P C52321 Pro X CS2321 PROJECT 5B STEGANOGRAPHY Your task for this project will b
ID: 3705477 • Letter: P
Question
P C52321 Pro X CS2321 PROJECT 5B STEGANOGRAPHY Your task for this project will be to create a program which can hide a mossage in a picture and thon extract the messago. This project will be worth 20 points. Please use proper formatting, comments and naming conventions The Wilipedia entry for stoganography provides the following: Steganography is the art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message, this is in contrast to cryptography, where the existence of the message itself is not disguised, but the content is obacured Generally, a steganographic message will appear to be something else: a picture, an article, a shopping list, or some other message. This apparent message is the cover text. Por instance, a message may be hidden by using invisible ink between the visible lines of innocuous documents. The advantage of steganography over cryptography alone is that messages do not attract attention to themaelves, to messengers, or to recipients. An unhidden coded message, no matter how unbreakable it is, will arouse suspicion and may in itself be incriminating, as in countries where encryption is illegal Whon we use the RGB values (red, green, blue) there are over 16 million different colors. The human eye cannot always distinguish between allExplanation / Answer
main.py
import base64, sys, os.path
sys.path.append('/usr/local/python3.5/site-packages')
import cv2 as cv
from LSBStegno import LSBStegno
#Hide text
def hide_text(text, in_image, out_image="res.png"):
carrier = cv.imread(in_image)
stegno = LSBStegno(carrier)
if (os.path.isfile(text)):
f = open(text,'r')
text = f.read()
stegno.hideText(text)
stegno.saveImage(out_image)
#Unhide text
def unhide_text(in_image):
im = cv.imread(in_image)
stegno = LSBStegno(im)
print(stegno.unhideText())
#Hide image
def hide_image(secret_img, carrier_img, out_image="res.png"):
imagetohide = cv.LoadImage(secret_img)
carrier = cv.LoadImage(carrier_img)
stegno = LSBStegno(carrier)
stegno.hideImage(imagetohide)
stegno.saveImage(out_image)
#Unhide image
def unhide_image(in_image,out_image):
inp = cv.LoadImage(in_image)
stegno = LSBStegno(inp)
dec = stegno.unhideImage()
cv.SaveImage(out_image, dec) #Image retrieve into the other image
#Hide binary
def hide_binary(in_image, out_image):
carrier = cv.LoadImage(in_image)
stegno = LSBStegno(carrier)
stegno.hideBin("ls") #I took the start binary I found
stegno.saveImage(out_image)
#Unhide binary
def unhide_binary(in_image):
inp = cv.LoadImage("res.png")
stegno = LSBStegno(inp)
bin = stegno.unhideBin()
f = open("res","wb") #Write the binary back to a file
f.write(bin)
f.close()
def helper():
example1 = """* to hide text * example: python3 main.py hide_text "hello world" original.png out.png"""
example2 = """* to unhide text * example: python3 main.py unhide_text out.png"""
example3 = """* other options * hide_image, unhide_image, hide_binary, unhide_binary"""
print(" ||| WELCOME TO LSB STEG ||| %s %s %s ENJOY " % (example1,example2,example3))
sys.exit()
if __name__=="__main__":
if len(sys.argv) < 2:
raise Exception("Arguments must be at least 1!")
else:
start = sys.argv[1]
if start == "hide_text":
hide_text(sys.argv[2],sys.argv[3],sys.argv[4])
elif start == "unhide_text":
unhide_text(sys.argv[2])
elif start == "hide_image":
hide_image(sys.argv[2],sys.argv[3],sys.argv[4])
elif start == "unhide_image":
unhide_image(sys.argv[2],sys.argv[3])
elif start == "hide_binary":
hide_binary(sys.argv[2],sys.argv[3])
elif start == "unhide_binary":
unhide_binary(sys.argv[2])
elif start == "-h":
helper()
else:
raise Exception(start+" was a not valid argument! run -h for help")
LSBStegno.py
#!/usr/local/bin/python3
# coding=UTF-8
try:
import cv2.cv as cv
except:
try:
import cv2 as cv
except:
exit("try sudo pip3 install opencv-python first")
import sys
class SteganographyException(Exception):
pass
class LSBSteg():
def __init__(self, im):
self.image = im
heights,widths,channels = im.shape
self.width = widths
self.height = heights
self.size = self.width * self.height
self.nbchannels = channels
self.mask1Values = [1,2,4,8,16,32,64,128]
#Mask used to put one ex:1->00000001, 2->00000010 .. associated with OR bitwise
self.mask1 = self.mask1Values.pop(0) #Will be used to do bitwise operations
self.mask0Values = [254,253,251,247,239,223,191,127]
#Mak used to put zero ex:254->11111110, 253->11111101 .. associated with AND bitwise
self.mask0 = self.mask0Values.pop(0)
self.curwidth = 0 #Current width position
self.curheight = 0 #Current height position
self.curchan = 0 #Current channel position
def saveImage(self,filename):
# Save the image using the given filename
cv.imwrite(filename, self.image)
def putBinaryValue(self, bits): #Put the bits in the image
for c in bits:
value = list(self.image[self.curheight,self.curwidth]) #Get the pixel valueue as a list
if int(c) == 1:
value[self.curchan] = int(value[self.curchan]) | self.mask1 #OR with mask1
else:
value[self.curchan] = int(value[self.curchan]) & self.mask0 #AND with mask0
self.image[self.curheight,self.curwidth] = tuple(value)
self.nextSpace() #Move "cursor" to the next space
def nextSpace(self):#Move to the next slot were information can be taken or put
if self.curchan == self.nbchannels-1: #Next Space is the following channel
self.curchan = 0
if self.curwidth == self.width-1: #Or the first channel of the next pixel of the same line
self.curwidth = 0
if self.curheight == self.height-1:#Or the first channel of the first pixel of the next line
self.curheight = 0
if self.mask1 == 128: #Mask 1000000, so the last mask
raise SteganographyException("Image filled")
else: #Or instead of using the first bit start using the second and so on..
self.mask1 = self.mask1Values.pop(0)
self.mask0 = self.mask0Values.pop(0)
else:
self.curheight +=1
else:
self.curwidth +=1
else:
self.curchan +=1
def readBit(self): #Read a single bit int the image
value = self.image[self.curheight,self.curwidth][self.curchan]
value = int(value) & self.mask1
self.nextSpace()
if value > 0:
return "1"
else:
return "0"
def readByte(self):
return self.readBits(8)
def readBits(self, nb): #Read the given number of bits
bits = ""
for i in range(nb):
bits += self.readBit()
return bits
def byteValue(self, value):
return self.binValue(value, 8)
def binValue(self, value, bitsize): #Return the binary valueue of an int as a byte
binvalue = bin(value)[2:]
if len(binvalue) > bitsize:
raise SteganographyException("binary valueue larger than the expected size")
while len(binvalue) < bitsize:
binvalue = "0"+binvalue
return binvalue
def hideText(self, txt):
l = len(txt)
binl = self.binValue(l, 16) #Length coded on 2 bytes so the text size can be up to 65536 bytes long
self.putBinaryValue(binl) #Put text length coded on 4 bytes
for char in txt: #And put all the chars
c = ord(char)
self.putBinaryValue(self.byteValue(c))
def unhideText(self):
ls = self.readBits(16) #Read the text size in bytes
l = int(ls,2)
i = 0
unhideTxt = ""
while i < l: #Read all bytes of the text
temp = self.readByte() #So one byte
i += 1
unhideTxt += chr(int(temp,2)) #Every chars concatenated to str
return unhideTxt
def hideImage(self, imtohide):
w = imtohide.width
h = imtohide.height
if self.width*self.height*self.nbchannels < w*h*imtohide.channels:
raise SteganographyException("Carrier image not big enough to hold all the datas to steganography")
binw = self.binValue(w, 16) #Width coded on to byte so width up to 65536
binh = self.binValue(h, 16)
self.putBinaryValue(binw) #Put width
self.putBinaryValue(binh) #Put height
for h in range(imtohide.height): #Iterate the hole image to put every pixel valueues
for w in range(imtohide.width):
for chan in range(imtohide.channels):
value = imtohide[h,w][chan]
self.putBinaryValue(self.byteValue(int(value)))
def unhideImage(self):
width = int(self.readBits(16),2) #Read 16bits and convert it in int
height = int(self.readBits(16),2)
unhideimg = cv.CreateImage((width,height), 8, 3) #Create an image in which we will put all the pixels read
for h in range(height):
for w in range(width):
for chan in range(unhideimg.channels):
value = list(unhideimg[h,w])
value[chan] = int(self.readByte(),2) #Read the valueue
unhideimg[h,w] = tuple(value)
return unhideimg
def hideBin(self, filename):
f = open(filename,'rb')
bin = f.read()
l = len(bin)
if self.width*self.height*self.nbchannels < l+64:
raise SteganographyException("Carrier image not big enough to hold all the datas to steganography")
self.putBinaryValue(self.binValue(l, 64))
for byte in bin:
self.putBinaryValue(self.byteValue(ord(byte)))
def unhideBin(self):
l = int(self.readBits(64),2)
output = ""
for i in range(l):
output += chr(int(self.readByte(),2))
return output
if __name__=="__main__":
pass
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