[tor-commits] [bridgedb/develop] Forbid non-ASCII and control chars, double quotes and backslashes in PT args

[isis at torproject.org]

commit ad7b5f9ab3354aef3d69db33933ab1fcebf16bd1
Author: Robert Ransom <rransom.8774 at gmail.com>
Date:   Thu Apr 30 08:41:08 2015 -0700

    Forbid non-ASCII and control chars, double quotes and backslashes in PT args
---
 lib/bridgedb/bridges.py |   19 +++++++++++++++++++
 lib/bridgedb/util.py    |   35 +++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/lib/bridgedb/bridges.py b/lib/bridgedb/bridges.py
index e2b2ff5..b799ca3 100644
--- a/lib/bridgedb/bridges.py
+++ b/lib/bridgedb/bridges.py
@@ -38,6 +38,7 @@ from bridgedb.parse.fingerprint import isValidFingerprint
 from bridgedb.parse.fingerprint import toHex
 from bridgedb.parse.fingerprint import fromHex
 from bridgedb.parse.nickname import isValidRouterNickname
+from bridgedb.util import isascii_noncontrol
 
 
 class PluggableTransportUnavailable(Exception):
@@ -351,6 +352,10 @@ class PluggableTransport(BridgeAddressBase):
 
           2. The :data:`arguments` is a dictionary.
 
+          3. The :data:`arguments` do not contain non-ASCII or control
+              characters or double quotes or backslashes, in keys or
+              in values.
+
         :raises MalformedPluggableTransport: if any of the above checks fails.
         """
         if not self.fingerprint:
@@ -372,6 +377,20 @@ class PluggableTransport(BridgeAddressBase):
                 ("Cannot create PluggableTransport with arguments type: %s")
                 % type(self.arguments))
 
+        for k, v in self.arguments.items():
+            kv = ''.join((k, v))
+            if not isascii_noncontrol(kv):
+                raise MalformedPluggableTransport(
+                    ("Cannot create PluggableTransport with non-ASCII or "
+                     "control characters in arguments: %r=%r")
+                    % (k, v))
+            if '"' in kv or '\\' in kv:
+                raise MalformedPluggableTransport(
+                    ("Cannot create PluggableTransport with double quotes or "
+                     "backslashes in arguments: %r=%r")
+                    % (k, v))
+            pass
+
         if not self._checkArguments():
             raise MalformedPluggableTransport(
                 ("Can't use %s transport with missing arguments. Arguments: "
diff --git a/lib/bridgedb/util.py b/lib/bridgedb/util.py
index 8034120..580f31f 100644
--- a/lib/bridgedb/util.py
+++ b/lib/bridgedb/util.py
@@ -200,6 +200,41 @@ def htmlify_string(s):
     """
     return ''.join(map((lambda ch: htmlify_string_map.get(ch, ch)), s))
 
+def isascii(s):
+    """Return True if there are no non-ASCII characters in s, False otherwise.
+
+    Note that this function differs from the str.is* methods in that
+    it returns True for the empty string, rather than False.
+
+    >>> isascii('\x80')
+    False
+    >>> isascii('foo\tbar\rbaz\n')
+    True
+    >>> isascii('foo bar')
+    True
+
+    :param str s: The string to check for non-ASCII characters.
+    """
+    return all(map((lambda ch: ord(ch) < 128), s))
+
+def isascii_noncontrol(s):
+    """Return True if there are no non-ASCII or control characters in
+    s, False otherwise.
+
+    Note that this function differs from the str.is* methods in that
+    it returns True for the empty string, rather than False.
+
+    >>> isascii_noncontrol('\x80')
+    False
+    >>> isascii_noncontrol('foo\tbar\rbaz\n')
+    False
+    >>> isascii_noncontrol('foo bar')
+    True
+
+    :param str s: The string to check for non-ASCII or control characters.
+    """
+    return all(map((lambda ch: 32 <= ord(ch) < 127), s))
+
 
 class JustifiedLogFormatter(logging.Formatter):
     """A logging formatter which pretty prints thread and calling function