Added slsb-gen.py and generators.py.

stegano/generators.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Stéganô - Stéganô is a basic Python Steganography module.
+# Copyright (C) 2010-2011  Cédric Bonhomme - http://cedricbonhomme.org/
+#
+# For more information : http://bitbucket.org/cedricbonhomme/stegano/
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>
+
+__author__ = "Cedric Bonhomme"
+__version__ = "$Revision: 0.1 $"
+__date__ = "$Date: 2011/12/28 $"
+__license__ = "GPLv3"
+
+import itertools
+
+def fermat():
+    """
+    Return the n-th Fermat Number.
+    """
+    n = 0
+    while True:
+        n += 1
+        yield pow(2, pow(2, n)) + 1
+
+def mersenne():
+    """
+    Return 2^k-1.
+    """
+    n = 0
+    while True:
+        n += 1
+        yield pow(2, n) - 1
+
+def eratosthenes():
+    """
+    Generate the prime numbers with the sieve of Eratosthenes.
+    """
+    d = {}
+    for i in itertools.count(2):
+        if i in d:
+            for j in d[i]:
+                d[i + j] = d.get(i + j, []) + [j]
+            del d[i]
+        else:
+            d[i * i] = [i]
+            yield i
+
+def eratosthenes_composite():
+    """ Generate the composite numbers with the sieve of Eratosthenes. """
+    p1 = 3
+    for p2 in eratosthenes():
+        for n in range(p1 + 1, p2):
+            yield n
+        p1 = p2
+
+def carmichael():
+    for m in eratosthenes_composite():
+        for a in range(2, m):
+            if pow(a,m,m) != a:
+                break
+        else:
+            yield m
+
+def ackermann(m, n):
+    if m == 0:
+        return n + 1
+    elif n == 0:
+        return ackermann(m - 1, 1)
+    else:
+        return ackermann(m - 1, ackermann(m, n - 1))
+
+def fibonacci():
+    """
+    A generator for Fibonacci numbers, goes to next number in series on each call.
+    """
+    a, b = 1, 2
+    while True:
+        yield a
+        a, b = b, a + b
+
+
+if __name__ == "__main__":
+    # Point of entry in execution mode.
+    f = fibonacci()
+    for x in range(13):
+        print f.next(), # 0 1 1 2 3 5 8 13 21 34 55 89 144

stegano/slsb-gen.py

@@ -0,0 +1,180 @@
+#!/usr/bin/env python
+#-*- coding: utf-8 -*-
+
+# Stéganô - Stéganô is a basic Python Steganography module.
+# Copyright (C) 2010-2011  Cédric Bonhomme - http://cedricbonhomme.org/
+#
+# For more information : http://bitbucket.org/cedricbonhomme/stegano/
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>
+
+__author__ = "Cedric Bonhomme"
+__version__ = "$Revision: 0.2 $"
+__date__ = "$Date: 2010/03/24 $"
+__license__ = "GPLv3"
+
+import sys
+
+from PIL import Image
+
+import tools
+import generators
+
+def hide(input_image_file, message, generator_function):
+    """
+    Hide a message (string) in an image with the
+    LSB (Least Significant Bit) technique.
+    """
+    img = Image.open(input_image_file)
+    img_list = list(img.getdata())
+    width, height = img.size
+    index = 0
+
+    message = str(len(message)) + ":" + message
+    #message_bits = tools.a2bits(message)
+    message_bits = "".join(tools.a2bits_list(message))
+
+    npixels = width * height
+    if len(message_bits) > npixels * 3:
+        return """Too long message (%s > %s).""" % (len(message_bits), npixels * 3)
+
+    generator = getattr(generators, generator_function)()
+    
+    while index + 3 <= len(message_bits) :
+        generated_number = generator.next()
+        (r, g, b) = img_list[generated_number]
+
+        # Change the Least Significant Bit of each colour component.
+        r = tools.setlsb(r, message_bits[index])
+        g = tools.setlsb(g, message_bits[index+1])
+        b = tools.setlsb(b, message_bits[index+2])
+
+        # Save the new pixel
+        img_list[generated_number] = (r, g , b)
+        
+        index += 3
+
+    # create empty new image of appropriate format
+    encoded = Image.new('RGB', (img.size))
+        
+    # insert saved data into the image
+    encoded.putdata(img_list)
+    
+    return encoded
+    
+
+
+def reveal(input_image_file, generator_function):
+    """
+    Find a message in an image
+    (with the LSB technique).
+    """
+    img = Image.open(input_image_file)
+    img_list = list(img.getdata())
+    width, height = img.size
+    buff, count = 0, 0
+    bitab = []
+    limit = None
+
+    generator = getattr(generators, generator_function)()
+
+    while True:
+        generated_number = generator.next()
+        # color = [r, g, b]
+        for color in img_list[generated_number]:
+            buff += (color&1)<<(7-count)
+            count += 1
+            if count == 8:
+                bitab.append(chr(buff))
+                buff, count = 0, 0
+                if bitab[-1] == ":" and limit == None:
+                    try:
+                        limit = int("".join(bitab[:-1]))
+                        print limit
+                    except:
+                        print bitab
+        if len(bitab)-len(str(limit))-1 == limit :
+            return "".join(bitab)[len(str(limit))+1:]
+
+    return ""
+
+def write(image, output_image_file):
+    """
+    """
+    try:
+        image.save(output_image_file)
+    except Exception, e:
+        # If hide() returns an error (Too long message).
+        print e
+
+if __name__ == '__main__':
+    # Point of entry in execution mode.
+    from optparse import OptionParser
+    parser = OptionParser(version=__version__)
+    parser.add_option('--hide', action='store_true', default=False,
+                      help="Hides a message in an image.")
+    parser.add_option('--reveal', action='store_true', default=False,
+                      help="Reveals the message hided in an image.")
+    # Original image
+    parser.add_option("-i", "--input", dest="input_image_file",
+                    help="Input image file.")
+
+    # Generator
+    parser.add_option("-g", "--generator", dest="generator_function",
+                    help="Generator")
+                    
+    # Image containing the secret
+    parser.add_option("-o", "--output", dest="output_image_file",
+                    help="Output image containing the secret.")
+
+    # Non binary secret message to hide
+    parser.add_option("-m", "--secret-message", dest="secret_message",
+                    help="Your secret message to hide (non binary).")
+
+    # Binary secret to hide (OGG, executable, etc.)
+    parser.add_option("-f", "--secret-file", dest="secret_file",
+                    help="Your secret to hide (Text or any binary file).")
+    # Output for the binary binary secret.
+    parser.add_option("-b", "--binary", dest="secret_binary",
+                    help="Output for the binary secret (Text or any binary file).")
+
+    parser.set_defaults(input_image_file = './pictures/Lenna.png',
+                        generator_function = 'fermat',
+                        output_image_file = './pictures/Lenna_enc.png',
+                        secret_message = '', secret_file = '', secret_binary = "")
+
+    (options, args) = parser.parse_args()
+
+
+    if options.hide:
+        if options.secret_message != "" and options.secret_file == "":
+            secret = options.secret_message
+        elif options.secret_message == "" and options.secret_file != "":
+            secret = tools.binary2base64(options.secret_file)
+
+        img_encoded = hide(options.input_image_file, secret, options.generator_function)
+        try:
+            img_encoded.save(options.output_image_file)
+        except Exception, e:
+            # If hide() returns an error (Too long message).
+            print e
+
+    elif options.reveal:
+        secret = reveal(options.input_image_file, options.generator_function)
+        if options.secret_binary != "":
+            data = tools.base642binary(secret)
+            with open(options.secret_binary, "w") as f:
+                f.write(data)
+        else:
+            print secret