[RndTbl] sshd: Corrupted MAC on input.

Hartmut W Sager hwsager at marityme.net
Fri Jul 31 08:44:52 CDT 2020

>> TCP checksums aren't perfect, and with very large transfers, there is
>> a statistically significant probability of errors getting through,

> I think they are 32-bit checksums in TCP?  Yes, between the
lower layer checksums and TCP my gut says errors should be rare.  Maybe
the math will spell differently though on really junky connections...
However short of wireless, no one should really have that junky a
connection anymore.

If those "32-bit checksums" are truly just checksums, i.e., sums mod 2^32,
then my math knowledge definitely agrees with Trevor.  A simple bit-flip of
two bits in the same bit position throughout the entire file would cancel
each other and go undetected.  And for a large file, that probability is
very significant.  As for the unlikelihood of "really junky connections"
nowadays, well, that's what checksums, CRCs, etc., are for, as a "just in
case" the unlikely event does occur, in addition to the occurrence of the
more likely events.

Hartmut W Sager - Tel +1-204-339-8331

On Fri, 31 Jul 2020 at 04:11, Trevor Cordes <trevor at tecnopolis.ca> wrote:

> On 2020-07-30 Gilbert E. Detillieux wrote:
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