"""Pwdlib Hashing Backend."""
from typing import TYPE_CHECKING, Any, Union
from advanced_alchemy.exceptions import MissingDependencyError
from advanced_alchemy.types.password_hash.base import HashingBackend
from advanced_alchemy.typing import PWDLIB_INSTALLED
if TYPE_CHECKING:
from pwdlib.hashers.base import HasherProtocol
from sqlalchemy import BinaryExpression, ColumnElement
__all__ = ("PwdlibHasher",)
[docs]
class PwdlibHasher(HashingBackend):
"""Hashing backend using Pwdlib."""
[docs]
def __init__(self, hasher: "HasherProtocol") -> None:
"""Initialize PwdlibBackend.
Args:
hasher: The Pwdlib hasher to use for hashing and verification.
Raises:
MissingDependencyError: If the ``pwdlib`` package is not installed.
"""
if not PWDLIB_INSTALLED:
raise MissingDependencyError(package="pwdlib")
self.hasher = hasher
[docs]
def hash(self, value: "Union[str, bytes]") -> str:
"""Hash the given value using the Pwdlib context.
Args:
value: The plain text value to hash. Will be converted to string.
Returns:
The hashed string.
"""
return self.hasher.hash(self._ensure_bytes(value))
[docs]
def verify(self, plain: "Union[str, bytes]", hashed: str) -> bool:
"""Verify a plain text value against a hash using the Pwdlib context.
Args:
plain: The plain text value to verify. Will be converted to string.
hashed: The hash to verify against.
Returns:
True if the plain text matches the hash, False otherwise.
"""
try:
return self.hasher.verify(self._ensure_bytes(plain), hashed)
except Exception: # noqa: BLE001
return False
[docs]
def needs_rehash(self, hashed: str) -> bool:
"""Return True if the wrapped hasher reports the stored hash as stale.
Args:
hashed: The stored hash string.
Returns:
True if the hash should be regenerated; False for an unparsable or foreign hash.
"""
try:
return self.hasher.check_needs_rehash(hashed)
except Exception: # noqa: BLE001
return False
[docs]
def compare_expression(self, column: "ColumnElement[str]", plain: Any) -> "BinaryExpression[bool]":
"""Direct SQL comparison is not supported for Pwdlib.
Raises:
NotImplementedError: Always raised.
"""
msg = "PwdlibHasher does not support direct SQL comparison."
raise NotImplementedError(msg)
