| commit | dc5d7972899ec1ab38a3b3a2aa424802b05ea4b1 | [log] [tgz] |
|---|---|---|
| author | Amin Hassani <ahassani@google.com> | Thu Mar 01 16:51:28 2018 -0800 |
| committer | Amin Hassani <ahassani@google.com> | Thu Mar 01 23:28:10 2018 -0800 |
| tree | 49ce7bafe0791566fb81b49291df98d9e7c1c329 | |
| parent | d7768d5c29e747020531b5f71e7c7cfe980ea861 [diff] |
Add missing invalid distance check In the puffin spec, we defined the distance on the wire to be zero based ([1..32768] on deflate RFC). But I missed it in the implementation and stored non-zero based distances. However, this is not a bug and since we have not shipped it yet, it is possible to change. Another change include, adding proper checks for finding invalid copy length or distance. Also more unittests for invalid copy length/distance values are added. Lack of these checks were found by running puffin_fuzzer on cluster fuzz. Bug: crbug.com/817733 Bug: crbug.com/817686 Test: unittests Test: test_corpus.py Change-Id: I38bf630904d7996a3c4f15919960517d26520987
Source code for Puffin: A utility for deterministic DEFLATE recompression.
TODO(ahassani): Describe the directory structure and how-tos.
Alphabet A value that occurs in the input stream. It can be either a literal:[0..255], and end of block sign [256], a length[257..285], or a distance [0..29].
Huffman code A variable length code representing the Huffman encoded of an alphabet. Huffman codes can be created uniquely using Huffman code length array.
Huffman code array An array which an array index identifies a Huffman code and the array element in that index represents the corresponding alphabet. Throughout the code, Huffman code arrays are identified by vectors with postfix hcodes_.
Huffman reverse code array An array which an array index identifies an alphabet and the array element in that index contains the Huffman code of the alphabet. Throughout the code, The Huffman reverse code arrays are identified by vectors with postfix rcodes_.
Huffman code length The number of bits in a Huffman code.
Huffman code length array An array of Huffman code lengths with the array index as the alphabet. Throughout the code, Huffman code length arrays are identified by vectors with postfix lens_.