前言https相较于http而言有很大的安全性,当我们一个服务开启https并与之通信时,往往需要证书的认证,如果是浏览器访问服务,只要在浏览器内设置信任证书即可,而如果是程序内访问服务(如java程序),则需要导入该服务的证书所信任的证书。实际情况中,内部系统的互相通信使用https,往往不可能向公有CA申请证书(申请证书需要很高的费用),故我们需要创建一个私有CA来申请证书实现https通信。名词介绍CA和证书认证详见我的一篇博文:https简单解读实现步骤环境介绍64位 centos 7.X操作系统装有openssl命令构建私有CACA要给别人签发证书,首先自己得有一个作为根证书,我们得在一切工作之前修改好CA的配置文件、序列号、索引等等。输入以下命令更改配置文件:vi /etc/pki/tls/openssl.cnf配置文件更改以下部分:[ CA_default ] dir = /etc/pki/CA # Where everything is keptcerts = $dir/certs # Where the issued certs are keptcrl_dir = $dir/crl # Where the issued crl are keptdatabase = $dir/index.txt # database index file.#unique_subject = no # Set to ’no’ to allow creation of # several ctificates with same subject.new_certs_dir = $dir/newcerts # default place for new certs. certificate = $dir/cacert.pem # The CA certificateserial = $dir/serial # The current serial numbercrlnumber = $dir/crlnumber # the current crl number # must be commented out to leave a V1 CRLcrl = $dir/crl.pem # The current CRLprivate_key = $dir/private/cakey.pem # The private keyRANDFILE = $dir/private/.rand # private random number file…default_days = 3650 # how long to certify for…# For the CA policy[ policy_match ]countryName = matchstateOrProvinceName = optionallocalityName = optionalorganizationName = optionalorganizationalUnitName = optionalcommonName = suppliedemailAddress = optional在/etc/pki/CA目录创建两个文件index.txt和serial:cd /etc/pki/CA && touch index.txt serial && echo 01 > serial仍在当前目录下生成一个CA私钥cakey.pem和自签证书cacert.pem:openssl genrsa -out private/cakey.pem 2048openssl req -new -x509 -key private/cakey.pem -out cacert.pem生成公钥的时候会提示输入一些信息,例子如下:Country Name (2 letter code) []:CN #国家名State or Province Name (full name) []:hangzhou #省份名Locality Name (eg, city) []:hangzhou #地名Organization Name (eg, company) []:company #公司名Organizational Unit Name (eg, section) []:unit #部门名Common Name (eg, your websites domain name) []:localhost #服务域名Email Address []: #电子邮件后面一些信息可按回车略过这里比较重要的是Comman Name填写的是服务的域名地址,即如果该证书用于某个服务则填该服务的域名地址(如用于百度服务器,则填写www.baidu.com)本方案的CA证书不用于某个服务,故可填localhost私有CA签署证书为一个服务生成私钥server.key和一个证书请求文件server.csr:openssl genrsa -out server.key 2048openssl req -new -key server.key -out server.csr生成证书请求文件时,仍会提示输入一些信息,例子如下:Country Name (2 letter code) []:CN #国家名State or Province Name (full name) []:hangzhou #省份名Locality Name (eg, city) []:hangzhou #地名Organization Name (eg, company) []:company #公司名Organizational Unit Name (eg, section) []:unit #部门名Common Name (eg, your websites domain name) []:XXX.XXX.XXX #服务域名Email Address []: #电子邮件这里的Common Name就应该填你实际服务所用的域名了下面将该证书请求文件server.csr由你构建的私有CA签署,生成一个server.crt证书:openssl x509 -req -in server.csr -CA /etc/pki/CA/cacert.pem -CAkey /etc/pki/CA/private/cakey.pem -CAcreateserial -out server.crt到此为止,server.crt证书可用于服务提供https访问,客户端若想访问该服务,导入CA根证书cacert.pem即可。