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SInPacket now tracks decryption/decompression failure. 

Previously there was no way to tell if an incoming packet was
incorrectly formatted. The new function SInPacket.isValid()
can be called after decryption/decompression to determine if
the packet wasn't decrypted and/or decompressed properly.

* Added "valid" attribute to SInPacket.
* Decryption routine unsets "valid" if buffer is not divisible by 16.
* Decompression routine unsets "valid" on receiving zlib error code.
This commit is contained in:
rna88 2018-03-15 20:12:33 -07:00
parent bcdf5b317c
commit 967378ae98
2 changed files with 29 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/SPacket.h
View File

@ -154,10 +154,14 @@ class SInPacket
/// Returns the size in bytes of the packet.
u32 getSize();
/// Returns true if the packet decompresses/decrypts successfully.
bool isValid();
private:
u32 pos;
core::array<c8> buff;
u16 playerid;
bool valid;
};
} // Close Net Namespace

30
source/SPacket.cpp
View File

@ -225,7 +225,7 @@ void SOutPacket::decryptPacket(const c8 key[16])
buff = tmpbuff;
}
SInPacket::SInPacket(const c8* buff, const u32 size) : pos(0), playerid(0)
SInPacket::SInPacket(const c8* buff, const u32 size) : pos(0), playerid(0), valid(true)
{
SInPacket::buff.set_used(size);
memcpy(SInPacket::buff.pointer(), buff, size);
@ -435,10 +435,19 @@ void SInPacket::deCompressPacket()
newBuff.set_used(newSize);
uLongf destLen = newSize;
uncompress((Bytef*)newBuff.pointer(), &destLen, (Bytef*)buff.pointer() + 4, buff.size() - 4);
newBuff.set_used(destLen);
buff = newBuff;
int ret = uncompress((Bytef*)newBuff.pointer(), &destLen, (Bytef*)buff.pointer() + 4, buff.size() - 4);
if (ret != Z_OK)
{
valid = false;
newBuff.set_used(0);
newBuff.clear();
}
else
{
newBuff.set_used(destLen);
buff = newBuff;
}
}
void SInPacket::encryptPacket(const c8 key[16])
@ -457,6 +466,12 @@ void SInPacket::encryptPacket(const c8 key[16])
void SInPacket::decryptPacket(const c8 key[16])
{
if (buff.size() % 16 != 0)
{
valid = false;
return;
}
CEncryption::SetEncryptionKey((u8*)&key[0]);
const u32 newSize = buff.size();
core::array<c8> tmpbuff;
@ -473,5 +488,10 @@ u32 SInPacket::getSize()
return buff.size();
}
bool SInPacket::isValid()
{
return valid;
}
} // Close Net Namespace
} // Close Irr namespace