Why and How to generate self-singed or public singed certificate ?

Why ?

Certificate can be self-singed or publicly singed , self-singed is singed by your server only and no public trusted authority know this certificate, it is good to be used for testing only, production servers/website services that may need a certificate , you have to generate a request file to be signed by public known authority and load the singed in your public website or service that may need this certificate.

How ?

1- generate a private key that will be used to generate a certificate request, this key is important to be kept with you for future needed in case .

 ## with password:

openssl genrsa -des3 -out private.key 2048

## without password:

openssl genrsa -out VISA_ACS1_PROD_Signing.key 2048

2- Create the Certificate Singed Request:

openssl req -new -key privkey.key -sha256  -out server.csr

If this certificate will be singed by public authority , you have to share “server.csr” and they will provide you a singed certiticate (mainly .csr or .crt ) file

3- For Selef-Singed Certificate do the below, First generate a server certificate that will act like private authority to singe the csr:

openssl x509 -req -days 1825 -in server.csr -signkey server.key -out server.crt

4- In many cases you may need to convert crt to PEM format, use the below:

openssl x509 -in server.crt -out server.pem -outform PEM