added file encryption and decryption tutorial

Author: x4nth055

README.md

@@ -16,6 +16,7 @@ This is a repository of all the tutorials of [The Python Code](https://www.thepy
 -[Writing a Keylogger in Python from Scratch](https://www.thepythoncode.com/article/write-a-keylogger-python). ([code](ethical-hacking/keylogger))
 -[Making a Port Scanner using sockets in Python](https://www.thepythoncode.com/article/make-port-scanner-python). ([code](ethical-hacking/port_scanner))
 -[How to Create a Reverse Shell in Python](https://www.thepythoncode.com/article/create-reverse-shell-python). ([code](ethical-hacking/reverse_shell))
+-[How to Encrypt and Decrypt Files in Python](https://www.thepythoncode.com/article/encrypt-decrypt-files-symmetric-python). ([code](ethical-hacking/file-encryption))
 
 -### [Machine Learning](https://www.thepythoncode.com/topic/machine-learning)
 -### [Natural Language Processing](https://www.thepythoncode.com/topic/nlp)

ethical-hacking/file-encryption/README.md

@@ -0,0 +1,36 @@
+# [How to Encrypt and Decrypt Files in Python](https://www.thepythoncode.com/article/encrypt-decrypt-files-symmetric-python)
+To run this:
+-`pip3 install -r requirements.txt`
+- 
+```
+python crypt --help
+```
+**Output:**
+```
+usage: crypt.py [-h] [-g] [-e] [-d] file
+
+Simple File Encryptor Script
+
+positional arguments:
+file File to encrypt/decrypt
+
+optional arguments:
+-h, --help show this help message and exit
+-g, --generate-key Whether to generate a new key or use existing
+-e, --encrypt Whether to encrypt the file, only -e or -d can be
+ specified.
+-d, --decrypt Whether to decrypt the file, only -e or -d can be
+ specified.
+```
+- If you want to encrypt `data.csv` using a new generated key:
+```
+ python crypt.py data.csv --generate-key --encrypt
+ ```
+- To decrypt it (must be same key, using `--generate-key` flag with decrypt won't be able to get the original file):
+ ```
+ python crypt.py data.csv --decrypt
+ ```
+- To encrypt another file using the same key generated previously:
+ ```
+ python crypt.py another_file --encrypt
+ ```

ethical-hacking/file-encryption/crypt.py

@@ -0,0 +1,86 @@
+fromcryptography.fernetimportFernet
+importos
+
+
+defwrite_key():
+"""
+ Generates a key and save it into a file
+ """
+key=Fernet.generate_key()
+withopen("key.key", "wb") askey_file:
+key_file.write(key)
+
+defload_key():
+"""
+ Loads the key from the current directory named `key.key`
+ """
+returnopen("key.key", "rb").read()
+
+
+defencrypt(filename, key):
+"""
+ Given a filename (str) and key (bytes), it encrypts the file and write it
+ """
+f=Fernet(key)
+withopen(filename, "rb") asfile:
+# read all file data
+file_data=file.read()
+# encrypt data
+encrypted_data=f.encrypt(file_data)
+# write the encrypted file
+withopen(filename, "wb") asfile:
+file.write(encrypted_data)
+
+
+defdecrypt(filename, key):
+"""
+ Given a filename (str) and key (bytes), it decrypts the file and write it
+ """
+f=Fernet(key)
+withopen(filename, "rb") asfile:
+# read the encrypted data
+encrypted_data=file.read()
+# decrypt data
+decrypted_data=f.decrypt(encrypted_data)
+# write the original file
+withopen(filename, "wb") asfile:
+file.write(decrypted_data)
+
+
+if__name__=="__main__":
+importargparse
+parser=argparse.ArgumentParser(description="Simple File Encryptor Script")
+parser.add_argument("file", help="File to encrypt/decrypt")
+parser.add_argument("-g", "--generate-key", dest="generate_key", action="store_true",
+help="Whether to generate a new key or use existing")
+parser.add_argument("-e", "--encrypt", action="store_true",
+help="Whether to encrypt the file, only -e or -d can be specified.")
+parser.add_argument("-d", "--decrypt", action="store_true",
+help="Whether to decrypt the file, only -e or -d can be specified.")
+
+args=parser.parse_args()
+file=args.file
+generate_key=args.generate_key
+
+ifgenerate_key:
+write_key()
+# load the key
+key=load_key()
+
+encrypt_=args.encrypt
+decrypt_=args.decrypt
+
+ifencrypt_anddecrypt_:
+raiseTypeError("Please specify whether you want to encrypt the file or decrypt it.")
+elifencrypt_:
+encrypt(file, key)
+elifdecrypt_:
+decrypt(file, key)
+else:
+raiseTypeError("Please specify whether you want to encrypt the file or decrypt it.")
+
+
+
+
+
+