updates

Backend/venv/lib/python3.12/site-packages/pyotp/otp.py

@@ -0,0 +1,68 @@
+import base64
+import hashlib
+import hmac
+from typing import Any, Optional
+
+
+class OTP(object):
+    """
+    Base class for OTP handlers.
+    """
+
+    def __init__(
+        self,
+        s: str,
+        digits: int = 6,
+        digest: Any = hashlib.sha1,
+        name: Optional[str] = None,
+        issuer: Optional[str] = None,
+    ) -> None:
+        self.digits = digits
+        if digits > 10:
+            raise ValueError("digits must be no greater than 10")
+        self.digest = digest
+        self.secret = s
+        self.name = name or "Secret"
+        self.issuer = issuer
+
+    def generate_otp(self, input: int) -> str:
+        """
+        :param input: the HMAC counter value to use as the OTP input.
+            Usually either the counter, or the computed integer based on the Unix timestamp
+        """
+        if input < 0:
+            raise ValueError("input must be positive integer")
+        hasher = hmac.new(self.byte_secret(), self.int_to_bytestring(input), self.digest)
+        hmac_hash = bytearray(hasher.digest())
+        offset = hmac_hash[-1] & 0xF
+        code = (
+            (hmac_hash[offset] & 0x7F) << 24
+            | (hmac_hash[offset + 1] & 0xFF) << 16
+            | (hmac_hash[offset + 2] & 0xFF) << 8
+            | (hmac_hash[offset + 3] & 0xFF)
+        )
+        str_code = str(10_000_000_000 + (code % 10**self.digits))
+        return str_code[-self.digits :]
+
+    def byte_secret(self) -> bytes:
+        secret = self.secret
+        missing_padding = len(secret) % 8
+        if missing_padding != 0:
+            secret += "=" * (8 - missing_padding)
+        return base64.b32decode(secret, casefold=True)
+
+    @staticmethod
+    def int_to_bytestring(i: int, padding: int = 8) -> bytes:
+        """
+        Turns an integer to the OATH specified
+        bytestring, which is fed to the HMAC
+        along with the secret
+        """
+        result = bytearray()
+        while i != 0:
+            result.append(i & 0xFF)
+            i >>= 8
+        # It's necessary to convert the final result from bytearray to bytes
+        # because the hmac functions in python 2.6 and 3.3 don't work with
+        # bytearray
+        return bytes(bytearray(reversed(result)).rjust(padding, b"\0"))