From 51a98929148e9ca08b33735fb0542759380c57a9 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Mon, 4 Nov 2019 10:19:41 -0500 Subject: doxygen: Take "lib" descriptions from doc/HACKING/design. This commit takes descriptions for src/lib and moves them into our doxygen hierarchy. I've covered everything from lib/cc through lib/sandbox here. --- src/lib/ctime/lib_ctime.dox | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'src/lib/ctime') diff --git a/src/lib/ctime/lib_ctime.dox b/src/lib/ctime/lib_ctime.dox index 476c95991c..bf95b03165 100644 --- a/src/lib/ctime/lib_ctime.dox +++ b/src/lib/ctime/lib_ctime.dox @@ -1,4 +1,16 @@ /** @dir lib/ctime -@brief lib/ctime +@brief lib/ctime: Constant-time code to avoid side-channels. + +This module contains constant-time implementations of various +data comparison and table lookup functions. We use these in preference to +memcmp() and so forth, since memcmp() can leak information about its inputs +based on how fast it returns. In general, your code should call tor_memeq() +and tor_memneq(), not memcmp(). + +We also define some _non_-constant-time wrappers for memcmp() here: Since we +consider calls to memcmp() to be in error, we require that code that actually +doesn't need to be constant-time to use the fast_memeq() / fast_memneq() / +fast_memcmp() aliases instead. + **/ -- cgit v1.2.3-54-g00ecf