$ echo "top secret text" | openssl enc -aes-256-cbc -base64
enter aes-256-cbc encryption password:
Verifying - enter aes-256-cbc encryption password:
<< encrypted text >>

$ echo "<< encrypted text >>" | openssl enc -d -aes-256-cbc -base64
enter aes-256-cbc decryption password:
top secret text

openssl genrsa -out private.pem 2048

openssl rsa -in private.pem -pubout -out public.pem

openssl rsautl -encrypt -in secret-transmission.txt -out secret-transmission.txt.enc -inkey public.pem -pubin

openssl rsautl -decrypt -in secret-transmission.txt.enc -out secret-transmission.txt -inkey private.pem

openssl rsautl -sign -in secret-transmission.txt -out secret-transmission.txt.enc.signed -inkey private.pem

openssl rsautl -verify -in secret-transmission.txt.enc.signed -out secret-transmission.txt -inkey public.pem -pubin

openssl rsa -in private.pem -des3 -out private-enc.pem

$ openssl version
LibreSSL 2.6.4

openssl list-cipher-commands