Hello, zlib deflate generates an adler32 checksum for the input uncompressed data. In order to gain some drop of performance we would like not to generate/check adler32 because we anyway protect our data by much stronger CRC32. How to correctly do that? My quick investigation has shown that it is possible if I pass the a negative windowBits parameter to the deflateInit2() function to achieve the goal. But this feature isn't noted in the deflate API description (include/linux/zlib.h) and is called "undocumented feature" in lib/zlib_deflate/deflate.c. So the question is: is it OK to use this undocumented feature? What are alternatives? I also noted that if I use deflate via crypto API, I'll get what I want since it does: #define DEFLATE_DEF_WINBITS 11 ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED, -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL, Z_DEFAULT_STRATEGY); (note the "minus" character before DEFLATE_DEF_WINBITS) I'm curious why crypto API omits adler32 by default? Thanks. -- Best Regards, Artem B. Bityuckiy, St.-Petersburg, Russia. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
