edx cybersecurity

In many network development scenarios, memory conversion is often encountered in the following scenarios: #define PACKAGE_PARSE_ERROR -1#define PACKAGE_PARSE_OK 0int parse_package( int* a, int* b, int* c, int* d, char* buf, int buf_len ){ if( !buf || buf_len This is a call in the Process of network unpacking, and the packet process is a reverse process. An application like this can be replaced by an integer forced conversion, and the efficiency will be at least doubled. To illustrate t

Reading Tips: 《Delphi Image ProcessingThe series focuses on efficiency. The general code is Pascal, and the core code is BaSm. 《C ++ Image ProcessingThe series focuses on code clarity and readability, and all uses C ++ code. Make sure that the two items are consistent and can be compared with each other. The code in this article must include the imagedata. Pas unit in "Delphi Image Processing-data type and public process. The minimum value processing of an image is centered on the current pixel

de facto standard? In other words, thefuck is not very tall. _ (: 3 "outputs) _ list of excellent Python projects (awesome-python) Vinta/awesome-python · GitHub Pycrumbs/pycrumbs. md at master · kirang89/pycrumbs · GitHub Svaksha/pythonidae · GitHub Checkcheckzz/python-github-projects · GitHub Rasbt/python_reference · GitHub Easy-Python And awesome-* Series Bayandin/awesome-awesomeness · GitHub Sqlmap! Goagent! By the way, there are also shadowsocks! Open

Tools:VC 7.0BCB 6.0Compilation options: Maximum Speed Optimization (VC 7.0 turns off the automatic inline function option)Decompilation tool: w32dasm Benchmark Test procedure:Void test (){Int A = 0, B = 1, C = 4;For (INT I = 0; I ++;}} Int main (){_ ASM {MoV edX, EDXNOP};Test ();} Purpose: To test the program's ability to optimize useless functions. Because test does not return any value or modify any external variables,Therefore, for programs, this i

: 77F061F8 _ NtQuerySystemInformation @ 16 In ntdll, the two functions of zw and nt are actually the same subject: . Text: 77F061F8 mov eax, 105 h; NtQuerySystemInformation . Text: 77F061F8; RtlGetNativeSystemInformation . Text: 77F061FD mov edx, 7FFE0300h . Text: 77F06202 call dword ptr [edx] . Text: 77F06204 retn 10 h Then compare the image: Check whether the Mode is usermode or kernelmode. Ntdll. the

Core tips: This experiment demonstrates that when calling a method in a class, all methods imply a self parameter, and this parameter is passed as the first parameter of the object method... First, create an empty form and put a button.The following two methods are declared under implementation: // The external method declares only one parameter. In this case, the standard Object internal event Method tpolicyevent is declared. In this declaration, the sender corresponds to the object pointer

edi.data:0040605f 8B mov ecx, [eax].data:00406061 8B mov EDX, [eax+4];. data:00406061;; Save String "Createfi". data:00406064 C7 FC xx 00+ mov [ebp+processor_architecture], 0.data:0040606b 4D F8 mov [Ebp+szcrea], ecx.data:0040606e, MOV [Ebp+sztefi], edx.data:00406071 64 A1 xx eax, large Fs:30h; Get _peb.data:00406077 8B 0C mov eax, [eax+0ch]; Get ldr_peb_ldr_data.data:0040607a 8B 1C mov esi, [eax+1ch]; Get

],al004113EE mov dword ptr [EBP-2CH],0FFFFFFFFH004113F5 Push offset string "Masefee" (415804h)004113FA Lea EAX,[EBP-20H]004113FD push EAX004113FE call @ILT +160 (_strcpy) (4110a5h)00411403 Add esp,800411406 push edx00411407 mov ecx,ebp00411409 push EAX0041140A Lea edx,[(411438h)]00411410 call @ILT +130 (@_rtc_checkstackvars@8) (411087h)00411415 pop eax00411416 pop edx00411417 Pop EDI00411418 pop ESI00411419 pop ebx0041141A mov ecx,dword ptr [ebp-4]004

other than esp. The scaling factor can be 1, 2, 4, or 8. The offset is an immediate number. For example, [ebp+edx*8+200] is a valid, valid address expression. Of course, in most cases you don't need to be so complicated, the address, scaling factor, and offset do not necessarily appear. The base unit of memory is bytes (byte). Each byte is 8 bits, so the maximum number of energy-saving expressions per word is 11111111, or 255 of the decimal. In gene

Traceback (most recent):File "manage.py", line all, in startup = Importlib.import_module (Edx_args.startup)File "/usr/lib/python2.7/importlib/__init__.py", line Notoginseng, in Import_module__IMPORT__ (name)File "/edx/app/edxapp/edx-platform/cms/startup.py", line 7, Settings. Installed_apps # pylint:disable=w0104File "/edx/app/edxapp/venvs/edxapp/local/lib/python

Use the cpuid Assembly command (machine code: 0fh a2h, if your compiler does not support cpuid command, only emit machine code), this command can be recognized by the following CPU: More than 486 of Intel CPUs, CPU above cyrix M1, CPU above amd am486 (1) obtain the cpu oem string to determine the CPU vendor Let eax = 0 first, then call cpuid InEl CPU will return: EBX: 756e6547h 'genu'EdX: 49656e69h 'inei'ECX: 6c65746eh 'ntel'EBX, EDX, and ECX

important parts abve are:1. The code at 77D55E9D. Which copies the address of the bmp file stringInto ecx. 2. The code at 77D55EA8. This checks if the hinst parameter passedLoadImage is NULL. If we jump to the code at address 77D57C6E becuase of thisLine: 77D55EB0 je _ LoadBmp @ 20 + 21 h (77D57C6Eh); If esi was NULL jumpsTo code at 77D57C6E This takes us to this assembly: 77D57C6E mov esi, dword ptr [_ hmodUser (77da01_h)]77D57C74 movzx eax, cx77D57C77 xor ebx, ebx77D57C79 sub eax, 7 FDCh77D57

FC Lea edx,[local.1]00441709 |. 8b83 C8020000 mov eax,dword ptr ds:[ebx+0x2c8]0044170f |. E8 901AFEFF call fireworx.004231a4; ; Calculates the length of the serial 00441714 |. 8b45 FC mov eax,[local.1]00441717 |. Push eax00441718 |. 8d55 F4 Lea edx,[local.3]0044171b |. 8b83 C4020000 mov eax,dword ptr ds:[ebx+0x2c4]00441721 |. E8 7e1afeff call fireworx.004231a4; ; Calculates the length of the name

first set breakpointsThen, two times shift+f9.Then, cancel the breakpoint. Alt+f9 and executes to user codeThen step away, and you'll reach Oep.5.1, after loading the program, you will find the first line has an address0040a86d > B8 74de4500 mov eax,qqspirit.0045de742, at the address of the next breakpoint BP 0045de743. Then shift+f9 run, and cancel breakpoint4, we are in the Retn next line set breakpoints, and then shift+f9 Run, and cancel the breakpoint045de74 B8 F9CB45F0 mov eax,f045cbf90045

. The source program entry is _start. As follows:Cpuid2.s # Cpuid2.s file.section. DataOutput: . Asciz "CPUID is '%s ' \ n". Section. BSS . Lcomm Buffer, 12. Section. Text.globl _start_start: NOP movl $,%eax cpuid movl $buffer,%edi movl%ebx, (%edi) MOVL%edx, 4 (%edi) movl%ecx, 8 (%edi) pushl $buffer pushl $output printf Addl $8,%esp PUSHL $ exit In the following three cases where the entry is _start,main,xx

If the assembly language to achieve the following C language functions, the compilation environment Ubuntu14.04 (32-bit).#include voidSwapint*p,int*q) { intTMP = *p; *p = *Q; *q =tmp;}intMain () {intA[] = {3,0,5,1,4,6,2,9,8,7}; intI, J; for(i =0; I Ten; i++) { for(j = i +1; J Ten; j + +) { if(A[i] >A[j]) {Swap (a[i], A[j]); } } } intK; for(k =0; K Ten; k++) {printf ("%d\n", A[k]); } return 0;} Assembly Code SORT.S . Section.

Linux Kernel Analysis Course summaryName: Wang ZhaoxianStudy No.: 20135114Note: Original works reproduced please specify the source + "Linux kernel analysis" MOOC course http://mooc.study.163.com/course/USTC-1000029000First, how the computer works 个人理解：计算机就是通过和用户进行交互，执行用户的指令，这些指令存放在内存中，通过寄存器存储，堆栈变化，来一步步顺序执行。Second, the storage program computer working model1.冯诺依曼体系结构—存储程序计算机 硬件角度（主板）：通过cpu中IP寄存器指向一个代码段运行某些指令；寄存区，指向内存的某一块区域（代码段） 程序员角度：将cpu抽象为一个for循环，只是执行下一条指令，从内存中取到下一条指令的内容。内存保存指令和数据，cpu

Introduction EFS Web server is a software that can manage server files over a Web side, and sending a GET request too long can trigger a buffer overflow vulnerabilityAnalysis Source: https://www.exploit-db.com/exploits/39008/ Experimental Environment WinXP SP3 Chinese versionEFS Web Server7.2Immunity DebuggerWinDbgIdaMona Vulnerability Analysis Because the author uses the address of the overlay Seh program in ImageLoad.dll, no ASLR, so the use of more stable, open on the pop-up calculator We w

(LOCK_PREFIX "decl (% eax) \ n" \ # as shown here, if count is first subtracted from the thread, SF is not equal to 1 (not equal to negative ), execute it later, that is, obtain the lock. then, if the thread that tries to obtain the lock executes this atomic operation (in the unlocked state), SF equals 1, so that void (*) (atomic_t *) is executed *) type Function to enter the waiting queue. therefore, this locking atomic operation can be completed with a single command. in non-SMP scenarios, a

have been learning about Windows kernel recently, write a blog for memo.The specific process of Windows system call in the Pan teacher's "Windows kernel Principle and implementation" in the 8th chapter has been written very clearly, first read the picture given in the.Take CreateFile as an example, after some parameter checking in Ring3 's CreateFile, the final call is NtCreateFile in Ntdll. There are also zwcreatefile, but their addresses point to the same area, so they are essentially the same