OpenSSL: Ciphering

Entering OpenSSL encryption and decryption

Caveat: This is an introductory for using OpenSSL for common use. Cryptography is hard to get right. We do not cover the CVEs for different versions of OpenSSL nor address the weaknesses of the cipher suites included or its lack of cipher suites.

We simplified the utility with the functions in the scripts, but may not use the optimal cryptographic algorithms or modes due to the limitation of the OpenSSL packages currently available.

To use the functions in the scripts, you might have to start with this:

$ source ./<file_name>.sh
$ <function_name_in_the_file>
Example(s):
$ source ./time.sh
$ get_timestamp
Output: 2020–04–19_1827hr_55sec

Encrypting Messages

Under [cipher_utility.sh],

cipher_message "<message>" <passcode> # encapsulate message with quotes (") as space may be included
decipher_message "<message>" <passcode>

You should do a test run with dummy keys (or dummy shared secrets) and messages to verify the functionality with your intended recipients of the messages.

Example(s):
$ cipher_message "Can you read me?" our-shared-secret 
output…