ASP.NET machineKey Generator

This is an application that will generate a valid machineKey block with random, secure, hard-coded keys that you can paste inside the <system.web> in your web.config or machine.config file.

Hard-coded encryption and validation keys are needed if you have a web farm/web garden, if you use passwordFormat=Encrypted with ASP.NET 2.0’s Membership provider, or if you have certain ViewState issues. I discuss those reasons more in-depth in my blog posts about “Invalid Viewstate” errors and the ASP.NET Membership Encrypted passwordFormat, or you can also read my machineKey CodeProject article for more background information.

Below is a random set of keys, generated by this page. Go ahead and refresh this page to get a new set of keys.

ASP.NET 1.1 machineKey

<machineKey validationKey="15FF041109C2EFCC444E6EF4CAFD774C04F1E211585419CFA9899FF704D0595CDAE680AA39251C746A53FC3EF5A8B484AFBE79CF8E757A43D99AD24D65054107"
 validation="SHA1" />

ASP.NET 2.0 machineKey

<machineKey validationKey="F74B1DA303EF08E84792849EF58AC1FBE336C737D675A8CBC4DFD6266D507A93439DF5AC89DF2D18E6999EAEC0EAC455E533403F790295D7B8DEB4520E71C08F"
 validation="SHA1" decryption="AES" />

If you want, you can also use the code below so you can generate the keys yourself:

using System;
using System.Text;
using System.Security;
using System.Security.Cryptography;

private void Button1_Click(object sender, System.EventArgs e)
	txtASPNET20.Text = getASPNET20machinekey();
	txtASPNET11.Text = getASPNET11machinekey();

public string getASPNET20machinekey()
	StringBuilder aspnet20machinekey = new StringBuilder();
	string key64byte = getRandomKey(64);
	string key32byte = getRandomKey(32);
	return aspnet20machinekey.ToString();

public string getASPNET11machinekey()
	StringBuilder aspnet11machinekey = new StringBuilder();
	string key64byte = getRandomKey(64);
	string key24byte = getRandomKey(24);

	return aspnet11machinekey.ToString();

public string getRandomKey(int bytelength)
	int len = bytelength * 2;
	byte[] buff = new byte[len / 2];
	RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
	StringBuilder sb = new StringBuilder(len);
	for (int i = 0; i < buff.Length; i++)
		sb.Append(string.Format("{0:X2}", buff[i]));
	return sb.ToString();