server/src/Core/Services/Implementations/AzureQueueBlockIpService.cs

using System;
using System.Threading.Tasks;
using Azure.Storage.Queues;
using Bit.Core.Settings;

namespace Bit.Core.Services
{
    public class AzureQueueBlockIpService : IBlockIpService
    {
        private readonly QueueClient _blockIpQueueClient;
        private readonly QueueClient _unblockIpQueueClient;
        private Tuple<string, bool, DateTime> _lastBlock;

        public AzureQueueBlockIpService(
            GlobalSettings globalSettings)
        {
            _blockIpQueueClient = new QueueClient(globalSettings.Storage.ConnectionString, "blockip");
            _unblockIpQueueClient = new QueueClient(globalSettings.Storage.ConnectionString, "unblockip");
        }

        public async Task BlockIpAsync(string ipAddress, bool permanentBlock)
        {
            var now = DateTime.UtcNow;
            if (_lastBlock != null && _lastBlock.Item1 == ipAddress && _lastBlock.Item2 == permanentBlock &&
                (now - _lastBlock.Item3) < TimeSpan.FromMinutes(1))
            {
                // Already blocked this IP recently.
                return;
            }

            _lastBlock = new Tuple<string, bool, DateTime>(ipAddress, permanentBlock, now);
            await _blockIpQueueClient.SendMessageAsync(ipAddress);
            if (!permanentBlock)
            {
                await _unblockIpQueueClient.SendMessageAsync(ipAddress, new TimeSpan(0, 15, 0));
            }
        }
    }
}