Bump dnspython from 2.3.0 to 2.4.2 (#2123)

* Bump dnspython from 2.3.0 to 2.4.2

Bumps [dnspython](https://github.com/rthalley/dnspython) from 2.3.0 to 2.4.2.
- [Release notes](https://github.com/rthalley/dnspython/releases)
- [Changelog](https://github.com/rthalley/dnspython/blob/master/doc/whatsnew.rst)
- [Commits](https://github.com/rthalley/dnspython/compare/v2.3.0...v2.4.2)

---
updated-dependencies:
- dependency-name: dnspython
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update dnspython==2.4.2

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: JonnyWong16 <9099342+JonnyWong16@users.noreply.github.com>

[skip ci]

lib/dns/dnssecalgs/base.py

@@ -0,0 +1,84 @@
+from abc import ABC, abstractmethod  # pylint: disable=no-name-in-module
+from typing import Any, Optional, Type
+
+import dns.rdataclass
+import dns.rdatatype
+from dns.dnssectypes import Algorithm
+from dns.exception import AlgorithmKeyMismatch
+from dns.rdtypes.ANY.DNSKEY import DNSKEY
+from dns.rdtypes.dnskeybase import Flag
+
+
+class GenericPublicKey(ABC):
+    algorithm: Algorithm
+
+    @abstractmethod
+    def __init__(self, key: Any) -> None:
+        pass
+
+    @abstractmethod
+    def verify(self, signature: bytes, data: bytes) -> None:
+        """Verify signed DNSSEC data"""
+
+    @abstractmethod
+    def encode_key_bytes(self) -> bytes:
+        """Encode key as bytes for DNSKEY"""
+
+    @classmethod
+    def _ensure_algorithm_key_combination(cls, key: DNSKEY) -> None:
+        if key.algorithm != cls.algorithm:
+            raise AlgorithmKeyMismatch
+
+    def to_dnskey(self, flags: int = Flag.ZONE, protocol: int = 3) -> DNSKEY:
+        """Return public key as DNSKEY"""
+        return DNSKEY(
+            rdclass=dns.rdataclass.IN,
+            rdtype=dns.rdatatype.DNSKEY,
+            flags=flags,
+            protocol=protocol,
+            algorithm=self.algorithm,
+            key=self.encode_key_bytes(),
+        )
+
+    @classmethod
+    @abstractmethod
+    def from_dnskey(cls, key: DNSKEY) -> "GenericPublicKey":
+        """Create public key from DNSKEY"""
+
+    @classmethod
+    @abstractmethod
+    def from_pem(cls, public_pem: bytes) -> "GenericPublicKey":
+        """Create public key from PEM-encoded SubjectPublicKeyInfo as specified
+        in RFC 5280"""
+
+    @abstractmethod
+    def to_pem(self) -> bytes:
+        """Return public-key as PEM-encoded SubjectPublicKeyInfo as specified
+        in RFC 5280"""
+
+
+class GenericPrivateKey(ABC):
+    public_cls: Type[GenericPublicKey]
+
+    @abstractmethod
+    def __init__(self, key: Any) -> None:
+        pass
+
+    @abstractmethod
+    def sign(self, data: bytes, verify: bool = False) -> bytes:
+        """Sign DNSSEC data"""
+
+    @abstractmethod
+    def public_key(self) -> "GenericPublicKey":
+        """Return public key instance"""
+
+    @classmethod
+    @abstractmethod
+    def from_pem(
+        cls, private_pem: bytes, password: Optional[bytes] = None
+    ) -> "GenericPrivateKey":
+        """Create private key from PEM-encoded PKCS#8"""
+
+    @abstractmethod
+    def to_pem(self, password: Optional[bytes] = None) -> bytes:
+        """Return private key as PEM-encoded PKCS#8"""