#!/bin/sh

# 16 bytes of random data in hex
openssl rand 16 -hex

# 16 bytes of random data in base64
openssl rand 16 -base64

# encrypt a file
openssl enc -aes-256-cbc -in /tmp/foo -out /tmp/foo.out

# alt to encrypt a file, add -a to output to base64, add -salt to use salt
openssl aes-256-cbc -in /tmp/foo -out /tmp/foo.enc

# decrypt
openssl aes-256-cbc -d -in /tmp/foo/enc -out /tmp/foo.dec

# generate RSA private key
# 4096-bit private key, protected by password with AES256
openssl genrsa -aes256 4096

# 4096-bit private key, no password
openssl genrsa 4096

# but genrsa is deprecated in favor of genpkey:
# 4096-bit private key, protected by password with AES256
openssl genpkey -algorithm RSA -aes-256-cbc -pkeyopt rsa_keygen_bits:4096

# 4096-bit private key, no password
openssl genpkey -algorithm RSA -aes-256-cbc -pkeyopt rsa_keygen_bits:4096

# Generate the matching public key
# Assume that we used "-out private.pem" in the generation
openssl rsa -in private.pem -pubout