Merge pull request #559 from public/rsa-keys

RSA keys

1 files changed, 149 insertions, 0 deletions

diff --git a/cryptography/hazmat/primitives/asymmetric/rsa.py b/cryptography/hazmat/primitives/asymmetric/rsa.py
new file mode 100644
index 00000000..1b33eaab
--- /dev/null
+++ b/cryptography/hazmat/primitives/asymmetric/rsa.py
@@ -0,0 +1,149 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import, division, print_function
+
+import sys
+
+import six
+
+from cryptography import utils
+from cryptography.hazmat.primitives import interfaces
+
+
+def _bit_length(x):
+    if sys.version_info >= (2, 7):
+        return x.bit_length()
+    else:
+        return len(bin(x)) - (2 + (x <= 0))
+
+
+@utils.register_interface(interfaces.RSAPublicKey)
+class RSAPublicKey(object):
+    def __init__(self, public_exponent, modulus):
+        if (
+            not isinstance(public_exponent, six.integer_types) or
+            not isinstance(modulus, six.integer_types)
+        ):
+            raise TypeError("RSAPublicKey arguments must be integers")
+
+        if modulus < 3:
+            raise ValueError("modulus must be >= 3")
+
+        if public_exponent < 3 or public_exponent >= modulus:
+            raise ValueError("public_exponent must be >= 3 and < modulus")
+
+        if public_exponent & 1 == 0:
+            raise ValueError("public_exponent must be odd")
+
+        self._public_exponent = public_exponent
+        self._modulus = modulus
+
+    @property
+    def key_size(self):
+        return _bit_length(self.modulus)
+
+    @property
+    def public_exponent(self):
+        return self._public_exponent
+
+    @property
+    def modulus(self):
+        return self._modulus
+
+    @property
+    def e(self):
+        return self.public_exponent
+
+    @property
+    def n(self):
+        return self.modulus
+
+
+@utils.register_interface(interfaces.RSAPrivateKey)
+class RSAPrivateKey(object):
+    def __init__(self, p, q, private_exponent, public_exponent, modulus):
+        if (
+            not isinstance(p, six.integer_types) or
+            not isinstance(q, six.integer_types) or
+            not isinstance(private_exponent, six.integer_types) or
+            not isinstance(public_exponent, six.integer_types) or
+            not isinstance(modulus, six.integer_types)
+        ):
+            raise TypeError("RSAPrivateKey arguments must be integers")
+
+        if modulus < 3:
+            raise ValueError("modulus must be >= 3")
+
+        if p >= modulus:
+            raise ValueError("p must be < modulus")
+
+        if q >= modulus:
+            raise ValueError("q must be < modulus")
+
+        if private_exponent >= modulus:
+            raise ValueError("private_exponent must be < modulus")
+
+        if public_exponent < 3 or public_exponent >= modulus:
+            raise ValueError("public_exponent must be >= 3 and < modulus")
+
+        if public_exponent & 1 == 0:
+            raise ValueError("public_exponent must be odd")
+
+        if p * q != modulus:
+            raise ValueError("p*q must equal modulus")
+
+        self._p = p
+        self._q = q
+        self._private_exponent = private_exponent
+        self._public_exponent = public_exponent
+        self._modulus = modulus
+
+    @property
+    def key_size(self):
+        return _bit_length(self.modulus)
+
+    def public_key(self):
+        return RSAPublicKey(self.public_exponent, self.modulus)
+
+    @property
+    def p(self):
+        return self._p
+
+    @property
+    def q(self):
+        return self._q
+
+    @property
+    def private_exponent(self):
+        return self._private_exponent
+
+    @property
+    def public_exponent(self):
+        return self._public_exponent
+
+    @property
+    def modulus(self):
+        return self._modulus
+
+    @property
+    def d(self):
+        return self.private_exponent
+
+    @property
+    def e(self):
+        return self.public_exponent
+
+    @property
+    def n(self):
+        return self.modulus