Instead of setting a "magic" global variable to force RAND to keep
consistent state and always generate the same bytestream, have
the fuzzing code install its own RAND_METHOD that does this. For
BN_RAND_DEBUG, we just don't do it; that debugging was about mucking
with BN's internal representation, not requiring predictable rand
bytes.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4025)
Approach was opportunistic in Windows context from its inception
and on top of that it was proven to be error-prone at link stage.
Correct answer is to introduce library-specific time function that
we can control in platform-neutral manner. Meanwhile we just let
be attempts to override time on Windows.
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3320)
This adds a way to use the last byte of the buffer to change the
behavior of the server. The last byte is used so that the existing
corpus can be reused either without changing it, or just adding a single
byte, and that it can still be used by other projects.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #2683
We want to be in the same global state each time we come in
FuzzerTestOneInput(). There are various reasons why we might not be that
include:
- Initialization that happens on first use. This is mostly the
RUN_ONCE() things, or loading of error strings.
- Results that get cached. For instance a stack that is sorted, RSA
blinding that has been set up, ...
So I try to trigger as much as possible in FuzzerInitialize(), and for
things I didn't find out how to trigger this it needs to happen in
FuzzerTestOneInput().
Reviewed-by: Rich Salz <rsalz@openssl.org>
GH: #2023
