public virtual ReadOnlyMemory <byte> MakeChecksum(
ReadOnlyMemory <byte> data,
KerberosKey key,
KeyUsage usage,
KeyDerivationMode kdf,
int hashSize)
{
throw new NotImplementedException();
}
private byte[] DK(byte[] key, KeyUsage usage, KeyDerivationMode kdf)
{
var constant = new byte[5];
Endian.ConvertToBigEndian((int)usage, constant);
constant[4] = (byte)kdf;
return(DK(key, constant));
}
public override ReadOnlyMemory <byte> MakeChecksum(
ReadOnlyMemory <byte> data,
KerberosKey key,
KeyUsage usage,
KeyDerivationMode kdf,
int hashSize
)
{
var ki = this.GetOrDeriveKey(key, usage, kdf).Slice(0, hashSize);
return(this.Hmac(ki, data).Slice(0, hashSize));
}
public override byte[] MakeChecksum(byte[] data, byte[] key, KeyUsage usage, KeyDerivationMode kdf, int hashSize)
{
var ki = DK(key, usage, kdf);
var hash = Hmac(ki, data);
var output = new byte[hashSize];
Buffer.BlockCopy(hash, 0, output, 0, hashSize);
return(output);
}
public override ReadOnlyMemory <byte> MakeChecksum(
ReadOnlyMemory <byte> data,
KerberosKey key,
KeyUsage usage,
KeyDerivationMode kdf,
int hashSize
)
{
var ki = key.GetOrDeriveKey(
this,
$"{usage}|{kdf}|{KeySize}|{BlockSize}",
k => DK(k, usage, kdf, KeySize, BlockSize)
);
return(Hmac(ki, data).Slice(0, hashSize));
}
public override ReadOnlyMemory <byte> MakeChecksum(
ReadOnlyMemory <byte> data,
KerberosKey key,
KeyUsage usage,
KeyDerivationMode kdf,
int hashSize
)
{
if (key == null)
{
throw new ArgumentNullException(nameof(key));
}
var ki = key.GetOrDeriveKey(
this,
$"{usage}|{kdf}|{this.KeySize}|{this.BlockSize}",
k => DK(k, usage, kdf, this.KeySize, this.BlockSize)
);
return(Hmac(ki, data).Slice(0, hashSize));
}
public virtual byte[] MakeChecksum(byte[] data, byte[] key, KeyUsage usage, KeyDerivationMode kdf, int hashSize)
{
throw new NotImplementedException();
}
private static ReadOnlyMemory <byte> DK(ReadOnlyMemory <byte> key, KeyUsage usage, KeyDerivationMode kdf, int keySize, int blockSize)
{
using (var constantPool = CryptoPool.RentUnsafe <byte>(5))
{
var constant = constantPool.Memory.Slice(0, 5);
Span <byte> span = constant.Span;
span.Clear();
BinaryPrimitives.WriteInt32BigEndian(span, (int)usage);
constant.Span[4] = (byte)kdf;
return(DK(key, constant, keySize, blockSize));
}
}
private static ReadOnlySpan <byte> DK(ReadOnlySpan <byte> key, KeyUsage usage, KeyDerivationMode kdf, int keySize, int blockSize)
{
var constant = new Span <byte>(new byte[5]);
Endian.ConvertToBigEndian((int)usage, constant);
constant[4] = (byte)kdf;
return(DK(key, constant, keySize, blockSize));
}
private static ReadOnlyMemory <byte> DK(ReadOnlySpan <byte> key, KeyUsage usage, KeyDerivationMode kdf, int keySize, int blockSize)
{
using (var constantPool = CryptoPool.RentUnsafe <byte>(5))
{
var constant = constantPool.Memory.Slice(0, 5);
constant.Span.Fill(0);
Endian.ConvertToBigEndian((int)usage, constant.Span);
constant.Span[4] = (byte)kdf;
return(DK(key, constant, keySize, blockSize));
}
}
internal new ReadOnlyMemory <byte> GetOrDeriveKey(KerberosKey key, KeyUsage usage, KeyDerivationMode mode)
{
return(base.GetOrDeriveKey(key, usage, mode));
}
protected ReadOnlyMemory <byte> GetOrDeriveKey(KerberosKey kerberosKey, KeyUsage usage, KeyDerivationMode mode)
{
if (kerberosKey == null)
{
throw new InvalidOperationException("Key cannot be null");
}
return(kerberosKey.GetOrDeriveKey(
this,
$"{usage}|{mode}|{this.KeySize}|{this.BlockSize}",
key => this.DK(key, usage, mode, this.KeySize, this.BlockSize)
));
}
