various improvements to rsa_recover_prime_factors per review feedback
diff --git a/docs/hazmat/primitives/asymmetric/rsa.rst b/docs/hazmat/primitives/asymmetric/rsa.rst
index 7a22c20..4423aa8 100644
--- a/docs/hazmat/primitives/asymmetric/rsa.rst
+++ b/docs/hazmat/primitives/asymmetric/rsa.rst
@@ -395,15 +395,14 @@
.. versionadded:: 0.8
+ Computes ``(p, q)`` given the modulus, public exponent, and private
+ exponent.
+
.. note::
When recovering prime factors this algorithm will always return ``p``
and ``q`` such that ``p < q``.
-
- Computes ``(p, q)`` given the modulus, public exponent, and private
- exponent.
-
:return: A tuple ``(p, q)``
diff --git a/src/cryptography/hazmat/primitives/asymmetric/rsa.py b/src/cryptography/hazmat/primitives/asymmetric/rsa.py
index 15aba3e..d267c38 100644
--- a/src/cryptography/hazmat/primitives/asymmetric/rsa.py
+++ b/src/cryptography/hazmat/primitives/asymmetric/rsa.py
@@ -138,7 +138,7 @@
# any candidate a leads to successful factoring.
# See "Digitalized Signatures and Public Key Functions as Intractable
# as Factorization", M. Rabin, 1979
- spotted = 0
+ spotted = False
a = 2
while not spotted and a < 1000:
k = t
@@ -150,11 +150,11 @@
# We have found a number such that (cand-1)(cand+1)=0 (mod n).
# Either of the terms divides n.
p = gcd(cand + 1, n)
- spotted = 1
+ spotted = True
break
- k = k * 2
+ k *= 2
# This value was not any good... let's try another!
- a = a + 2
+ a += 2
if not spotted:
raise ValueError("Unable to compute factors p and q from exponent d.")
# Found !
diff --git a/tests/hazmat/primitives/test_rsa.py b/tests/hazmat/primitives/test_rsa.py
index 3de228b..33e5373 100644
--- a/tests/hazmat/primitives/test_rsa.py
+++ b/tests/hazmat/primitives/test_rsa.py
@@ -1719,14 +1719,8 @@
# Unfortunately there is no convention on which prime should be p
# and which one q. The function we use always makes p < q, but the
# NIST vectors are not so consistent. Accordingly we verify we've
- # recovered the proper (p, q) by being willing to match against either
- # one and then altering the asserts accordingly.
- if p == private["p"]:
- assert p == private["p"]
- assert q == private["q"]
- else:
- assert p == private["q"]
- assert q == private["p"]
+ # recovered the proper (p, q) by sorting them and asserting on that.
+ assert sorted([p, q]) == sorted([private["p"], private["q"]])
def test_invalid_recover_prime_factors(self):
with pytest.raises(ValueError):