This creates a bigger RSA key. Not really relevant in our case because
the connection stays local (proxy to client), but it's a good example.
# Generate proxy CA key file.
certtool --generate-privkey \
+ --sec-param=high \
--outfile proxy-ca-key.pem
# Generate proxy CA.
echo 'cn = tlsproxy CA' > "$tempfile"
# Generate proxy key file.
certtool --generate-privkey \
+ --sec-param=high \
--outfile proxy-key.pem
# Generate proxy "invalid" server certificate. It's used for problematic