Merge lp:~justin-fathomdb/nova/bug732277 into lp:~hudson-openstack/nova/trunk

[justinsb]

Don't generate insecure passwords where it's easy to use urandom instead

[Soren Hansen (soren)]

I think we should allow lowercase letters as well. I'm pretty confident the increase in key space will make up for the slight bias caused by not having the size of the key space be a power of two.

review: Needs Fixing

[Soren Hansen (soren)]

If you want to avoid the bias, you could randomise chrs (random.shuffle or something should be fine). Alternatively, replace the whole thing with random.SystemRandom.sample?

[justinsb (justin-fathomdb)]

Using random.SystemRandom - thanks for the suggestion. Avoids the whole need to get clever with the number of characters.

Symbol set not defaults to uppers and lowers with digits, with 0,O and I,l,1 removed. Can be specified via an optional parameter...

[Soren Hansen (soren)]

Looks good.

review: Approve

[Devin Carlen (devcamcar)]

lgtm

review: Approve

=== modified file 'nova/console/manager.py'
--- nova/console/manager.py	2011-02-21 07:16:10 +0000
+++ nova/console/manager.py	2011-03-15 18:26:31 +0000
@@ -69,7 +69,7 @@
         except exception.NotFound:
             logging.debug(_("Adding console"))
             if not password:
-                password = self.driver.generate_password()
+                password = utils.generate_password(8)
             if not port:
                 port = self.driver.get_port(context)
             console_data = {'instance_name': name,

=== modified file 'nova/console/xvp.py'
--- nova/console/xvp.py	2011-03-09 20:33:20 +0000
+++ nova/console/xvp.py	2011-03-15 18:26:31 +0000
@@ -91,10 +91,6 @@
         """Trim password to length, and encode"""
         return self._xvp_encrypt(password)
 
-    def generate_password(self, length=8):
-        """Returns random console password"""
-        return os.urandom(length * 2).encode('base64')[:length]
-
     def _rebuild_xvp_conf(self, context):
         logging.debug(_("Rebuilding xvp conf"))
         pools = [pool for pool in

=== modified file 'nova/utils.py'
--- nova/utils.py	2011-03-14 17:59:41 +0000
+++ nova/utils.py	2011-03-15 18:26:31 +0000
@@ -262,13 +262,25 @@
     return ':'.join(map(lambda x: "%02x" % x, mac))
 
 
-def generate_password(length=20):
-    """Generate a random sequence of letters and digits
-    to be used as a password. Note that this is not intended
-    to represent the ultimate in security.
+# Default symbols to use for passwords. Avoids visually confusing characters.
+# ~6 bits per symbol
+DEFAULT_PASSWORD_SYMBOLS = ("23456789"  # Removed: 0,1
+                            "ABCDEFGHJKLMNPQRSTUVWXYZ"  # Removed: I, O
+                            "abcdefghijkmnopqrstuvwxyz")  # Removed: l
+
+
+# ~5 bits per symbol
+EASIER_PASSWORD_SYMBOLS = ("23456789"  # Removed: 0, 1
+                           "ABCDEFGHJKLMNPQRSTUVWXYZ")  # Removed: I, O
+
+
+def generate_password(length=20, symbols=DEFAULT_PASSWORD_SYMBOLS):
+    """Generate a random password from the supplied symbols.
+
+    Believed to be reasonably secure (with a reasonable password length!)
     """
-    chrs = string.letters + string.digits
-    return "".join([random.choice(chrs) for i in xrange(length)])
+    r = random.SystemRandom()
+    return "".join([r.choice(symbols) for _i in xrange(length)])
 
 
 def last_octet(address):