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| author | Nick Mathewson <nickm@torproject.org> | 2019-11-05 08:05:49 -0500 |
|---|---|---|
| committer | Nick Mathewson <nickm@torproject.org> | 2019-11-05 08:05:49 -0500 |
| commit | 8933789fef0e2014852df6ae55b5435b9d3256b2 (patch) | |
| tree | 03cba4960d76656fd248e60d4d749152bdc62340 /src/lib/ctime/lib_ctime.dox | |
| parent | 60d5ff303d65bb7caf5c064675c661faac4cecf1 (diff) | |
| parent | aac80a004f91a453733fed0ba62c00d7d1e2b76d (diff) | |
| download | tor-8933789fef0e2014852df6ae55b5435b9d3256b2.tar.gz tor-8933789fef0e2014852df6ae55b5435b9d3256b2.zip | |
Merge branch 'doxygen_libs'
Diffstat (limited to 'src/lib/ctime/lib_ctime.dox')
| -rw-r--r-- | src/lib/ctime/lib_ctime.dox | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/lib/ctime/lib_ctime.dox b/src/lib/ctime/lib_ctime.dox index 476c95991c..2bcd0f036a 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 +@dir /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. + **/ |