CURL模拟登陆SINA微博问题

<?php$username =base64_encode("xxxxxx@sina.com"); $data = file_get_contents('http://login.sina.com.cn/sso/prelogin.php?entry=miniblog&callback=&user='.$username.'&client=ssologin.js(v1.3.16)');$json = json_decode($data);$pw = strtolower(sha1(strtolower(sha1(strtolower("111111"))).$json->servertime.$json->nonce));$CookieFile = '/sinacookie/'.$username.'_sinacookie.tmp';		$post_data = array(		"entry"=>"weibo",		"gateway"=>"1",		"from"=>"",		"savestate"=>"7",		"useticket"=>"1",		"ssosimplelogin"=>"1",		"username"=>$username, // base 64之后的用户名		"service"=>"miniblog",		"servertime"=>$json->servertime, //上步得到的服务器时间		"nonce"=>$json->nonce, //上步得到随机生成的字符串		"pwencode"=>"wsse",		"password"=>$pw, //加密的密码		"encoding"=>"utf-8",		"url"=>"+ HttpUtility.UrlEncode('http:'//'weibo.com/ajaxlogin.php?framelogin=1&callback=parent.sinaSSOController.feedBackUrlCallBack')",		"returntype"=>"META");		 $ch = curl_init();curl_setopt($ch, CURLOPT_URL, "http://login.sina.com.cn/sso/login.php?client=ssologin.js(v1.3.16)");curl_setopt($ch, CURLOPT_POST, true);curl_setopt($ch, CURLOPT_POSTFIELDS,$post_data);curl_setopt($ch, CURLOPT_COOKIEJAR, $CookieFile);curl_setopt($ch, CURLOPT_COOKIEFILE, $CookieFile);curl_exec($ch);curl_close($ch);?>