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Diffstat (limited to 'CHANGES')
| -rw-r--r-- | CHANGES | 27 |
1 files changed, 27 insertions, 0 deletions
@@ -7,6 +7,33 @@ Changelog Daniel (27 October 2004) +- Dan Fandrich: + + An improvement to the gzip handling of libcurl. There were two problems with + the old version: it was possible for a malicious gzip file to cause libcurl + to leak memory, as a buffer was malloced to hold the header and never freed + if the header ended with no file contents. The second problem is that the + 64 KiB decompression buffer was allocated on the stack, which caused + unexpectedly high stack usage and overflowed the stack on some systems + (someone complained about that in the mailing list about a year ago). + + Both problems are fixed by this patch. The first one is fixed when a recent + (1.2) version of zlib is used, as it takes care of gzip header parsing + itself. A check for the version number is done at run-time and libcurl uses + that feature if it's present. I've created a define OLD_ZLIB_SUPPORT that + can be commented out to save some code space if libcurl is guaranteed to be + using a 1.2 version of zlib. + + The second problem is solved by dynamically allocating the memory buffer + instead of storing it on the stack. The allocation/free is done for every + incoming packet, which is suboptimal, but should be dwarfed by the actual + decompression computation. + + I've also factored out some common code between deflate and gzip to reduce + the code footprint somewhat. I've tested the gzip code on a few test files + and I tried deflate using the freshmeat.net server, and it all looks OK. I + didn't try running it with valgrind, however. + - Added a --retry option to curl that takes a numerical option for the number of times the operation should be retried. It is retried if a transient error is detected or if a timeout occurred. By default, it will first wait one |