如果我们的网站需要和另一个域名做统一认证，也就是在我们网站登录，但真正的功能却在另一个网站来提供。许多都以 passport 的方式。
整个认证可以分三步完成
第一步：本地验证
这个很简单，输入本地的用户名和密码，然后服务器认证通过，并返回正确的Cookie;
第二步：做远程认证，并返回远程连接
通过本地Cookie,确认用户合法性，然后服务器端调用远程的登录程序，返回一个远程认证号的URL,这个URL里面包含了一个唯一的认证码，使用Location的方式
第三步：远程登录
客户端使用前一步的URL,访问远程的服务器，服务器确认认证码的正确性，再返回正确的远程Cookie.
至此，本地认证，通过一个URL,实现了远程认证。
以下是师范代码，是Verycd的武林英雄的认证过程，其登录服务是verycd提供的，而真实服务时9wee提供的。
package org.javaren.hero;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.net.Socket;import java.net.URLEncoder;import java.util.Scanner;/** * 跨服务器登录验证(单点登录SSO)的过程和Java实现 * * @author JAVA世纪网(java2000.net, laozizhu.com) */public class Login { public static String getCookie() { System.out.print("输入用户名:"); Scanner in = new Scanner(System.in); String username = in.next(); System.out.print("输入密码:"); String password = in.next(); try { // 本地认证 String cookie = postLogin(username, password); if (cookie == null) { return null; } // 服务器远程认证 String url = getLogin2(cookie); if (url == null) { return null; } // 远程访问认证 String cookie2 = getLogin3(url.substring("http://s4.verycd.9wee.com".length())); // System.out.println(cookie2); return cookie2; } catch (Exception ex) { ex.printStackTrace(); return null; } } private static String postLogin(String username, String password) throws Exception { Socket socket = new Socket("secure.verycd.com", 80); try { StringBuilder sb = new StringBuilder(); sb.append("POST /signin?f=out HTTP/1.1/r/n"); sb.append("Host: secure.verycd.com/r/n"); sb.append("User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3/r/n"); sb.append("Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8/r/n"); sb.append("Accept-Language: zh-cn,zh;q=0.5/r/n"); sb.append("Accept-Encoding: gzip,deflate/r/n"); sb.append("Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7/r/n"); sb.append("Referer: http://secure.verycd.com/3rdServices/50hero/r/n"); sb.append("Content-Type: application/x-www-form-urlencoded/r/n"); String data = "ru=http%3A%2F%2Fsecure.verycd.com%2F3rdServices%2F50hero&login_submit=%E7%99%BB%E5%BD%95&username=" + URLEncoder.encode(username, "UTF-8") + "&password=" + URLEncoder.encode(password, "UTF-8"); sb.append("Content-Length: " + data.getBytes("UTF-8").length + "/r/n"); sb.append("/r/n"); sb.append(data); OutputStream os = socket.getOutputStream(); os.write(sb.toString().getBytes("UTF-8")); os.flush(); InputStream is = socket.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8")); // 读取结果 String line; StringBuilder cookieSb = new StringBuilder(); int index; while ((line = reader.readLine()) != null) { if (line.startsWith("Set-Cookie:")) { if (!line.contains("=deleted;")) { index = line.indexOf(";"); if (index > 12) { cookieSb.append(line.substring(12, index + 1)); } } } else if (line.startsWith("location:")) { if (line.contains("error_code")) { return null; } } } is.close(); reader.close(); return cookieSb.toString(); } finally { socket.close(); } } private static String getLogin2(String cookie) throws Exception { Socket socket = new Socket("secure.verycd.com", 80); try { StringBuilder sb = new StringBuilder(); sb.append("GET /signin?ak=50hero&ru=http%3A%2F%2Fs4.verycd.9wee.com%2Fpassport.php HTTP/1.1/r/n"); sb.append("Host: secure.verycd.com/r/n"); sb.append("User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3/r/n"); sb.append("Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8/r/n"); sb.append("Accept-Language: zh-cn,zh;q=0.5/r/n"); sb.append("Accept-Encoding: gzip,deflate/r/n"); sb.append("Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7/r/n"); sb.append("Referer: http://secure.verycd.com/3rdServices/50hero/r/n"); sb.append("Cookie: " + cookie + "/r/n"); sb.append("/r/n"); OutputStream os = socket.getOutputStream(); os.write(sb.toString().getBytes("UTF-8")); os.flush(); InputStream is = socket.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8")); // 读取结果 String line; while ((line = reader.readLine()) != null) { if (line.startsWith("location:")) { return line.substring(10); } } is.close(); reader.close(); return null; } finally { socket.close(); } } private static String getLogin3(String url) throws Exception { Socket socket = new Socket("s4.verycd.9wee.com", 80); try { StringBuilder sb = new StringBuilder(); sb.append("GET " + url + " HTTP/1.1/r/n"); sb.append("Host: s4.verycd.9wee.com/r/n"); sb.append("User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3/r/n"); sb.append("Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8/r/n"); sb.append("Accept-Language: zh-cn,zh;q=0.5/r/n"); sb.append("Accept-Encoding: gzip,deflate/r/n"); sb.append("Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7/r/n"); sb.append("Referer: http://secure.verycd.com/3rdServices/50hero/r/n"); sb.append("/r/n/r/n"); OutputStream os = socket.getOutputStream(); os.write(sb.toString().getBytes("UTF-8")); os.flush(); InputStream is = socket.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8")); // 读取结果 String line; StringBuilder cookieSb = new StringBuilder(); int index; while ((line = reader.readLine()) != null) { if (line.length() == 0) { break; } if (line.startsWith("Set-Cookie:")) { index = line.indexOf(";"); if (index > 12) { cookieSb.append(line.substring(12, index + 1)); } } } is.close(); reader.close(); return cookieSb.toString(); } finally { socket.close(); } }}
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