From 8e9c984d5d85db83c5fa45f6f2083d6b5e15326b Mon Sep 17 00:00:00 2001
From: Paul Kehrer <paul.l.kehrer@gmail.com>
Date: Thu, 13 Feb 2014 12:23:27 -0600
Subject: expose dmp1, dmq1, iqmp getters on RSAPrivateKey

---
 cryptography/hazmat/primitives/asymmetric/rsa.py | 12 ++++++++++++
 docs/hazmat/primitives/interfaces.rst            | 24 +++++++++++++++++++++++-
 tests/hazmat/primitives/test_rsa.py              |  6 +++---
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/cryptography/hazmat/primitives/asymmetric/rsa.py b/cryptography/hazmat/primitives/asymmetric/rsa.py
index dbe56b47..01218592 100644
--- a/cryptography/hazmat/primitives/asymmetric/rsa.py
+++ b/cryptography/hazmat/primitives/asymmetric/rsa.py
@@ -166,6 +166,18 @@ class RSAPrivateKey(object):
     def d(self):
         return self.private_exponent
 
+    @property
+    def dmp1(self):
+        return self._dmp1
+
+    @property
+    def dmq1(self):
+        return self._dmq1
+
+    @property
+    def iqmp(self):
+        return self._iqmp
+
     @property
     def e(self):
         return self.public_exponent
diff --git a/docs/hazmat/primitives/interfaces.rst b/docs/hazmat/primitives/interfaces.rst
index cbca5ed6..df17e59d 100644
--- a/docs/hazmat/primitives/interfaces.rst
+++ b/docs/hazmat/primitives/interfaces.rst
@@ -160,6 +160,27 @@ Asymmetric Interfaces
 
         The private exponent. Alias for :attr:`private_exponent`.
 
+    .. attribute:: dmp1
+
+        :type: int
+
+        A `Chinese remainder theorem`_ coefficient used to speed up RSA
+        operations. Calculated as: d mod (p-1)
+
+    .. attribute:: dmq1
+
+        :type: int
+
+        A `Chinese remainder theorem`_ coefficient used to speed up RSA
+        operations. Calculated as: d mod (q-1)
+
+    .. attribute:: iqmp
+
+        :type: int
+
+        A `Chinese remainder theorem`_ coefficient used to speed up RSA
+        operations. Calculated as: q\ :sup:`-1` mod p
+
     .. attribute:: n
 
         :type: int
@@ -279,4 +300,5 @@ Key Derivation Functions
         something like checking whether a user's password attempt matches the
         stored derived key.
 
-.. _`RSA`: http://en.wikipedia.org/wiki/RSA_(cryptosystem)
+.. _`RSA`: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
+.. _`Chinese remainder theorem`: https://en.wikipedia.org/wiki/Chinese_remainder_theorem
diff --git a/tests/hazmat/primitives/test_rsa.py b/tests/hazmat/primitives/test_rsa.py
index 9dc1a9e4..312d5a6f 100644
--- a/tests/hazmat/primitives/test_rsa.py
+++ b/tests/hazmat/primitives/test_rsa.py
@@ -45,9 +45,9 @@ def _check_rsa_private_key(skey):
     assert skey.private_exponent
     assert skey.p * skey.q == skey.modulus
     assert skey.key_size
-    assert skey._dmp1 == skey.d % (skey.p - 1)
-    assert skey._dmq1 == skey.d % (skey.q - 1)
-    assert skey._iqmp == _modinv(skey.q, skey.p)
+    assert skey.dmp1 == skey.d % (skey.p - 1)
+    assert skey.dmq1 == skey.d % (skey.q - 1)
+    assert skey.iqmp == _modinv(skey.q, skey.p)
 
     pkey = skey.public_key()
     assert pkey
-- 
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