tree d9002f77b4d5641b80784e014cf8a0e0a8f8f9be
parent 7bfcbbfcd4967f1bcb528bf1a972781f46e9ac29
author martinduke <martinduke@google.com> 1786550880 -0700
committer Copybara-Service <copybara-worker@google.com> 1786550905 -0700

Fix ASAN error revealed by a new fuzz test.

The QUIC-LB spec allows nonce lengths of 18 bytes, although this is an extreme case. For convenience, the LoadBalancerEncoder implementation limits it to 16 bytes so that it fits in a 128-bit integer.

The fuzz test revealed that if the nonce is 16 bytes long, the code that confines the 128-bit integer to the configured length has a bit overflow (i.e. 1 << 128 is out of range).

In the refactoring to fix this, the code switches from starting the nonce at seed_ and decrementing, and instead incrementing. One test of multiple consecutive connection IDs therefore has to change.

This part of the code is not in production. Even when QUIC-LB is deployed, we will not use 16 byte nonces. Nevertheless, the OSS implementation should be as flexible as possible.

PiperOrigin-RevId: 963480631