数字证书原理
http://www.cnblogs.com/JeffreySun/archive/2010/06/24/1627247.html
证书链
http://blog.csdn.net/win15135173776/article/details/61193997
https://www.cnblogs.com/cioliuguilan/p/5525845.html
用已有的私钥和证书(公钥)导入到keystore 中
https://stackoverflow.com/questions/17695297/importing-the-private-key-public-certificate-pair-in-the-java-keystore
http://blog.csdn.net/u013944791/article/details/73551253
Import Certificates from a p7b package into your Java Keystore (试了没成功)
https://www.attachmate.com/documentation/gateway-1-1/gateway-admin-guide/data/fxg_keytool_importp7b.htm
用keytool创建秘钥库以及导入导出数字证书等操作
http://blog.csdn.net/pucao_cug/article/details/70136159