C_2.1.3

Security release.

Faulty handling of input files exposes users to potential security issues. While there is very low probability of being exploited (the worst outcome is likely to be denial of service through memory allocation failures), we nonetheless recommend all users upgrade.

Details: reject malformed/crafted store files whose item descriptors contain length and offset fields that overflow when bounds-checked (e.g. a huge array_len whose byte size wraps past file_size). Such a file previously passed validation and could cause an under-allocated buffer to be returned with a large reported length, leading to an out-of-bounds read in the caller. Zero-length keys are also now rejected on read.