tree 4934f1d371ae6068a0f9730753230e874ffda942
parent 368fc65f80db347fa10849dbf3081969056a79c2
author Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com> 1595926386 +0200
committer Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com> 1595928084 +0200

Add MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN

This option allows to test the constant-flow nature of selected code, using
MemSan and the fundamental observation behind ctgrind that the set of
operations allowed on undefined memory by dynamic analysers is the same as the
set of operations allowed on secret data to avoid leaking it to a local
attacker via side channels, namely, any operation except branching and
dereferencing.

(This isn't the full story, as on some CPUs some instructions have variable
execution depending on the inputs, most notably division and on some cores
multiplication. However, testing that no branch or memory access depends on
secret data is already a good start.)

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>