Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Sign up
Appearance settings

Commit 93b3fc9

Browse files
Merge pull request #298 from AswinPKumar01/add-encryption-project
Added a new and innovative Project AES File Encryption Tool
2 parents 02ab593 + a458115 commit 93b3fc9

File tree

2 files changed

+215
-0
lines changed

2 files changed

+215
-0
lines changed

‎A/AES-File-Encryption-Tool/README.md

Lines changed: 87 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,87 @@
1+
# AES Encryption Tool
2+
3+
This tool provides a simple interface to encrypt and decrypt files using the AES (Advanced Encryption Standard) encryption algorithm. It uses the AES-CBC mode for encryption, ensuring that your data remains secure and private. A password-based key derivation function (PBKDF2 with HMAC-SHA256) is used to derive the encryption key from the provided password, adding another layer of security.
4+
5+
## Features
6+
7+
- **Encrypt Files**: Securely encrypt any file with a password.
8+
- **Decrypt Files**: Decrypt previously encrypted files using the same password.
9+
- **Automatic Padding**: Automatically handles file padding to ensure proper encryption even for files that are not a multiple of the AES block size.
10+
- **Salt and IV Generation**: Generates a random salt and initialization vector (IV) for each encryption to enhance security.
11+
12+
## Installation
13+
14+
### Prerequisites:
15+
16+
1. Python 3.x
17+
2. `cryptography` package
18+
19+
### To install the required package:
20+
21+
```bash
22+
pip install cryptography
23+
```
24+
25+
## Usage
26+
27+
### Command-line Arguments
28+
29+
- `mode`: Choose between `encrypt` or `decrypt` mode.
30+
- `input_file`: The path to the file you want to encrypt or decrypt.
31+
- `output_file` (optional): The desired path for the encrypted or decrypted output file. If not provided, the tool will generate a default name:
32+
- For encryption: `input_file.enc`
33+
- For decryption: If the input file ends with `.enc`, it will remove this extension, otherwise it appends `.dec`.
34+
35+
### Encrypting a File
36+
37+
```bash
38+
python aes_tool.py encrypt <input_file> <output_file>
39+
```
40+
41+
**Example:**
42+
43+
```bash
44+
python aes_tool.py encrypt example.txt
45+
```
46+
47+
This will prompt you for a password and create an encrypted file called `example.txt.enc`.
48+
49+
### Decrypting a File
50+
51+
```bash
52+
python aes_tool.py decrypt <input_file> <output_file>
53+
```
54+
55+
**Example:**
56+
57+
```bash
58+
python aes_tool.py decrypt example.txt.enc
59+
```
60+
61+
This will prompt you for the password and decrypt the file to `example.txt`.
62+
63+
### Important Notes:
64+
65+
- You must remember the password used for encryption. The same password is required for decryption.
66+
- If you provide an incorrect password during decryption, the tool will notify you of the failure and delete any incomplete output files to prevent corruption.
67+
68+
## How It Works
69+
70+
1. **Encryption:**
71+
72+
- The tool generates a random 16-byte salt and initialization vector (IV).
73+
- The salt is used with PBKDF2HMAC (HMAC-SHA256) to derive a cryptographic key from the password.
74+
- AES encryption (in CBC mode) is applied to the input file data.
75+
- The encrypted file contains the salt, IV, and the encrypted data.
76+
77+
2. **Decryption:**
78+
- The tool reads the salt and IV from the encrypted file.
79+
- It derives the cryptographic key using the same password-based key derivation function (PBKDF2HMAC).
80+
- AES decryption is applied, and the original file content is recovered.
81+
82+
## Author
83+
84+
- **Name**: Aswin P Kumar
85+
- **GitHub**: [AswinPKumar01](https://github.com/AswinPKumar01)
86+
87+
---

‎A/AES-File-Encryption-Tool/aes_tool.py

Lines changed: 128 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,128 @@
1+
import os
2+
import sys
3+
import argparse
4+
import getpass
5+
from cryptography.hazmat.backends import default_backend
6+
from cryptography.hazmat.primitives import hashes, padding as sym_padding
7+
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
8+
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
9+
10+
def derive_key(password, salt, key_size):
11+
# Derive a cryptographic key from the password
12+
kdf = PBKDF2HMAC(
13+
algorithm=hashes.SHA256(),
14+
length=key_size // 8,
15+
salt=salt,
16+
iterations=100000,
17+
backend=default_backend()
18+
)
19+
key = kdf.derive(password.encode())
20+
return key
21+
22+
def encrypt_file(input_file, output_file, password):
23+
# Generate salt and IV
24+
salt = os.urandom(16)
25+
iv = os.urandom(16)
26+
27+
# Derive key
28+
key = derive_key(password, salt, 256)
29+
30+
# Initialize cipher
31+
cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
32+
encryptor = cipher.encryptor()
33+
34+
# Read input file and encrypt
35+
with open(input_file, 'rb') as f_in, open(output_file, 'wb') as f_out:
36+
# Write salt and IV to the output file
37+
f_out.write(salt)
38+
f_out.write(iv)
39+
40+
# Read the file in chunks
41+
while True:
42+
chunk = f_in.read(1024)
43+
if len(chunk) == 0:
44+
break
45+
elif len(chunk) % 16 != 0:
46+
padder = sym_padding.PKCS7(128).padder()
47+
chunk = padder.update(chunk) + padder.finalize()
48+
encrypted_chunk = encryptor.update(chunk)
49+
f_out.write(encrypted_chunk)
50+
# Finalize encryption
51+
f_out.write(encryptor.finalize())
52+
53+
print(f"File encrypted successfully: {output_file}")
54+
55+
def decrypt_file(input_file, output_file, password):
56+
with open(input_file, 'rb') as f_in:
57+
# Read salt and IV from the input file
58+
salt = f_in.read(16)
59+
iv = f_in.read(16)
60+
61+
# Derive key
62+
key = derive_key(password, salt, 256)
63+
64+
# Initialize cipher
65+
cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
66+
decryptor = cipher.decryptor()
67+
68+
# Prepare to write decrypted data
69+
try:
70+
with open(output_file, 'w+b') as f_out:
71+
# Read the encrypted file in chunks
72+
while True:
73+
chunk = f_in.read(1024)
74+
if len(chunk) == 0:
75+
break
76+
decrypted_chunk = decryptor.update(chunk)
77+
f_out.write(decrypted_chunk)
78+
# Finalize decryption
79+
decrypted_chunk = decryptor.finalize()
80+
f_out.write(decrypted_chunk)
81+
# Remove padding
82+
f_out.seek(0)
83+
data = f_out.read()
84+
unpadder = sym_padding.PKCS7(128).unpadder()
85+
data = unpadder.update(data) + unpadder.finalize()
86+
f_out.seek(0)
87+
f_out.write(data)
88+
f_out.truncate()
89+
print(f"File decrypted successfully: {output_file}")
90+
except Exception as e:
91+
print("Decryption failed. Incorrect password or corrupted file.")
92+
# Ensure the file is closed before deletion
93+
if not f_out.closed:
94+
f_out.close()
95+
if os.path.exists(output_file):
96+
os.remove(output_file)
97+
98+
99+
def main():
100+
parser = argparse.ArgumentParser(description='AES File Encryption Tool')
101+
parser.add_argument('mode', choices=['encrypt', 'decrypt'], help='Mode of operation')
102+
parser.add_argument('input_file', help='Input file path')
103+
parser.add_argument('output_file', nargs='?', help='Output file path')
104+
args = parser.parse_args()
105+
106+
if not os.path.exists(args.input_file):
107+
print("Input file does not exist.")
108+
sys.exit(1)
109+
110+
if not args.output_file:
111+
# Generate default output file name
112+
if args.mode == 'encrypt':
113+
args.output_file = args.input_file + '.enc'
114+
else:
115+
if args.input_file.endswith('.enc'):
116+
args.output_file = args.input_file[:-4]
117+
else:
118+
args.output_file = args.input_file + '.dec'
119+
120+
password = getpass.getpass(prompt='Enter password: ')
121+
122+
if args.mode == 'encrypt':
123+
encrypt_file(args.input_file, args.output_file, password)
124+
else:
125+
decrypt_file(args.input_file, args.output_file, password)
126+
127+
if __name__ == '__main__':
128+
main()

0 commit comments

Comments
(0)

AltStyle によって変換されたページ (->オリジナル) /