Aes 32 Byte Key Generator
- Aes 32 Byte Key Generator Manual
- Aes 32 Byte Key Generator For Sale
- Aes 32 Byte Key Generator Free
- Random Byte Generator
Key generator This page generates a wide range of encryption keys based on a pass phrase. Passphrase: aes-128-cbc: aes-128-cfb: aes-128-cfb1: aes-128-cfb8. What is AES encryption? AES (acronym of Advanced Encryption Standard) is a symmetric encryption algorithm. The algorithm was developed by two Belgian cryptographer Joan Daemen and Vincent Rijmen. AES was designed to be efficient in both hardware and software, and supports a block length of 128 bits and key lengths of 128, 192, and 256 bits. If you don't make the IV random (i.e., you use some repeating group of numbers), it will be easier to figure out the key if the cookie always start with the same clear text. The IV size for AES-128 is 128 bits. IIRC, the IV is the same size as the cipher block. 128 bits is 16 bytes. 32 bytes if you store it as a ASCII hex string.
How do you run a key generator. AES Example - Input (128 bit key and message) Key in English: Thats my Kung Fu (16 ASCII characters, 1 byte each) Translation into Hex: T h a t s m y K u n g F u.
I was looking for some simple examples of using AES symmetric encryption to encrypt and decrypt data in C#. Though there are some very helpful resources out there, what I needed were basic routines that:
– Take clear text and key as byte arrays and return encrypted text as a byte array.
– Take encrypted text and key as byte arrays and return clear text as a byte array.
The most informative resources I found were:
– .NET Security blog: Generating a key from a password.
This covers, and explains, the key generation code very well. I.e. how to convert a pass phrase into a secure key for symmetric encryption.
– .NET documentation for the AESManaged class.
Describes available methods and has a complete AES example which disposes of object correctly.
Since neither reference had exactly what I needed, I combined elements from both to create the following example routines which encrypt and decrypt byte arrays, using an AES key size of 256:
using System.Security.Cryptography;
using System.IO;
private byte[] AESEncryptBytes(byte[] clearBytes, byte[] passBytes, byte[] saltBytes)
{
byte[] encryptedBytes = null;
// create a key from the password and salt, use 32K iterations – see note
var key = new Rfc2898DeriveBytes(passBytes, saltBytes, 32768);
// create an AES object
using (Aes aes = new AesManaged())
{
// set the key size to 256
aes.KeySize = 256;
aes.Key = key.GetBytes(aes.KeySize / 8);
aes.IV = key.GetBytes(aes.BlockSize / 8);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, aes.CreateEncryptor(),
CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
encryptedBytes = ms.ToArray();
}
}
return encryptedBytes;
}
private byte[] AESDecryptBytes(byte[] cryptBytes, byte[] passBytes, byte[] saltBytes)
{
byte[] clearBytes = null;
// create a key from the password and salt, use 32K iterations
var key = new Rfc2898DeriveBytes(passBytes, saltBytes, 32768);
using (Aes aes = new AesManaged())
{
// set the key size to 256
aes.KeySize = 256;
aes.Key = key.GetBytes(aes.KeySize / 8);
aes.IV = key.GetBytes(aes.BlockSize / 8);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cryptBytes, 0, cryptBytes.Length);
cs.Close();
}
clearBytes = ms.ToArray();
}
}
return clearBytes;
}
Note the routines take a salt argument in addition to a password. Enforcing the use of a salt makes for a more secure password hash. The salt argument can be any data of at least 8 bytes. For testing you could hardcode it; how you generate it depends on your application requirements.
Aes 32 Byte Key Generator Manual
The key in the example above is created using Rfc2898DeriveBytes which implements Password-Based Key Derivation Function 2 (PBKDF2) – an RSA standard for secure key derivation. I’ve not seen any definitive guidelines on the number of iterations to use, but keep in mind the following:
– The initial standard, written in 2000, recommended 1000 iterations.
– More iterations make a key more secure, up to a point (i.e. millions).
– As CPU speeds get faster, the number of iterations need to increase to maintain the same level of security.
– Key generation takes noticeably longer as you increase the number of iterations.
In my example I somewhat arbitrarily chose 32768 iterations as the highest number that doesn’t cause much noticeable lag during key generation when the program is run.
Suppose you want to use these routines to encrypt/decrypt strings instead of byte arrays? You could change the routines directly, or write wrappers to convert the strings before calling them like this:
private string AESEncryptString(string clearText, string passText, string saltText)
{
byte[] clearBytes = Encoding.UTF8.GetBytes(clearText);
byte[] passBytes = Encoding.UTF8.GetBytes(passText);
byte[] saltBytes = Encoding.UTF8.GetBytes(saltText);
return Convert.ToBase64String(AESEncryptBytes(clearBytes, passBytes, saltBytes));
}Generate a aes256 symmetric key.
private string AesDecryptString(string cryptText, string passText, string saltText)
{
byte[] cryptBytes = Convert.FromBase64String(cryptText);
byte[] passBytes = Encoding.UTF8.GetBytes(passText);
byte[] saltBytes = Encoding.UTF8.GetBytes(saltText);
Aes 32 Byte Key Generator For Sale
return Encoding.UTF8.GetString(AESDecryptBytes(cryptBytes, passBytes, saltBytes));
}
Aes 32 Byte Key Generator Free
As an example, here’s a program I wrote that uses these routines, a password vault for Windows desktop called Keyache: https://github.com/gbowerman/KeyCache.