| public static Compute ( IDigest hash, byte key, byte data ) : byte[] | ||
| hash | IDigest | |
| key | byte | |
| data | byte | |
| 리턴 | byte[] | |
private unsafe void CreateResumeTicket(Guid userToken, out byte[] ticket, out byte[] sessionSecret)
{
#if SQLCLR
ticket = null;
sessionSecret = null;
#else
State state = m_state;
//Ticket Structure:
// byte TicketVersion = 1
// Guid ServerKeyName
// DateTime AuthenticationTime
// byte[16] IV
// byte[] Encrypted Session Data 32+16
// byte[32] HMAC (Sha2-256)
const int encryptedLength = 32 + 16;
const int ticketSize = 1 + 16 + 8 + 16 + encryptedLength + 32;
byte[] initializationVector = SaltGenerator.Create(16);
sessionSecret = SaltGenerator.Create(32);
byte[] userTokenBytes = userToken.ToRfcBytes();
byte[] dataToEncrypt = new byte[encryptedLength];
sessionSecret.CopyTo(dataToEncrypt, 0);
userTokenBytes.CopyTo(dataToEncrypt, sessionSecret.Length);
ticket = new byte[ticketSize];
using (Aes aes = Cipher.CreateAes())
{
aes.Key = state.ServerEncryptionkey;
aes.IV = initializationVector;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
ICryptoTransform decrypt = aes.CreateEncryptor();
byte[] encryptedData = decrypt.TransformFinalBlock(dataToEncrypt, 0, dataToEncrypt.Length);
fixed(byte *lp = ticket)
{
BinaryStreamPointerWrapper stream = new BinaryStreamPointerWrapper(lp, ticket.Length);
stream.Write((byte)1);
stream.Write(state.ServerKeyName);
stream.Write(DateTime.UtcNow.RoundDownToNearestMinute());
stream.Write(initializationVector);
stream.Write(encryptedData); //Encrypted data, 32 byte session key, n byte user token
stream.Write(HMAC <Sha256Digest> .Compute(state.ServerHMACKey, ticket, 0, ticket.Length - 32));
}
}
#endif
}
public void TestHMACs2(int key, int value)
{
byte[] keyB = new byte[key];
byte[] valueB = new byte[value];
rng.GetBytes(keyB);
rng.GetBytes(valueB);
var code = HMAC <Sha1Digest> .Compute(keyB, valueB);
HMACSHA1 hmac1 = new HMACSHA1(keyB);
var code2 = hmac1.ComputeHash(valueB);
if (!code.SequenceEqual(code2))
{
throw new Exception();
}
hmac1.Dispose();
}
private unsafe bool TryLoadTicket(byte[] ticket, out byte[] sessionSecret, out Guid userToken)
{
#if SQLCLR
sessionSecret = null;
userToken = Guid.Empty;
return(false);
#else
State state = m_state;
const int encryptedLength = 32 + 16;
const int ticketSize = 1 + 16 + 8 + 16 + encryptedLength + 32;
userToken = default(Guid);
sessionSecret = null;
//Ticket Structure:
// byte TicketVersion = 1
// Guid ServerKeyName
// DateTime AuthenticationTime
// byte[16] IV
// byte[] Encrypted Session Data 32+16
// byte[32] HMAC (Sha2-256)
if (ticket == null || ticket.Length != ticketSize)
return(false);
fixed(byte *lp = ticket)
{
var stream = new BinaryStreamPointerWrapper(lp, ticket.Length);
if (stream.ReadUInt8() != 1)
{
return(false);
}
if (!state.ServerKeyName.SecureEquals(stream.ReadGuid()))
{
return(false);
}
long currentTime = DateTime.UtcNow.Ticks;
long issueTime = stream.ReadInt64();
if (issueTime <= currentTime)
{
//Issue time is before current time.
if (currentTime - issueTime > TimeSpan.TicksPerMinute * TicketExpireTimeMinutes)
{
return(false);
}
}
else
{
//For some reason, the issue time is after the current time.
//This could be due to a clock sync on the server after the ticket was issued.
//Allow up to 1 minute of clock skew
if (issueTime - currentTime > TimeSpan.TicksPerMinute)
{
return(false);
}
}
byte[] initializationVector = stream.ReadBytes(16);
//Verify the signature if everything else looks good.
//This is last because it is the most computationally complex.
//This limits denial of service attackes.
byte[] hmac = HMAC <Sha256Digest> .Compute(state.ServerHMACKey, ticket, 0, ticket.Length - 32);
if (!hmac.SecureEquals(ticket, ticket.Length - 32, 32))
{
return(false);
}
byte[] encryptedData = stream.ReadBytes(encryptedLength);
var aes = new RijndaelManaged();
aes.Key = state.ServerEncryptionkey;
aes.IV = initializationVector;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
var decrypt = aes.CreateDecryptor();
encryptedData = decrypt.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
sessionSecret = new byte[32];
Array.Copy(encryptedData, 0, sessionSecret, 0, 32);
userToken = encryptedData.ToRfcGuid(32);
return(true);
}
#endif
}