1Release History
2===============
3
43.0.0 (2017-03-29)
5------------------
6
7**API Changes (Backward Incompatible)**
8
9- Removed nghttp2 support. This support had rotted and was essentially
10  non-functional, so it has now been removed until someone has time to re-add
11  the support in a functional form.
12- Attempts by the encoder to exceed the maximum allowed header table size via
13  dynamic table size updates (or the absence thereof) are now forbidden.
14
15**API Changes (Backward Compatible)**
16
17- Added a new ``InvalidTableSizeError`` thrown when the encoder does not
18  respect the maximum table size set by the user.
19- Added a ``Decoder.max_allowed_table_size`` field that sets the maximum
20  allowed size of the decoder header table. See the documentation for an
21  indication of how this should be used.
22
23**Bugfixes**
24
25- Up to 25% performance improvement decoding HPACK-packed integers, depending
26  on the platform.
27- HPACK now tolerates receiving multiple header table size changes in sequence,
28  rather than only one.
29- HPACK now forbids header table size changes anywhere but first in a header
30  block, as required by RFC 7541 § 4.2.
31- Other miscellaneous performance improvements.
32
332.3.0 (2016-08-04)
34------------------
35
36**Security Fixes**
37
38- CVE-2016-6581: HPACK Bomb. This release now enforces a maximum value of the
39  decompressed size of the header list. This is to avoid the so-called "HPACK
40  Bomb" vulnerability, which is caused when a malicious peer sends a compressed
41  HPACK body that decompresses to a gigantic header list size.
42
43  This also adds a ``OversizedHeaderListError``, which is thrown by the
44  ``decode`` method if the maximum header list size is being violated. This
45  places the HPACK decoder into a broken state: it must not be used after this
46  exception is thrown.
47
48  This also adds a ``max_header_list_size`` to the ``Decoder`` object. This
49  controls the maximum allowable decompressed size of the header list. By
50  default this is set to 64kB.
51
522.2.0 (2016-04-20)
53------------------
54
55**API Changes (Backward Compatible)**
56
57- Added ``HeaderTuple`` and ``NeverIndexedHeaderTuple`` classes that signal
58  whether a given header field may ever be indexed in HTTP/2 header
59  compression.
60- Changed ``Decoder.decode()`` to return the newly added ``HeaderTuple`` class
61  and subclass. These objects behave like two-tuples, so this change does not
62  break working code.
63
64**Bugfixes**
65
66- Improve Huffman decoding speed by 4x using an approach borrowed from nghttp2.
67- Improve HPACK decoding speed by 10% by caching header table sizes.
68
692.1.1 (2016-03-16)
70------------------
71
72**Bugfixes**
73
74- When passing a dictionary or dictionary subclass to ``Encoder.encode``, HPACK
75  now ensures that HTTP/2 special headers (headers whose names begin with
76  ``:`` characters) appear first in the header block.
77
782.1.0 (2016-02-02)
79------------------
80
81**API Changes (Backward Compatible)**
82
83- Added new ``InvalidTableIndex`` exception, a subclass of
84  ``HPACKDecodingError``.
85- Instead of throwing ``IndexError`` when encountering invalid encoded integers
86  HPACK now throws ``HPACKDecodingError``.
87- Instead of throwing ``UnicodeDecodeError`` when encountering headers that are
88  not UTF-8 encoded, HPACK now throws ``HPACKDecodingError``.
89- Instead of throwing ``IndexError`` when encountering invalid table offsets,
90  HPACK now throws ``InvalidTableIndex``.
91- Added ``raw`` flag to ``decode``, allowing ``decode`` to return bytes instead
92  of attempting to decode the headers as UTF-8.
93
94**Bugfixes**
95
96- ``memoryview`` objects are now used when decoding HPACK, improving the
97  performance by avoiding unnecessary data copies.
98
992.0.1 (2015-11-09)
100------------------
101
102- Fixed a bug where the Python HPACK implementation would only emit header
103  table size changes for the total change between one header block and another,
104  rather than for the entire sequence of changes.
105
1062.0.0 (2015-10-12)
107------------------
108
109- Remove unused ``HPACKEncodingError``.
110- Add the shortcut ability to import the public API (``Encoder``, ``Decoder``,
111  ``HPACKError``, ``HPACKDecodingError``) directly, rather than from
112  ``hpack.hpack``.
113
1141.1.0 (2015-07-07)
115------------------
116
117- Add support for emitting 'never indexed' header fields, by using an optional
118  third element in the header tuple. With thanks to @jimcarreer!
119
1201.0.1 (2015-04-19)
121------------------
122
123- Header fields that have names matching header table entries are now added to
124  the header table. This improves compression efficiency at the cost of
125  slightly more table operations. With thanks to `Tatsuhiro Tsujikawa`_.
126
127.. _Tatsuhiro Tsujikawa: https://github.com/tatsuhiro-t
128
1291.0.0 (2015-04-13)
130------------------
131
132- Initial fork of the code from `hyper`_.
133
134.. _hyper: https://hyper.readthedocs.org/
135