66 lines
2.8 KiB
Prolog
66 lines
2.8 KiB
Prolog
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<><><><><><><><><><><><><><><><><><>><>
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><> CRASH PROTECTING GBBS ][ <><
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<><><><><><><><><><><><><><>><><><><><>
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BY INIT HELLO
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LETS DISPENSE WITH FORMALITIES AND GO DIRECTLY TO THE MATTER AT HAND. THIS
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TUTUORIAL WILL OUTLINE THE WAYS IN WHICH A GBBS II CAN BE CRASHED AND OFFER
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SOLUTIONS. IF ALL DIRECTIONS ARE FOLLOWED, THEN YOUR BOARD WILL BE IMPERVIOUS
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YO USER INTERFERENCE.
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(A) THE MOST COMMON AND MOST ELEMEN- TARY METHODS IS BY WHAT IS COMMONLY
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REFERED TO AS "THE OLD SPACE TRICK". WHAT IS DONE IS A PERSON ENTERS AS A "NEW"
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USER AND USES THE SYSOP'S NAME. THIS BYPASSES ALL THE "NAME IN USE" CHECKS BUT
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AWARDS A SYSOP SECURITY OF 64 UPON ENTRY. THE SIMPLE REMEDY WOULD BE TO NOT
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ALLOW SPACE IN A NAME THAT AREN'T IMBEDDED. FOR EXAMPLE:
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510 O$=EL$+"LAST NAME-->":GOSUB 7000 : GOSUB200:A2$=I$...ETC.
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ADD THE LINE: 515 IFLEFT$(I$,1)=" "THEN510
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THIS SHOULD BE ALSO ENTERED ON A LINE AFTER THE FIRST NAME IS INPUTTED.
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(B) ANOTHER COMMON METHOD IS TAKING ADVANTAGE OF THE SYSOP'S MODS, NAMELY,
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ONERR GOTO STATEMENTS. WHAT A PERSON CAN DO IS PURPOSELY MAKE AN ERROR TO GET
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HIM TO WHERE THE ONERR GOTO STATE- MENT IS POINTING. THIS MIGHT BE AN AREA THAT
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THE USER DOES NOT HAVE ACCESS TO. TO PREVENT THIS, NULLIFY ALL YOU ONERR GOTO
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STATEMENTS AFTER YOU'RE DONE WITH THEM WITH A "POKE 216,0". WHEN THE ONERR FLAG
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IS RESET WITH THIS STATEMENT ALL ERRORS WILL RESULT IN A PROMPT LOG- OFF.
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COMMON METHODS OF CREATING ERRORS ARE:
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1) WHEN THE PROGRAM ASKS FOR A NUMBER, ENTERING A "99E99".
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2) WHEN ASKING FOR A PASSWORD, ENTERING A NEGITIVE NUMBER IMBEDDED IN THE
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LETTERS. (IE. G-99FFF, OR A-01AAA)
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3) THEN THERE ARE THE FATAL ERRORS THAT WILL BE COVERED IN SECTION C.
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(C) HERE IS THE GOOD PART. THE GBBS II DRIVER IGNORES THE ENTRY OF ALL
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CHARACTERS WITH AN ASCII EQUILIVENT OF HEXADECIMAL ($20) AND BELOW, EXEPT... A
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BIG EXEPT FOR A FEW!! NOW THESE FEW CHARACTERS WHEN ENTERED, GOES UNNOTICED..
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THAT IS.. UNLESS ENOUGH OF THE ARE ENTERED, (WHICH WOULD TAKE A LONG TIME
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WITHOUT A REPEAT KEY), THEN THE BUFFER SUFFERS WHAT I CALL A "FATAL ERROR" WHICH
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WILL PROMPTLY PUT THE USER INTO MACHINE LANGUAGE WITH DOS INTACT. OH NOOOOOOO!!
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BUT THERE IS GOOD NEWS! IF THE FOLLOWING POKES ARE ENTERED DIRECTLY AFTER THE
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GBBS DRIVER IS LOADED, LET'S SAY ON LINE 60, THEN IT WILL TREAT THOSE CERTAIN
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CHARACTERS LIKE ALL THE REAT OF THE TRASH AND IGNORE THEM!!
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60 POKE 36942,37:
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POKE 36943,208:
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POKE 36944,35:
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POKE 36945,76:
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POKE 36946,95:
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POKE 36947,255
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POKE 36948,234
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AND THATS IT! ALL THE ABOVE HAS BEEN CAREFULLY TESTED AND RETESTED SO THE
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INFORMATION IS VALID. THIS TUTORIAL HAS BEEN WRITTED IN A WAY TO DISCOURAGE
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THOSE SEEKING WAYS TO CRASH PEOPLE'S BOARDS AS WELL AS POSSIBLE.
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]INIT HELLO
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---------------------------------------
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