Cryptography fernet

Author: boraxpr

264/clamy_fernet.py

@@ -0,0 +1,57 @@
+import base64
+from cryptography.fernet import Fernet  # type: ignore
+from cryptography.hazmat.backends import default_backend  # type: ignore
+from cryptography.hazmat.primitives import hashes  # type: ignore
+from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC  # type: ignore
+from dataclasses import dataclass
+from os import urandom
+from typing import ByteString, Tuple, Optional
+
+
+@dataclass
+class ClamyFernet:
+    """Fernet implementation by clamytoe
+
+    Takes a bytestring as a password and derives a Fernet
+    key from it. If a key is provided, that key will be used.
+    """
+    password: ByteString = b"pybites"
+    key: Optional[ByteString] = None
+
+    def __post_init__(self):
+        """Initializes the class"""
+        self.salt = urandom(16)
+        self.algorithm = hashes.SHA512()
+        self.length = 32
+        self.iterations = 100_000
+        self.backend = default_backend()
+
+        if self.key is None:
+            self.key = base64.urlsafe_b64encode(self.kdf.derive(self.password))
+
+    @property
+    def kdf(self) -> PBKDF2HMAC:
+        """Derives the key from the password
+
+        Uses PBKDF2HMAC to generate a secure key.
+        """
+        return PBKDF2HMAC(
+            algorithm=self.algorithm,
+            length=self.length,
+            salt=self.salt,
+            iterations=self.iterations,
+            backend=self.backend,
+        )
+
+    @property
+    def clf(self):
+        """Generates a Fernet object"""
+        return Fernet(self.key)
+
+    def encrypt(self, message: str) -> ByteString:
+        """Encrypts the message passed to it"""
+        return self.clf.encrypt(str.encode(message))
+
+    def decrypt(self, token: ByteString) -> str:
+        """Decrypts the encrypted message passed to it"""
+        return self.clf.decrypt(token).decode("utf-8")

264/submissions/save1_passed.py

@@ -0,0 +1,57 @@
+import base64
+from cryptography.fernet import Fernet  # type: ignore
+from cryptography.hazmat.backends import default_backend  # type: ignore
+from cryptography.hazmat.primitives import hashes  # type: ignore
+from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC  # type: ignore
+from dataclasses import dataclass
+from os import urandom
+from typing import ByteString, Tuple, Optional
+
+
+@dataclass
+class ClamyFernet:
+    """Fernet implementation by clamytoe
+
+    Takes a bytestring as a password and derives a Fernet
+    key from it. If a key is provided, that key will be used.
+    """
+    password: ByteString = b"pybites"
+    key: Optional[ByteString] = None
+
+    def __post_init__(self):
+        """Initializes the class"""
+        self.salt = urandom(16)
+        self.algorithm = hashes.SHA512()
+        self.length = 32
+        self.iterations = 100_000
+        self.backend = default_backend()
+
+        if self.key is None:
+            self.key = base64.urlsafe_b64encode(self.kdf.derive(self.password))
+
+    @property
+    def kdf(self) -> PBKDF2HMAC:
+        """Derives the key from the password
+
+        Uses PBKDF2HMAC to generate a secure key.
+        """
+        return PBKDF2HMAC(
+            algorithm=self.algorithm,
+            length=self.length,
+            salt=self.salt,
+            iterations=self.iterations,
+            backend=self.backend,
+        )
+
+    @property
+    def clf(self):
+        """Generates a Fernet object"""
+        return Fernet(self.key)
+
+    def encrypt(self, message: str) -> ByteString:
+        """Encrypts the message passed to it"""
+        return self.clf.encrypt(str.encode(message))
+
+    def decrypt(self, token: ByteString) -> str:
+        """Decrypts the encrypted message passed to it"""
+        return self.clf.decrypt(token).decode("utf-8")

264/test_clamy_fernet.py

@@ -0,0 +1,63 @@
+from datetime import datetime
+from random import choice
+from tempfile import NamedTemporaryFile
+
+import pytest
+
+from clamy_fernet import PBKDF2HMAC, ByteString, ClamyFernet, Fernet
+
+KEYS = (
+    b"rvxePMSDUcZFowEaNxnFb8Pifn1KmhkF70Mz1ZQe2Bw=",
+    b"2gODW4C4Lc7H9bjuuhPyn48HkVHriqa96P8lmstABo8=",
+    b"mAbAfF5CW3EGlngOEEroDqtxlxVlJILzoUE4TJScMIw=",
+)
+MESSAGE = "This is my secret message"
+TMP_FILE = NamedTemporaryFile(delete=False)
+FILE = TMP_FILE.name
+
+
+@pytest.fixture(scope="function")
+def rcf():
+    password = b"#clamybite"
+    key = choice(KEYS)
+    return ClamyFernet(password, key)
+
+
+@pytest.fixture(scope="module")
+def cf():
+    return ClamyFernet(key=KEYS[0])
+
+
+def test_clamyfernet_no_args(rcf):
+    tmp_cf = ClamyFernet()
+    assert tmp_cf.key is not None
+    assert tmp_cf.password == b"pybites"
+
+
+def test_clamyfernet_random_key(rcf):
+    token = rcf.encrypt("secret msg")
+    ts = rcf.clf.extract_timestamp(token)
+    dt = datetime.fromtimestamp(ts)
+    assert isinstance(rcf, ClamyFernet)
+    assert isinstance(rcf.clf, Fernet)
+    assert isinstance(rcf.key, ByteString)
+    assert isinstance(rcf.kdf, PBKDF2HMAC)
+    assert dt.year == datetime.now().year
+
+
+def test_clamyfernet(cf):
+    token = cf.encrypt(MESSAGE)
+    og_message = cf.decrypt(token)
+    assert len(token) == 120
+    assert isinstance(token, bytes)
+    assert cf.key == KEYS[0]
+    assert og_message == MESSAGE
+
+
+def test_clamyfernet_random(rcf):
+    token = rcf.encrypt(MESSAGE)
+    og_message = rcf.decrypt(token)
+    assert len(token) == 120
+    assert isinstance(token, bytes)
+    assert rcf.key in KEYS
+    assert og_message == MESSAGE