public static void ComputeAesParameters(byte[] newNonce, byte[] serverNonce, out AesKeyData aesKeyData)
{
using (var hash = SHA1.Create())
{
var nonces = new byte[48];
newNonce.CopyTo(nonces, 0);
serverNonce.CopyTo(nonces, 32);
var hash1 = hash.ComputeHash(nonces);
serverNonce.CopyTo(nonces, 0);
newNonce.CopyTo(nonces, 16);
var hash2 = hash.ComputeHash(nonces);
nonces = new byte[64];
newNonce.CopyTo(nonces, 0);
newNonce.CopyTo(nonces, 32);
var hash3 = hash.ComputeHash(nonces);
using (var keyBuffer = new MemoryStream(32))
using (var ivBuffer = new MemoryStream(32))
{
keyBuffer.Write(hash1, 0, hash1.Length);
keyBuffer.Write(hash2, 0, 12);
ivBuffer.Write(hash2, 12, 8);
ivBuffer.Write(hash3, 0, hash3.Length);
ivBuffer.Write(newNonce, 0, 4);
aesKeyData = new AesKeyData(keyBuffer.ToArray(), ivBuffer.ToArray());
}
}
}
public static byte[] EncryptAes(AesKeyData key, byte[] plaintext)
{
return(EncryptIge(plaintext, key.Key, key.Iv));
}
public static byte[] DecryptAes(AesKeyData key, byte[] ciphertext)
{
return(DecryptIge(ciphertext, key.Key, key.Iv));
}
