certdiff

Show the difference between 2 certificate files.

Usage

$ certdiff /path/to/file1.crt /path/to/file2.crt

Output

Differences are highlighted using the diff -y output (side-by-side diff), output with the | character in between indicates differences between the files.

$ ./certdiff cronweekly.com/cert.pem sysca.st/cert.pem
subject= /CN=cronweekly.com                               |  subject= /CN=sysca.st
issuer= /C=US/O=Let's Encrypt/CN=Let's Encrypt Authority     issuer= /C=US/O=Let's Encrypt/CN=Let's Encrypt Authority
notBefore=Feb 15 08:48:00 2016 GMT                        |  notBefore=Feb 15 09:11:00 2016 GMT
notAfter=May 15 08:48:00 2016 GMT                         |  notAfter=May 15 09:11:00 2016 GMT

If there are no differences, the tool will tell you.

$ ./certdiff cronweekly.com/cert.pem othercert/cert.pem
No differences, the data (FQDN, SAN, ...) is the same.