computer security fundamentals

2018-2019-1 20165228 "The foundation of Information security system design" The second week study summary textbook learning content Summary information = bit + context Unsigned encoding: Represents a number greater than or equal to zero based on the traditional binary notation Complement coding: represents the most common way to sign a certificate, a number that can be expressed or positive or negative Floating-point encoding: A two-base versi

employee ID (curly) login, just change the value toNaturally shows the information of the first employee (Larry); 7), Database backdoors 1. Target: Use string SQL injection to execute multiple SQL statements. The first phase uses a vulnerable field to create two SQL statements. The first one is the system, the second one is entirely yours. Your account ID is 101. This page allows you to view passwords, SSN, and payroll. Try to inject another update to update your salary 2, inp

specified as a double word, the size of the block is the integer multiple of the double word, not the rounding to Yes.Explicit idle linked list Difference（1）分配时间 隐式的，分配时间是块总数的线性时间 但是显式的，是空闲块数量的线性时间。（2）链表形式 隐式——隐式空闲链表 显式——双向链表，有前驱和后继，比头部脚部好使 Sorting policy:?后进先出?按照地址顺序维护Detached List of idle links Separating storage is a popular way to reduce allocation time. The general idea is to divide all possible block sizes into equivalent class/size classes The allocator maintains an a

FeelingsJust beginning to touch Java, feel both confused and hard, because they have not been in a self-learning way to contact a new programming course, long time to find more difficult. I think, teacher and student relationship is eldest brother and brother! Why do you say that, because the teacher experienced the student age and more understanding of the situation of students, leading students to learn and impart some experience, so that students less detours, and exchange ideas with students

shift x>>k: Move the K-bit right and the value at the left to complement K's most significant bit Logical right Shift x>>>k: Move K-bit right, left complement K 0 Use arithmetic right shift for signed number, logical right shift for unsigned numberInteger representation Information = bit + context unsigned integer: b2u4[0011]=0 2^3+0 2^2+1 2^1+1 2^0=3 Signed integer-complement code: B2t4[1011]=-1 2^3+0 2^2+1 2^1+1 2^0=-5 Unsigned number means you need to append the suf

20145321 "The basis of information security system Design" 7th Week study summary textbook study content summary sixth chapterA memory system is a hierarchical structure of storage devices with different capacities, costs, and access times.6.1 Storage TechnologyThree common storage technologies: ram/rom/disk(1) Random access memory RAM There are two categories: Static RAM (SRAM) and dynamic RAM (DRAM) static RAM (SRAM) faster than dynamic RAM

path does not appear in Chinese, the component, the patch package and the main body need to be installed under the same path. And then you need to start cracking. (But I already have the Quartus II 11.0 program on my computer in my previous studies)The work required for each program Program Quartus II 11.0 Open the experimental file, follow the instructions in the experiment instructions to complete the compilation, configuration pins and other

that there are already compiled. yo files that can be viewed with vimThe code in Figure 4-7 of the No. 239 page of the textbook, called Asum.yo in the system, prints its contents on the screen:It can be seen that the results are consistent with the 240 pages of the textbook.Textbook page No. 251 of Figure 4-17, I first used to build a 417.ys enter after entering:Then compile with make 417.yo and use Vim to enter 417.yo after compiling.Reference, I saw Shang she summed up than I have more organi

handler is called, the new signal screen word created by the system automatically includes the signal being delivered. This ensures that when a given signal is processed, if the signal occurs again, it will be blocked until the end of the processing of the previous signal; The response function is set to be valid and not resetThe implementation of sleep () should be divided into three steps: Register a signal signal (sigalrm,handler). Call the alarm () function. Pause () suspen

that divides the cache into chunks, transfers blocks between different tiers, determines whether they are hit or miss, and processes themCache memoryGeneral-Purpose Cache Memory Architecture:Each memory address has a M-bit, which forms m=2^m different address cache groups: Array cache lines for S=2^s cache groups: b=2^b bytes of data blocks make up a valid bit: Indicates whether the row contains meaningful information marker bits: Uniquely identifies the block stored in this cache line, T=m-( B

status code stat from the result of the instruction execution, based on Icode,imem_error,instr_valid,dmem_error. update pc stage generates a new value for the program counter, depending on the type of instruction and whether to select the branch, the new PC may be valc, Valm, or Valp. Please explain why there is only one if statement in the C language code, and the assembly code contains two conditional branches?A: The first conditional branch is part of th

1. Machine-Level Code(1) Two kinds of abstract Defines the format and behavior of machine-level programs by ISA The memory address used by the machine-level program is the virtual address 2. Data format3. Operand designator4. Press in and eject stack data Follow the principle of first in and out Push Press in, pop delete Pushq press four words into the stack popq four words pop-up stack 5. Arithmetic and logical operations LEAQ Load Valid address INC plus a D

non-gate or non-gate HCL integer Expression Case Expression Format: [ select 1: expr 1 select 2: expr 2 . select k: expr k ] Set Relationship:iexp in{ iexp1,iexp2,...iexpk } Arithmetic/logic unit (ALU) Sequential implementation of Y86-64 Organize the processing into stages Value fetch--> decoding decode--> performing execute--> memory--> writeback write back write back--> update PC update SEQ

week's exam error summary 1.The following jump commands are related to ZF ()A. jmpB. JeC. jsD. JaE. JBF. JbeAnalytical:2.Assuming that the function of the C-expression T=a+b is completed with the add instruction, the correct statement about the condition Code Register is ()A. If t==0, then zf=1B. If tC. If tD. if (aE. if (aF. LEAQ directive does not affect the condition code registerG. CMP directives do not affect the condition code registerAnalysis: Textbook p135ZF: 0 logo. The result of the r

I. Learning Objectives Understanding the role of ISA abstraction Master Isa, and be able to learn other architecture extrapolate Understanding the pipeline and how it is implemented Second, the Learning content y86-64 directive MOVQ directive IRMOVQ rrmovq mrmovq RMMOVQ Four integer manipulation instructions Addq,subq,andq,xorq only the Register data 7 Jump Instructions Cmovle cmovl cmove cmovne cmovge CMOVG The call command returns the address to the stack, and then j

1.Y86-64 Instruction Set architecture①Y86-64 directive MOVQ directive IRMOVQ rrmovq mrmovq RMMOVQ Four integer manipulation instructions Addq,subq,andq,xorq only the Register data 7 Jump Instructions Cmovle cmovl cmove cmovne cmovge CMOVG The call command returns the address to the stack, and then jumps to the destination address, and the RET instruction returns from such calls Pushq and POPQ instructions are implemented into the stack and out of the stack Execution of Halt

specific framework is divided into four categories: 1. For OPL (integer and logical Operations), RRMOVL (register-register transfer) and IRMOVL (immediate count-register transfer)2. For RMMOVL and MRMOVL3. For PUSHL and POPL4. For jump, call and RET The summary is that the clock is used to control the updating of the state elements, and the values are propagated by the combinatorial logic. ExperimentAfter you run the make commandTo view the contents of the directory, you can see o

Tags: alt padding command ble language jump Edit RDA SystemStack traceFirst edit a program Compile with GCC, then debug with GDB and find GDB has not been downloaded Re-run gdb after download Set Breakpoint: B + line number or "main" Run: R Frame: The printed information: the stack's layer number, the current function name, the function parameter value, the file and line number where the function is located, and the statement to which the function executes. Info frame: Print out informatio

-up processBIOS (Basic Input Output System): A set of program small operating systems that are cured to a ROM chip on the motherboard of a computer, the main function is to provide the most direct hardware settings and control for the computer. Operating system startup process: Power on, run the BIOS, System self-test, read the CMOS parameters, start the corresponding device-read sector content, read-in boo

EXP9 the basic practice of Web security Fundamentals Answer 1, SQL injection attack principle, how to defend?1.对用户的输入进行校验，可以通过正则表达式，双"-"进行转换等。2.不要使用动态拼装sql，可以使用参数化的sql或者直接使用存储过程进行数据查询存取。3.不要使用管理员权限的数据库连接，为每个应用使用单独的权限有限的数据库连接。4.不要把机密信息直接存放，加密或者hash掉密码和敏感的信息。5.应用的异常信息应该给出尽可能少的提示。6.采取辅助软件或网站平台来检测sql注入。2, how to defend the principle of XSS attack?在表单提交或者url参数传递前，对需要的参数进行过滤；检查用户输入的内容中是否有非法内容，如尖括号、引号等，严格控制输出。3, C