use GOST for random bytes generation

PATH

@@ -0,0 +1 @@
+/home/Vadzik/Data/Maxim/University/ВКР/disk_eraser/venv/bin:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin

app/utils_drive.py

@@ -1,8 +1,9 @@
 import threading
 import os
+import pygost.gost3412 as gost
 
-from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+# from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
-from cryptography.hazmat.backends import default_backend
+# from cryptography.hazmat.backends import default_backend
 
 erasing_methods = {
     "2 прохода": {
@@ -31,12 +32,17 @@ erasing_methods = {
 
 def get_random_bytes(size):
     seed=os.urandom(32)
-    backend = default_backend()
+    # backend = default_backend()
-    cipher = Cipher(algorithms.AES(seed), modes.CTR(b'\0'*16), backend=backend)
+    # cipher = Cipher(algorithms.AES(seed), modes.CTR(b'\0'*16), backend=backend)
-    encryptor = cipher.encryptor()
+    # encryptor = cipher.encryptor()
 
     nulls=b'\0'*(size)
-    return encryptor.update(nulls)
+    enc = gost.GOST3412Kuznechik(seed)
+    rounds = int(size / 32)
+    data = b''
+    for i in range(512):
+        data += enc.encrypt(nulls)
+    return data
 
 class Drive():
 
@@ -84,7 +90,7 @@ class Drive():
                         else:
                             data = erasing_methods[method]["data"][i] * write_size
                         drive.write(data)
-                        len_write += write_size
+                        len_write += len(data)
                         cur_percent = len_write/self.capacity
                         if cur_percent - prev_percent > 0.01:
                             progressbar.set(cur_percent)