建立你自己的 CA 服务：OpenSSL 命令行 CA 操作快速指南

这些是关于使用 OpenSSL 生成证书授权（CA）、中间证书授权和末端证书的速记随笔，内容包括 OCSP、CRL 和 CA 颁发者信息，以及指定颁发和有效期限等。

我们将建立我们自己的根 CA，我们将使用根 CA 来生成一个中间 CA 的例子，我们将使用中间 CA 来签署末端用户证书。

根 CA

创建根 CA 授权目录并切换到该目录：

mkdir ~/SSLCA/root/cd ~/SSLCA/root/

为我们的根 CA 生成一个8192位长的 SHA-256 RSA 密钥：

openssl genrsa -aes256 -out rootca.key 8192

样例输出：

Generating RSA private key, 8192 bit long modulus

.........++

....................................................................................................................++

e is 65537 (0x10001)

如果你想要用密码保护该密钥，请添加 -aes256 选项。

创建自签名根 CA 证书 ca.crt；你需要为你的根 CA 提供一个身份：

openssl req -sha256 -new -x509 -days 1826 -key rootca.key -out rootca.crt

样例输出：

You are about to be asked to enter information that will be incorporated

into your certificate request.

What you are about to enter is what is called a Distinguished Name or a DN.

There are quite a few fields but you can leave some blank

For some fields there will be a default value,

If you enter '.', the field will be left blank.

-----

Country Name (2 letter code) [AU]:NL

State or Province Name (full name) [Some-State]:Zuid Holland

Locality Name (eg, city) []:Rotterdam

Organization Name (eg, company) [Internet Widgits Pty Ltd]:Sparkling Network

Organizational Unit Name (eg, section) []:Sparkling CA

Common Name (e.g. server FQDN or YOUR name) []:Sparkling Root CA

Email Address []:

创建一个存储 CA 序列的文件：

touch certindex

echo 1000 > certserial

echo 1000 > crlnumber

放置 CA 配置文件，该文件持有 CRL 和 OCSP 末端的存根。

# vim ca.conf

[ ca ]

default_ca = myca

[ crl_ext ]

issuerAltName=issuer:copy 

authorityKeyIdentifier=keyid:always

 [ myca ]

 dir = ./

 new_certs_dir = $dir

 unique_subject = no

 certificate = $dir/rootca.crt

 database = $dir/certindex

 private_key = $dir/rootca.key

 serial = $dir/certserial

 default_days = 730

 default_md = sha1

 policy = myca_policy

 x509_extensions = myca_extensions

 crlnumber = $dir/crlnumber

 default_crl_days = 730

 [ myca_policy ]

 commonName = supplied

 stateOrProvinceName = supplied

 countryName = optional

 emailAddress = optional

 organizationName = supplied

 organizationalUnitName = optional

 [ myca_extensions ]

 basicConstraints = critical,CA:TRUE

 keyUsage = critical,any

 subjectKeyIdentifier = hash

 authorityKeyIdentifier = keyid:always,issuer

 keyUsage = digitalSignature,keyEncipherment,cRLSign,keyCertSign

 extendedKeyUsage = serverAuth

 crlDistributionPoints = @crl_section

 subjectAltName  = @alt_names

 authorityInfoAccess = @ocsp_section

 [ v3_ca ]

 basicConstraints = critical,CA:TRUE,pathlen:0

 keyUsage = critical,any

 subjectKeyIdentifier = hash

 authorityKeyIdentifier = keyid:always,issuer

 keyUsage = digitalSignature,keyEncipherment,cRLSign,keyCertSign

 extendedKeyUsage = serverAuth

 crlDistributionPoints = @crl_section

 subjectAltName  = @alt_names

 authorityInfoAccess = @ocsp_section

 [alt_names]

 DNS.0 = Sparkling Intermidiate CA 1

 DNS.1 = Sparkling CA Intermidiate 1

 [crl_section]

 URI.0 = http://pki.sparklingca.com/SparklingRoot.crl

 URI.1 = http://pki.backup.com/SparklingRoot.crl

 [ocsp_section]

 caIssuers;URI.0 = http://pki.sparklingca.com/SparklingRoot.crt

 caIssuers;URI.1 = http://pki.backup.com/SparklingRoot.crt

 OCSP;URI.0 = http://pki.sparklingca.com/ocsp/

 OCSP;URI.1 = http://pki.backup.com/ocsp/

如果你需要设置某个特定的证书生效/过期日期，请添加以下内容到[myca]：

# format: YYYYMMDDHHMMSS

default_enddate = 20191222035911

default_startdate = 20181222035911

创建中间 CA

生成中间 CA （名为 intermediate1）的私钥：

openssl genrsa -out intermediate1.key 4096

生成中间 CA 的 CSR：

openssl req -new -sha256 -key intermediate1.key -out intermediate1.csr

样例输出：

You are about to be asked to enter information that will be incorporated

into your certificate request.

What you are about to enter is what is called a Distinguished Name or a DN.

There are quite a few fields but you can leave some blank

For some fields there will be a default value,

If you enter '.', the field will be left blank.

-----

Country Name (2 letter code) [AU]:NL

State or Province Name (full name) [Some-State]:Zuid Holland

Locality Name (eg, city) []:Rotterdam

Organization Name (eg, company) [Internet Widgits Pty Ltd]:Sparkling Network

Organizational Unit Name (eg, section) []:Sparkling CA

Common Name (e.g. server FQDN or YOUR name) []:Sparkling Intermediate CA

Email Address []:

Please enter the following 'extra' attributes

to be sent with your certificate request

A challenge password []:

An optional company name []:

确保中间 CA 的主体（CN）和根 CA 不同。

用根 CA 签署中间 CA 的 CSR：

openssl ca -batch -config ca.conf -notext -in intermediate1.csr -out intermediate1.crt

样例输出：

Using configuration from ca.conf

Check that the request matches the signature

Signature ok

The Subject's Distinguished Name is as follows

countryName           :PRINTABLE:'NL'

stateOrProvinceName   :ASN.1 12:'Zuid Holland'

localityName          :ASN.1 12:'Rotterdam'

organizationName      :ASN.1 12:'Sparkling Network'

organizationalUnitName:ASN.1 12:'Sparkling CA'

commonName            :ASN.1 12:'Sparkling Intermediate CA'

Certificate is to be certified until Mar 30 15:07:43 2017 GMT (730 days)

Write out database with 1 new entries

Data Base Updated

生成 CRL（同时采用 PEM 和 DER 格式）：

openssl ca -config ca.conf -gencrl -keyfile rootca.key -cert rootca.crt -out rootca.crl.pem

openssl crl -inform PEM -in rootca.crl.pem -outform DER -out rootca.crl

每次使用该 CA 签署证书后，请生成 CRL。

如果你需要撤销该中间证书：

openssl ca -config ca.conf -revoke intermediate1.crt -keyfile rootca.key -cert rootca.crt

配置中间 CA

为该中间 CA 创建一个新文件夹，然后进入该文件夹：

mkdir ~/SSLCA/intermediate1/

cd ~/SSLCA/intermediate1/

从根 CA 拷贝中间证书和密钥：

cp ~/SSLCA/root/intermediate1.key ./

cp ~/SSLCA/root/intermediate1.crt ./

创建索引文件：

touch certindex

echo 1000 > certserial

echo 1000 > crlnumber

创建一个新的 ca.conf 文件：

# vim ca.conf

[ ca ]

default_ca = myca

[ crl_ext ]

issuerAltName=issuer:copy 

authorityKeyIdentifier=keyid:always

 [ myca ]

 dir = ./

 new_certs_dir = $dir

 unique_subject = no

 certificate = $dir/intermediate1.crt

 database = $dir/certindex

 private_key = $dir/intermediate1.key

 serial = $dir/certserial

 default_days = 365

 default_md = sha1

 policy = myca_policy

 x509_extensions = myca_extensions

 crlnumber = $dir/crlnumber

 default_crl_days = 365

 [ myca_policy ]

 commonName = supplied

 stateOrProvinceName = supplied

 countryName = optional

 emailAddress = optional

 organizationName = supplied

 organizationalUnitName = optional

 [ myca_extensions ]

 basicConstraints = critical,CA:FALSE

 keyUsage = critical,any

 subjectKeyIdentifier = hash

 authorityKeyIdentifier = keyid:always,issuer

 keyUsage = digitalSignature,keyEncipherment

 extendedKeyUsage = serverAuth

 crlDistributionPoints = @crl_section

 subjectAltName  = @alt_names

 authorityInfoAccess = @ocsp_section

 [alt_names]

 DNS.0 = example.com

 DNS.1 = example.org

 [crl_section]

 URI.0 = http://pki.sparklingca.com/SparklingIntermidiate1.crl

 URI.1 = http://pki.backup.com/SparklingIntermidiate1.crl

 [ocsp_section]

 caIssuers;URI.0 = http://pki.sparklingca.com/SparklingIntermediate1.crt

 caIssuers;URI.1 = http://pki.backup.com/SparklingIntermediate1.crt

 OCSP;URI.0 = http://pki.sparklingca.com/ocsp/

 OCSP;URI.1 = http://pki.backup.com/ocsp/

修改 [alt_names] 部分，添加你需要的主体备选名。如果你不需要主体备选名，请移除该部分包括subjectAltName = @alt_names的行。

如果你需要设置一个指定的生效/到期日期，请添加以下内容到 [myca]：

# format: YYYYMMDDHHMMSS

default_enddate = 20191222035911

default_startdate = 20181222035911

生成一个空白 CRL（同时以 PEM 和 DER 格式）：

openssl ca -config ca.conf -gencrl -keyfile rootca.key -cert rootca.crt -out rootca.crl.pem

openssl crl -inform PEM -in rootca.crl.pem -outform DER -out rootca.crl

生成末端用户证书

我们使用这个新的中间 CA 来生成一个末端用户证书，请重复以下操作来使用该 CA 为每个用户签署。

mkdir enduser-certs

生成末端用户的私钥：

openssl genrsa -out enduser-certs/enduser-example.com.key 4096

生成末端用户的 CSR：

openssl req -new -sha256 -key enduser-certs/enduser-example.com.key -out enduser-certs/enduser-example.com.csr

样例输出：

You are about to be asked to enter information that will be incorporated

into your certificate request.

What you are about to enter is what is called a Distinguished Name or a DN.

There are quite a few fields but you can leave some blank

For some fields there will be a default value,

If you enter '.', the field will be left blank.

-----

Country Name (2 letter code) [AU]:NL

State or Province Name (full name) [Some-State]:Noord Holland

Locality Name (eg, city) []:Amsterdam

Organization Name (eg, company) [Internet Widgits Pty Ltd]:Example Inc

Organizational Unit Name (eg, section) []:IT Dept

Common Name (e.g. server FQDN or YOUR name) []:example.com

Email Address []:

Please enter the following 'extra' attributes

to be sent with your certificate request

A challenge password []:

An optional company name []:

使用中间 CA 签署末端用户的 CSR：

openssl ca -batch -config ca.conf -notext -in enduser-certs/enduser-example.com.csr -out enduser-certs/enduser-example.com.crt

样例输出：

Using configuration from ca.conf

Check that the request matches the signature

Signature ok

The Subject's Distinguished Name is as follows

countryName           :PRINTABLE:'NL'

stateOrProvinceName   :ASN.1 12:'Noord Holland'

localityName          :ASN.1 12:'Amsterdam'

organizationName      :ASN.1 12:'Example Inc'

organizationalUnitName:ASN.1 12:'IT Dept'

commonName            :ASN.1 12:'example.com'

Certificate is to be certified until Mar 30 15:18:26 2016 GMT (365 days)

Write out database with 1 new entries

Data Base Updated

生成 CRL（同时以 PEM 和 DER 格式）：

openssl ca -config ca.conf -gencrl -keyfile intermediate1.key -cert intermediate1.crt -out intermediate1.crl.pem

openssl crl -inform PEM -in intermediate1.crl.pem -outform DER -out intermediate1.crl

每次你使用该 CA 签署证书后，都需要生成 CRL。

如果你需要撤销该末端用户证书：

openssl ca -config ca.conf -revoke enduser-certs/enduser-example.com.crt -keyfile intermediate1.key -cert intermediate1.crt

样例输出：

Using configuration from ca.conf

Revoking Certificate 1000.

Data Base Updated

通过连接根证书和中间证书来创建证书链文件。

cat ../root/rootca.crt intermediate1.crt > enduser-certs/enduser-example.com.chain

发送以下文件给末端用户：

enduser-example.com.crt

enduser-example.com.key

enduser-example.com.chain

你也可以让末端用户提供他们自己的 CSR，而只发送给他们这个 .crt 文件。不要把它从服务器删除，否则你就不能撤销了。

校验证书

你可以对证书链使用以下命令来验证末端用户证书：

openssl verify -CAfile enduser-certs/enduser-example.com.chain enduser-certs/enduser-example.com.crt 

enduser-certs/enduser-example.com.crt: OK

你也可以针对 CRL 来验证。首先，将 PEM 格式的 CRL 和证书链相连接：

cat ../root/rootca.crt intermediate1.crt intermediate1.crl.pem > enduser-certs/enduser-example.com.crl.chain

验证证书：

openssl verify -crl_check -CAfile enduser-certs/enduser-example.com.crl.chain enduser-certs/enduser-example.com.crt

没有撤销时的输出：

enduser-certs/enduser-example.com.crt: OK

撤销后的输出如下：

enduser-certs/enduser-example.com.crt: CN = example.com, ST = Noord Holland, C = NL, O = Example Inc, OU = IT Dept

error 23 at 0 depth lookup:certificate revoked

编译自：https://raymii.org/s/tutorials/OpenSSL_command_line_Root_and_Intermediate_CA_including_OCSP_CRL%20and_revocation.html作者： Remy van Elst
原创：LCTT https://linux.cn/article-5443-1.html译者： joeren