A look at the MS-SQL worm
Posted Jan 30, 2003 15:11 UTC (Thu) by utoddl
In reply to: A look at the MS-SQL worm
Parent article: A look at the MS-SQL worm
BTW the formal proving methods I studied at the university usually concentrated on what the program should do with the correct input. They didn't deal with incorrect inputs (i.e. it was enough to prove, that the program works on the specified inputs, noone cared, what happens with incorrect input, because it was out of scope)
[way off topic, but...] One of the most interesting assignments in my second programming class spelled out what constituted correct input and that the program should handle incorrect input. The instructor was going to run each of our programs against an unspecified input stream, and we would be graded in part on how well we handled bad input.
We were still using punch cards back then, and there were plenty of discarded punch cards lying around -- old data sets, discarded (literally!) lines from old programs, etc. The input the instructor chose was... handfulls of old punch cards he pulled from the trash in the key punch room. Snippets of FORTRAN, PL/I, raw data, arbitrary text, etc. made various programs produce, er, interesting results. It was a real eye opener to most of us; we had though "bad input" might mean something not in the right column, or a keyword slightly mispelled. Very few of the programs could handle garbage -- literal garbage -- as input.
Sorry for the Old Man tale. You kids go back to your discussion...
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