Generate random bytes for TripleDES key C#
I need to generate byte array for TripleDES e开发者_StackOverflow社区ncryption. I don't want to use .generateKey()
because I need to know the bytes in the key to pass them to another application.
Thanks for the replies but I forgot to mention one thing: the bytes have to be odd parity. Otherwise I can't generate a TripleDES key from them. I'm not so familiar with the odd parity, so I guess have to create a byte check if it has odd parity or not; then if it does put it in the array, otherwise not.
If you need to ensure the odd parity, you have to compute it yourself. This should do:
var rng = new RNGCryptoServiceProvider();
var key = new byte[24];
rng.GetBytes(key);
for(var i = 0; i < key.Length; ++i)
{
int keyByte = key[i] & 0xFE;
var parity = 0;
for (var b = keyByte; b != 0; b >>= 1) parity ^= b & 1;
key[i] = (byte)(keyByte | (parity == 0 ? 1 : 0));
}
return key;
How about:
RandomNumberGenerator rng = RandomNumberGenerator.Create();
byte[] key = new byte[24]; // For a 192-bit key
rng.GetBytes(key);
tripleDes.Key = key;
Note that RandomNumberGenerator
is suitable for crypto work (in terms of reasonably secure, hard-to-predict random data), whereas System.Random
isn't.
But ... what's the problem with just:
TripleDES provider = TripleDES.Create();
byte[] key = provider.Key;
There you get your key used by the en- and decryptor created with this instance.
Note that the other answers lack a TripleDES.IsWeakKey
.
The GetBytes method returns crypthographically strong sequence of values:
var rng = System.Security.Cryptography.RandomNumberGenerator.Create();
byte [] barr = new byte[128];
rng.GetBytes(barr);
foreach (var b in barr)
{
Console.WriteLine(b);
}
What about Random.NextBytes()
More info here.
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