如何使用OpenSSL生成具有SubjectAltName的自签名证书？

Question

我正在尝试使用带有SubjectAltName的OpenSSL生成一个自签名证书.虽然我正在为证书生成csr,但我猜我必须使用OpenSSL x509的v3扩展.我在用 :

openssl req -new -x509 -v3 -key private.key -out certificate.pem -days 730

有人可以用确切的语法帮助我吗？

Answer 1

有人可以用确切的语法帮助我吗？

它是一个三步过程,它涉及修改openssl.cnf文件.您可能只能使用命令行选项来执行此操作,但我不这样做.

找到你的openssl.cnf文件.它可能位于/usr/lib/ssl/openssl.cnf:

$ find /usr/lib -name openssl.cnf
/usr/lib/openssl.cnf
/usr/lib/openssh/openssl.cnf
/usr/lib/ssl/openssl.cnf

在我的Debian系统上,/usr/lib/ssl/openssl.cnf由内置openssl程序使用.在最近的Debian系统上,它位于/etc/ssl/openssl.cnf

您可以openssl.cnf通过向XXX文件添加虚假来查看是否正在使用哪个,并查看是否存在openssl阻塞.

首先,修改req参数.添加一个alternate_names部分以openssl.cnf包含您要使用的名称.没有现有的alternate_names部分,因此添加它的位置无关紧要.

[ alternate_names ]

DNS.1        = example.com
DNS.2        = www.example.com
DNS.3        = mail.example.com
DNS.4        = ftp.example.com

接下来,将以下内容添加到现有 [ v3_ca ]部分.搜索确切的字符串[ v3_ca ]:

subjectAltName      = @alternate_names

您可以更改keyUsage为以下内容[ v3_ca ]:

keyUsage = digitalSignature, keyEncipherment

digitalSignature并且keyEncipherment是服务器证书的标准公平.别担心nonRepudiation.对于想成为律师的comp sci家伙来说,这是一个无用的想法.它在法律世界中没有任何意义.

最后,IETF(RFC 5280),浏览器和CA运行速度快且松散,因此您提供的密钥用法可能无关紧要.

其次,修改签名参数.在以下CA_default部分找到这一行:

# Extension copying option: use with caution.
# copy_extensions = copy

并将其更改为:

# Extension copying option: use with caution.
copy_extensions = copy

这可确保将SAN复制到证书中.复制dns名称的其他方法也被破坏了.

三,生成自签名:

$ openssl genrsa -out private.key 3072
$ openssl req -new -x509 -key private.key -sha256 -out certificate.pem -days 730
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.
...

最后,检查证书:

$ openssl x509 -in certificate.pem -text -noout
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 9647297427330319047 (0x85e215e5869042c7)
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=US, ST=MD, L=Baltimore, O=Test CA, Limited, CN=Test CA/emailAddress=test@example.com
        Validity
            Not Before: Feb  1 05:23:05 2014 GMT
            Not After : Feb  1 05:23:05 2016 GMT
        Subject: C=US, ST=MD, L=Baltimore, O=Test CA, Limited, CN=Test CA/emailAddress=test@example.com
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (3072 bit)
                Modulus:
                    00:e2:e9:0e:9a:b8:52:d4:91:cf:ed:33:53:8e:35:
                    ...
                    d6:7d:ed:67:44:c3:65:38:5d:6c:94:e5:98:ab:8c:
                    72:1c:45:92:2c:88:a9:be:0b:f9
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Subject Key Identifier: 
                34:66:39:7C:EC:8B:70:80:9E:6F:95:89:DB:B5:B9:B8:D8:F8:AF:A4
            X509v3 Authority Key Identifier: 
                keyid:34:66:39:7C:EC:8B:70:80:9E:6F:95:89:DB:B5:B9:B8:D8:F8:AF:A4

            X509v3 Basic Constraints: critical
                CA:FALSE
            X509v3 Key Usage: 
                Digital Signature, Non Repudiation, Key Encipherment, Certificate Sign
            X509v3 Subject Alternative Name: 
                DNS:example.com, DNS:www.example.com, DNS:mail.example.com, DNS:ftp.example.com
    Signature Algorithm: sha256WithRSAEncryption
         3b:28:fc:e3:b5:43:5a:d2:a0:b8:01:9b:fa:26:47:8e:5c:b7:
         ...
         71:21:b9:1f:fa:30:19:8b:be:d2:19:5a:84:6c:81:82:95:ef:
         8b:0a:bd:65:03:d1