#!/usr/bin/env python3 """ Stego GUI pentru embed/extract într-un fișier de biți aleatori (datebinare). - Fișier input implicit pentru embed: datebinare.txt (conține doar 0/1) - Fișier output implicit pentru embed: datecriptate.txt (conține header + bitstring) - Pentru extract: încarcă datecriptate.txt și introduce cheia pentru decodare. Folosiți o cheie puternică; algoritmul folosește SHA-256 pentru keystream și selecție deterministă de poziții. Autor: ChatGPT (script generat la cererea utilizatorului) """ import tkinter as tk from tkinter import filedialog, messagebox, scrolledtext import hashlib, os, sys # --- utilitare bit/bytes --- def bytes_to_bits(b: bytes): out = [] for byte in b: for i in range(8): out.append((byte >> (7-i)) & 1) return out def bits_to_bytes(bits): extra = (-len(bits)) % 8 if extra: bits = bits + [0]*extra out = bytearray() for i in range(0, len(bits), 8): byte = 0 for j in range(8): byte = (byte << 1) | bits[i+j] out.append(byte) return bytes(out) def str_to_bits(s: str, encoding='utf-8'): return bytes_to_bits(s.encode(encoding)) def bits_to_str(bits, encoding='utf-8'): b = bits_to_bytes(bits) try: return b.rstrip(b'\x00').decode(encoding) except Exception: return b.decode(encoding, errors='replace') # --- SHA256 keystream generator --- def sha256_stream(key: bytes, nbits: int): out_bits = [] counter = 0 while len(out_bits) < nbits: h = hashlib.sha256() h.update(key) h.update(counter.to_bytes(8, 'big')) block = h.digest() # 256 bits per block out_bits.extend(bytes_to_bits(block)) counter += 1 return out_bits[:nbits] # --- deterministc selection of k positions from range(n) using Fisher-Yates partial shuffle --- def deterministic_sample_positions(key: bytes, n: int, k: int): if k > n: raise ValueError("k > n") indices = list(range(n)) counter = 0 # shuffle last k elements for i in range(n-1, n-k-1, -1): h = hashlib.sha256() h.update(key) h.update(counter.to_bytes(8,'big')) rnd = int.from_bytes(h.digest()[:8], 'big') j = rnd % (i+1) indices[i], indices[j] = indices[j], indices[i] counter += 1 return indices[-k:] # --- embed: encrypt message with keystream, then write payload_bits into selected positions (replace) --- def embed_into_noise(noise_bits, message, key): n = len(noise_bits) msg_bits = str_to_bits(message) m = len(msg_bits) if m == 0: raise ValueError("Mesaj gol.") if m > n: raise ValueError("Mesajul e prea lung pentru fisierul de zgomot.") keyb = key.encode('utf-8') ks = sha256_stream(keyb + b'::ks::msg', m) payload = [mb ^ kb for mb,kb in zip(msg_bits, ks)] positions = deterministic_sample_positions(keyb + b'::pos', n, m) stego = noise_bits.copy() for pos, pbit in zip(positions, payload): stego[pos] = pbit # REPLACE # header: STEGO1|m= header = f"STEGO1|m={m}|hk={hashlib.sha256(keyb).hexdigest()}\\n" return header, stego def extract_from_stego(stego_bits, key, m): n = len(stego_bits) if m > n: raise ValueError("Lungimea mesajului (m) > n") keyb = key.encode('utf-8') positions = deterministic_sample_positions(keyb + b'::pos', n, m) payload = [stego_bits[pos] for pos in positions] ks = sha256_stream(keyb + b'::ks::msg', m) msg_bits = [p ^ k for p,k in zip(payload, ks)] return bits_to_str(msg_bits) # --- file helpers --- def read_bitfile(path): with open(path, 'r') as f: s = f.read().strip() if any(c not in '01' for c in s): raise ValueError("Fișierul trebuie sa conțină numai 0 și 1.") return [int(c) for c in s] def save_stego_file(path, header, bits): with open(path, 'w') as f: f.write(header) f.write(''.join(str(b) for b in bits)) def parse_stego_file(path): with open(path, 'r') as f: first = f.readline().strip() rest = f.read().strip() if not first.startswith("STEGO1|"): raise ValueError("Header invalid sau fișier necompatibil.") parts = {} for p in first.split('|')[1:]: if '=' in p: k,v = p.split('=',1) parts[k]=v if 'm' not in parts: raise ValueError("Header nu conține lungimea mesajului 'm'.") m = int(parts['m']) hk = parts.get('hk','') if any(c not in '01' for c in rest): raise ValueError("Corpul fișierului are caractere invalide.") bits = [int(c) for c in rest] return m, hk, bits # --- GUI --- class StegoGUI(tk.Tk): def __init__(self): super().__init__() self.title("Stego în zgomot cuantic - Embed / Extract") self.geometry("720x520") # Embed frame frm_e = tk.LabelFrame(self, text="Embed / Ascunde mesaj", padx=8, pady=8) frm_e.pack(fill='both', expand=False, padx=8, pady=6) tk.Label(frm_e, text="Fișier zgomot (implicit datebinare.txt):").grid(row=0, column=0, sticky='w') self.ent_noise = tk.Entry(frm_e, width=60) self.ent_noise.grid(row=0, column=1, padx=6) self.ent_noise.insert(0, "datebinare.txt") tk.Button(frm_e, text="Browse", command=self.browse_noise).grid(row=0, column=2) tk.Label(frm_e, text="Mesaj text de ascuns:").grid(row=1, column=0, sticky='nw') self.txt_msg = scrolledtext.ScrolledText(frm_e, width=60, height=6) self.txt_msg.grid(row=1, column=1, columnspan=2, pady=6) tk.Label(frm_e, text="Cheie:").grid(row=2, column=0, sticky='w') self.ent_key_e = tk.Entry(frm_e, width=40, show='*') self.ent_key_e.grid(row=2, column=1, sticky='w') tk.Button(frm_e, text="Embed -> datecriptate.txt", command=self.do_embed).grid(row=3, column=1, sticky='w', pady=6) # Extract frame frm_d = tk.LabelFrame(self, text="Extract / Dezvăluie mesaj", padx=8, pady=8) frm_d.pack(fill='both', expand=False, padx=8, pady=6) tk.Label(frm_d, text="Fișier stego (implicit datecriptate.txt):").grid(row=0, column=0, sticky='w') self.ent_stego = tk.Entry(frm_d, width=60) self.ent_stego.grid(row=0, column=1, padx=6) self.ent_stego.insert(0, "datecriptate.txt") tk.Button(frm_d, text="Browse", command=self.browse_stego).grid(row=0, column=2) tk.Label(frm_d, text="Cheie:").grid(row=1, column=0, sticky='w') self.ent_key_d = tk.Entry(frm_d, width=40, show='*') self.ent_key_d.grid(row=1, column=1, sticky='w') tk.Label(frm_d, text="Lungime mesaj (biți) - opțional (dacă header valid, se completează automat):").grid(row=2, column=0, sticky='w') self.ent_m = tk.Entry(frm_d, width=20) self.ent_m.grid(row=2, column=1, sticky='w') tk.Button(frm_d, text="Extractează mesaj", command=self.do_extract).grid(row=3, column=1, sticky='w', pady=6) tk.Label(self, text="Rezultat / Log:").pack(anchor='w', padx=8) self.txt_out = scrolledtext.ScrolledText(self, width=88, height=10) self.txt_out.pack(padx=8, pady=6) def log(self, s): self.txt_out.insert('end', s + "\n") self.txt_out.see('end') def browse_noise(self): p = filedialog.askopenfilename(title="Selectează fișierul de zgomot", filetypes=[("Text files","*.txt"),("All","*.*")]) if p: self.ent_noise.delete(0,'end'); self.ent_noise.insert(0,p) def browse_stego(self): p = filedialog.askopenfilename(title="Selectează fișierul stego", filetypes=[("Text files","*.txt"),("All","*.*")]) if p: self.ent_stego.delete(0,'end'); self.ent_stego.insert(0,p) try: m,hk,bits = parse_stego_file(p) self.ent_m.delete(0,'end'); self.ent_m.insert(0,str(m)) self.log(f"Header găsit: m={m}, hk={hk}.") except Exception as e: self.log(f"Nu s-a putut citi header: {e}") def do_embed(self): noise_path = self.ent_noise.get().strip() or "datebinare.txt" if not os.path.exists(noise_path): messagebox.showerror("Eroare", f"Fișier '{noise_path}' nu găsit.") return try: noise_bits = read_bitfile(noise_path) except Exception as e: messagebox.showerror("Eroare", str(e)); return msg = self.txt_msg.get('1.0','end').strip() key = self.ent_key_e.get().strip() if not key: messagebox.showerror("Eroare", "Introduceți o cheie.") return try: header, stego = embed_into_noise(noise_bits, msg, key) except Exception as e: messagebox.showerror("Eroare la embed: ", str(e)); return out = "datecriptate.txt" save_stego_file(out, header, stego) self.log(f"Embed realizat cu succes. Fișier salvat: {out}. Header: {header.strip()}") messagebox.showinfo("Gata", f"Embed realizat. Fișier salvat: {out}") def do_extract(self): stego_path = self.ent_stego.get().strip() or "datecriptate.txt" if not os.path.exists(stego_path): messagebox.showerror("Eroare", f"Fișier '{stego_path}' nu găsit."); return key = self.ent_key_d.get().strip() if not key: messagebox.showerror("Eroare", "Introduceți cheia.") return # parse file header if present try: m_header, hk, stego_bits = parse_stego_file(stego_path) m = m_header self.log(f"Header citit: m={m}, hk={hk}") except Exception as e: # If can't parse header, read user's provided m try: m = int(self.ent_m.get().strip()) except Exception: messagebox.showerror("Eroare", f"Nu pot determina lungimea mesajului din header și câmpul 'm' nu e completat: {e}") return try: with open(stego_path,'r') as f: # assume file contains only bits (no header) s = f.read().strip() if any(c not in '01' for c in s): raise ValueError("Fișier nevalid (caractere non 0/1).") stego_bits = [int(c) for c in s] except Exception as e2: messagebox.showerror("Eroare la citire stego:", str(e2)); return try: msg = extract_from_stego(stego_bits, key, m) except Exception as e: messagebox.showerror("Eroare la extragere:", str(e)); return self.log("Mesaj extras:") self.log(msg) messagebox.showinfo("Mesaj extras", f"Mesaj extras:\\n{msg}") def main(): app = StegoGUI() app.mainloop() if __name__ == '__main__': main()