OpenSSL Generate 4096-bit Certificate (Public/Private Key Encryption) with SHA256 Fingerprint

gencert.sh

# Generate Private Key and Certificate using RSA 256 encryption (4096-bit key)
openssl req -x509 -newkey rsa:4096 -keyout privatekey.pem -out certificate.pem -days 365
# Alternatively, setting the "-newkey" parameter to "rsa:2048" will generate a 2048-bit key.

# Generate PKCS#12 (P12) file for cert; combines both key and certificate together
openssl pkcs12 -export -inkey privatekey.pem -in certificate.pem -out cert.pfx

# Generate SHA256 Fingerprint for Certificate and export to a file
openssl x509 -noout -fingerprint -sha256 -inform pem -in certificate.pem >> fingerprint.txt

# Generate SHA1 Fingerprint for Certificate and export to a file
#openssl x509 -noout -fingerprint -sha1 -inform pem -in certificate.pem >> fingerprint.txt
# FYI, it's best practice to use SHA256 instead of SHA1 for better security, but this shows how to do it if you REALLY need to.