Using Stéganô in command line for your scripts
==============================================

Display help
------------

.. code-block:: bash

    $ lsb --help
    usage: lsb [-h] {hide,reveal} ...

    positional arguments:
      {hide,reveal}  sub-command help
        hide         hide help
        reveal       reveal help

    optional arguments:
      -h, --help     show this help message and exit


.. code-block:: bash

    $ lsb hide --help
    usage: lsb hide [-h] -i INPUT_IMAGE_FILE (-m SECRET_MESSAGE | -f SECRET_FILE)
                    -o OUTPUT_IMAGE_FILE

    optional arguments:
      -h, --help            show this help message and exit
      -i INPUT_IMAGE_FILE, --input INPUT_IMAGE_FILE
                            Input image file.
      -m SECRET_MESSAGE     Your secret message to hide (non binary).
      -f SECRET_FILE        Your secret to hide (Text or any binary file).
      -o OUTPUT_IMAGE_FILE, --output OUTPUT_IMAGE_FILE
                            Output image containing the secret.


.. code-block:: bash

    $ lsb reveal --help
    usage: lsb reveal [-h] -i INPUT_IMAGE_FILE [-o SECRET_BINARY]

    optional arguments:
      -h, --help            show this help message and exit
      -i INPUT_IMAGE_FILE, --input INPUT_IMAGE_FILE
                            Input image file.
      -o SECRET_BINARY      Output for the binary secret (Text or any binary
                            file)


Hide and reveal a text message with the LSB method
--------------------------------------------------

.. code-block:: bash

    $ lsb hide -i ./tests/sample-files/Lenna.png -m 'Hello World!' -o ./Lenna_enc.png
    $ lsb reveal -i ./Lenna_enc.png
    Hello World!

Hide and reveal a binary file
-----------------------------

.. code-block:: bash

    $ wget http://www.gnu.org/music/free-software-song.ogg
    $ lsb hide -i ./tests/sample-files/Montenach.png -f ./free-software-song.ogg -o ./Montenach_enc.png
    $ rm free-software-song.ogg
    $ lsb reveal -i ./Montenach_enc.png -o ./song.ogg

Hide and reveal a text message with the LSB method and generated sets
---------------------------------------------------------------------

Sets are used in order to select the pixels where the message will be hidden.

.. code-block:: bash

    # Hide the message with the Sieve of Eratosthenes
    $ lsb-set hide -i ./tests/sample-files/Montenach.png --generator eratosthenes -m 'Joyeux Noël!' -o ./surprise.png

    # Try to reveal with Mersenne numbers
    $ lsb-set reveal --generator mersenne -i ./surprise.png

    # Try to reveal with fermat numbers
    $ lsb-set reveal --generator fermat -i ./surprise.png

    # Try to reveal with carmichael numbers
    $ lsb-set reveal --generator carmichael -i ./surprise.png

    # Try to reveal with Sieve of Eratosthenes
    $ lsb-set reveal --generator eratosthenes -i ./surprise.png

    # List all available generators
    $ lsb-set list-generators
    OEIS_A000217
        http://oeis.org/A000217
        Triangular numbers: a(n) = C(n+1,2) = n(n+1)/2 = 0+1+2+...+n.

    ackermann
        Ackermann number.

    carmichael
        https://oeis.org/A002997
        Composite numbers n such that a^(n-1) == 1 (mod n) for every a coprime to n.

    eratosthenes
        Generate the prime numbers with the sieve of Eratosthenes.

    composite
        Generate the composite numbers using the sieve of Eratosthenes.

    fermat
        Generate the n-th Fermat Number.

    fibonacci
        https://oeis.org/A000045
        A generator for Fibonacci numbers, goes to next number in series on each call.
        This generator start at 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, ...

    identity
        f(x) = x

    log_gen
        Logarithmic generator.

    mersenne
        Generate 2^n-1.

    syracuse
        Generate the sequence of Syracuse


An other example:

.. code-block:: bash

    # Hide the message - LSB with a set defined by the identity function (f(x) = x).
    lsb-set hide -i ./tests/sample-files/Montenach.png --generator identity -m 'I like steganography.' -o ./enc-identity.png

    # Hide the message - LSB only.
    lsb hide -i ./tests/sample-files/Montenach.png -m 'I like steganography.' -o ./enc.png

    # Check if the two generated files are the same.
    sha1sum ./enc-identity.png ./enc.png

    # The output of lsb is given to lsb-set.
    lsb-set reveal -i ./enc.png --generator identity

    # The output of lsb-set is given to lsb.
    lsb reveal -i ./enc-identity.png


Hide and reveal a text message with the red portion of a pixel
--------------------------------------------------------------

.. code-block:: bash

    $ stegano-red hide --help
    usage: stegano-red hide [-h] [-i INPUT_IMAGE_FILE] [-m SECRET_MESSAGE]
                        [-o OUTPUT_IMAGE_FILE]

    optional arguments:
    -h, --help            show this help message and exit
    -i INPUT_IMAGE_FILE, --input INPUT_IMAGE_FILE
                        Image file
    -m SECRET_MESSAGE     Your secret message to hide (non binary).
    -o OUTPUT_IMAGE_FILE, --output OUTPUT_IMAGE_FILE
                        Image file

    $ stegano-red hide -i ./tests/sample-files/Lenna.png -m 'Basic steganography technique.' -o ~/Lenna1.png

    $ stegano-red reveal -i ~/Lenna1.png
    Basic steganography technique.