CVE-2026-14682: Possible OOM from unbounded up-front allocation on a definite-length read

Affects Bouncy Castle for Java LTS before 2.73.12. Definite-length ASN.1 parsing allocated the entire declared object length as soon as the header was read. A few crafted header bytes arriving over a non-rewindable stream, such as a TLS record layer or a socket-backed certificate read, could trigger a near-heap-sized allocation before any content byte was consumed. Definite-length objects are now grown incrementally through the stream, so a short payload fails as a truncation error instead.