.NET Obfuscation and Intellectual Property
By Brent Rector, August 01, 2002
Protecting the intellectual property in your compiled app from reverse engineering is a concern regardless of what language you use, but the metadata in .NET code increases its susceptibility to reverse engineering. Obfuscation can help thwart such attempts. Brent explores the benefits of several obfuscation strategies.
August 2002/.NET Obfuscation and Intellectual Property
Example 1: IL Disassembly of GetNewName
method private hidebysig instance string
GetNewString(string currentString,
int32 requiredLength) cil managed
{
// Code size 94 (0x5e)
.maxstack 3
.locals (int32 V_0)
IL_0000: ldarg.2
IL_0001: ldc.i4.1
IL_0002: add
IL_0003: starg.s requiredLength
IL_0005: ldarg.2
IL_0006: ldarg.0
IL_0007: ldfld int32 System.Text.StringBuilder::m_MaxCapacity
IL_000c: ble.s IL_0023
IL_000e: ldstr "ArgumentOutOfRange_NegativeCapacity"
IL_0013: call string System.Environment::GetResourceString (string)
IL_0018: ldstr "requiredLength"
IL_001d: newobj instance void System.ArgumentOutOfRangeException::.ctor(string,
string)
IL_0022: throw
IL_0023: ldarg.1
IL_0024: callvirt instance int32 System.String::get_Capacity()
IL_0029: ldc.i4.2
IL_002a: mul
IL_002b: stloc.0
IL_002c: ldloc.0
IL_002d: ldarg.2
IL_002e: bge.s IL_0032
IL_0030: ldarg.2
IL_0031: stloc.0
IL_0032: ldloc.0
IL_0033: ldarg.0
IL_0034: ldfld int32 System.Text.StringBuilder::m_MaxCapacity
IL_0039: ble.s IL_0042
IL_003b: ldarg.0
IL_003c: ldfld int32 System.Text.StringBuilder::m_MaxCapacity
IL_0041: stloc.0
IL_0042: ldloc.0
IL_0043: ldc.i4.0
IL_0044: bgt.s IL_0056
IL_0046: ldstr "ArgumentOutOfRange_NegativeCapacity"
IL_004b: call string System.Environment::GetResourceString(string)
IL_0050: newobj instance void System.ArgumentOutOfRangeException::.ctor(string)
IL_0055: throw
IL_0056: ldarg.1
IL_0057: ldloc.0
IL_0058: call string System.String::GetStringForStringBuilder(string,
int32)
IL_005d: ret
} // end of method StringBuilder::GetNewString
