OpenSSL Commands

Generate RSA private key

openssl genrsa -out server.key 2048

Generate CSR

openssl req -new -key server.key -out server.csr -subj "/CN=example.com/O=Org/C=US"

Self-signed cert (365 days)

openssl req -x509 -newkey rsa:2048 -keyout server.key -out server.crt -days 365 -nodes -subj "/CN=example.com"

View certificate info

openssl x509 -in server.crt -text -noout

Check cert expiry

echo | openssl s_client -connect example.com:443 2>/dev/null | openssl x509 -noout -dates

Convert PEM to DER

openssl x509 -in server.crt -out server.der -outform DER