tree add1b920882f740248bb4992c69cb1ff530044a8
parent e51d9e7905e7902794970c5eef438424b489c23d
author dschinazi <dschinazi@google.com> 1614027947 -0800
committer Copybara-Service <copybara-worker@google.com> 1614027992 -0800

Reduce CPU impact of QUIC stateless reset packet generation

In b/180640485 we saw that QUIC stateless reset packet generation is causing noticeable CPU impact on our servers.

The randomness in IETF QUIC stateless reset packets only exists to prevent middleboxes from comparing the entire packet to a known value. Therefore it has no cryptographic use, and does not need a secure cryptographic pseudo-random number generator. This CL introduces the notion of insecure randomness, which uses the non-secure and fast PRNG xoshiro256++. In a release build, this function was empirically shown to perform 150x faster than its secure counterpart.

Protected by FLAGS_quic_reloadable_flag_quic_stateless_reset_faster_randomness.

PiperOrigin-RevId: 358886449
Change-Id: I31ba3e19f802f3012a497ac7220430ba0d93fb9d