255 lines
6.7 KiB
Python
255 lines
6.7 KiB
Python
# This file is dual licensed under the terms of the Apache License, Version
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# 2.0, and the BSD License. See the LICENSE file in the root of this repository
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# for complete details.
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from __future__ import absolute_import, division, print_function
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import abc
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import six
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from cryptography import utils
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@six.add_metaclass(abc.ABCMeta)
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class DSAParameters(object):
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@abc.abstractmethod
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def generate_private_key(self):
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"""
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Generates and returns a DSAPrivateKey.
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"""
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@six.add_metaclass(abc.ABCMeta)
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class DSAParametersWithNumbers(DSAParameters):
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@abc.abstractmethod
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def parameter_numbers(self):
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"""
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Returns a DSAParameterNumbers.
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"""
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@six.add_metaclass(abc.ABCMeta)
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class DSAPrivateKey(object):
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@abc.abstractproperty
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def key_size(self):
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"""
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The bit length of the prime modulus.
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"""
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@abc.abstractmethod
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def public_key(self):
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"""
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The DSAPublicKey associated with this private key.
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"""
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@abc.abstractmethod
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def parameters(self):
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"""
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The DSAParameters object associated with this private key.
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"""
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@abc.abstractmethod
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def signer(self, signature_algorithm):
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"""
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Returns an AsymmetricSignatureContext used for signing data.
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"""
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@abc.abstractmethod
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def sign(self, data, algorithm):
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"""
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Signs the data
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"""
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@six.add_metaclass(abc.ABCMeta)
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class DSAPrivateKeyWithSerialization(DSAPrivateKey):
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@abc.abstractmethod
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def private_numbers(self):
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"""
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Returns a DSAPrivateNumbers.
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"""
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@abc.abstractmethod
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def private_bytes(self, encoding, format, encryption_algorithm):
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"""
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Returns the key serialized as bytes.
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"""
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@six.add_metaclass(abc.ABCMeta)
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class DSAPublicKey(object):
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@abc.abstractproperty
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def key_size(self):
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"""
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The bit length of the prime modulus.
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"""
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@abc.abstractmethod
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def parameters(self):
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"""
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The DSAParameters object associated with this public key.
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"""
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@abc.abstractmethod
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def verifier(self, signature, signature_algorithm):
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"""
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Returns an AsymmetricVerificationContext used for signing data.
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"""
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@abc.abstractmethod
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def public_numbers(self):
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"""
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Returns a DSAPublicNumbers.
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"""
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@abc.abstractmethod
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def public_bytes(self, encoding, format):
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"""
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Returns the key serialized as bytes.
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"""
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@abc.abstractmethod
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def verify(self, signature, data, algorithm):
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"""
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Verifies the signature of the data.
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"""
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DSAPublicKeyWithSerialization = DSAPublicKey
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def generate_parameters(key_size, backend):
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return backend.generate_dsa_parameters(key_size)
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def generate_private_key(key_size, backend):
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return backend.generate_dsa_private_key_and_parameters(key_size)
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def _check_dsa_parameters(parameters):
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if parameters.p.bit_length() not in [1024, 2048, 3072]:
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raise ValueError("p must be exactly 1024, 2048, or 3072 bits long")
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if parameters.q.bit_length() not in [160, 224, 256]:
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raise ValueError("q must be exactly 160, 224, or 256 bits long")
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if not (1 < parameters.g < parameters.p):
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raise ValueError("g, p don't satisfy 1 < g < p.")
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def _check_dsa_private_numbers(numbers):
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parameters = numbers.public_numbers.parameter_numbers
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_check_dsa_parameters(parameters)
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if numbers.x <= 0 or numbers.x >= parameters.q:
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raise ValueError("x must be > 0 and < q.")
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if numbers.public_numbers.y != pow(parameters.g, numbers.x, parameters.p):
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raise ValueError("y must be equal to (g ** x % p).")
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class DSAParameterNumbers(object):
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def __init__(self, p, q, g):
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if (
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not isinstance(p, six.integer_types) or
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not isinstance(q, six.integer_types) or
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not isinstance(g, six.integer_types)
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):
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raise TypeError(
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"DSAParameterNumbers p, q, and g arguments must be integers."
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)
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self._p = p
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self._q = q
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self._g = g
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p = utils.read_only_property("_p")
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q = utils.read_only_property("_q")
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g = utils.read_only_property("_g")
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def parameters(self, backend):
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return backend.load_dsa_parameter_numbers(self)
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def __eq__(self, other):
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if not isinstance(other, DSAParameterNumbers):
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return NotImplemented
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return self.p == other.p and self.q == other.q and self.g == other.g
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def __ne__(self, other):
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return not self == other
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def __repr__(self):
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return (
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"<DSAParameterNumbers(p={self.p}, q={self.q}, g={self.g})>".format(
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self=self
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)
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)
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class DSAPublicNumbers(object):
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def __init__(self, y, parameter_numbers):
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if not isinstance(y, six.integer_types):
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raise TypeError("DSAPublicNumbers y argument must be an integer.")
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if not isinstance(parameter_numbers, DSAParameterNumbers):
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raise TypeError(
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"parameter_numbers must be a DSAParameterNumbers instance."
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)
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self._y = y
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self._parameter_numbers = parameter_numbers
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y = utils.read_only_property("_y")
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parameter_numbers = utils.read_only_property("_parameter_numbers")
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def public_key(self, backend):
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return backend.load_dsa_public_numbers(self)
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def __eq__(self, other):
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if not isinstance(other, DSAPublicNumbers):
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return NotImplemented
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return (
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self.y == other.y and
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self.parameter_numbers == other.parameter_numbers
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)
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def __ne__(self, other):
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return not self == other
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def __repr__(self):
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return (
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"<DSAPublicNumbers(y={self.y}, "
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"parameter_numbers={self.parameter_numbers})>".format(self=self)
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)
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class DSAPrivateNumbers(object):
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def __init__(self, x, public_numbers):
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if not isinstance(x, six.integer_types):
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raise TypeError("DSAPrivateNumbers x argument must be an integer.")
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if not isinstance(public_numbers, DSAPublicNumbers):
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raise TypeError(
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"public_numbers must be a DSAPublicNumbers instance."
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)
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self._public_numbers = public_numbers
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self._x = x
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x = utils.read_only_property("_x")
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public_numbers = utils.read_only_property("_public_numbers")
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def private_key(self, backend):
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return backend.load_dsa_private_numbers(self)
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def __eq__(self, other):
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if not isinstance(other, DSAPrivateNumbers):
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return NotImplemented
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return (
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self.x == other.x and self.public_numbers == other.public_numbers
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)
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def __ne__(self, other):
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return not self == other
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