Make random_bytes() enforce sane size limits

This makes random_bytes() refuse to generate more than 1MiB of data
at a time. This should almost never be necessary, and we have chased
actual gate OOM failures related to sloppy handling of even
moderately-sized test buffers.

Change-Id: I9cebe778a9309a0f4f5d78be97d062864e1849f1
2 files changed