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