diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/dns/dnssecalgs/rsa.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/dns/dnssecalgs/rsa.py | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/dns/dnssecalgs/rsa.py b/.venv/lib/python3.12/site-packages/dns/dnssecalgs/rsa.py new file mode 100644 index 00000000..27537aad --- /dev/null +++ b/.venv/lib/python3.12/site-packages/dns/dnssecalgs/rsa.py @@ -0,0 +1,124 @@ +import math +import struct + +from cryptography.hazmat.backends import default_backend +from cryptography.hazmat.primitives import hashes +from cryptography.hazmat.primitives.asymmetric import padding, rsa + +from dns.dnssecalgs.cryptography import CryptographyPrivateKey, CryptographyPublicKey +from dns.dnssectypes import Algorithm +from dns.rdtypes.ANY.DNSKEY import DNSKEY + + +class PublicRSA(CryptographyPublicKey): + key: rsa.RSAPublicKey + key_cls = rsa.RSAPublicKey + algorithm: Algorithm + chosen_hash: hashes.HashAlgorithm + + def verify(self, signature: bytes, data: bytes) -> None: + self.key.verify(signature, data, padding.PKCS1v15(), self.chosen_hash) + + def encode_key_bytes(self) -> bytes: + """Encode a public key per RFC 3110, section 2.""" + pn = self.key.public_numbers() + _exp_len = math.ceil(int.bit_length(pn.e) / 8) + exp = int.to_bytes(pn.e, length=_exp_len, byteorder="big") + if _exp_len > 255: + exp_header = b"\0" + struct.pack("!H", _exp_len) + else: + exp_header = struct.pack("!B", _exp_len) + if pn.n.bit_length() < 512 or pn.n.bit_length() > 4096: + raise ValueError("unsupported RSA key length") + return exp_header + exp + pn.n.to_bytes((pn.n.bit_length() + 7) // 8, "big") + + @classmethod + def from_dnskey(cls, key: DNSKEY) -> "PublicRSA": + cls._ensure_algorithm_key_combination(key) + keyptr = key.key + (bytes_,) = struct.unpack("!B", keyptr[0:1]) + keyptr = keyptr[1:] + if bytes_ == 0: + (bytes_,) = struct.unpack("!H", keyptr[0:2]) + keyptr = keyptr[2:] + rsa_e = keyptr[0:bytes_] + rsa_n = keyptr[bytes_:] + return cls( + key=rsa.RSAPublicNumbers( + int.from_bytes(rsa_e, "big"), int.from_bytes(rsa_n, "big") + ).public_key(default_backend()) + ) + + +class PrivateRSA(CryptographyPrivateKey): + key: rsa.RSAPrivateKey + key_cls = rsa.RSAPrivateKey + public_cls = PublicRSA + default_public_exponent = 65537 + + def sign( + self, + data: bytes, + verify: bool = False, + deterministic: bool = True, + ) -> bytes: + """Sign using a private key per RFC 3110, section 3.""" + signature = self.key.sign(data, padding.PKCS1v15(), self.public_cls.chosen_hash) + if verify: + self.public_key().verify(signature, data) + return signature + + @classmethod + def generate(cls, key_size: int) -> "PrivateRSA": + return cls( + key=rsa.generate_private_key( + public_exponent=cls.default_public_exponent, + key_size=key_size, + backend=default_backend(), + ) + ) + + +class PublicRSAMD5(PublicRSA): + algorithm = Algorithm.RSAMD5 + chosen_hash = hashes.MD5() + + +class PrivateRSAMD5(PrivateRSA): + public_cls = PublicRSAMD5 + + +class PublicRSASHA1(PublicRSA): + algorithm = Algorithm.RSASHA1 + chosen_hash = hashes.SHA1() + + +class PrivateRSASHA1(PrivateRSA): + public_cls = PublicRSASHA1 + + +class PublicRSASHA1NSEC3SHA1(PublicRSA): + algorithm = Algorithm.RSASHA1NSEC3SHA1 + chosen_hash = hashes.SHA1() + + +class PrivateRSASHA1NSEC3SHA1(PrivateRSA): + public_cls = PublicRSASHA1NSEC3SHA1 + + +class PublicRSASHA256(PublicRSA): + algorithm = Algorithm.RSASHA256 + chosen_hash = hashes.SHA256() + + +class PrivateRSASHA256(PrivateRSA): + public_cls = PublicRSASHA256 + + +class PublicRSASHA512(PublicRSA): + algorithm = Algorithm.RSASHA512 + chosen_hash = hashes.SHA512() + + +class PrivateRSASHA512(PrivateRSA): + public_cls = PublicRSASHA512 |