1 Name: BSDiff 2 URL: http://www.daemonology.net/bsdiff/ 3 Source URL: http://www.daemonology.net/bsdiff/bsdiff-4.3.tar.gz 4 Version: 4.3 5 License: BSD 6 License File: LICENSE 7 8 Description: 9 Binary diff/patch utility. There are other copies of BSDiff in the Chromium 10 repository, but they're all different. The other copies are based on Mozilla's 11 fork of BSDiff, which serves a different set of needs. Relative to upstream 12 BSDiff, Mozilla's version removes all compression, adds a CRC-32 check of the 13 original file, replaces the custom off_t encoding with signed 32-bit 14 big-endian integers, and contains a total reorganization of the code. The 15 version in this directory contains no Mozilla code and builds directly on the 16 upstream version. It retains and enhances the compression, uses SHA1 to check 17 both the original file and the patched file, uses a different off_t encoding 18 more compatible with the original, and involves minimal changes to the 19 original code. 20 21 Theoretically, a hash of the original file should be enough to guarantee data 22 integrity, but in the event of algorithmic or programming bugs or other 23 unexpected conditions, a hash of the patched file provides a better guarantee. 24 This implementation now checks the integrity of both the original and the 25 patched files. SHA1, rather than CRC-32, is used to minimize the likelihood 26 that an original file that has been intentionally tampered with will produce 27 an altered patched file without being detected. 28 29 Local Modifications: 30 - Added LICENSE file by copying the license block from bsdiff.c and 31 bspatch.c. 32 - The following modifications are relative to the original unpatched version, 33 checked in to the Chromium repository at r49280. 34 - Created goobsdiff.gyp for GYP build system integration. 35 - Renamed bsdiff.c to goobsdiff.c and bspatch.c to goobspatch.c. 36 - Added sha1_adapter.cc, sha1_adapter.h, and empty.cc to facilitate hashing. 37 - Added #include <sys/types.h> to goobspatch.c so that it compiles. (Oops!) 38 - Changed the magic number in the header from BSDIFF40 to BSDIFF4G. 39 - Expanded the header to include SHA1 hashes of the original and new files, 40 and added hash checks to the patcher. 41 - Expanded the header to include the lengths of the control, diff, and extra 42 blocks in the patch file, and added patch file length validation to the 43 patcher. 44 - Replaced custom off_t encoding with signed 64-bit little-endian integers. 45 - The control, diff, and extra blocks can be compressed with bzip2, gzip, or 46 xz/lzma2, or left uncompressed, independently of one another, depending on 47 which is smallest. This often results in a net reduction in patch size of 48 about 3%-5%. 49 - Error messages in the patcher are slightly more descriptive. 50 - The patcher treats a few more unexpected read cases as errors than it did 51 previously. This will theoretically cause it to exit with an error instead 52 of sitting in a busy loop or crashing when certain malformatted patch files 53 are provided. 54
