Looking for data validation, I find the CRC stage. But 16-bit checksums
are much in disrepute -- probably good enough for detecting noise, but
not sound cryptographically. (Heck, even the 128-bit MD5 is now suspect.)
Is better available somewhere? SHA-1? Or even the lowly MD5? Weakness
notwithstanding, MD5 has the advantage of being readily available on
other platforms.
And I readily suspected and proved a weakness in PIPE CRC: files
with content:
a
bc
and:
ab
c
show identical CRC checksums -- apparently the algorithm ignores record
boundaries. This is unfortunate because such framing errors are readily
introduced by transfer to a stream-oriented workstation and back. And
consider Melinda's(?) assertion that CMS Pipelines is superior to other
pipe utilities because not all data should be treated as streams. I
suppose PIPE PACK | CRC can be used to overcome the record boundary
deficiency.
For my testing, I would have liked a stage comparable to the Rexx C2X
function. Of course, it's easy to write, but has someone else already
invented that wheel?
Thanks,
gil
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