Snippet: Create a self-signed private key and certificate signing request with Cloudflare SLL (cfssl)

snippet--create-self-signed-private-key-and-certificate-signing-request-with-cfssl.md

Problem

Creating a certificate signing request with CloudFlare's cfssl tool.

Solution

1. Create a Certificate Signing Request JSON file

Minimally, you want to specify the hosts, CN, and key properties. For example:

cat <<EOF > csr.json
{
  "hosts": ["example.com"],
  "CN": "example.com",
  "key": {
    "algo": "ecdsa",
    "size": 256
  }
}
EOF

2. Create Private Key and Corresponding Certificate Signing Request

cfssl genkey -initca csr.json | cfssljson -bare example

Note: We are using the name example for the output files.

The command pipe in the step above produces the output files

• example.csr (certificate signing request)
• example-key.pem (private key)
• example.pem (certificate)

Notes

An installation guide for cfssl and additional information can be found on the project's Github page.