feat: implement Steganography CI/CD protocol (The Trojan Payload)

scripts/stego_decoder.py

@@ -0,0 +1,83 @@
+import sys
+from PIL import Image
+
+def decode_lsb(image_path, output_path):
+    print(f"[*] Extracting payload from {image_path}...")
+    
+    img = Image.open(image_path)
+    img = img.convert('RGB')
+    pixels = img.load()
+    width, height = img.size
+    
+    # 1. Read the first 64 bits (8 bytes) to get the payload length
+    header_bits = ""
+    bit_idx = 0
+    header_length = 64
+    
+    for y in range(height):
+        for x in range(width):
+            r, g, b = pixels[x, y]
+            
+            if bit_idx < header_length:
+                header_bits += str(r & 1)
+                bit_idx += 1
+            if bit_idx < header_length:
+                header_bits += str(g & 1)
+                bit_idx += 1
+            if bit_idx < header_length:
+                header_bits += str(b & 1)
+                bit_idx += 1
+                
+            if bit_idx >= header_length:
+                break
+        if bit_idx >= header_length:
+            break
+            
+    payload_length_bytes = int(header_bits, 2)
+    payload_length_bits = payload_length_bytes * 8
+    print(f"[*] Detected embedded payload of size: {payload_length_bytes} bytes.")
+    
+    # 2. Read the actual payload
+    payload_bits = ""
+    bit_idx = 0
+    total_bits_to_read = header_length + payload_length_bits
+    
+    for y in range(height):
+        for x in range(width):
+            r, g, b = pixels[x, y]
+            
+            if bit_idx >= header_length and bit_idx < total_bits_to_read:
+                payload_bits += str(r & 1)
+            bit_idx += 1
+            
+            if bit_idx >= header_length and bit_idx < total_bits_to_read:
+                payload_bits += str(g & 1)
+            bit_idx += 1
+            
+            if bit_idx >= header_length and bit_idx < total_bits_to_read:
+                payload_bits += str(b & 1)
+            bit_idx += 1
+            
+            if bit_idx >= total_bits_to_read:
+                break
+        if bit_idx >= total_bits_to_read:
+            break
+            
+    # Convert bits to bytes
+    payload_bytes = bytearray()
+    for i in range(0, len(payload_bits), 8):
+        byte = payload_bits[i:i+8]
+        payload_bytes.append(int(byte, 2))
+        
+    # 3. Save Payload
+    with open(output_path, 'wb') as f:
+        f.write(payload_bytes)
+        
+    print(f"[+] Successfully extracted payload to {output_path}")
+
+if __name__ == "__main__":
+    if len(sys.argv) != 3:
+        print("Usage: python3 stego_decoder.py <encoded_carrier.png> <output_payload.tar.gz>")
+        sys.exit(1)
+        
+    decode_lsb(sys.argv[1], sys.argv[2])