In FIPS mode, we maintain a lock in order to implement clearing DRBG
state on process shutdown. This lock serves two purposes:
1. It protects the linked list of all DRBG states, which needs to be
updated the first time a thread touches RAND_bytes, when a thread
exits, and on process exit.
2. It ensures threads alive during process shutdown do not accidentally
touch DRBGs after they are cleared, by way of taking a ton of read
locks in RAND_bytes across some potentially time-consuming points.
This means that when one of the rare events in (1) happens, it must
contend with the flurry of read locks in (2). Split these uses into two
locks. The second lock now only ever sees read locks until process
shutdown, and the first lock is only accessed in rare cases.
Change-Id: Ib856c7a3bb937bbfa5d08534031dbf4ed3315cab
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45844
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Rather than the FIPS module actively collecting entropy from the CPU or
OS, this change configures Android FIPS to passively receive entropy.
See FIPS IG 7.14 section two.
Change-Id: Ibfc5c5042e560718474b89970199d35b67c21296
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44305
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Adam Langley
David Benjamin