utils2.py

from PIL import Image

prime = 19
p_base = 1
arr1=[]
arr2=[]
gidx =0
msglog1 = []
gidxlog1 =[]
msglog2 = []
gidxlog2 =[]
base_log1 = []
base_log2 = []
def reverse_slicing(s):
    return s[::-1]

def getbinary(msg):
  binary = ""
  for char in msg:
    pc = format(ord(char), '08b')
    c = pc[1:]
    c = reverse_slicing(c)
    binary += c
  return binary

def getSkips(char):
    global p_base
    global prime
    p_base = (p_base*prime)%100;
    first = p_base%10+1;
    tmp = int(p_base/10)
    second=tmp%10+1;
    if(char=='0'):
        return first
    return second

def iterateSecret(binary_secret):
    global gidx
    t = binary_secret[gidx];
    m = getSkips(t);
    gidx=(gidx+1)%len(binary_secret);
    return m;

def unravel(bt):
    text = ""
    for i in range(0, len(bt), 7):
        tc= bt[i:i+7]
        tc = reverse_slicing(tc)
        tc = '0'+tc
        text +=tc;
    final=''
    for i in range(0, len(text), 8):
        final += chr(int(text[i:i+8], 2))
    return final
    

def encrypt(text,key, image):
    global arr1, gidx,msglog1,gidxlog1,p_base,base_log1
    p_base = 1
    final=''
    pc=''
    for cz in text:
        pc += format(ord(cz), '08b')
    c = pc[1:]
    for i in range(0, len(pc), 8):
        final += chr(int(pc[i:i+8], 2))
    print(final)
    gidx = 0;
    pixels = list(image.getdata())
    binary_msg = getbinary(text)
    binary_secret = getbinary(key)
    mod = len(pixels)
    i=0
    base_log1.clear();
    gidxlog1.clear();
    msglog1.clear();
    arr1.clear()
    base_log1+=[p_base]
    binary_msg+='011111111'
    print(binary_msg)
    skips = 0;
    new_pixels = []
    for rgb in pixels:
        if type(rgb) == tuple:
            tcr = []
            for clr in rgb:
                if skips == 0:
                    skips+=iterateSecret(binary_secret)
                    gidxlog1+=[gidx]
                    base_log1+=[p_base]
                    msglog1+=[binary_secret[gidx]]
                    arr1+=[skips]
                    if i < len(binary_msg):
                        if binary_msg[i]=='0':
                            if clr%2!=0:
                                clr-=1
                        else:
                            if clr%2==0:
                                clr+=1
                        i+=1
                else:
                    skips-=1;
                tcr+=[clr]
            new_pixels += [tuple(tcr)]
        elif type(rgb) == int:
            clr = rgb
            if skips == 0:
                skips+=iterateSecret(binary_secret)
                gidxlog1+=[gidx]
                base_log1+=[p_base]
                msglog1+=[binary_secret[gidx]]
                arr1+=[skips]
                if i < len(binary_msg):
                    if binary_msg[i]=='0':
                        if clr%2!=0:
                            clr-=1
                    else:
                        if clr%2==0:
                            clr+=1
                    i+=1
            else:
                skips-=1;
            new_pixels+=[clr]
    new_image = Image.new(image.mode, image.size)
    new_image.putdata(new_pixels)
    return new_image

def decrypt(key,image):
    global arr2,gidxlog2,msglog2,p_base,base_log2,gidx
    p_base = 1
    gidx = 0
    pixels = list(image.getdata())
    base_log2.clear()
    msglog2.clear()
    gidxlog2.clear()
    arr2.clear()
    base_log2+=[p_base]
    binary_secret = getbinary(key)
    ones =0;
    skips = 0;
    binary_msg = ""
    flag =0
    for rgb in pixels:
        if type(rgb) == tuple:  
            for clr in rgb:
                if skips ==0:
                    cnt = clr%2;
                    if cnt ==1:
                        ones+=1;
                    else:
                        ones=0; 
                    binary_msg += str(cnt);
                    if ones ==8:
                        flag =1;
                        break
                    skips+=iterateSecret(binary_secret)
                    gidxlog2+=[gidx]
                    base_log2+=[p_base]
                    msglog2+=[binary_secret[gidx]]
                    arr2+=[skips]
                else:
                    skips-=1
        elif type(rgb) == int:
            clr = rgb
            if skips ==0:
                cnt = clr%2;
                if cnt ==1:
                    ones+=1;
                else:
                    ones=0; 
                binary_msg += str(cnt);
                if ones ==8:
                    flag =1;
                    break
                skips+=iterateSecret(binary_secret)
                gidxlog2+=[gidx]
                base_log2+=[p_base]
                msglog2+=[binary_secret[gidx]]
                arr2+=[skips]
            else:
                skips-=1
        if flag ==1:
            break;
    print(binary_msg)
    binary_msg = binary_msg[:-9]
    print(binary_msg)
    txt = unravel(binary_msg)
    print(txt)
    print(arr1[:10],arr2[:10])
    print(msglog1[:10],gidxlog1[:10])
    print(msglog2[:10],gidxlog2[:10]);
    print(base_log1[0:10],base_log2[0:10])
    return txt