OpenSSL

openssl genrsa -out example.org.key 2048
openssl rsa -in example.org.key -noout -text # introspect

openssl rsa -in example.org.key -pubout -out example.org.pubkey
openssl rsa -in example.org.pubkey -pubin -noout -text

openssl req -new -key example.org.key -out example.org.csr
openssl req -in example.org.csr -noout -text

openssl genrsa -out ca.key 2048
openssl req -new -x509 -key ca.key -out ca.crt

openssl x509 -req -in example.org.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out example.org.crt
openssl x509 -in example.org.crt -noout -text
cat example.org.crt ca.crt > example.org.bundle.crt

# 查看服务器证书
openssl s_client -servername cloudflare.com -connect cloudflare.com:443
# 获取证书
openssl s_client -servername cloudflare.com -connect cloudflare.com:443 < /dev/null | openssl x509 -outform PEM > cloudflare.com.crt
# 证书信息
# cloudflare.com, *.amp.cloudflare.com, *.cloudflare.com, *.dns.cloudflare.com, *.staging.cloudflare.com
openssl x509 -in cloudflare.com.crt -text -noout | grep -E 'Subject:|DNS:'

# FP
echo -sha256 -sha1 -md5 | xargs -n1 openssl x509 -noout -fingerprint -inform pem -in ca.crt

# 查看证书时间
# notBefore=
# notAfter=
openssl x509 -in wener.me.crt -noout -dates
# 查看域名
openssl x509 -in wener.me.crt -noout -text | grep -E 'Subject:|DNS:'

openssl s_client -servername wener.me -connect wener.me:443