以下是一些Ubuntu下OpenSSL命令行的使用技巧：
sudo apt update，sudo apt install openssl。openssl version。openssl enc -aes-256-cbc -salt -in input.txt -out encrypted.enc，解密文件openssl enc -d -aes-256-cbc -in encrypted.enc -out decrypted.txt。openssl genrsa -out private.pem 2048，openssl rsa -in private.pem -pubout -out public.pem；用公鑰加密openssl rsautl -encrypt -inkey public.pem -pubin -in file.txt -out encrypted.enc，用私鑰解密openssl rsautl -decrypt -inkey private.pem -in encrypted.enc -out decrypted.txt。openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes。openssl x509 -in cert.pem -text -noout。openssl rand -hex 32 > key.txt。openssl sha256 file.zip。openssl s_client -connect example.com:443 -verbose。
