openssl

Cryptography / TLS swiss-army knife.

$ openssl s_client -connect host:443 -servername host -showcerts

$ openssl x509 -in cert.pem -noout -text
$ openssl x509 -in cert.pem -noout -dates -fingerprint -sha256

$ openssl genrsa -out key.pem 4096
$ openssl req -new -key key.pem -out req.csr
$ openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes

$ openssl dgst -sha256 file

$ openssl enc -aes-256-gcm -pbkdf2 -in plain -out cipher