====== OpenSSL ======

== remove passphrase from private key ==
<code bash>
openssl rsa -in asdf.key -out asdf.key
</code>

== show technical infos about private key ==
<code bash>
openssl rsa -in asdf.key -text
</code>

== show certificate details ==
<code bash>
openssl x509 -in asdf.cert -text
</code>

== show certificate of a mail server (STARTTLS) ==
<code>
printf "QUIT" | openssl s_client -connect mail.example.org:25 -starttls smtp | openssl x509 -text -noout
</code>

== show remote certificate dates ==
<code>
printf "\r\n" | openssl s_client -connect example.org:443 2>/dev/null | openssl x509 -dates -noout
</code>

== generate CSR (length: 4096bit) ==
<code bash>
openssl req -newkey rsa:4096 -keyout asdf.key -out asdf.csr
</code>

== create pkcs12 file from cert an private key ==
//(ex. for Thunderbird S/MIME with StartSSL Cert)//
<code bash>
openssl pkcs12 -export -out asdf@example.org.pfx -inkey asdf@example.org.key -in 2_asdf@example.org.crt -certfile 1_Intermediate.crt
</code>