Crypto Play

description:

Crypto play is a python3 script to encrypt and decrypt files content not file itself, using AES 256bits CTR, EAX modes and RSA. It uses PyCryptodome library to perform its operation.

To install dependencies :

In order to be able to run this script, you have to install the required librairies as follows:

pip3 install -r requirements.txt

Block Ciphers used:

• AES:
  • size: 256
  • mode: CTR, EAX. By default it uses CTR mode
• RSA:
  • size: 2048 by default. one can specify other key size i.e 4096

Expected Input:

• The script expect an input file containing the data to encrypt or decrypt.

• An output file where to save the result of operation (optional)

• When encrypting in AES, a secret code will be asked so that it can be used with a generated salt to derive the key

Expected Output:

• If output file is specified, the operation result will be saved in it.

• In all cases the result will be printed on screen.

• in RSA, when a key is not specified it will generate a keypair (public & private) following this pattern: public_FILENAME.pem / private_FILENAME.pem

• NB: After being encrypted , the contents are encoded in base64. Hence the output file contains the encoded of the ciphered text.

Usage:

let's suppose we are in the script directory and there is a file in it called: confidiential.txt.

To encrypt the content using AES EAX mode:

  ./cryptoplay.py encrypt -a aes -m eax -if confidential.txt -of secrets.enc

To decrypt in that same mode:

  ./cryptoplay.py decrypt -a aes -m eax -if secrets.enc -of pt.txt

To encrypt in RSA with a key size 4096 bits

python3 cryptoplay.py encrypt -a rsa -b 4096 -if INPUT_FILE -of OUTPUT_FILE

To decrypt in RSA :

python3 cryptoplay.py decrypt -a rsa -k PRIVATE_KEY -if CIPHERED_FILE -of OUTPUT_FILE

For more Information:

 python3 cryptoplay.py --help