Life's random bits By b1thunt3r (aka Ishan Jain)…
Download Website Certificates

Download Website Certificates

Ishan jain
Sometimes we need to download a websites certificate locally

There are times we need to download a certificate a website uses.

We can use openssl to download a certificate:

HOST=<hostname>; PORT=<port>; IP=<IP_Address>; \
echo | openssl s_client -servername $HOST -connect $IP:$PORT | \
sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /<destination_folder>/$HOST.crt

Where:

  • hostname: hostname for the site
  • port: TCP port, default is 443
  • IP_Address: ip address to the server, can be $HOST
  • destination_folder: destination folder to save certificate in

For example, following command will download certificate from example.com on port 443, and save it in /tmp/ folder:

HOST=example.com; PORT=443; IP=$HOST; \
echo | openssl s_client -servername $HOST -connect $IP:$PORT | \
sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/$HOST.crt

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