If you’ve ever had to handle certificates, it can sometimes – especially when renewing them – become confusing to know which certificate is which. Enter certdiff, a handy diff tool for certificates, by Mattias Geniar: $ ./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 …