问如何扩展文档DB资源令牌的到期时间

EN

 string GenerateAuthToken(string verb, string resourceId, string resourceType, string key, string keyType, string tokenVersion)
    {
        var hmacSha256 = new System.Security.Cryptography.HMACSHA256 { Key = Convert.FromBase64String(key) };

        string verbInput = verb ?? "";
        string resourceIdInput = resourceId ?? "";
        string resourceTypeInput = resourceType ?? "";

        string dateString = DateTime.UtcNow.ToString("r").ToLower();

        string payLoad = string.Format(System.Globalization.CultureInfo.InvariantCulture,
            "{0}\n{1}\n{2}\n{3}\n{4}\n",
                verb.ToLowerInvariant(),
                resourceType.ToLowerInvariant(),
                resourceId,
                dateString,
                ""
        );

        byte[] hashPayLoad = hmacSha256.ComputeHash(System.Text.Encoding.UTF8.GetBytes(payLoad));
        string signature = Convert.ToBase64String(hashPayLoad);

        return System.Web.HttpUtility.UrlEncode(String.Format(System.Globalization.CultureInfo.InvariantCulture, "type={0}&ver={1}&sig={2}",
            keyType,
            tokenVersion,
            signature));
    }