fix: use hmac.compare_digest in verify method

src/otpauth/core.py

@@ -1,4 +1,5 @@
 import base64
+from urllib.parse import quote
 from abc import ABCMeta, abstractmethod
 
 
@@ -34,6 +35,10 @@ def from_b32encode(cls, secret: bytes):
         obj._b32_secret = b32_secret
         return obj
 
+    def _get_base_uri(self, label: str, issuer: str) -> str:
+        label = quote(label, safe="/@")
+        return f"otpauth://hotp/{label}?secret={self.b32_secret}&issuer={issuer}&algorithm={self.algorithm}&digits={self.digit}"
+
     @abstractmethod
     def generate(self, *args, **kwargs) -> int:
         ...

src/otpauth/rfc4226.py

@@ -22,7 +22,7 @@ def verify(self, code: int, counter: int) -> bool:
         """
         if len(str(code)) > self.digit:
             return False
-        return hashlib.compare_digest(bytes(self.generate(counter)), bytes(code))
+        return hmac.compare_digest(bytes(self.generate(counter)), bytes(code))
 
     def to_uri(self, label: str, issuer: str, counter: int) -> str:
         """Generate the otpauth protocal string for HOTP.
@@ -31,7 +31,7 @@ def to_uri(self, label: str, issuer: str, counter: int) -> str:
         :param issuer: The company, the organization or something else.
         :param counter: Initial counter of the HOTP algorithm.
         """
-        uri = f"otpauth://hotp/{label}?secret={self.b32_secret}&issuer={issuer}&algorithm={self.algorithm}&digits={self.digit}"
+        uri = self._get_base_uri(label, issuer)
         return uri + f"&counter={counter}"
 
 

src/otpauth/rfc6238.py

@@ -1,5 +1,5 @@
 import time
-import hashlib
+import hmac
 from .core import OTP
 from .rfc4226 import generate_hotp
 
@@ -26,15 +26,15 @@ def verify(self, code: int, timestamp: int = None) -> bool:
         """
         if len(str(code)) > self.digit:
             return False
-        return hashlib.compare_digest(bytes(self.generate(timestamp)), bytes(code))
+        return hmac.compare_digest(bytes(self.generate(timestamp)), bytes(code))
 
     def to_uri(self, label: str, issuer: str) -> str:
         """Generate the otpauth protocal string for TOTP.
 
         :param label: Label of the identifier.
         :param issuer: The company, the organization or something else.
         """
-        uri = f"otpauth://totp/{label}?secret={self.b32_secret}&issuer={issuer}&algorithm={self.algorithm}&digits={self.digit}"
+        uri = self._get_base_uri(label, issuer)
         return uri + f"&period={self.period}"