/// <summary>
/// This an optimized version of doing HttpUtility.UrlEncode(Convert.ToBase64String(hashPayLoad)).
/// This avoids the over head of converting it to a string and back to a byte[].
/// </summary>
private static unsafe string OptimizedConvertToBase64string(byte[] hashPayLoad)
{
// Create a large enough buffer that URL encode can use it.
// Increase the buffer by 3x so it can be used for the URL encoding
int capacity = Base64.GetMaxEncodedToUtf8Length(hashPayLoad.Length) * 3;
byte[] rentedBuffer = ArrayPool <byte> .Shared.Rent(capacity);
try
{
Span <byte> encodingBuffer = rentedBuffer;
// This replaces the Convert.ToBase64String
OperationStatus status = Base64.EncodeToUtf8(
hashPayLoad,
encodingBuffer,
out int _,
out int bytesWritten);
if (status != OperationStatus.Done)
{
throw new ArgumentException($"Authorization key payload is invalid. {status}");
}
return(AuthorizationHelper.UrlEncodeBase64SpanInPlace(encodingBuffer, bytesWritten));
}
finally
{
if (rentedBuffer != null)
{
ArrayPool <byte> .Shared.Return(rentedBuffer);
}
}
}