Introduce a new argument in a2bits_list in order to specify the encoding of the string (unicode)

stegano/lsb/lsb.py

@@ -20,8 +20,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 __author__ = "Cedric Bonhomme"
-__version__ = "$Revision: 0.2.2 $"
+__version__ = "$Revision: 0.3 $"
 __date__ = "$Date: 2016/08/04 $"
+__revision__ = "$Date: 2017/05/04 $"
 __license__ = "GPLv3"
 
 import sys
@@ -30,7 +31,10 @@ from PIL import Image
 
 from stegano import tools
 
-def hide(input_image_file: str, message, auto_convert_rgb: bool = False):
+def hide(input_image_file: str,
+        message,
+        encoding='UTF-8',
+        auto_convert_rgb: bool = False):
     """Hide a message (string) in an image with the
     LSB (Least Significant Bit) technique.
     """
@@ -53,7 +57,7 @@ def hide(input_image_file: str, message, auto_convert_rgb: bool = False):
     index = 0
 
     message = str(message_length) + ":" + str(message)
-    message_bits = "".join(tools.a2bits_list(message))
+    message_bits = "".join(tools.a2bits_list(message, encoding))
     message_bits += '0' * ((3 - (len(message_bits) % 3)) % 3)
 
     npixels = width * height
@@ -90,7 +94,7 @@ def hide(input_image_file: str, message, auto_convert_rgb: bool = False):
                 return encoded
 
 
-def reveal(input_image_file):
+def reveal(input_image_file, encoding='UTF-8'):
     """Find a message in an image (with the LSB technique).
     """
     img = Image.open(input_image_file)
@@ -106,9 +110,9 @@ def reveal(input_image_file):
             if img.mode == 'RGBA':
                 pixel = pixel[:3] # ignore the alpha
             for color in pixel:
-                buff += (color&1)<<(31-count)
+                buff += (color&1)<<(tools.ENCODINGS[encoding]-1 - count)
                 count += 1
-                if count == 32:
+                if count == tools.ENCODINGS[encoding]:
                     bitab.append(chr(buff))
                     buff, count = 0, 0
                     if bitab[-1] == ":" and limit == None:

stegano/lsbset/lsbset.py

@@ -32,7 +32,11 @@ from PIL import Image
 from stegano import tools
 from . import generators
 
-def hide(input_image_file, message, generator, auto_convert_rgb=False):
+def hide(input_image_file,
+        message,
+        generator,
+        encoding='UTF-8',
+        auto_convert_rgb=False):
     """Hide a message (string) in an image with the
     LSB (Least Significant Bit) technique.
     """
@@ -55,7 +59,7 @@ def hide(input_image_file, message, generator, auto_convert_rgb=False):
     index = 0
 
     message = str(message_length) + ":" + str(message)
-    message_bits = "".join(tools.a2bits_list(message))
+    message_bits = "".join(tools.a2bits_list(message, encoding))
     message_bits += '0' * ((3 - (len(message_bits) % 3)) % 3)
 
     npixels = width * height
@@ -90,7 +94,7 @@ def hide(input_image_file, message, generator, auto_convert_rgb=False):
     return encoded
 
 
-def reveal(input_image_file, generator):
+def reveal(input_image_file, generator, encoding='UTF-8'):
     """Find a message in an image (with the LSB technique).
     """
     img = Image.open(input_image_file)
@@ -104,9 +108,9 @@ def reveal(input_image_file, generator):
         generated_number = next(generator)
         # color = [r, g, b]
         for color in img_list[generated_number]:
-            buff += (color&1)<<(31-count)
+            buff += (color&1)<<(tools.ENCODINGS[encoding]-1 - count)
             count += 1
-            if count == 32:
+            if count == tools.ENCODINGS[encoding]:
                 bitab.append(chr(buff))
                 buff, count = 0, 0
                 if bitab[-1] == ":" and limit == None:

stegano/tools.py

@@ -20,9 +20,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 __author__ = "Cedric Bonhomme"
-__version__ = "$Revision: 0.2 $"
+__version__ = "$Revision: 0.3 $"
 __date__ = "$Date: 2010/10/01 $"
-__revision__ = "$Date: 2016/08/03 $"
+__revision__ = "$Date: 2017/05/04 $"
 __license__ = "GPLv3"
 
 import base64
@@ -30,6 +30,11 @@ import itertools
 from typing import List, Iterator, Tuple, Union
 from functools import reduce
 
+ENCODINGS = {
+    'UTF-8': 8,
+    'UTF-32LE': 32
+}
+
 def a2bits(chars: str) -> str:
     """Converts a string to its bits representation as a string of 0's and 1's.
 
@@ -38,7 +43,7 @@ def a2bits(chars: str) -> str:
     """
     return bin(reduce(lambda x, y : (x<<8)+y, (ord(c) for c in chars), 1))[3:]
 
-def a2bits_list(chars: str) -> List[str]:
+def a2bits_list(chars: str, encoding: str ='UTF-8') -> List[str]:
     """Convert a string to its bits representation as a list of 0's and 1's.
 
     >>>  a2bits_list("Hello World!")
@@ -57,8 +62,7 @@ def a2bits_list(chars: str) -> List[str]:
     >>> "".join(a2bits_list("Hello World!"))
     '010010000110010101101100011011000110111100100000010101110110111101110010011011000110010000100001'
     """
-    #return [bin(ord(x))[2:].rjust(8,"0") for x in chars]
-    return [bin(ord(x))[2:].rjust(32,"0") for x in chars]
+    return [bin(ord(x))[2:].rjust(ENCODINGS[encoding],"0") for x in chars]
 
 def bs(s: int) -> str:
     """Converts an int to its bits representation as a string of 0's and 1's.