Beispiel #1
0
 uint readUInt32(uint offset)
 {
     return(peImage.offsetReadUInt32(methodInfosOffset + offset));
 }
Beispiel #2
0
        DumpedMethods createDumpedMethods(PeImage peImage, byte[] fileData, byte[] methodsData)
        {
            var dumpedMethods = new DumpedMethods();

            var methodsDataReader = new BinaryReader(new MemoryStream(methodsData));
            var fileDataReader    = new BinaryReader(new MemoryStream(fileData));

            var  metadataTables  = peImage.Cor20Header.createMetadataTables();
            var  methodDef       = metadataTables.getMetadataType(MetadataIndex.iMethodDef);
            uint methodDefOffset = methodDef.fileOffset;

            for (int i = 0; i < methodDef.rows; i++, methodDefOffset += methodDef.totalSize)
            {
                uint bodyRva = peImage.offsetReadUInt32(methodDefOffset);
                if (bodyRva == 0)
                {
                    continue;
                }
                uint bodyOffset = peImage.rvaToOffset(bodyRva);

                var dm = new DumpedMethod();
                dm.token       = (uint)(0x06000001 + i);
                dm.mdImplFlags = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[1].offset);
                dm.mdFlags     = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[2].offset);
                dm.mdName      = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[3].offset, methodDef.fields[3].size);
                dm.mdSignature = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[4].offset, methodDef.fields[4].size);
                dm.mdParamList = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[5].offset, methodDef.fields[5].size);

                byte b = peImage.offsetReadByte(bodyOffset);
                uint codeOffset;
                if ((b & 3) == 2)
                {
                    if (b != 2)
                    {
                        continue;                               // not zero byte code size
                    }
                    dm.mhFlags          = 2;
                    dm.mhMaxStack       = 8;
                    dm.mhLocalVarSigTok = 0;
                    codeOffset          = bodyOffset + 1;
                }
                else
                {
                    if (peImage.offsetReadUInt32(bodyOffset + 4) != 0)
                    {
                        continue;                               // not zero byte code size
                    }
                    dm.mhFlags          = peImage.offsetReadUInt16(bodyOffset);
                    dm.mhMaxStack       = peImage.offsetReadUInt16(bodyOffset + 2);
                    dm.mhLocalVarSigTok = peImage.offsetReadUInt32(bodyOffset + 8);
                    codeOffset          = bodyOffset + (uint)(dm.mhFlags >> 12) * 4;
                }
                fileDataReader.BaseStream.Position = codeOffset;

                if (!decrypter.decrypt(fileDataReader, dm))
                {
                    continue;
                }

                dumpedMethods.add(dm);
            }

            return(dumpedMethods);
        }
Beispiel #3
0
        DumpedMethods decryptMethods()
        {
            var dumpedMethods = new DumpedMethods();

            var methodInfos = new MethodInfos(mainType, peImage, peHeader, mcKey);

            methodInfos.initializeInfos();

            var  metadataTables  = peImage.Cor20Header.createMetadataTables();
            var  methodDef       = metadataTables.getMetadataType(MetadataIndex.iMethodDef);
            uint methodDefOffset = methodDef.fileOffset;

            for (int i = 0; i < methodDef.rows; i++, methodDefOffset += methodDef.totalSize)
            {
                uint bodyRva = peImage.offsetReadUInt32(methodDefOffset);
                if (bodyRva == 0)
                {
                    continue;
                }

                var info = methodInfos.lookup(bodyRva);
                if (info == null)
                {
                    continue;
                }

                uint   bodyOffset = peImage.rvaToOffset(bodyRva);
                ushort magic      = peImage.offsetReadUInt16(bodyOffset);
                if (magic != 0xFFF3)
                {
                    continue;
                }

                var dm = new DumpedMethod();
                dm.token       = (uint)(0x06000001 + i);
                dm.mdImplFlags = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[1].offset);
                dm.mdFlags     = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[2].offset);
                dm.mdName      = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[3].offset, methodDef.fields[3].size);
                dm.mdSignature = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[4].offset, methodDef.fields[4].size);
                dm.mdParamList = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[5].offset, methodDef.fields[5].size);

                var  reader = new BinaryReader(new MemoryStream(info.body));
                byte b      = reader.ReadByte();
                if ((b & 3) == 2)
                {
                    dm.mhFlags          = 2;
                    dm.mhMaxStack       = 8;
                    dm.mhCodeSize       = (uint)(b >> 2);
                    dm.mhLocalVarSigTok = 0;
                }
                else
                {
                    reader.BaseStream.Position--;
                    dm.mhFlags          = reader.ReadUInt16();
                    dm.mhMaxStack       = reader.ReadUInt16();
                    dm.mhCodeSize       = reader.ReadUInt32();
                    dm.mhLocalVarSigTok = reader.ReadUInt32();
                    uint codeOffset = (uint)(dm.mhFlags >> 12) * 4;
                    reader.BaseStream.Position += codeOffset - 12;
                }

                dm.code = reader.ReadBytes((int)dm.mhCodeSize);
                if ((dm.mhFlags & 8) != 0)
                {
                    reader.BaseStream.Position = (reader.BaseStream.Position + 3) & ~3;
                    dm.extraSections           = reader.ReadBytes((int)(reader.BaseStream.Length - reader.BaseStream.Position));
                }

                dumpedMethods.add(dm);
            }

            return(dumpedMethods);
        }
Beispiel #4
0
        public bool decrypt(PeImage peImage, ISimpleDeobfuscator simpleDeobfuscator, ref DumpedMethods dumpedMethods, Dictionary <uint, byte[]> tokenToNativeCode)
        {
            if (encryptedResource.Method == null)
            {
                return(false);
            }

            encryptedResource.init(simpleDeobfuscator);
            if (!encryptedResource.FoundResource)
            {
                return(false);
            }
            var methodsData = encryptedResource.decrypt();

            bool hooksJitter = findDnrCompileMethod(encryptedResource.Method.DeclaringType) != null;

            xorKey = getXorKey();
            xorEncrypt(methodsData);

            var methodsDataReader = new BinaryReader(new MemoryStream(methodsData));
            int patchCount        = methodsDataReader.ReadInt32();
            int mode = methodsDataReader.ReadInt32();

            int tmp = methodsDataReader.ReadInt32();

            methodsDataReader.BaseStream.Position -= 4;
            if ((tmp & 0xFF000000) == 0x06000000)
            {
                // It's method token + rva. DNR 3.7.0.3 (and earlier?) - 3.9.0.1
                methodsDataReader.BaseStream.Position += 8L * patchCount;
                patchCount = methodsDataReader.ReadInt32();
                mode       = methodsDataReader.ReadInt32();

                patchDwords(peImage, methodsDataReader, patchCount);
                while (methodsDataReader.BaseStream.Position < methodsData.Length - 1)
                {
                    uint token     = methodsDataReader.ReadUInt32();
                    int  numDwords = methodsDataReader.ReadInt32();
                    patchDwords(peImage, methodsDataReader, numDwords / 2);
                }
            }
            else if (!hooksJitter || mode == 1)
            {
                // DNR 3.9.8.0, 4.0, 4.1, 4.2, 4.3, 4.4
                patchDwords(peImage, methodsDataReader, patchCount);
                while (methodsDataReader.BaseStream.Position < methodsData.Length - 1)
                {
                    uint rva   = methodsDataReader.ReadUInt32();
                    uint token = methodsDataReader.ReadUInt32();                        // token, unknown, or index
                    int  size  = methodsDataReader.ReadInt32();
                    if (size > 0)
                    {
                        peImage.dotNetSafeWrite(rva, methodsDataReader.ReadBytes(size));
                    }
                }
            }
            else
            {
                // DNR 4.0 - 4.4 (jitter is hooked)

                var  metadataTables = peImage.Cor20Header.createMetadataTables();
                var  methodDef      = metadataTables.getMetadataType(MetadataIndex.iMethodDef);
                var  rvaToIndex     = new Dictionary <uint, int>((int)methodDef.rows);
                uint offset         = methodDef.fileOffset;
                for (int i = 0; i < methodDef.rows; i++)
                {
                    uint rva = peImage.offsetReadUInt32(offset);
                    offset += methodDef.totalSize;
                    if (rva == 0)
                    {
                        continue;
                    }

                    if ((peImage.readByte(rva) & 3) == 2)
                    {
                        rva++;
                    }
                    else
                    {
                        rva += (uint)(4 * (peImage.readByte(rva + 1) >> 4));
                    }
                    rvaToIndex[rva] = i;
                }

                patchDwords(peImage, methodsDataReader, patchCount);
                int count = methodsDataReader.ReadInt32();
                dumpedMethods = new DumpedMethods();
                while (methodsDataReader.BaseStream.Position < methodsData.Length - 1)
                {
                    uint rva          = methodsDataReader.ReadUInt32();
                    uint index        = methodsDataReader.ReadUInt32();
                    bool isNativeCode = index >= 0x70000000;
                    int  size         = methodsDataReader.ReadInt32();
                    var  methodData   = methodsDataReader.ReadBytes(size);

                    int methodIndex;
                    if (!rvaToIndex.TryGetValue(rva, out methodIndex))
                    {
                        Log.w("Could not find method having code RVA {0:X8}", rva);
                        continue;
                    }
                    uint methodToken = 0x06000001 + (uint)methodIndex;

                    if (isNativeCode)
                    {
                        totalEncryptedNativeMethods++;
                        if (tokenToNativeCode != null)
                        {
                            tokenToNativeCode[methodToken] = methodData;
                        }

                        // Convert return true / false methods. The others are converted to
                        // throw 0xDEADCODE.
                        if (DeobUtils.isCode(nativeLdci4, methodData))
                        {
                            uint val = BitConverter.ToUInt32(methodData, 4);
                            // ldc.i4 XXXXXXXXh / ret
                            methodData    = new byte[] { 0x20, 0, 0, 0, 0, 0x2A };
                            methodData[1] = (byte)val;
                            methodData[2] = (byte)(val >> 8);
                            methodData[3] = (byte)(val >> 16);
                            methodData[4] = (byte)(val >> 24);
                        }
                        else if (DeobUtils.isCode(nativeLdci4_0, methodData))
                        {
                            // ldc.i4.0 / ret
                            methodData = new byte[] { 0x16, 0x2A };
                        }
                        else
                        {
                            tokenToNativeMethod[methodToken] = methodData;

                            // ldc.i4 0xDEADCODE / conv.u4 / throw
                            methodData = new byte[] { 0x20, 0xDE, 0xC0, 0xAD, 0xDE, 0x6D, 0x7A };
                        }
                    }

                    var dm = new DumpedMethod();
                    dm.token = methodToken;
                    dm.code  = methodData;

                    offset         = methodDef.fileOffset + (uint)(methodIndex * methodDef.totalSize);
                    rva            = peImage.offsetReadUInt32(offset);
                    dm.mdImplFlags = peImage.offsetReadUInt16(offset + (uint)methodDef.fields[1].offset);
                    dm.mdFlags     = peImage.offsetReadUInt16(offset + (uint)methodDef.fields[2].offset);
                    dm.mdName      = peImage.offsetRead(offset + (uint)methodDef.fields[3].offset, methodDef.fields[3].size);
                    dm.mdSignature = peImage.offsetRead(offset + (uint)methodDef.fields[4].offset, methodDef.fields[4].size);
                    dm.mdParamList = peImage.offsetRead(offset + (uint)methodDef.fields[5].offset, methodDef.fields[5].size);

                    if ((peImage.readByte(rva) & 3) == 2)
                    {
                        dm.mhFlags          = 2;
                        dm.mhMaxStack       = 8;
                        dm.mhCodeSize       = (uint)dm.code.Length;
                        dm.mhLocalVarSigTok = 0;
                    }
                    else
                    {
                        dm.mhFlags          = peImage.readUInt16(rva);
                        dm.mhMaxStack       = peImage.readUInt16(rva + 2);
                        dm.mhCodeSize       = (uint)dm.code.Length;
                        dm.mhLocalVarSigTok = peImage.readUInt32(rva + 8);
                    }

                    dumpedMethods.add(dm);
                }
            }

            return(true);
        }
Beispiel #5
0
        public bool decrypt(PeImage peImage, ref DumpedMethods dumpedMethods)
        {
            dumpedMethods = new DumpedMethods();

            bool decrypted = false;

            var  metadataTables  = peImage.Cor20Header.createMetadataTables();
            var  methodDef       = metadataTables.getMetadataType(MetadataIndex.iMethodDef);
            uint methodDefOffset = methodDef.fileOffset;

            for (int i = 0; i < methodDef.rows; i++, methodDefOffset += methodDef.totalSize)
            {
                uint bodyRva = peImage.offsetReadUInt32(methodDefOffset);
                if (bodyRva == 0)
                {
                    continue;
                }
                uint bodyOffset = peImage.rvaToOffset(bodyRva);

                var dm = new DumpedMethod();
                dm.token = (uint)(0x06000001 + i);

                byte[] code, extraSections;
                peImage.Reader.BaseStream.Position = bodyOffset;
                var mbHeader = MethodBodyParser.parseMethodBody(peImage.Reader, out code, out extraSections);

                if (code.Length < 6 || code[0] != 0x2A || code[1] != 0x2A)
                {
                    continue;
                }
                dm.code          = code;
                dm.extraSections = extraSections;

                int seed = BitConverter.ToInt32(code, 2);
                Array.Copy(newCodeHeader, code, newCodeHeader.Length);
                if (seed == 0)
                {
                    decrypt(code);
                }
                else
                {
                    decrypt(code, seed);
                }

                dm.mdImplFlags = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[1].offset);
                dm.mdFlags     = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[2].offset);
                dm.mdName      = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[3].offset, methodDef.fields[3].size);
                dm.mdSignature = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[4].offset, methodDef.fields[4].size);
                dm.mdParamList = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[5].offset, methodDef.fields[5].size);

                dm.mhFlags          = mbHeader.flags;
                dm.mhMaxStack       = mbHeader.maxStack;
                dm.mhCodeSize       = (uint)dm.code.Length;
                dm.mhLocalVarSigTok = mbHeader.localVarSigTok;

                dumpedMethods.add(dm);
                decrypted = true;
            }

            return(decrypted);
        }
Beispiel #6
0
        List <CsHeaderVersion> getCsHeaderVersions(uint codeHeaderOffset, MetadataType methodDefTable)
        {
            if (sigType == SigType.Old)
            {
                return new List <CsHeaderVersion> {
                           CsHeaderVersion.V10
                }
            }
            ;
            if (!isOldHeader(methodDefTable))
            {
                return new List <CsHeaderVersion> {
                           CsHeaderVersion.V52
                }
            }
            ;
            if (csRtType.isAtLeastVersion50())
            {
                return new List <CsHeaderVersion> {
                           CsHeaderVersion.V50
                }
            }
            ;
            if (isCsHeader40(codeHeaderOffset))
            {
                return(new List <CsHeaderVersion> {
                    CsHeaderVersion.V40,
                    CsHeaderVersion.V30,
                });
            }
            return(new List <CsHeaderVersion> {
                CsHeaderVersion.V45,
                CsHeaderVersion.V50,
            });
        }

        bool isCsHeader40(uint codeHeaderOffset)
        {
            try {
                uint offset       = codeHeaderOffset + codeHeader.totalCodeSize + 0x28;
                uint prevCodeOffs = 0;
                for (int i = 0; i < (int)codeHeader.numMethods; i++, offset += 4)
                {
                    uint codeOffs = peImage.offsetReadUInt32(offset);
                    if (prevCodeOffs != 0 && codeOffs != 0 && codeOffs < prevCodeOffs)
                    {
                        return(false);
                    }
                    if (codeOffs != 0)
                    {
                        prevCodeOffs = codeOffs;
                    }
                }

                return(true);
            }
            catch (IOException) {
                return(false);
            }
        }

        bool isOldHeader(MetadataType methodDefTable)
        {
            if (methodDefTable.totalSize != codeHeader.methodDefElemSize)
            {
                return(true);
            }
            if (methodDefTable.fileOffset - peImage.rvaToOffset(peImage.Cor20Header.metadataDirectory.virtualAddress) != codeHeader.methodDefTableOffset)
            {
                return(true);
            }

            return(false);
        }

        ICsHeader createCsHeader(CsHeaderVersion version)
        {
            switch (version)
            {
            case CsHeaderVersion.V30: return(new CsHeader30(this));

            case CsHeaderVersion.V40: return(new CsHeader40(this));

            case CsHeaderVersion.V45: return(new CsHeader45(this));

            case CsHeaderVersion.V50: return(new CsHeader5(this, 0x28));

            case CsHeaderVersion.V52: return(new CsHeader5(this, 0x30));

            default: throw new ApplicationException("Unknown CS header");
            }
        }
Beispiel #7
0
        public bool decrypt2(ref DumpedMethods dumpedMethods)
        {
            uint offset = peImage.rvaToOffset(peImage.Cor20Header.metadataDirectory.virtualAddress + peImage.Cor20Header.metadataDirectory.size);

            if (!readCodeHeader(offset))
            {
                return(false);
            }

            var metadataTables = peImage.Cor20Header.createMetadataTables();
            var methodDefTable = metadataTables.getMetadataType(MetadataIndex.iMethodDef);

            if (methodDefTable.totalSize != codeHeader.methodDefElemSize)
            {
                return(false);
            }

            var methodInfos = getMethodInfos(offset + 0x30 + codeHeader.totalCodeSize);

            offset = methodDefTable.fileOffset - methodDefTable.totalSize;
            foreach (var methodInfo in methodInfos)
            {
                offset += methodDefTable.totalSize;
                if (methodInfo.flags == 0 || methodInfo.codeOffs == 0)
                {
                    continue;
                }
                uint rva = peImage.offsetReadUInt32(offset);
                peImage.writeUint16(rva, (ushort)methodInfo.flags);
                peImage.writeUint32(rva + 8, methodInfo.localVarSigTok);
            }

            dumpedMethods = new DumpedMethods();
            offset        = methodDefTable.fileOffset;
            for (int i = 0; i < methodInfos.Count; i++, offset += methodDefTable.totalSize)
            {
                var methodInfo = methodInfos[i];
                if (methodInfo.codeOffs == 0)
                {
                    continue;
                }

                var dm = new DumpedMethod();
                dm.token = 0x06000001 + (uint)i;

                uint rva = peImage.offsetReadUInt32(offset);
                dm.mdImplFlags = peImage.offsetReadUInt16(offset + (uint)methodDefTable.fields[1].offset);
                dm.mdFlags     = peImage.offsetReadUInt16(offset + (uint)methodDefTable.fields[2].offset);
                dm.mdName      = peImage.offsetRead(offset + (uint)methodDefTable.fields[3].offset, methodDefTable.fields[3].size);
                dm.mdSignature = peImage.offsetRead(offset + (uint)methodDefTable.fields[4].offset, methodDefTable.fields[4].size);
                dm.mdParamList = peImage.offsetRead(offset + (uint)methodDefTable.fields[5].offset, methodDefTable.fields[5].size);

                dm.code = decrypter.decrypt(methodInfo);

                if ((peImage.readByte(rva) & 3) == 2)
                {
                    dm.mhFlags          = 2;
                    dm.mhMaxStack       = 8;
                    dm.mhCodeSize       = (uint)dm.code.Length;
                    dm.mhLocalVarSigTok = 0;
                }
                else
                {
                    dm.mhFlags          = peImage.readUInt16(rva);
                    dm.mhMaxStack       = peImage.readUInt16(rva + 2);
                    dm.mhCodeSize       = (uint)dm.code.Length;
                    dm.mhLocalVarSigTok = peImage.readUInt32(rva + 8);
                }

                dumpedMethods.add(dm);
            }

            return(true);
        }