Initial commit

venv/Lib/site-packages/jose/backends/native.py

@@ -0,0 +1,76 @@
+import hashlib
+import hmac
+import os
+
+from jose.backends.base import Key
+from jose.constants import ALGORITHMS
+from jose.exceptions import JWKError
+from jose.utils import base64url_decode, base64url_encode
+
+
+def get_random_bytes(num_bytes):
+    return bytes(os.urandom(num_bytes))
+
+
+class HMACKey(Key):
+    """
+    Performs signing and verification operations using HMAC
+    and the specified hash function.
+    """
+
+    HASHES = {ALGORITHMS.HS256: hashlib.sha256, ALGORITHMS.HS384: hashlib.sha384, ALGORITHMS.HS512: hashlib.sha512}
+
+    def __init__(self, key, algorithm):
+        if algorithm not in ALGORITHMS.HMAC:
+            raise JWKError("hash_alg: %s is not a valid hash algorithm" % algorithm)
+        self._algorithm = algorithm
+        self._hash_alg = self.HASHES.get(algorithm)
+
+        if isinstance(key, dict):
+            self.prepared_key = self._process_jwk(key)
+            return
+
+        if not isinstance(key, str) and not isinstance(key, bytes):
+            raise JWKError("Expecting a string- or bytes-formatted key.")
+
+        if isinstance(key, str):
+            key = key.encode("utf-8")
+
+        invalid_strings = [
+            b"-----BEGIN PUBLIC KEY-----",
+            b"-----BEGIN RSA PUBLIC KEY-----",
+            b"-----BEGIN CERTIFICATE-----",
+            b"ssh-rsa",
+        ]
+
+        if any(string_value in key for string_value in invalid_strings):
+            raise JWKError(
+                "The specified key is an asymmetric key or x509 certificate and"
+                " should not be used as an HMAC secret."
+            )
+
+        self.prepared_key = key
+
+    def _process_jwk(self, jwk_dict):
+        if not jwk_dict.get("kty") == "oct":
+            raise JWKError("Incorrect key type. Expected: 'oct', Received: %s" % jwk_dict.get("kty"))
+
+        k = jwk_dict.get("k")
+        k = k.encode("utf-8")
+        k = bytes(k)
+        k = base64url_decode(k)
+
+        return k
+
+    def sign(self, msg):
+        return hmac.new(self.prepared_key, msg, self._hash_alg).digest()
+
+    def verify(self, msg, sig):
+        return hmac.compare_digest(sig, self.sign(msg))
+
+    def to_dict(self):
+        return {
+            "alg": self._algorithm,
+            "kty": "oct",
+            "k": base64url_encode(self.prepared_key).decode("ASCII"),
+        }