How to convert an SSL certificate into a different format

Prerequisites

1. Install OpenSSL
2. My OpenSSL is in the following location: C:\Program Files (x86)\GnuWin32\bin\

Convert .PFX to .PEM:

openssl pkcs12 -in wc.pfx -out C:\temp\wildcard.pem -nodes

Convert .PFX to .CRT:

openssl pkcs12 -in wc.pfx -clcerts -nokeys -out C:\temp\wc.crt`

Convert .PFX to .CER

openssl.exe pkcs12 -in .\wildcard.example.MDC.pfx -out example-wc.cer -nodes

Get certificate from a public website

This will return a string, copy the Begin and End certificate string and save as .cer or .crt

openssl.exe s_client -connect smtp.office365.com:587 -starttls smtp
openssl.exe s_client -connect smtp.office365.com:443

Reference:

• https://stackoverflow.com/questions/13732826/convert-pem-to-crt-and-key
• https://www.feistyduck.com/library/openssl-cookbook/online/ch-testing-with-openssl.html