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Usages

To use Kryptoxin, pass the kryptoxin module to your Python interpreter using the python -m kryptoxin command. You can use the --help command-line parameter at any given time to lists the available options for a specific command:

Usage: python -m kryptoxin [OPTIONS] COMMAND [ARGS]...

Options:
  --version  Show the version and exit.
  --help     Show this message and exit.

Commands:
  encrypt  This command perform encryption on the supplied input.
  decrypt  This command perform decryption on the supplied input.

At this time of writing, Kryptoxin supports the encrypt and decrypt commands. As their name implies they are used to respectively perform encryption and decryption of a given input.

Encryption (encrypt)

As the name implies the encrypt command perform encryption on the supplied input.

Default encryption parameters

By default Kryptoxin uses the AES symmetric algorithm with a 256-bits key. The block cipher operation mode is CBC and uses the key-derivation function PBKDF2 with the SHA-1 digest algorithm. These parameters have been selected because they are widely supported by popular languages and frameworks such as PowerShell and .NET.

Mandatory command-line option

Only one command-line option is required and mandatory to perform payload encryption, namely the -k or --key option. If a file is not provided using the -i or --in option, Kryptoxin will read on the standard input (or stdin) until you hit the Ctrl+D keys combination.

Quick Encryption

The commands below perform encryption using the default parameters and options:

$ echo -n 'test' | python -m kryptoxin encrypt -k 12345
5bP32GKoJa57IcKL4sWeUQ==

$ python -m kryptoxin encrypt -k 12345 -i input_file.txt
5bP32GKoJa57IcKL4sWeUQ==
What the above commands do ?

Let's break down the above commands, options and outputs:

  • python -m kryptoxin calls the kryptoxin module, which should be in your sys.path after installation.
  • The -k 12345 option provide the encryption key to be passed to the block cipher algorithm.
  • Finally, -i input_file.txt specify the input file to read from, here a text file.
  • Alternatively, you can use the standard Unix/Linux pipes to redirect the output to the standard input or the other way around.

Once the encryption operation is performed, Kryptoxin will return a base64 encoded output by default. The latter can be copy/pasted into variables, or can be stored in a file by using the -o or --out command-line option.

Fine-tuned AES Encryption

Encrypt a .dll to a file

To encrypt a binary file such as a Dynamic Link Library (or .dll), you can use the command below:

$ python -m kryptoxin encrypt --key 12345 --key_size 128 \
--in MediaConverter.dll --alg AES --hmac SHA256 --mode CBC \
--iv 17ad017117ed47f902c524cd4351d0f9 --out MediaConverter.dll.encrypted
What the above command-line options do ?

For this example we use the AES block cipher algorithm with a 128-bits key. We also specify the SHA256 digest algorithm for the HMAC function. The block cipher operation mode is CBC and its initialization vector is manually specified. The latter must match the block cipher's block size, which is here 16 bytes. Finally, the output is written to the file specified by the --out command-line option.

Decryption (decrypt)

The decrypt command as the name implies, allow you to perform decryption of a given ciphertext. If the decryption process is successful, kryptoxin will write the plaintext directly on the console's standard output or will write the result into the file given by the --out option.

Quick Decryption

To perform "a quick" decryption of a given input with the default parameters and options, you can use the command below:

$ echo '5bP32GKoJa57IcKL4sWeUQ==' | python -m kryptoxin decrypt -k 12345
test

$ python -m kryptoxin decrypt -k 12345 -i encrypted.txt
test