# Generating Certificates ## Name Constraints Examples The following commands were used along with `extensions.conf` to generate the certificates in `nc.pem` and `nc_fail.pem`. ``` bash # Once for each certificate. $ openssl genrsa -out keyN.pem 2048 $ openssl req -new -key keyN.pem -out certN.csr # will be v3_ca_nc for the intermediate and v3_req for the device. $ openssl x509 -req -in certN.csr -CA certN-1.pem -CAkey keyN-1.pem -CAcreateserial -extensions -extfile extensions.conf -out certN.pem -days 365 -sha256 ``` Note: it looks like `openssl req` also accepts extensions via `-reqexts` but there is a known bug in openssl where extensions are transferred between CSRs and X509 certs.