Merge pull request #1163 from reaperhulk/dsa-numbers-classes

DSA*Numbers classes

3 files changed, 198 insertions, 0 deletions

diff --git a/cryptography/hazmat/primitives/asymmetric/dsa.py b/cryptography/hazmat/primitives/asymmetric/dsa.py
index a9ae9ecb..4d78679e 100644
--- a/cryptography/hazmat/primitives/asymmetric/dsa.py
+++ b/cryptography/hazmat/primitives/asymmetric/dsa.py
@@ -181,3 +181,74 @@ class DSAPublicKey(object):
     def parameters(self):
         return DSAParameters(self._modulus, self._subgroup_order,
                              self._generator)
+
+
+class DSAParameterNumbers(object):
+    def __init__(self, p, q, g):
+        if (
+            not isinstance(p, six.integer_types) or
+            not isinstance(q, six.integer_types) or
+            not isinstance(g, six.integer_types)
+        ):
+            raise TypeError(
+                "DSAParameterNumbers p, q, and g arguments must be integers."
+            )
+
+        self._p = p
+        self._q = q
+        self._g = g
+
+    @property
+    def p(self):
+        return self._p
+
+    @property
+    def q(self):
+        return self._q
+
+    @property
+    def g(self):
+        return self._g
+
+
+class DSAPublicNumbers(object):
+    def __init__(self, y, parameter_numbers):
+        if not isinstance(y, six.integer_types):
+            raise TypeError("DSAPublicNumbers y argument must be an integer.")
+
+        if not isinstance(parameter_numbers, DSAParameterNumbers):
+            raise TypeError(
+                "parameter_numbers must be a DSAParameterNumbers instance."
+            )
+
+        self._y = y
+        self._parameter_numbers = parameter_numbers
+
+    @property
+    def y(self):
+        return self._y
+
+    @property
+    def parameter_numbers(self):
+        return self._parameter_numbers
+
+
+class DSAPrivateNumbers(object):
+    def __init__(self, x, public_numbers):
+        if not isinstance(x, six.integer_types):
+            raise TypeError("DSAPrivateNumbers x argument must be an integer.")
+
+        if not isinstance(public_numbers, DSAPublicNumbers):
+            raise TypeError(
+                "public_numbers must be a DSAPublicNumbers instance."
+            )
+        self._public_numbers = public_numbers
+        self._x = x
+
+    @property
+    def x(self):
+        return self._x
+
+    @property
+    def public_numbers(self):
+        return self._public_numbers
diff --git a/docs/hazmat/primitives/asymmetric/dsa.rst b/docs/hazmat/primitives/asymmetric/dsa.rst
index 6848d84c..2167e528 100644
--- a/docs/hazmat/primitives/asymmetric/dsa.rst
+++ b/docs/hazmat/primitives/asymmetric/dsa.rst
@@ -210,6 +210,73 @@ DSA
         :returns:
             :class:`~cryptography.hazmat.primitives.interfaces.AsymmetricVerificationContext`
 
+.. class:: DSAParameterNumbers(p, q, g)
+
+    .. versionadded:: 0.5
+
+    The collection of integers that make up a set of DSA parameters.
+
+    .. attribute:: p
+
+        :type: int
+
+        The public modulus.
+
+    .. attribute:: q
+
+        :type: int
+
+        The sub-group order.
+
+    .. attribute:: g
+
+        :type: int
+
+        The generator.
+
+.. class:: DSAPublicNumbers(y, parameter_numbers)
+
+    .. versionadded:: 0.5
+
+    The collection of integers that make up a DSA public key.
+
+    .. attribute:: y
+
+        :type: int
+
+        The public value ``y``.
+
+    .. attribute:: parameter_numbers
+
+        :type: :class:`~cryptography.hazmat.primitives.dsa.DSAParameterNumbers`
+
+        The :class:`~cryptography.hazmat.primitives.dsa.DSAParameterNumbers`
+        associated with the public key.
+
+.. class:: DSAPrivateNumbers(x, public_numbers)
+
+    .. versionadded:: 0.5
+
+    The collection of integers that make up a DSA private key.
+
+    .. warning::
+
+        Revealing the value of ``x`` will compromise the security of any
+        cryptographic operations performed.
+
+    .. attribute:: x
+
+        :type: int
+
+        The private value ``x``.
+
+    .. attribute:: public_numbers
+
+        :type: :class:`~cryptography.hazmat.primitives.dsa.DSAPublicNumbers`
+
+        The :class:`~cryptography.hazmat.primitives.dsa.DSAPublicNumbers`
+        associated with the private key.
+
 .. _`DSA`: https://en.wikipedia.org/wiki/Digital_Signature_Algorithm
 .. _`public-key`: https://en.wikipedia.org/wiki/Public-key_cryptography
 .. _`FIPS 186-4`: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf
diff --git a/tests/hazmat/primitives/test_dsa.py b/tests/hazmat/primitives/test_dsa.py
index cbe10e9c..51a03c48 100644
--- a/tests/hazmat/primitives/test_dsa.py
+++ b/tests/hazmat/primitives/test_dsa.py
@@ -872,3 +872,63 @@ def test_dsa_generate_invalid_backend():
     with raises_unsupported_algorithm(
             _Reasons.BACKEND_MISSING_INTERFACE):
         dsa.DSAPrivateKey.generate(pretend_parameters, pretend_backend)
+
+
+class TestDSANumbers(object):
+    def test_dsa_parameter_numbers(self):
+        parameter_numbers = dsa.DSAParameterNumbers(p=1, q=2, g=3)
+        assert parameter_numbers.p == 1
+        assert parameter_numbers.q == 2
+        assert parameter_numbers.g == 3
+
+    def test_dsa_parameter_numbers_invalid_types(self):
+        with pytest.raises(TypeError):
+            dsa.DSAParameterNumbers(p=None, q=2, g=3)
+
+        with pytest.raises(TypeError):
+            dsa.DSAParameterNumbers(p=1, q=None, g=3)
+
+        with pytest.raises(TypeError):
+            dsa.DSAParameterNumbers(p=1, q=2, g=None)
+
+    def test_dsa_public_numbers(self):
+        parameter_numbers = dsa.DSAParameterNumbers(p=1, q=2, g=3)
+        public_numbers = dsa.DSAPublicNumbers(
+            y=4,
+            parameter_numbers=parameter_numbers
+        )
+        assert public_numbers.y == 4
+        assert public_numbers.parameter_numbers == parameter_numbers
+
+    def test_dsa_public_numbers_invalid_types(self):
+        with pytest.raises(TypeError):
+            dsa.DSAPublicNumbers(y=4, parameter_numbers=None)
+
+        with pytest.raises(TypeError):
+            parameter_numbers = dsa.DSAParameterNumbers(p=1, q=2, g=3)
+            dsa.DSAPublicNumbers(y=None, parameter_numbers=parameter_numbers)
+
+    def test_dsa_private_numbers(self):
+        parameter_numbers = dsa.DSAParameterNumbers(p=1, q=2, g=3)
+        public_numbers = dsa.DSAPublicNumbers(
+            y=4,
+            parameter_numbers=parameter_numbers
+        )
+        private_numbers = dsa.DSAPrivateNumbers(
+            x=5,
+            public_numbers=public_numbers
+        )
+        assert private_numbers.x == 5
+        assert private_numbers.public_numbers == public_numbers
+
+    def test_dsa_private_numbers_invalid_types(self):
+        parameter_numbers = dsa.DSAParameterNumbers(p=1, q=2, g=3)
+        public_numbers = dsa.DSAPublicNumbers(
+            y=4,
+            parameter_numbers=parameter_numbers
+        )
+        with pytest.raises(TypeError):
+            dsa.DSAPrivateNumbers(x=4, public_numbers=None)
+
+        with pytest.raises(TypeError):
+            dsa.DSAPrivateNumbers(x=None, public_numbers=public_numbers)