1. 下面这句话怎么解释?
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Note: According to current US export law, RSA moduli larger than 512 bits may not be used for key exchange in software exported from the US. With this message, larger RSA keys may be used as signature-only certificates to sign temporary shorter RSA keys for key exchange. |
为什么超过512位只允许用于签名而不允许用户密钥交换?难道超过512位用于密钥交换不是更加安全吗?
2. Server Key Exchange Message 的作用
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The server key exchange message is sent by the server if it has no certificate, has a certificate only used for signing (e.g., DSS [<a title=""Digital Signature Standard"" href="http://tools.ietf.org/html/rfc6101#ref-DSS">DSS</a>] certificates, signing-only RSA [<a title=""A Method for Obtaining Digital Signatures and Public-Key Cryptosystems"" href="http://tools.ietf.org/html/rfc6101#ref-RSA">RSA</a>] certificates), or FORTEZZA KEA key exchange is used. This message is not used if the server certificate contains Diffie-Hellman [<a title=""New Directions in Cryptography"" href="http://tools.ietf.org/html/rfc6101#ref-DH1">DH1</a>] parameters. Note: According to current US export law, RSA moduli larger than 512 bits may not be used for key exchange in software exported from the US. With this message, larger RSA keys may be used as signature-only certificates to sign temporary shorter RSA keys for key exchange. |
如果server没有证书,或者server的证书只用于签名(如DSS证书,或只用于签名的RSA证书),这时候server端就会生成一对临时的公私钥,用户密钥交换。
3. 客户端是如何确认sever端的身份的?
首先,通过证书的校验机制,验证证书的有效性;然后,使用证书公钥
4. 共享密钥的交换过程是怎样的?
5. 关于ssl的sessionid的概念?
如果sessionid标识的session在server端没有过期的话,就不需要再校验证书,协商密钥套件了。(如果server端的配置有问题的话,你会发现依然有证书校验的过程),该sessionid在客户端一般不会落地的,比如: 重启浏览器后该sessionid就消失了
6. ssl与tls的关系
ietf对ssl做了标准化,在ssl3.0的基础上定义了tls1.0 规范
7. curl -H “Host: login.sina.com.cn” -v “https://10.54.38.18/httpsdetector.php”
curl 不会使用-H指定的域名来和返回的证书做匹配的。也不会把ip作为server_name 写到ssl的扩展字段中,如果使用
curl “https://login.sina.com.cn/httpsdetector.php”
则会把 login.sina.com.cn 写到 ssl的server_name 的扩展字段中的
参考资料:
http://rrsongzi-gmail-com.iteye.com/blog/603015
http://wenku.baidu.com/view/1f64701a10a6f524ccbf8595.html