SSL

Check certificate
https://www.ssllabs.com/ssltest/analyze.html
http://www.panticz.de/Check-SSL-TLS-server-encryption-support

Determine SSL certificate expiration date

openssl x509 -enddate -noout -in www.example.com.pem

List certificate domains

cat cert.pem | openssl x509 -text | grep DNS
openssl s_client -showcerts -connect www.example.com:443 | openssl x509 -text  | grep DNS

Remove password from private key

openssl rsa -in www.example.key.pass -out www.example.key

Cat / deploy certificate to remote host

ssh host1.example.com cat /root/certificates/example.com/{fullchain1.pem,privkey1.pem} | ssh ${HOST} "cat > /etc/haproxy/ssl/example.com.pem"

Get certificate information

openssl x509 -in certificate.crt -text -noout

Show expiration date for multiple certificates

for DIR in $(find * -maxdepth 0 -type d); do
    echo -n "${DIR}: "
    eval openssl x509 -enddate -noout -in "${DIR}/cert*.pem"
done

Letsencrypt
http://www.panticz.de/letsencrypt

Links
http://panticz.de/apache2_openssl_certificate
http://www.panticz.de/Install-SSL-CA-Certificate