openssl
echo -n "MESSAGE" | openssl sha1 echo -n "MESSAGE" | openssl dgst -md5 echo -n "MESSAGE" | openssl dgst -sha256
openssl genrsa 1024 openssl genrsa 2048
openssl rsa -in private-key.pem -pubout -out public-key.pem
openssl rsautl -encrypt -pubin -inkey public-key.pem -in sample.txt -out sample.rsa
openssl rsautl -decrypt -inkey private-key.pem -in sample.rsa
openssl rsa -in private-key.pem -text -noout
openssl rsa -pubin -in public-key.pem -text -noout