Create a certificate

This procedure allows you to create a certificate.

1. Create the certificate serial file:

   $ echo 01 > MyCert.srl

   This command creates a serial file with an initial HEX value 01. OpenSSL uses this file to track the serial numbers of certificates it creates. The serial file is typically given the same name as the cert with the extension .srl.

2. Create a Certificate Signing Request (CSR):

   $ openssl req -new -out MyCert.csr

   Follow the instructions to create the CSR. This command also creates a privkey.pem file containing the RSA private key of the CSR certificate that is protected by a password you provide.
3. Remove the private key password (Optional):

   $ openssl rsa -in privkey.pem -out MyCert.pem

   Note: The unprotected private key is output in MyCert.pem.
4. Create a certificate from the CSR that is trusted by the Certificate Authority:

   $ openssl x509 -in MyCert.csr -out MyCert.crt -req -signkey MyCert.pem
    -CA MyCA.crt -CAkey MyCA.pem -days 365

   Note: About the CSR and its private key:

   • If you want an official Certificate Authority, you must send the CSR file to one of the self-established Certificate Authority companies on the Internet (instead of creating it with openssl. See Encryption and authentication).

   • The CSR file is also used to encrypt messages that only its corresponding private key can decrypt.