Now, the main reason I'm answering you is the CRC issue: We all agreed
that a CRC for base64 would be a good thing, but we were unable to agree
on one. It is, however, the kind of thing that can be phased in later
without much pain, which is why decided to defer it. (Imagine a
"Content-CRC:" header, for example.)
I don't think that would be a too good way to do it, I'd prefer to see it
a part of base64. That way you could "sprinkle" the checksums into the
encoded material as tight or as loose as you want.
I think the alternatives for quickie algorithms would boil down to "sum"
and "brik". Both are free, widely used and implemented, though brik is
implemented inside a rather large program. Of course, you could go for
some standard CCITT CRC-algorithm, but it should be calculated effectively
with XOR-tables and register shifts.
Finally, I would not be too surprised if the garbling you've seen is the
result of using uuencode instead of base64. The whole point of base64
is that it is much less prone to being garbled than uuencode! This
doesn't mean that a CRC is not a good idea, merely that the problem
you've had may be further evidence of the desirability of base64.
I doubt that this is the case. If so, I would see the same problems
continuously on the same sites as their feed is screwing it up.
However, I have had several cases where people have mailed me saying
"I never thought I'd do this, but... part x of y of nasty-fornication.jpg
arrived at our site with a wrong checksum. It's never happened before !"
and once I've sent them the damaged part they have had other parts of
the image decode perfect and I've never heard of them since... even though
I've said "don't hesitate to get in touch again if you have these problems".
I suspect that hidden somewhere deep in some news feed sites there are
bugs which show up only occasionally when the phase of the moon is right
(or wrong, which ever you choose -- "full moon tonight, you feel lucky" ?).
Anyway, I'm really sorry if you feel attacked -- that was NOT my
intention at all!
No, I didn't feel attacked.
The bit about defence exhibit A was more of a joke...
--
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