Public-key encryption example using OpenSSL

public_enc_example.sh

#!/bin/bash
#
# Public-Key Encryption and Decryption
# * http://www.openssl.org/
# * http://barelyenough.org/blog/2008/04/fun-with-public-keys/
#
# Mac OS X 10.6.4
# OpenSSL 0.9.8l 5 Nov 2009

# Generate keys
openssl genrsa -out key.pem
openssl rsa -in key.pem -out key.pub -pubout

# Encrypt and Decrypt a file (using public key to encrypt)
echo --pass-- > pass.txt
openssl rsautl -in pass.txt -out pass.enc -pubin -inkey key.pub -encrypt
openssl rsautl -in pass.enc -out pass.dec -inkey key.pem -decrypt
cat pass.dec

# Compress, Encrypt, Decyrpt, Uncompress a file (using password in pass.txt)
echo content > file.txt
gzip file.txt
openssl bf -in file.txt.gz -out file.enc -pass file:pass.txt -e
openssl bf -in file.enc -out file.dec.gz -pass file:pass.dec -d 
gzip -d file.dec.gz
cat file.dec

great share!

greate !! thx

How to encrypt large files without using AES?

You can use the below commands to encrypt large files.
openssl enc -aes-256-cbc -salt -in sample_1.csv -out sample_1.csv.enc -pass file:./key.pub

You can use the below commands to encrypt large files. openssl enc -aes-256-cbc -salt -in sample_1.csv -out sample_1.csv.enc -pass file:./key.pub

@ppatel8-wooliex your approach seem like a bad idea to me. It just uses the public key as a passphrase and not as a public key in the sense of asymmetric encryption. The content can be decrypted by using the same public key - which as the name says, is public. So no protection at all ...