Added Steg_Tool Script (#234)

Co-authored-by: Shankar JP <shankarjp12@outlook.com>

README.md

@@ -184,6 +184,7 @@ So far, the following projects have been integrated to this repo:
 |[Plagiarism_detector](https://github.com/hastagAB/Awesome-Python-Scripts/tree/master/Plagiarism_detector)|[Akshita Singhal](https://github.com/akshitasinghal4444)|
 |[csv_to_json](https://github.com/hastagAB/Awesome-Python-Scripts/tree/master/csv_to_json)|[MoiZ](https://github.com/TechBoyy6)|
 |[Battery_notification](https://github.com/hastagABAwesome-Python-Scripts/Battery_notification/)|[Krishna Sharma](https://github.com/krishnasharma1386)|
+|[Steg_Tool](https://github.com/hastagABAwesome-Python-Scripts/Steg_Tool/)|[Shankar JP](https://github.com/shankarjp)|
 
 ## How to use :
 

Steg_Tool/README.md

@@ -0,0 +1,21 @@
+# Steganography Tool
+
+* Advanced Image Steganography Tool used to hide files inside Images.
+* Uses LSB (Least Significant Bit) Algorithm to store file data inside the image
+* Works with only .png format
+
+Commands
+```
+python3 steg.py
+```
+Input
+```
+encode <input_image_name> <output_image_name> <file_name>
+
+decode <encoded_image_name> <extracted_file_name>
+```
+Example
+```
+encode image.png image_new.png secret.txt
+decode image_new.png secret_new.txt
+```

Steg_Tool/secret.txt

@@ -0,0 +1 @@
+secret

Steg_Tool/steg.py

@@ -0,0 +1,174 @@
+#Image Stego using LSB
+import cv2
+
+def encode(input_image_name, output_image_name, file_name):
+    input_image = cv2.imread(input_image_name)
+
+    height, width, nbchannels = input_image.shape
+    size = width*height
+    current_width = 0
+    current_height = 0
+    current_channel = 0
+
+    maskonevalues = [1, 2, 4, 8, 16, 32, 64, 128]
+    maskone = maskonevalues.pop(0)
+    maskzerovalues = [254, 253, 251, 247, 239, 223, 191, 127]
+    maskzero = maskzerovalues.pop(0)
+
+    data = open(file_name, "rb").read()
+    length = len(data)
+    if(width*height*nbchannels < length + 64):
+        raise Exception("Not enough space to hold all steganographic data")
+    binary_value = bin(length)[2:]
+    if(len(binary_value) > 64):
+        raise Exception("Binary Value larger than expected")
+    else:
+        while(len(binary_value) < 64):
+            binary_value = "0" + binary_value
+    for c in binary_value:
+        value = list(input_image[current_height, current_width])
+        if(int(c) == 1):
+            value[current_channel] = int(value[current_channel]) | maskone
+        else:
+            value[current_channel] = int(value[current_channel]) & maskzero
+        input_image[current_height, current_width] = tuple(value)
+        if(current_channel == nbchannels-1):
+            current_channel = 0
+            if(current_width == width-1):
+                current_width = 0
+                if(current_height == height-1):
+                    current_height = 0
+                    if maskone == 128:
+                        raise Exception("No more space available in image")
+                    else:
+                        maskone = maskonevalues.pop(0)
+                        maskzero = maskzerovalues.pop(0)
+                else:
+                    current_height += 1
+            else:
+                current_width += 1
+        else:
+            current_channel += 1
+    for byte in data:
+        if(isinstance(byte, int)):
+            pass
+        else:
+            byte = ord(byte)
+        binv = bin(byte)[2:]
+        if(len(binv) > 8):
+            raise Exception("Binary Value larger than expected")
+        else:
+            while(len(binv) < 8):
+                binv = "0" + binv
+        for c in binv:
+            val = list(input_image[current_height, current_width])
+            if(int(c) == 1):
+                val[current_channel] = int(val[current_channel]) | maskone
+            else:
+                val[current_channel] = int(val[current_channel]) & maskzero
+            input_image[current_height, current_width] = tuple(val)
+            if(current_channel == nbchannels-1):
+                current_channel = 0
+                if(current_width == width-1):
+                    current_width = 0
+                    if(current_height == height-1):
+                        current_height = 0
+                        if maskone == 128:
+                            raise Exception("No more space available in image")
+                        else:
+                            maskone = maskonevalues.pop(0)
+                            maskzero = maskzerovalues.pop(0)
+                    else:
+                        current_height += 1
+                else:
+                    current_width += 1
+            else:
+                current_channel += 1
+        cv2.imwrite(output_image_name, input_image)
+
+
+def decode(encoded_image_name, extracted_file_name):
+    encoded_image = cv2.imread(encoded_image_name)
+
+    height, width, nbchannels = encoded_image.shape
+    size = width*height
+    current_width = 0
+    current_height = 0
+    current_channel = 0
+
+    maskonevalues = [1, 2, 4, 8, 16, 32, 64, 128]
+    maskone = maskonevalues.pop(0)
+    maskzerovalues = [254, 253, 251, 247, 239, 223, 191, 127]
+    maskzero = maskzerovalues.pop(0)
+
+    bits = ""
+    for i in range(64):
+        value = encoded_image[current_height, current_width][current_channel]
+        value = int(value) & maskone
+        if(current_channel == nbchannels-1):
+            current_channel = 0
+            if(current_width == width-1):
+                current_width = 0
+                if(current_height == height-1):
+                    current_height = 0
+                    if(maskone == 128):
+                        raise Exception("No more space available in image")
+                    else:
+                        maskone = maskonevalues.pop(0)
+                        maskzero = maskzerovalues.pop(0)
+                else:
+                    current_height += 1
+            else:
+                current_width += 1
+        else:
+            current_channel += 1
+        if(value > 0):
+            bits += "1"
+        else:
+            bits += "0"
+    length = int(bits, 2)
+    output = b""
+    for i in range(length):
+        bits = ""
+        for i in range(8):
+            value = encoded_image[current_height, current_width][current_channel]
+            value = int(value) & maskone
+            if(current_channel == nbchannels-1):
+                current_channel = 0
+                if(current_width == width-1):
+                    current_width = 0
+                    if(current_height == height-1):
+                        current_height = 0
+                        if(maskone == 128):
+                            raise Exception("No more space available in image")
+                        else:
+                            maskone = maskonevalues.pop(0)
+                            maskzero = maskzerovalues.pop(0)
+                    else:
+                        current_height += 1
+                else:
+                    current_width += 1
+            else:
+                current_channel += 1
+            if(value > 0):
+                bits += "1"
+            else:
+                bits += "0"
+        output += bytearray([int(bits, 2)])
+    f = open(extracted_file_name, "wb")
+    f.write(output)
+    f.close()
+
+if __name__ == "__main__":
+    input_string = input()
+    #encode input_image_name output_image_name file_name
+    #decode encoded_image_name extracted_file_name
+    input_list = input_string.split()
+    if input_list[0] == "encode":
+        encode(input_list[1], input_list[2], input_list[3])
+        print(f"{input_list[2]}")
+    elif input_list[0] == "decode":
+        decode(input_list[1], input_list[2])
+        print(f"{input_list[2]}")
+    else:
+        print("Invalid Entry")