ZXzCNpZR

1import os, random, struct
2from Cryptodome.Cipher import AES
3
4
5def decrypt_file(key, input_file):
6    """ Decrypts a file using AES CBC mode with the
7        given key.
8    """
9
10    # This the block size of data we read, decrypt and write.
11    # It should be a multiple of 16 for AES.
12    chunksize=16*4*1024
13
14    # get rid of the .aes ending
15    output_filename = os.path.splitext(input_file)[0]
16
17    with open(input_file, 'rb') as in_file:
18        # retrieve the original size of the encrypted data
19        origsize = struct.unpack('<Q', in_file.read(struct.calcsize('Q')))[0]
20        # retrieve the initialization vector
21        initial_vector = in_file.read(16)
22        decryptor = AES.new(key, AES.MODE_CBC, initial_vector)
23
24        # read block for block the encrypted data, decrypt and write
25        with open(output_filename, 'wb') as out_file:
26            while True:
27                chunk = in_file.read(chunksize)
28                if len(chunk) == 0:
29                    break
30                out_file.write(decryptor.decrypt(chunk))
31
32            out_file.truncate(origsize)
33
34
35def main():
36    # secret_key = b'--> I am a random secret key <--'
37
38    secret_key = input("Give me your secret key (16, 24 or 32 characters):").encode("utf-8")
39    while len(secret_key) != 16 and len(secret_key) != 24 and len(secret_key) != 32:
40        print("\nThere was an error! Please try again with 16, 24 or 32 characters:")
41        secret_key = input("\nGive me your secret key (16, 24 or 32 characters):").encode("utf-8")
42
43    path = input("\nGive me a path or file to decrypt:")
44    while os.path.isdir(path) != True and os.path.isfile(path) != True:
45        print("\nThere was an error! Please try again with a correct path or file to decrypt:")
46        path = input("\nGive me a path or file to decrypt:")
47
48    # path = directory?
49    if os.path.isdir(path):
50        files = []
51        # traverse all subfolders and save path + filename
52        for root, d_names, f_names in os.walk(path):
53            for f in f_names:
54                files.append(os.path.join(root, f))  # these are all files in all subfolders
55        for file in files:
56            # better skip not encrypted files
57            if file.endswith(".aes"):
58                print("\nDecrypting ", file)
59                decrypt_file(secret_key, file)
60                # after decryption we could delete the file.. ;)
61                # just remove the '#' in the next line
62                # os.remove(file)
63
64    # path is no directory, but must be a file
65    else:
66        # better skip not encrypted files
67        if path.endswith(".aes"):
68            print("\nDecrypting ", path)
69            decrypt_file(secret_key, path)
70            # after decryption we could delete the file.. ;)
71            # just remove the '#' in the next line
72            # os.remove(path)
73
74main()