diff options
| author | Jens Wiklander <jens.wiklander@linaro.org> | 2018-03-28 11:26:54 +0200 |
|---|---|---|
| committer | Jérôme Forissier <jerome.forissier@linaro.org> | 2018-03-29 22:57:23 +0800 |
| commit | 21b948d229bbf5c6efe71a28f9e565f2ff11d7e3 (patch) | |
| tree | 9893b4634480eb94109d8b154aeb0a4eb8cc9ed7 /documentation | |
| parent | ad22421a6641cf2118de682d1676f81d83538b7e (diff) | |
doc: add a note on PRNG weakness
Adds a note on the software PRNG weakness in the porting guidelines.
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'documentation')
| -rw-r--r-- | documentation/porting_guidelines.md | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/documentation/porting_guidelines.md b/documentation/porting_guidelines.md index 01ccb728..27710bb0 100644 --- a/documentation/porting_guidelines.md +++ b/documentation/porting_guidelines.md @@ -286,6 +286,11 @@ you have, we have not written how that should be done. It might be that we do that in the future when get hold of a device where we can use the crypto block. +By default OP-TEE is configured with a software PRNG. The entropy is added +to software PRNG at various places, but unfortunately it is still quite +easy to predict the data added as entropy. As a consequence, unless the RNG +is based on hardware the generated random will be quite weak. + ## 7. Power Management / PSCI In section 2 when we talked about the file `main.c`, we added a couple of handlers related to power management, we are talking about the following lines: |