Before verifying a downloaded archive, both updaters slurped it into a
string with an istreambuf_iterator, which grows the buffer repeatedly
and reallocates as it reads a multi-megabyte file. It also placed no
upper bound on the size it would read into memory.
- A shared readFileExact helper sizes the file first and reads it in a
single allocation, failing closed if the file is missing, empty,
larger than a caller-supplied cap, or comes up short. A truncated read
can never reach the SHA-256 / signature verifier.
- Both updaters use it with the existing max-archive cap.
Tests cover a good read, a read exactly at the cap, over the cap, an
empty file, and a missing file.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
DanSandClaude Opus 4.8
8168e26d93