Tool to rebase System.Reactive to the .net framework

rx-rebase.cs

using System;
using System.Globalization;
using System.Linq;

using Mono.Cecil;

class Rebase {

	static void Main ()
	{
		const string file = "System.Reactive.dll";

		var assembly = AssemblyFactory.GetAssembly (file);
		assembly.Name.PublicKey = null;
		assembly.Name.HasPublicKey = false;

		foreach (AssemblyNameReference reference in assembly.MainModule.AssemblyReferences) {
			switch (reference.Name) {
			case "mscorlib":
			case "System":
				reference.Version = new Version (2, 0, 0, 0);
				break;
			case "System.Core":
				reference.Version = new Version (3, 5, 0, 0);
				break;
			}
			reference.PublicKeyToken = GetPublicKeyToken ("b77a5c561934e089");
		}

		AssemblyFactory.SaveAssembly (assembly, file);
	}

	static byte [] GetPublicKeyToken (string str)
	{
		var pktoken = new byte [str.Length / 2];

		for (int i = 0; i < pktoken.Length; i++)
			pktoken [i] = Byte.Parse (str.Substring (i * 2, 2), NumberStyles.HexNumber);

		return pktoken;
	}
}