Merge pull request #932 from kaliappan01/aes-py

aes_py added

Author: pawangeek

aes_py/README.md

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+# aes_py
+This script will be able to encrypt and decrypt text using AES256 using password based key. -
+
+## Usage
+`
+$ python3 main.py --text "this is a secret message" -op 0  
+Enter password : 
+b'8jeJABqjpdK0aVExWZars2Uzd+vBZIWQFRvdIqt5DJz3X/bSuHBnX4YW7MjYCrSg'  
+$ python3 main.py --text "8jeJABqjpdK0aVExWZars2Uzd+vBZIWQFRvdIqt5DJz3X/bSuHBnX4YW7MjYCrSg" -op 1
+Enter password : 
+b'this is a secret message'
+`

aes_py/aes_tool.py

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+import base64
+from Crypto.Cipher import AES
+from Crypto import Random
+from Crypto.Protocol.KDF import PBKDF2
+
+BLOCK_SIZE = 16
+
+
+def pad(s):
+    return s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * chr(
+        BLOCK_SIZE - len(s) % BLOCK_SIZE
+    )
+
+
+def unpad(s):
+    return s[: -ord(s[len(s) - 1:])]
+
+
+def get_private_key(password):
+    salt = b"this is a salt"
+    kdf = PBKDF2(password, salt, 64, 1000)
+    key = kdf[:32]
+    return key
+
+
+def encrypt(raw, password):
+    private_key = get_private_key(password)
+    raw = pad(raw)
+    iv = Random.new().read(AES.block_size)
+    cipher = AES.new(private_key, AES.MODE_CBC, iv)
+    cipher = iv + cipher.encrypt(raw.encode("utf-8"))
+    return base64.b64encode(cipher)
+
+
+def decrypt(enc, password):
+    private_key = get_private_key(password)
+    enc = base64.b64decode(enc)
+    iv = enc[:16]
+    cipher = AES.new(private_key, AES.MODE_CBC, iv)
+    return unpad(cipher.decrypt(enc[16:]))
+
+
+if __name__ == "__main__":
+    password = input("Enter encryption password: ")
+    # First let us encrypt secret message
+    encrypted = encrypt("This is a secret message", password)
+    print(encrypted)
+
+    # Let us decrypt using our original password
+    decrypted = decrypt(encrypted, password)
+    print(bytes.decode(decrypted))

aes_py/main.py

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+import argparse
+from getpass import getpass
+import aes_tool
+
+
+parser = argparse.ArgumentParser(description="Aes \
+ encryption and decryption command")
+
+parser.add_argument("--text", help=argparse.SUPPRESS)
+parser.add_argument(
+    "--operation",
+    "-op",
+    choices=["0", "1"],
+    help="0 for encryption and 1 for decryption",
+)
+args = parser.parse_args()
+password = getpass("Enter password : ")
+
+if args.operation == "0":
+    print(aes_tool.encrypt(args.text, password))
+
+elif args.operation == "1":
+    print(aes_tool.decrypt(args.text, password))

aes_py/makefile

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+VENV ?= .venv
+REQUIREMENTS_FILE ?= requirements.txt
+
+init:
+	python3 -m venv $(VENV)
+	$(VENV)/bin/python -m pip install --upgrade pip
+	if [ -f $(REQUIREMENTS_FILE) ]; \
+	    then $(VENV)/bin/python -m pip install -r $(REQUIREMENTS_FILE); \
+    fi

aes_py/requirements.txt

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+pycryptodome==3.15.0