In `quic_record_transfer()`, the unsigned subtraction
`qr->end - qr->start` could wrap around if `end < start`, and the
subsequent `len <= 0` check was ineffective on a `word32`. Move the
comparison before the subtraction so the function returns `0` safely.
In `GetEchConfig()`, `XSTRLEN(config->publicName)` was assigned to a
single byte, silently truncating names longer than 255 characters while
`XMEMCPY` still copied the full string. Add a 255-byte length
validation in both `wolfSSL_CTX_GenerateEchConfig()` and
`GetEchConfig()`, and cache the length in a local variable to avoid
redundant `XSTRLEN` calls.
Andrew Hutchings
b7c3bbf101