「有点儿相关」渣浪登录v1.4用的rsa算法用c#算

以前的登录用wssa算法，现在用rsa。渣浪好像用rsa加密发送出去的不仅仅是密码
1。c#怎么算rsa？
2。向渣浪发的sp=xxx到底掺了什么一起加密？金坷垃吗？附：渣浪爱问登录抓包结果，UserName填写abcde，PWD是123456 
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发送内容是： 
entry=zhishiren&gateway=1&from=&savestate=0&useticket=0&su=YWJjZGU%3D&service=sso&servertime=1344264649&nonce=GHX9BZ&pwencode=rsa&rsakv=1330428213&sp=cb487c9cd3321971879228ea8c7fd0243d8ce9ed74f6ecd2a0ca31db2cf543994ddf2e1ed6c9a027daad495133ad0432f0a3ec5f21753d1dbc970d2c0dcef26eb1f58127ead7ea0c4558bb98cd9db3fefdd6e7bb6ba28390fef05eddb2a1cdb480bcde8cb91966e09240fb808730e0ba82f6e9289378193c273d207077897130&encoding=UTF-8&prelt=62&url=http%3A%2F%2Fiask.sina.com.cn%2Flogin%2Fajaxlogin.php%3Fframelogin%3D1%26callback%3Dparent.sinaSSOController.feedBackUrlCallBack&returntype=META