Mask 2.0 (Shareware version) Copyright (c) 1994-1995, Jos‚ M. L. Lopes OVERVIEW: MASK provides several features, including: þ Advanced anti-hacking routine þ Security checksum envelope þ Multiple level encryption þ Ultra-complex encryption þ Random encryption (* registered version only *) þ Compatible with 8088 or greater processors þ 100% pure assembler code þ Hacked code warning þ Checksum modification warning Have you ever developped a program, then found out the next day that your software had been cracked and uploaded to all the BBS across the world? If your answer is yes then your solution is MASK executable encryptor. MASK is more than a simple program that encrypts your software, infact is a powrful tool that prevents your software from beeing cracked or hacked. A file protected with MASK will hang if anyone tries to follow is execution under any kind of debugger. MASK is not like any other software that claims to protect your software and as lots of programs all around all BBS to remove that kind of protection. MASK encryption is more than a simple xor to your original file. MASK relies on a complex encryption algorithm and several layers of encryption, each one decrypted with the values provided by the previous layer. Trying to trace a MASK protected file is a nightmare, because there's no possible way to place a breakpoint inside MASK envelope without affecting the normal execution of the decryption routine. MASK as also multiple traps to deliberatly make the debugger hangs or follow a diferent route than the normal route of the routine running under the DOS prompt. MASK knows the best debuggers in the market and has specific traps to prevent tracing under that particular program. MASK has also specific calls to internal pre-established breakpoints, that prevent any hacker to proceed under a debugger (just imagine trying to trace a loop that interrupts his execution several thousands of times).Inside MASK everithing is checked: the flags, the keyboard state, the stack, the places were most likely the hacker will place a breakpoint... and MASK reacts to every intrusion hanging the machine, rebooting the computer, locking the keyboard, placing the hacker inside infinite loops, going the wrong way. MASK as also an unique feature that no other program has: is impossible to place a breakpoint after MASK execution (that is, other programs like MASK may have a good security envelope, but one hacker could place a breakpoint, lets say, in DOS version check, passing throug the encryption routine and intercepting the original file when running), under MASK there's no possible way to do that. By these and other reasons, you must use MASK when you release a shareware program with a registration option, a commercial copy-protected program, or any program that you don't want hacked, cracked or modified in any way. DISCLAIMER: THE AUTHOR MAKES NO CLAIMS AND OFFERS NO WARRANTIES OF ANY SORT WITH MASK EXECUTABLE ENCRYPTOR. THE AUTHOR ASSUMES NO RESPONSABILITY FOR ANY DAMAGE (MENTAL OR PHYSICAL) RESULTING FROM THE APPARENT OR ACTUAL USE OF MASK. THE PROGRAM PROVIDED IS NOT GUARANTEED AS TO MERCHANTABILITY OR FITNESS FOR ITS ULTIMATE USE. THE USER ACCEPTS ALL RESPONSABILITY FOR USE AND MAY NOT RESELL THE PROGRAM. SYSTEM REQUIREMENTS: MASK will run on any IBM/PC compatible, operating under DOS 2.0 or later, with at least 64 Kb of free memory, and 8086/8088 or later CPU (also on Pentium processors). USING MASK: MASK [-D] filename[.ext] Filename is the name of the program you want to protect. If no extension is given, .COM is assumed first, then .EXE. The -D prefix creates documentation file MASK.DOC. MASK ERROR MESSAGES: "Error reading file!": Thats what you get when you buy those cheap floppy disks. "File too big!". MASK still has some file size problems, wich should be solved in future revisions. By now the maximum size of the target file must not be greater than 62 Kb. "File too small!" means that your file has less than 6 bytes. This is the smallest file you could find to loss several years of sleep trying to break the 600 bytes MASK security envelope (given or taken a few bytes). "Give up hacker !!!" appears when (and if) you arrive to the first real problem within MASK security envelope. Keep trying. "I don't think so..." means that you have tried to protect a file that has already been protected with MASK. Upgrade MASK to the registered version. "Packed file is corrupt". This is not really a MASK error message, but an EXEPACK message, meaning that you have to use LOADFIX to run your protected file. "Warning: Bad CRC !!! Execution terminated." means that either your file is corrupted or you have tried to debug throug MASK security envelope. In the first option give up, if your file is really damaged well... replace it by a new one. "Windows or OS/2 file. Cannot be protected." MASK does not handle OS/2 or Microsoft Windows executable files. COMMON PROBLEMS: MASK has several traps to avoid tracing using debugging tools. If executed under one of this tools, most particularly Soft-ICE, MASK may simply hang the system, but could also start beeping through the PC speaker, or also reboot the computer. Most likely, MASK will cause a system crash generating an exception 6 error, because debugging mekes the decryption routines not to work properly. REGISTERING: Unregistered version of MASK accepts only one level of protection, meaning that you can't add several encryptions to your files. Also, registering adds random encryption to your files. The registered version does not put the label "Unregistered evaluation copy" to your encrypted files. To register fill up and send the included ORDER.FRM, or the order form included below in this documentation file. REVISION HISTORY: Version 2.0, 02-Mar-1995: Fixed a bug with the keyboard lock feature. Added more traps. MASK runs now faster than version 2.0á. Version 2.0á, 15-Feb-1995: Added support for small .EXE files. Added more traps. Version 1.7, 12-Feb-1995: Added more traps. Changed the security envelope to provide compatibility with 8086/8088 processors. Version 1.6, 10-Feb-1995: Added more traps. Version 1.5, 14-Jan-1995: Added multiple levels of encryption. Added random encryption. The number of debubbing traps has been increased. After this version, MASK appears in two distinct forms, a shareware version and a registered version. Corrected also a bug with the processor internal instruction cache. The encryption routine seems to have become too complex too 8086/8088 processors. MASK requires now 80286 or grater processor. Version 1.4, 13-Dec-1994: Corrected a bug with the security envelope. Version 1.3, 30-Nov-1994: Added several traps to avoid debugging. Added also a security checksum envelope. Versions 1.0, 21-Feb-1994, up to 1.2, 11-Jul-1994: The first releases, no more than a simple method to protect some files against the curiosity of a few lamers. Very easy to break for serious hackers. ------------------------ // ----------------------- MASK 2.0 order form SPECIAL OFFER: If you register this software before 1995-Mar-15, you will only pay US $10 (or 1700 PTE). To receive your registered version of the latest MASK executable encryptor, send a cheque or money order payable to: Jos‚ M. L. Lopes Rua de S. Miguel N§ 18 - 3§ 1100 Lisboa PORTUGAL Fill out and print the form below. Include it with your letter. =============================================================================== FROM: Name: ___________________________________________________________ [Company]: ______________________________________________________ Reg Name: _______________________________________________________ [Used to register your software, 30 characters max] Address: ________________________________________________________ City: ______________________________ State: _____________________ Country: ____________________________ Postal Code: ______________ Phone: ________________________ Fax: ____________________________ Where did you obtain MASK shareware from? _______________________ _________________________________________________________ What do you intend to use MASK for? _____________________________ _________________________________________________________ _________________________________________________________ Have you tried to trace MASK shareware programs, and if so, how did you find them? _________________________________________ _________________________________________________________ Future product suggestions: _____________________________________ _________________________________________________________ _________________________________________________________ ===============================================================================