Beispiel #1
0
        public bool decrypt(PeImage peImage, ref DumpedMethods dumpedMethods)
        {
            this.peImage = peImage;

            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(PE.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;
        }