Generating certificate using openssl commands

Method 1:

 #To check supported curves

openssl ecparam -list_curves

#Generate certificate and key

openssl ecparam -out key.pem -name prime256v1 -genkey

#Signing request

openssl req -new -sha256 -key key.pem -out sign.csr

#Self Signing

openssl req -x509 -sha256 -days 365 -key key.pem -in sign.csr -out cert.pem

Method 2:

#Creating CA Private Key

mkdir pki

cd pki

openssl genrsa -aes256 -out ca_priv.key 2048 

ENTER PASSWORD

#Creating CA - Certificate Authourity

openssl req -new -x509 -key ca_priv.key -sha256 -days 365 -out ca.pem

#To generate the key

openssl genrsa -out www.site.com.key 2048

#To generate CSR - Certificate signing request

openssl req -new -key ww.site.com.key -out www.site.com.csr

#To sign. For below command we need CA.pem and CA.key. otherinfo.ext is SAN detail (subject alternative name)

openssl x509 -req -in ww.site.com.csr -CA ca.pem -CAkey ca_priv.key -out ww.site.com.crt -days 365 -sha256 -CAcreateserial -extfile otherinfo.ext