better comment, cleanup

src/allmydata/crypto/rsa.py

@@ -28,8 +28,15 @@ def create_signing_keypair(key_size):
 
     :returns: 2-tuple of (private_key, public_key)
     """
+    # as per
+    # https://cryptography.io/en/latest/hazmat/primitives/asymmetric/rsa/#cryptography.hazmat.primitives.asymmetric.rsa.generate_private_key
+    # and
+    # https://www.daemonology.net/blog/2009-06-11-cryptographic-right-answers.htmlhttps://www.daemonology.net/blog/2009-06-11-cryptographic-right-answers.html
+    # the public exponent is 65537
+    # (I *believe* that pycryptopp would have used cryptopp's default,
+    # though, which is 17)
     priv_key = rsa.generate_private_key(
-        public_exponent=65537,  # serisously don't change this value
+        public_exponent=65537,
         key_size=key_size,
         backend=default_backend()
     )

src/allmydata/test/test_util.py

@@ -793,8 +793,6 @@ class FileUtil(ReallyEqualMixin, unittest.TestCase):
         f = EncryptedTemporaryFile()
         f.write("foobar")
         f.close()
-        print(f.file)
-        print(dir(f.file))
 
 
 class PollMixinTests(unittest.TestCase):