Unity发送HTTPS请求

本文主要介绍2中发送HTTPS方法，其中第二种方法支持代理模式。代理模式可以有效节省DNS时间
对于延迟要求敏感的应用可以采用

一、常规HTTPS请求

直接使用发送HTTP请求一样的方法，参见Unity发送HTTP请求和文件下载

二、使用SslStream模拟HTTPS请求，代码如下：

/// <summary>
/// 发送HTTPS请求
/// </summary>
/// <returns>The SSLP roxy request.</returns>
/// <param name="url">URL.</param>
/// <param name="proxyIp">Proxy ip.</param>
/// <param name="method">Method.</param>
/// <param name="paramsMap">Parameters map.</param>
/// <param name="timeout">Timeout.</param>
public static string SendSSLProxyRequest(string url, string proxyIp, string method = "GET", Dictionary<string, string> paramsMap = null, int timeout = 2000)
{
    if (method == "GET")
    {
        url = BuildURL(url, paramsMap);
    }
    Uri uri = new Uri(url);
    TcpClient client = null;
    SslStream sslStream = null;
    try
    {
        // Connect socket
        client = new TcpClient(proxyIp, 443);
        // Wrap in SSL stream
        sslStream = new SslStream(client.GetStream(), false, certificateValidationCallback, null);
        sslStream.ReadTimeout = timeout;
        sslStream.WriteTimeout = timeout;
        // 进行校验
        sslStream.AuthenticateAsClient(uri.Host);
        // Send request
        string sendData = @"{0} {1} HTTP/1.1
Host: {2}
";
        sendData = string.Format(sendData, method, uri.AbsoluteUri, uri.Host);
        // 检查POST内容
        int length = -1;
        if ("POST".Equals(method) && null != paramsMap)
        {
            StringBuilder postBuilder = new StringBuilder();
            foreach (var pair in paramsMap)
            {
                if (postBuilder.Length > 0)
                {
                    postBuilder.Append("&");
                }
                postBuilder.Append(pair.Key).Append("=").Append(pair.Value);
            }
            length = Encoding.UTF8.GetBytes(postBuilder.ToString()).Length;
            sendData += string.Format(@"Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Content-Length: {0}

{1}", length, postBuilder.ToString());
        }
        else
        {
            sendData += "\r\n";
        }
        // 发送数据
        byte[] bytes = Encoding.UTF8.GetBytes(sendData);
        sslStream.Write(bytes, 0, bytes.Length);
        sslStream.Flush();
        // 读取数据
        byte[] buffer = new byte[2048];
        length = -1;
        int contentLength = -1;
        int dataLen = -1;
        int statusCode = -1;
        string statusMsg = null;
        StringBuilder responseBuilder = new StringBuilder();
        do
        {
            length = sslStream.Read(buffer, 0, buffer.Length);
            if (length <= 0) {
                break;
            }
            string content = Encoding.UTF8.GetString(buffer, 0, length);
            responseBuilder.Append(content);
            if (contentLength == -1)
            {
                int contentIndex = content.IndexOf("\r\n\r\n");
                if (contentIndex > 0)
                {
                    content = responseBuilder.ToString();
                    // 获取响应代码
                    string statusString = content.Substring(0, content.IndexOf("\r\n"));
                    string[] statusArray = statusString.Split(' ');
                    statusCode = Convert.ToInt32(statusArray[1]);
                    statusMsg = statusArray[2];
                    // 获取内容长度
                    int start = content.IndexOf("Content-Length:");
                    int end = content.IndexOf("\r\n", start);
                    contentLength = Convert.ToInt32(content.Substring(start + 16, end - start - 16));
                    content = content.Substring(contentIndex + 4);
                    responseBuilder.Length = 0;
                    responseBuilder.Append(content);
                    dataLen = Encoding.UTF8.GetBytes(content).Length;
                }
            }
            else
            {
                dataLen += length;
            }
            if (dataLen >= contentLength)
            {
                break;
            }
        } while (length != 0);
        if (statusCode == 200) {
            return responseBuilder.ToString();
        } else {
            Log.Instance.errorFormat("send request error, url:{0}, responseCode:{1}, error:{2}", url, statusCode, statusMsg);
        }
    }
    catch (Exception e)
    {
        Log.Instance.errorFormat("send request error, url:{0}", e, url);
    }
    finally
    {
        if (null != sslStream)
        {
            sslStream.Close();
        }
        if (null != client)
        {
            client.Close();
        }
    }
    return null;
}
/// <summary>
/// 构建GET URL
/// </summary>
/// <returns>The UR.</returns>
/// <param name="url">URL.</param>
/// <param name="paramsMap">Parameters map.</param>
private static string BuildURL(string url, Dictionary<string, string> paramsMap)
{
    if (null == paramsMap)
    {
        return url;
    }
    StringBuilder builder = new StringBuilder();
    foreach (var pair in paramsMap)
    {
        if (builder.Length > 0)
        {
            builder.Append("&");
        }
        builder.Append(pair.Key).Append("=").Append(UrlEncode(pair.Value));
    }
    if (url.IndexOf("?") != -1)
    {
        url = url + "&" + builder.ToString();
    }
    else
    {
        url = url + "?" + builder.ToString();
    }
    return url;
}