CMOS password crack
We have seen a lot of articles on the crack of CMOS password, and most crack methods are as follows:
Enter the debug command under DOS, but this is actually just a more old 386,486 machine, and the machine now 586, 686 can be said to be basically invalid, do not believe you can try it on your machine Try here, I must first talk about the principle of CMOS password crack. IBM PC-based machine assignment 70h and 71h ports to CMOS, through these two ports we can access or modify CMOS configuration information. First access 70h Determine the address (0H-80H) of the CMOS (0H-80H), and then enter the appropriate data to the determined CMOS address to achieve the purpose of destroying the CMOS checksum. Here I must also explain, most award bios in CMOS Address 38H-3DH Save password encrypted after the Hash algorithm, but this is not necessarily, so we don't need to determine the address of the CMOS to save the password, just destroy the CMOS checksum, you can reach the CMOS password, I will break down. Program: Enter the debug command under DOS 100-15d2: 0100 MOV Al, 10 (any value of 0-100) -15D2: 0102 OUT 70, Al (directly access I / O port must pass through the Al register) -15D2: 0104 OUT 71, Al (destroying checksum) -15D2: 0106 INT 20 (End Procedure) -15D2: 0108 (Enter) -g = 0100 (executable program) -q This program is in multiple AWARD or AMI The machine is passed. Please note: Many crack programs cannot be used under WindowsNT, Windows 2000, because WindowsNT's DOS is analog, and it is forbidden to write to CMOS.
CMOS backup and recovery
CMOS settings are a more headache for a general computer user. Someone will help you set CMOS, but when you suddenly lose your own or forget your password, you need to reset CMOS. For beginners, it is a more headache. I will ask others. For this reason, why can't you save the configured CMOS? When you need to reset, then run the program to recover, you can remove the reconfiguration. Of course we can also read it from reading CMOS information file gets "Dongdong". CMOS is a 128-byte size storage area that stores important information about the machine BIOS configuration, and the BIOS has CMOS setup program. Based on IBM PC The machine assigns 70h and 71H ports to CMOS. We can access or modify CMOS configuration information. Access 70h, determine the address of the CMOS (0H-80H), then access to the determined CMOS address 71H Data ports to reach access or modify the purpose of data within CMOS. The assembler is the best choice for CMOS access or modification. The following two programs cmos.exe and restore.exe are written in assembly language. CMOS.exe is backup your CMOS configuration program, restore.exe is a program that recovers your CMOS.; ************************ *****************; this is cmos asm file, it could backup your cmos; *************** ***************************************** TITLE FIRSTDATA Segmentna DB 'CMOS.DAT', 0BUFFER DB 80H DUP (?) Handle DW ? data endscode segmentassume ds: data, cs: codemain proc farstart: push dssub ax, axpush axmov ax, datamov ds, axmov cx, 0lea bx, buffermov ax, 0get: out 70H, al; get your cmos configuration (get your cmos Configuration Information) IN AL, 71HMOV [BX], ALINC CXINC BXMOV AX, CXCMP CX, 80HJB GET MOV AH, 3CH; CREATE A NEW FILE (Call INT21H New One File) Lea DX, Namov CX, 20HINT 21H MOV HANDLE, AXMOV AH, 40H; Write to the New File (Call INT21H to write CMOS to this file) MOV BX, Handlelea DX, Buffermov CX, 80HINT 21HRETMAIN ENDPCODE Endsend Start; ******** *******************************************; this is restore asm file, IT Could Restore Your CMOS; **************************************************** ******* Title Restoredata Segmentna DB "CMOS.DAT", 0Buffers DB 80H DUP (?) Data Endscode Segmentassume CS: Code, DS: DataMain Proc Farbegin: Push Dssub AX, Axpush Axmov AX, Datamov DS, AXLEA DX , Na; get the file handle and open the file, open the file number of the cmos.dat file, open the file) MOV Al, 0MOV AH, 3DHINT 21HMOV BX, AX; Read The File (read file content) MOV CX, 80H MOV AH, 3FHLEA DX, BUFFERSINT 21HMOV CX, 0MOV AX, 0LEA BX, BUFFERSWRITE: OUT 70H, Al Download Adobe Reader
Restore CMOS (Configuration of CMOS) MOV AX, [BX] OUT 71H, ALINC CXINC BXMOV AX, CXCMP CX, 80HJB Writeretmain Endpcode Endsend Begin These two programs are commissioned on my Award BIOS, support current most IBM compatible PC. I got CMOS.EXE, RESTORE.EXE with the MASM compiler. Must be noted that after you run CMOS.exe, get a 128-byte CMOS in the directory where the program is located. .dat file, this file is both a CMOS configuration file. This file is a binary. You can see the CMOS configuration with a binary editor such as WinHex. You can easily view the CMOS configuration. When running the recovery RESTORE.EXE program, you need to put CMOS. The DAT file is copied to the directory where the RESTORE.EXE program is located. If you don't have a compilation editor, you can go to my website to download (http://owlbird.xiloo.com/download.htm), provide the assembly editor and compiled Procedure. Please note: In WindowsNT, Windows 2000, many direct access to the CMOS program cannot be used.
