Merge pull request #184 from mailgun/maxim/limits

Remove unnecessary parsing limits

flanker/mime/message/headers/encoding.py

@@ -11,12 +11,6 @@
 
 _log = logging.getLogger(__name__)
 
-# max length for a header line is 80 chars
-# max recursion depth is 1000
-# 80 * 1000 for header is too much for the system
-# so we allow just 100 lines for header
-_MAX_HEADER_LENGTH = 8000
-
 _ADDRESS_HEADERS = ('From', 'To', 'Delivered-To', 'Cc', 'Bcc', 'Reply-To')
 
 
@@ -43,8 +37,6 @@ def encode(name, value):
 
 
 def _encode_unstructured(name, value):
-    if len(value) > _MAX_HEADER_LENGTH:
-        return to_utf8(value)
     try:
         return Header(
             value.encode("ascii"), "ascii",

flanker/mime/message/headers/parsing.py

@@ -8,7 +8,6 @@
 from flanker.utils import is_pure_ascii
 
 _RE_HEADER = regex.compile(r'^(From |[\041-\071\073-\176]+:|[\t ])')
-_MAX_LINE_LENGTH = 10000
 
 
 def normalize(header_name):
@@ -59,9 +58,6 @@ def _read_header_lines(fp):
     """Read lines with headers until the start of body"""
     lines = deque()
     for line in fp:
-        if len(line) > _MAX_LINE_LENGTH:
-            raise DecodingError('Line is too long: %d' % len(line))
-
         if is_empty(line):
             break
 

setup.py

@@ -3,7 +3,7 @@
 from setuptools import setup, find_packages
 
 setup(name='flanker',
-      version='0.8.4',
+      version='0.8.5',
       description='Mailgun Parsing Tools',
       long_description=open('README.rst').read(),
       classifiers=[],

tests/mime/message/create_test.py

@@ -363,3 +363,16 @@ def create_newlines_in_headers_test():
     text = create.from_string(text.to_string())
     eq_('Hello,newline', text.headers['Subject'])
     eq_(u'Превед, медвед!', text.headers['To'])
+
+
+def test_bug_line_is_too_long():
+    # It was possible to create a message with a very long header value, but
+    # it was impossible to parse such message.
+
+    msg = create.text('plain', 'foo', 'utf-8')
+    msg.headers.add('bar', 'y' * 10000)
+    encoded_msg = msg.to_string()
+    decoded_msg = create.from_string(encoded_msg)
+
+    # When/Then
+    decoded_msg.headers

tests/mime/message/headers/encoding_test.py

@@ -56,31 +56,16 @@ def max_header_length_test():
     message = create.from_string(LONG_HEADER)
 
     # this used to fail because exceeded max depth recursion
-    ok_(message.headers.getraw('subject').encode("utf-8") in message.to_string())
+    message.to_string()
 
-    unicode_subject = (u"Это сообщение с длинным сабжектом "
-                       u"специально чтобы проверить кодировки")
     ascii_subject = "This is simple ascii subject"
+    eq_(Header(ascii_subject.encode("ascii"), "ascii", header_name="Subject"),
+        _encode_unstructured("Subject", ascii_subject))
 
-    with patch.object(
-        headers.encoding, '_MAX_HEADER_LENGTH', len(ascii_subject) + 1):
-
-        eq_(Header(ascii_subject.encode("ascii"), "ascii", header_name="Subject"),
-            _encode_unstructured("Subject", ascii_subject))
-
-    with patch.object(
-        headers.encoding, '_MAX_HEADER_LENGTH', len(unicode_subject) + 1):
-
-        eq_(Header(unicode_subject.encode("utf-8"), "utf-8", header_name="Subject"),
-            _encode_unstructured("Subject", unicode_subject))
-
-    with patch.object(headers.encoding, '_MAX_HEADER_LENGTH', 1):
-
-        eq_(ascii_subject.encode("utf-8"),
-            _encode_unstructured("Subject", ascii_subject))
-
-        eq_(unicode_subject.encode("utf-8"),
-            _encode_unstructured("Subject", unicode_subject))
+    unicode_subject = (u"Это сообщение с длинным сабжектом "
+                       u"специально чтобы проверить кодировки")
+    eq_(Header(unicode_subject.encode("utf-8"), "utf-8", header_name="Subject"),
+        _encode_unstructured("Subject", unicode_subject))
 
 
 def add_header_preserve_original_encoding_test():

tests/mime/message/headers/headers_test.py

@@ -135,8 +135,7 @@ def headers_parsing_empty_test():
 def headers_parsing_ridiculously_long_line_test():
     val = "abcdefg"*100000
     header = "Hello: {0}\r\n".format(val)
-    assert_raises(
-        DecodingError, MimeHeaders.from_stream, six.StringIO(header))
+    MimeHeaders.from_stream(six.StringIO(header))
 
 
 def headers_parsing_binary_stuff_survives_test():