ShuriZma
/
mgba
mirror of https://github.com/mgba-emu/mgba.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Util: Perform checksum validation on BPS patches

This commit is contained in:
Jeffrey Pfau 2015-01-11 06:22:37 -08:00
parent 8c2d3e5d59
commit 1fe5a7847a
1 changed files with 19 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/util/patch-ups.c
View File

@ -110,7 +110,18 @@ bool _UPSApplyPatch(struct Patch* patch, void* in, size_t inSize, void* out, siz
}
bool _BPSApplyPatch(struct Patch* patch, void* in, size_t inSize, void* out, size_t outSize) {
// TODO: Input checksum
patch->vf->seek(patch->vf, IN_CHECKSUM, SEEK_END);
uint32_t expectedInChecksum;
uint32_t expectedOutChecksum;
patch->vf->read(patch->vf, &expectedInChecksum, sizeof(expectedInChecksum));
patch->vf->read(patch->vf, &expectedOutChecksum, sizeof(expectedOutChecksum));
uint32_t inputChecksum = doCrc32(in, inSize);
uint32_t outputChecksum = 0;
if (inputChecksum != expectedInChecksum) {
return false;
}
ssize_t filesize = patch->vf->size(patch->vf);
patch->vf->seek(patch->vf, 4, SEEK_SET);
@ -137,6 +148,7 @@ bool _BPSApplyPatch(struct Patch* patch, void* in, size_t inSize, void* out, siz
case 0x0:
// SourceRead
memmove(&writeBuffer[writeLocation], &readBuffer[writeLocation], length);
outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation], length);
writeLocation += length;
break;
case 0x1:
@ -144,6 +156,7 @@ bool _BPSApplyPatch(struct Patch* patch, void* in, size_t inSize, void* out, siz
if (patch->vf->read(patch->vf, &writeBuffer[writeLocation], length) != length) {
return false;
}
outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation], length);
writeLocation += length;
break;
case 0x2:
@ -158,6 +171,7 @@ bool _BPSApplyPatch(struct Patch* patch, void* in, size_t inSize, void* out, siz
return false;
}
memmove(&writeBuffer[writeLocation], &readBuffer[readSourceLocation], length);
outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation], length);
writeLocation += length;
readSourceLocation += length;
break;
@ -178,9 +192,13 @@ bool _BPSApplyPatch(struct Patch* patch, void* in, size_t inSize, void* out, siz
++writeLocation;
++readTargetLocation;
}
outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation - length], length);
break;
}
}
if (expectedOutChecksum != outputChecksum) {
return false;
}
return true;
}