Use same same Redis connection for IDistributedCache and DataProtection

DataProtectionBuilderExtensions.cs

public static class DataProtectionBuilderExtensions
{
    public static IDataProtectionBuilder PersistKeysToStackExchangeRedisCache(this IDataProtectionBuilder builder, RedisKey key)
    {
        builder.Services.AddOptions<KeyManagementOptions>()
            .Configure<IDistributedCache>((options, distributedCache) => options.XmlRepository = new RedisXmlRepository(() => GetDatabase(distributedCache), key));
        return builder;
    }

    private static IDatabase GetDatabase(IDistributedCache store)
    {
        const BindingFlags bindingFlags = BindingFlags.NonPublic | BindingFlags.Instance;
        var redisCache = (RedisCache)store;
        var redisCacheType = typeof(RedisCache);
        var connectMethod = redisCacheType.GetMethod("Connect", bindingFlags);
        var cacheField = redisCacheType.GetField("_cache", bindingFlags);

        connectMethod.Invoke(redisCache, null);
        return (IDatabase)cacheField.GetValue(redisCache);
    }
}