Should this implementation enforce ltfs hash xattr format and names

[hugo-hur]

In the SNIA documents it is clearly stated that only specific ltfs.hash.<hashtype>:s xattrs and formats are conforming:

hashtype	algorithm	bits	hex chars
crc32sum	ANSI X3.66	32	8
md5sum	RFC 1321	128	32
sha1sum	FIPS 180-4	160	40
sha256sum	FIPS 180-4	256	64
sha512sum	FIPS 180-4	512	128

Currently this implementation allows for writing any values and with any names into the ltfs.hash.<hashtype> xattrs.

To Reproduce
Steps to reproduce the behavior on linux builds (all examples here use non conforming attribute names):

setfattr -n user.ltfs.hash.sha256 -v "tooshort"        file   # text, wrong length (spec wants 64 hex chars)
setfattr -n user.ltfs.hash.crc32  -v 0xdeadbeef        file   # 0x… = raw BINARY bytes (spec wants UTF-8 hex text)
setfattr -n user.ltfs.hash.md5    -v 0sBgYGBgYG…==     file   # 0s… = raw bytes from base64

Expected behavior
LTFS should prevent from writing non-conformant information in the xatrrs.

Any thoughts on this?