/// <summary>
/// Try to get the header.
/// </summary>
/// <param name="header"></param>
/// <param name="alg"></param>
/// <param name="base64UrlHeader"></param>
/// <returns></returns>
public bool TryGetHeader(JwtObject header, SignatureAlgorithm alg, [NotNullWhen(true)] out byte[]?base64UrlHeader)
{
if (header.TryGetValue(HeaderParameters.KidUtf8, out var kidProperty) &&
kidProperty.Type == JwtTokenType.String &&
!(kidProperty.Value is null) &&
!(alg is null) &&
header.Count == 2)
{
var kid = (string)kidProperty.Value;
var keyId = kid.AsSpan();
var node = _head;
while (node != null)
{
if (keyId.SequenceEqual(node.Kid.AsSpan()))
{
if (node.Entries.TryGetValue(alg.Id, out var entry))
{
base64UrlHeader = entry;
if (node != _head)
{
MoveToHead(node);
}
return(true);
}
goto NotFound;
}
node = node.Next;
}
}
NotFound:
base64UrlHeader = null;
return(false);
}
/// <summary>
/// Adds a base64url encoded header to the cache.
/// </summary>
/// <param name="header"></param>
/// <param name="alg"></param>
/// <param name="base6UrlHeader"></param>
public void AddHeader(JwtObject header, SignatureAlgorithm alg, ReadOnlySpan <byte> base6UrlHeader)
{
if (header.TryGetValue(HeaderParameters.KidUtf8, out var kidProperty) &&
kidProperty.Type == JwtTokenType.String &&
!(kidProperty.Value is null) &&
!(alg is null) &&
header.Count == 2)
{
var kid = (string)kidProperty.Value;
bool lockTaken = false;
try
{
_spinLock.Enter(ref lockTaken);
var node = _head;
while (node != null)
{
if (string.Equals(node.Kid, kid, StringComparison.Ordinal))
{
break;
}
node = node.Next;
}
var key = alg.Id;
if (node is null)
{
node = new Bucket(kid, new Dictionary <long, byte[]>(1)
{
{ key, base6UrlHeader.ToArray() }
})
{
Next = _head
};
}
else
{
if (node.Entries.ContainsKey(key))
{
node.Entries[key] = base6UrlHeader.ToArray();
}
}
if (_count >= MaxSize)
{
RemoveLeastRecentlyUsed();
}
else
{
_count++;
}
if (_head != null)
{
_head.Previous = node;
}
_head = node;
if (_tail is null)
{
_tail = node;
}
}
finally
{
if (lockTaken)
{
_spinLock.Exit();
}
}
}
}