Source code for pyotp.hotp

import hashlib
from typing import Any, Optional

from . import utils
from .otp import OTP


[docs]class HOTP(OTP): """ Handler for HMAC-based OTP counters. """ def __init__(self, s: str, digits: int = 6, digest: Any = hashlib.sha1, name: Optional[str] = None, issuer: Optional[str] = None, initial_count: int = 0) -> None: """ :param s: secret in base32 format :param initial_count: starting HMAC counter value, defaults to 0 :param digits: number of integers in the OTP. Some apps expect this to be 6 digits, others support more. :param digest: digest function to use in the HMAC (expected to be sha1) :param name: account name :param issuer: issuer """ self.initial_count = initial_count super().__init__(s=s, digits=digits, digest=digest, name=name, issuer=issuer)
[docs] def at(self, count: int) -> str: """ Generates the OTP for the given count. :param count: the OTP HMAC counter :returns: OTP """ return self.generate_otp(self.initial_count + count)
[docs] def verify(self, otp: str, counter: int) -> bool: """ Verifies the OTP passed in against the current counter OTP. :param otp: the OTP to check against :param counter: the OTP HMAC counter """ return utils.strings_equal(str(otp), str(self.at(counter)))
[docs] def provisioning_uri( self, name: Optional[str] = None, initial_count: Optional[int] = None, issuer_name: Optional[str] = None, image: Optional[str] = None) -> str: """ Returns the provisioning URI for the OTP. This can then be encoded in a QR Code and used to provision an OTP app like Google Authenticator. See also: https://github.com/google/google-authenticator/wiki/Key-Uri-Format :param name: name of the user account :param initial_count: starting HMAC counter value, defaults to 0 :param issuer_name: the name of the OTP issuer; this will be the organization title of the OTP entry in Authenticator :returns: provisioning URI """ return utils.build_uri( self.secret, name=name if name else self.name, initial_count=initial_count if initial_count else self.initial_count, issuer=issuer_name if issuer_name else self.issuer, algorithm=self.digest().name, digits=self.digits, image=image, )