自己签发CA证书再签发服务器证书的场景非常简单。把根CA证书导入到浏览器后,就可以信任由这个根CA直接签发的服务器证书。
但是实际上网站使用的证书肯定都不是由根CA直接签发的,比如
像百度这种,网站使用的证书就是由二级CA颁发的证书。
本文就来演示,自签CA,由自签CA签发二级CA,最后由二级CA签发网站证书
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系统环境:
Ubuntu 18.10
OpenSSL 1.1.1 11 Sep 2018
一:创建根CA
1:依次创建如下目录
mkdir -p /opt/ca/root
mkdir /opt/ca/root/key
2:vim /opt/ca/root/openssl.cnf
[ ca ]
default_ca = CA_default
[ CA_default ]
dir = /opt/ca/root
certs = $dir/certs
crl_dir = $dir/crl
database = $dir/index.txt
new_certs_dir = $dir/newcerts
certificate = $dir/key/cacert.crt
serial = $dir/serial
crlnumber = $dir/crlnumber
crl = $dir/crl.pem
private_key = $dir/key/cakey.pem
RANDFILE = $dir/key/.rand
unique_subject = no
x509_extensions = usr_cert
copy_extensions = copy
name_opt = ca_default
cert_opt = ca_default
default_days = 365
default_crl_days= 30
default_md = sha256
preserve = no
policy = policy_ca
[ policy_ca ]
countryName = supplied
stateOrProvinceName = supplied
organizationName = supplied
organizationalUnitName = supplied
commonName = supplied
emailAddress = optional
[ req ]
default_bits = 2048
default_keyfile = privkey.pem
distinguished_name = req_distinguished_name
attributes = req_attributes
x509_extensions = v3_ca
string_mask = utf8only
utf8 = yes
prompt = no
[ req_distinguished_name ]
countryName = CN
stateOrProvinceName = beijing
localityName = beijing
organizationName = Global Google CA Inc
organizationalUnitName = Root CA
commonName = Global Google Root CA
[ usr_cert ]
basicConstraints = CA:TRUE
[ v3_ca ]
basicConstraints = CA:TRUE
[ req_attributes ]
3:创建如下目录及文件
mkdir /opt/ca/root/newcerts
touch /opt/ca/root/index.txt
touch /opt/ca/root/index.txt.attr
echo 01 > /opt/ca/root/serial
4:创建根CA私钥
openssl genrsa -out /opt/ca/root/key/cakey.pem 2048
5:创建根CA证书请求文件
openssl req -new -key /opt/ca/root/key/cakey.pem -out /opt/ca/root/key/ca.csr -config /opt/ca/root/openssl.cnf
6:自签根CA证书
openssl ca -selfsign -in /opt/ca/root/key/ca.csr -out /opt/ca/root/key/cacert.crt -config /opt/ca/root/openssl.cnf
7:查看证书信息(可选)
openssl x509 -text -in /opt/ca/root/key/cacert.crt
经过以上几个步骤,就生成了根CA的相关证书和私钥,可以用于签发其他的CA(二级CA),不可签发服务器证书
二:创建二级CA
1:依次创建如下目录
mkdir /opt/ca/agent
mkdir /opt/ca/agent/key
2:vim /opt/ca/agent/openssl.cnf
[ ca ]
default_ca = CA_default
[ CA_default ]
dir = /opt/ca/agent
certs = $dir/certs
crl_dir = $dir/crl
database = $dir/index.txt
new_certs_dir = $dir/newcerts
certificate = $dir/key/cacert.crt
serial = $dir/serial
crlnumber = $dir/crlnumber
crl = $dir/crl.pem
private_key = $dir/key/cakey.pem
RANDFILE = $dir/key/.rand
unique_subject = no
x509_extensions = usr_cert
copy_extensions = copy
name_opt = ca_default
cert_opt = ca_default
default_days = 365
default_crl_days= 30
default_md = sha256
preserve = no
policy = policy_ca
[ policy_ca ]
countryName = supplied
stateOrProvinceName = supplied
organizationName = supplied
organizationalUnitName = supplied
commonName = supplied
emailAddress = optional
[ req ]
default_bits = 2048
default_keyfile = privkey.pem
distinguished_name = req_distinguished_name
attributes = req_attributes
x509_extensions = v3_ca
string_mask = utf8only
utf8 = yes
prompt = no
[ req_distinguished_name ]
countryName = CN
stateOrProvinceName = Guangdong
localityName = Guangzhou
organizationName = Global Google CA Inc
organizationalUnitName = Google 2019 CA
commonName = Google 2019 CA
[ usr_cert ]
basicConstraints = CA:FALSE
[ v3_ca ]
basicConstraints = CA:TRUE
[ req_attributes ]
3:创建如下目录及文件
mkdir /opt/ca/agent/newcerts
touch /opt/ca/agent/index.txt
touch /opt/ca/agent/index.txt.attr
echo 01 > /opt/ca/agent/serial
4:创建二级CA私钥
openssl genrsa -out /opt/ca/agent/key/cakey.pem 2048
5:创建二级CA证书请求文件
openssl req -new -key /opt/ca/agent/key/cakey.pem -out /opt/ca/agent/key/ca.csr -config /opt/ca/agent/openssl.cnf
6:使用根CA签发二级CA
openssl ca -in /opt/ca/agent/key/ca.csr -out /opt/ca/agent/key/cacert.crt -config /opt/ca/root/openssl.cnf
7:查看证书信息(可选)
openssl x509 -text -in /opt/ca/agent/key/cacert.crt
经过以上几个步骤,就生成了一个二级CA,这个二级CA可以签发服务器证书(不能签发其他的CA)
三:使用二级CA签发服务器端证书
1:mkdir /opt/ca/taobao
2:vim /opt/ca/taobao/openssl.cnf
[ req ]
prompt = no
distinguished_name = server_distinguished_name
req_extensions = req_ext
x509_extensions = v3_req
attributes = req_attributes
[ server_distinguished_name ]
commonName = taobao2018.cn
stateOrProvinceName = zhejiang
countryName = CN
organizationName = Alibaba Taobao Inc
organizationalUnitName = Taobao IT
[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
[ req_attributes ]
[ req_ext ]
subjectAltName = @alternate_names
[ alternate_names ]
DNS.1 = taobao2018.cn
DNS.2 = bbs.taobao2018.cn
DNS.3 = taobao2019.cn
3:生成网站私钥
openssl genrsa -out /opt/ca/taobao/privkey.pem 2048
4:生成证书请求文件(csr文件)
openssl req -new -key /opt/ca/taobao/privkey.pem -out /opt/ca/taobao/taobao.csr -config /opt/ca/taobao/openssl.cnf
5:使用二级CA进行签发证书(这里不能用根CA签发)
openssl ca -in /opt/ca/taobao/taobao.csr -out /opt/ca/taobao/taobao.crt -config /opt/ca/agent/openssl.cnf
6:聚合证书(重要)
由于是二级CA颁发的证书,所以,服务器需要把根CA、二级CA等证书都要发送给浏览器,所以给到web服务器的证书是要一个聚合的证书
cat /opt/ca/taobao/taobao.crt /opt/ca/agent/key/cacert.crt /opt/ca/root/key/cacert.crt | tee /opt/ca/taobao/taobao_all.crt
PS:注意顺序
7:查看证书信息(可选)
openssl x509 -text -in /opt/ca/taobao/taobao_all.crt
经过以上几个步骤,就生成了由二级CA签发的证书了
四:配置nginx的ssl
server {
listen 443 ssl;
server_name taobao2018.cn bbs.taobao2018.cn taobao2019.cn;
ssl_certificate /opt/ca/taobao/taobao_all.crt;
ssl_certificate_key /opt/ca/taobao/privkey.pem;
ssl_session_cache shared:SSL:1m;
ssl_session_timeout 5m;
ssl_ciphers HIGH:!aNULL:!MD5;
ssl_prefer_server_ciphers on;
location / {
root html;
index index.html index.htm;
}
}
五:导入自建CA的根证书(二级CA证书无需导入)
这里以Firefox为例,打开:选项 -> 隐私与安全 -> 查看证书,在证书颁发机构里面选择导入,
选择文件 /opt/ca/root/key/cacert.crt 导入并勾选2个信任的复选框
六:配置hosts
192.168.133.134 taobao2018.cn
192.168.133.134 bbs.taobao2018.cn
192.168.133.134 taobao2019.cn
最后,使用https方式访问上面的三个url中的任意一个均可
访问之后,也可以在Firefox上查看证书
注意:
一:
CA和证书是有区别的,CA是用来颁发证书和签发二级CA的,且两者是互斥的。也就是说,一个CA要么是用来签发二级CA的,要么是用来签发证书的。
如何判断?
在 /opt/ca/root/openssl.cnf配置文件中,有如下配置
[ usr_cert ]
basicConstraints = CA:TRUE
[ v3_ca ]
basicConstraints = CA:TRUE
usr_cert下面的basicConstraints代表的是当前CA的配置,
CA:TRUE是当前CA签发的是CA(二级CA),不能签发证书,
CA:FALSE是当前CA签发的是证书,不能签发CA(二级CA)
v3_ca下面的basicConstraints代表的是请求的证书是CA还是证书
CA:TRUE表示当前请求的是CA(二级CA)
CA:FALSE表示当前请求的是证书
二:
如果是CA(二级CA),则证书请求中的commonName不需要填写域名,可以填写组织机构
如果是证书,则证书请求中的commonName需要填写域名(一般是主域名),当然了,这个主域名也要在后面的subjectAltName属性中