigned int le_nl,le_el;
char name[256];
@ -282,19 +285,45 @@ int QC_EnumerateFilesFromBlob(const void *blob, size_t blobsize, void (*cb)(cons
return ret;
}
//treat it as a zip
//treat it as a zip (with no comment, too lazy to scan)
eocd = blob;
eocd += blobsize-22;
if (QC_ReadRawInt(eocd+0) != 0x06054b50)
for (cdlen = 0; ; eocd--, cdlen++)
{
if (cdlen > 65535 || eocd < (const unsigned char*)blob)
{
printf("No zip EOCD\n");
return ret;
}
if (QC_ReadRawInt(eocd+0) == 0x06054b50)
break;
}
if (QC_ReadRawShort(eocd+4) || QC_ReadRawShort(eocd+6) || QC_ReadRawShort(eocd+20)!=cdlen || QC_ReadRawShort(eocd+8) != QC_ReadRawShort(eocd+10))
{ //this-disk start-disk comment-length numfiles_thisdisk numfiles_all
printf("Unsupported zip\n");
return ret;
if (QC_ReadRawShort(eocd+4) || QC_ReadRawShort(eocd+6) || QC_ReadRawShort(eocd+20) || QC_ReadRawShort(eocd+8) != QC_ReadRawShort(eocd+10))
return ret;
cd = blob;
cd += QC_ReadRawInt(eocd+16);
}
cdstart = QC_ReadRawInt(eocd+16);
cdlen = QC_ReadRawInt(eocd+12);
cdentries = QC_ReadRawShort(eocd+10);
if (cd+cdlen>=(const unsigned char*)blob+blobsize)
return ret;
cd = blob;
cd += cdstart + zipoffset;
if (cdlen < 46 || cd+cdlen>=(const unsigned char*)blob+blobsize || cd[0]!='P'||cd[1]!='K'||cd[2]!=1||cd[3]!=2)
{ //cd looks corrupt? assume eocd starts right after the cd and use that as an offset at the start of the zip (concatenated onto a binary or w/e)
zipoffset += (eocd-(const unsigned char*)blob) - (cdstart+cdlen);
cd = blob;
cd += cdstart + zipoffset;
if (cdlen < 46 || zipoffset > blobsize || cd+cdlen>=(const unsigned char*)blob+blobsize || cd[0]!='P'||cd[1]!='K'||cd[2]!=1||cd[3]!=2)
{
printf("Zip CentralDir not found: %s\n", cd);
return ret;
}
//okay, we're at an offset.
printf("Zip offset is %u\n", zipoffset);
}
for(; cdentries --> 0 && (QC_ReadRawInt(cd+0) == 0x02014b50); cd += 46 + cd_nl+cd_el+cd_cl)
@ -327,7 +356,7 @@ int QC_EnumerateFilesFromBlob(const void *blob, size_t blobsize, void (*cb)(cons
{
if (ofs_le+46 < blobsize)
{
le = (const unsigned char*)blob + QC_ReadRawInt(cd+42);
le = (const unsigned char*)blob + zipoffset + QC_ReadRawInt(cd+42);
if (QC_ReadRawInt(le+0) == 0x04034b50) //needs proper local entry tag
if (!(QC_ReadRawShort(le+6) & ~0x80e)) //ignore unsupported general purpose flags
@ -337,20 +366,73 @@ int QC_EnumerateFilesFromBlob(const void *blob, size_t blobsize, void (*cb)(cons
if (cd_nl == le_nl) //name (length) must match...
// if (cd_el != le_el) //extras does NOT match
{
csize = QC_ReadRawInt(le+18);
usize = QC_ReadRawInt(le+22);
unsigned short gpflags = QC_ReadRawShort(le+6);
if (gpflags & (1u<<3))
{ //stream-compressed (csize+usize+crc are AFTER the data... just fall back to the central directory instead)
csize = QC_ReadRawInt(cd+20);
usize = QC_ReadRawInt(cd+24);
}
else
{
csize = QC_ReadRawInt(le+18);
usize = QC_ReadRawInt(le+22);
}
//parse extra
if (le_el)
{
const pbyte *extra = le + 30 + le_nl, *extraend = extra + le_el;
unsigned short extrachunk_tag;
unsigned short extrachunk_len;
while(extra+4 < extraend)
{
extrachunk_tag = QC_ReadRawShort(extra+0);
extrachunk_len = QC_ReadRawShort(extra+2);
if (extra + extrachunk_len > extraend)
break; //error
extra += 4;
switch(extrachunk_tag)
{
case 1: //zip64 extended information extra field. the attributes are only present if the reegular file info is nulled out with a -1
if (usize == 0xffffffffu)
{
usize = QC_ReadRawInt/*64*/(extra);
if (QC_ReadRawInt(extra+4))
method=-1-method;
extra += 8;
}
if (csize == 0xffffffffu)
{
csize = QC_ReadRawInt/*64*/(extra);
if (QC_ReadRawInt(extra+4))
method=-1-method;
extra += 8;
}
break;
default:
/* printf("Unknown chunk %x\n", extrachunk_tag);
case 0x000a: //NTFS (timestamps)
case 0x5455: //extended timestamp
case 0x7875: //unix uid/gid
*/ extra += extrachunk_len;
break;
}
}
}
data = le+30+le_nl+le_el;
method = QC_ReadRawShort(le+8);
if (method != 0
if (method >= 0 && (method != 0
#ifdef AVAIL_ZLIB
&& method != 8
#endif
#ifdef ZLIB_DEFLATE64
&& method != 9
#endif
)
))
method=-1-method;
}
}