Tighten up checks on port ranges and path character sets.

3 files changed, 37 insertions, 13 deletions

diff --git a/netlib/http.py b/netlib/http.py
index 2c9e69cb..0f2caa5a 100644
--- a/netlib/http.py
+++ b/netlib/http.py
@@ -1,5 +1,5 @@
 import string, urlparse, binascii
-import odict
+import odict, utils
 
 class HttpError(Exception):
     def __init__(self, code, msg):
@@ -12,6 +12,22 @@ class HttpError(Exception):
 class HttpErrorConnClosed(HttpError): pass
 
 
+def _is_valid_port(port):
+    if not 0 <= port <= 65535:
+        return False
+    return True
+
+
+def _is_valid_host(host):
+    try:
+        host.decode("idna")
+    except ValueError:
+        return False
+    if "\0" in host:
+        return None
+    return True
+
+
 def parse_url(url):
     """
         Returns a (scheme, host, port, path) tuple, or None on error.
@@ -42,17 +58,11 @@ def parse_url(url):
     path = urlparse.urlunparse(('', '', path, params, query, fragment))
     if not path.startswith("/"):
         path = "/" + path
-    try:
-        host.decode("idna")
-    except ValueError:
+    if not _is_valid_host(host):
         return None
-    if "\0" in host:
+    if not utils.isascii(path):
         return None
-    try:
-        path.decode("ascii")
-    except ValueError:
-        return None
-    if not 0 <= port <= 65535:
+    if not _is_valid_port(port):
         return None
     return scheme, host, port, path
 
@@ -236,6 +246,10 @@ def parse_init_connect(line):
         port = int(port)
     except ValueError:
         return None
+    if not _is_valid_port(port):
+        return None
+    if not _is_valid_host(host):
+        return None
     return host, port, httpversion
 
 
@@ -260,7 +274,8 @@ def parse_init_http(line):
     if not v:
         return None
     method, url, httpversion = v
-
+    if not utils.isascii(url):
+        return None
     if not (url.startswith("/") or url == "*"):
         return None
     return method, url, httpversion
diff --git a/netlib/utils.py b/netlib/utils.py
index 7621a1dc..61fd54ae 100644
--- a/netlib/utils.py
+++ b/netlib/utils.py
@@ -1,4 +1,12 @@
 
+def isascii(s):
+    try:
+        s.decode("ascii")
+    except ValueError:
+        return False
+    return True
+
+
 def cleanBin(s, fixspacing=False):
     """
         Cleans binary data to make it safe to display. If fixspacing is True,
diff --git a/test/test_http.py b/test/test_http.py
index f7d861fd..e98a891f 100644
--- a/test/test_http.py
+++ b/test/test_http.py
@@ -136,6 +136,8 @@ def test_parse_http_protocol():
 
 def test_parse_init_connect():
     assert http.parse_init_connect("CONNECT host.com:443 HTTP/1.0")
+    assert not http.parse_init_connect("CONNECT \0host.com:443 HTTP/1.0")
+    assert not http.parse_init_connect("CONNECT host.com:444444 HTTP/1.0")
     assert not http.parse_init_connect("bogus")
     assert not http.parse_init_connect("GET host.com:443 HTTP/1.0")
     assert not http.parse_init_connect("CONNECT host.com443 HTTP/1.0")
@@ -164,11 +166,10 @@ def test_parse_init_http():
     assert m == "GET"
     assert u == "/test"
     assert httpversion == (1, 1)
-
     assert not http.parse_init_http("invalid")
     assert not http.parse_init_http("GET invalid HTTP/1.1")
     assert not http.parse_init_http("GET /test foo/1.1")
-
+    assert not http.parse_init_http("GET /test\xc0 HTTP/1.1")
 
 class TestReadHeaders:
     def _read(self, data, verbatim=False):