How do I do public-key encryption with
OpenSSL is a public-key crypto library (plus some other random stuff). Here’s how to do the basics: key generation, encryption and decryption. We’ll use RSA keys, which means the relevant
openssl commands are
# Alice generates her private key `priv_key.pem` openssl genrsa -out priv_key.pem 2048 # Alice extracts the public key `pub_key.pem` and sends it to Bob openssl rsa -pubout -in priv_key.pem -out pub_key.pem # Bob encrypts a message and sends `encrypted_with_pub_key` to Alice openssl rsautl -encrypt -in cleartext -out encrypted_with_pub_key -inkey pub_key.pem -pubin # Alice decrypts Bob's message openssl rsautl -decrypt -in encrypted_with_pub_key -inkey priv_key.pem
I wrote this because I'm learning about SSL/TLS by going through the `openssl` commands. This post is not associated with my employer.