gistfile1.md

SSL 驗證方式:

# 簡單查詢
echo | openssl s_client -connect xxx.xxx.xxx:443 | openssl x509 -noout -dates
# 簡單查詢 指定 tls1.2
echo | openssl s_client -connect xxx.xxx.xxx:443 -tls1_2 | openssl x509 -noout -dates
# 簡單查詢 指定 tls1.2 指定 domain
echo | openssl s_client -connect xxx.xxx.xxx:443 -tls1_2 -servername xxx.xxx.xxx | openssl x509 -noout -dates
# 完整顯示
echo | openssl s_client -connect xxx.xxx.xxx:443

lets-encrypt-certificates-are-expired.md

lets encrypt certificates expired

$ irb
:001 > require 'open-uri'
:002 > open(url)
# OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=error: certificate verify failed

The reason is that the "DST Root CA X3" certificate has expired yesterday.

To fix it, just disable the certificate on your server. Run:

sudo dpkg-reconfigure ca-certificates

• On the first screen that prompts "Trust new certificates from certificate authorities?" choose "yes".
• On the next screen press the down arrow key on your keyboard until you find mozilla/DST_Root_CA_X3.crt,
• press the space bar to deselect it (the [*] should turn into [ ]) and press Enter.

https://superuser.com/questions/1679204/curl-on-ubuntu-14-all-lets-encrypt-certificates-are-expired-error-60