**Return-oriented programming** bezeichnet eine gewiefte IT-Angriffstechnik, die im Prinzip eine Verallgemeinerung von *return-to-libc*-Attacken ist, welche wiederum zu den *stack buffer overflow exploits* gehören.
Wem das alles nichts sagt - keine Angst: Im Vortrag werden zunächst die Grundlagen von Puffer-Überläufen und deren Angriffspotential erläutert und einige historische Beispiele aufgezeigt, bevor schrittweise die Brücke zu **ROP** geschlagen wird. Zum Abschluss werden kurz einige Abwehrmaßnahmen vorgestellt und im Hinblick auf Umsetzbarkeit und Wirkungsgrad bewertet.
So die Demo-Götter es wollen, wird live u.A. ein Beispiel-Programm mithilfe von **ROP**-Tools gecrackt.
You have more to secure than ever before. A data breach can happen to any organization, and it's a growing concern among companies both large and small. Take a look at these best practices and see if any of these have gotten lost as you consider your 2017 plan.
**Return-oriented programming** bezeichnet eine gewiefte IT-Angriffstechnik, die im Prinzip eine Verallgemeinerung von *return-to-libc*-Attacken ist, welche wiederum zu den *stack buffer overflow exploits* gehören.
Wem das alles nichts sagt - keine Angst: Im Vortrag werden zunächst die Grundlagen von Puffer-Überläufen und deren Angriffspotential erläutert und einige historische Beispiele aufgezeigt, bevor schrittweise die Brücke zu **ROP** geschlagen wird. Zum Abschluss werden kurz einige Abwehrmaßnahmen vorgestellt und im Hinblick auf Umsetzbarkeit und Wirkungsgrad bewertet.
So die Demo-Götter es wollen, wird live u.A. ein Beispiel-Programm mithilfe von **ROP**-Tools gecrackt.
You have more to secure than ever before. A data breach can happen to any organization, and it's a growing concern among companies both large and small. Take a look at these best practices and see if any of these have gotten lost as you consider your 2017 plan.
4bit pc report[cse 08-section-b2_group-02]shibbirtanvin
Report on Very Simple Computer Design & Implementation_
4bit PC_DSD_report[CSE-08_Section-B2_Group-02]
Courtesy:
Tanvir Al Amin Popel
Tanvir Ahmed Khan
Imtiaz Ahmad
CSCI 2121- Computer Organization and Assembly Language Labor.docxannettsparrow
CSCI 2121- Computer Organization and Assembly Language
Laboratory No. 5
Week of March 12th, 2018
Submission Instructions:
1. Save the files as shift.sv and vending.sv
2. Put all files into one folder.
3. Compress the folder into a .zip file.
4. Submit the zip file on Brightspace.
5. Submission Deadline: Sunday, April 15th, 2018, 11.55PM
SRC CHIP PROJECT
In order to proceed on the project for this course, there are several key Verilog concepts which are
necessary in the implementation of this code.
Part 0: More Verilog concepts.
Shared busses and tri-state buffers
Before we begin implementing the CPU, let's go over a few concepts which will be needed for the lab
assignment. The first is the concept of a shared bus. We've already seen busses in Verilog in terms of an
array of wires or registers, however in the context of our CPU, the word "bus" has another meaning. Our
CPU uses a shared "bus" which is a wire connected between the inputs and outputs of many different
registers, in order to share data:
This can be easily modelled in Verilog, using the inout keyword for a module. This defines a wire which
can act as both an input and an output to our module. However, there is one critically important design
concept which goes along with the usage of shared busses:
Only one signal can be written to a shared bus at any given time.
If two signals are written to the bus, the result is a bus collision, and the value is undefined. In the
simulation, this is represented as "X", but in real life this would cause garbage data to exist on the bus,
potentially corrupting any process which is running on the CPU. As Verilog programmers, it's our job to
ensure that a bus collision never happens. To facilitate this, we'll use a digital logic component called a
tri-state buffer:
The purpose of a tri-state buffer is to act as a switch. If B is 1, then the data can pass through the buffer,
but if not, it simply disconnects the wire, outputting a high-impedance state (in Verilog, denoted by Z).
hz943141
A B C
0 0 Z
0 1 0
1 0 Z
1 1 1
In Verilog, we can't directly write a tri-state buffer, but it can be easily synthesized using a ternary
operator as shown on line 11:
Line 11 shows the construction of a ternary operator to use as a tri-state buffer. If the input called
activate_out is set to 1, then the tri-state buffer is activated, and the circuit will put my_result on the
bus. Otherwise, it puts the value 32'bz on the bus, which will disconnect my_result from the bus, and
allow another circuit to write to the bus.
Note: It is important that during your lab assignment, any circuits which write to the bus have a tri-
state buffer implemented to prevent bus collisions.
Verilog Tasks:
Verilog tasks are like object functions in Java. Read more about them here. You may find that they are
useful in separating the code for instructions within a module, particularly for th.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
When stars align: studies in data quality, knowledge graphs, and machine lear...
Design
1. SYSTEM DESIGN
1.1 Introduction
In this section we would be discussing the system design and implementation of
OIVM. The Complete Project has been written in C++. It is a windows 32bit console
program and has a CLI interface.The processor design consists of the following components :
Processor Registers
Stack
BootRom
Instructions
Instruction Codes
1.2 Processor Registers
In computer architecture, a processor register is a small amount of storage available as
part of a CPU or other digital processor. Such registers are (typically) addressed by
mechanisms other than main memory and can be accessed more quickly. Almost all
computers, load-store architecture or not, load data from a larger memory into registers where
it is used for arithmetic, manipulated, or tested, by some machine instruction. Manipulated
data is then often stored back in main memory, either by the same instruction or a subsequent
one.
Register Name
Size(Bits)
Data Type
Functionality
A
32
INT
General Purpose
B
32
INT
General Purpose
C
32
INT
General Purpose
D
32
INT
General Purpose
SP
32
INT
Holds address of a location on the stack
IP
32
Unsigned INT
Holds Current Instruction Offset
FLAG
32
INT
Stores Results of Compares
Table 1 : Processor Registers
2. 1.2.1 General Purpose Registers
Registers A, B, C, and D are general purpose registers that is we use as variables in
the architecture and any value to be manipulated in the program gets stored in the register and
is then manipulated. Each of these is 32 bit in length. They are however declared as int in the
source file written in C.
1.2.2 Stack Pointer
Stack which is a continuous memory segment is required for various functionalities
which would be discussing shortly. However, the stack requires a pointer which can hold the
address of a memory location on the stack so that when ever anything is to be pushed or
moved from/to the stack this pointer can be used. This is facilitated by the SP register. In our
architecture. This register is 32bits long and is declared as an int in the source file. Whenever
something is pushed on the stack. The stack pointer is incremented and whenever something
is popped it is decremented.
1.2.3 Instruction Pointer
The IP is the program counter for the bootrom. (To be discussed shortly). The input
stream which is the bootrom, is a flat file containing the instructions, this is fed into the
processor and the IP keeps the track of the instruction that is to be executed next via holding
an offset. After each instruction the pointer is incremented and in some cases it is as well
decremented. This typically happens in cases where we take a backward jump. It is a 32 bit
register and is implemented an unsigned int in the program code since it cannot have a
negative value.
1.2.4 FLAG register
The flag register is a crucial register for performing arithmetic or even comparisons.
Typically the flag register is implemented by a set of flags represented by different bits of the
register. These bits are set on the basis or results of a comparison or different arithmetic
operations. However in our case we are dealing with a level language implementation hence
instead of 0 and 1 the flag can hold negative values as well. Thus, we declare this 32 bit
register as int. The current architecture supports different kinds of instructions which check
the FLAG register for a negative, positive or 0 zero value to proceed execution.
3. 1.3 Stack
A stack is a basic computer science data structure and can be defined in an abstract,
implementation-free manner, or it can be generally defined as a linear list of items in which
all additions and deletion are restricted to one end that is Top. That is, whenever we put in
more data on the stack it would be added on the top of the stack, unless of course we wish to
overwrite the existing values.
The stack in the x86 architecture is implemented such that it grows downwards that is the
starting address is the highest address and the consecutive addresses keep decreasing as you
add more stuff.
However in our implemented we have implemented the stack as the memory that grows
upwards that is when you push in data the value of the next address is higher. The total size
allocated to the stack is 65,636. Each value being the size of an int. Hence the total data it can
hold is 2,62,144 bytes.
Traditionally the stack can have two implementations either as a linked list or as an array, we
in this architecture have implemented the structure as an array. This helps us reduce the
overhead of maintaining the node pointers.
Now the stack basically consists of two functions:
Push: a push operation, in which a data item is placed at the location pointed to by the stack
pointer, and the address in the stack pointer is adjusted by the size of the data item;
Pop: And a pop or pull operation: a data item at the current location pointed to by the stack
pointer is removed, and the stack pointer is adjusted by the size of the data item.
Figure 1 : Stack Operation
4. However in our architecture we implement this logic via a MOV instruction. Which is used to
both push a value or retrieve the value from the stack. The Register SP maintains the address
of a value on the stack as already discussed.
1.4 BootROM
This is the source code of the program that is to be run on OIVM. BOOTROM is a
read-only file which contains the instructions to be executed on the processor. When the
processor starts it accesses this file and then copies the file to an internal variable ROM, from
where it is executed instruction by instruction. The boot room is a text file however a hex
editor is required to edit or view the file in the format required.
Example:
A text file might display :
?% /?8?8A=
<L!% /|gcUda8g|c8Uda87A=ÉE??h<% /†Å8A=
However the real source code is :
3F 11 25 00 2F 08 3F 38 3F 38 41 3D 09 1B 3C 4C 21 25 00 2F 14 7C 67 63 55 64 61 38 67
7C 63 38 55 64 61 38 37 41 3D 15 C9 45 3F 11 3F 12 18 68 3C 25 00 2F 08 12 86 C5 38 41
3D 09 00 02 04 06 08
Hence the program that we need to be executed has to be written in this file.
1.5 Instructions
After having covered the underline architecture we are now equipped to talk about the
functioning of the processor. The first and foremost thing is the language for any program.
And for us it assembly language. That is we write are program code not in lines but in
instructions.
1.5.1 What is an Assembly Instruction ?
An instruction is the simplest meaningful, executable code of an assembly language.
They are very simple operations and usually a combination of instructions forms a similar
high level language construct.
Example: A while loop in C would be written as
while(A=1){
//do this
}
5. However the similar program in assembly language would be written as :
LOC1: CMP A,1
JE LOC2
//Do this
LOC2 :JMP LOC1
Things do get complex when writing directly in a low level language however that is
precisely what we want. Typically any instruction is made of various byte/opcodes for
example MOV A,B in machine would be 0x08 0xB3. However in our format we implement
one byte for each instruction, that is MOV A,B is 0x13 and in some cases two bytes are
required where in the second byte is not an instruction but a hardcoded value. For instance
JUMP is implemented as 2F 06. Which means 06 is the hardcoded value. Hence in the
bootrom, each byte represents a different instruction.
1.6 Instruction Codes
The total number of instructions is 183. The Instruction Set is divided into 11 basic
categories which are as follows:
Move: It includes various instructions to move contents from stack to register, within
registers, from and to various other pointers like IP, Sp etc.
Addition: It includes various instructions to add contents of various registers or add explicit 1
byte data to contents of a particular register.
Subtraction: It includes various instructions to subtract contents of various registers or
subtracts explicit 1 byte data to contents of a particular register.
Inc (Increment): It includes various instructions to increment the contents of registers
(A,B,SP).
Dec (Decrement): It includes various instructions to increment the contents of registers
(A,B,SP).
Compare: It includes various instructions to set the flag value while comparing the contents
of 2 registers by subtracting their contents and checking for zero/non-zero value.
JMP (jump): It includes various instructions to implement Jump functionality to instruction
stored in any of the registers.
JE (Jump if Equal): It includes various instructions to implement ‘Jump if Equal ’
functionality to instruction stored in any of the registers.
Jne (Jump if Not Equal): It includes various instructions to implement ‘Jump if not Equal to
’ functionality to instruction stored in any of the registers.
6. JGE (Jump if greater than): It includes various instructions to implement ‘Jump if Greater
than ’ functionality to instruction stored in any of the registers.
JLE (Jump if lesser than): It includes various instructions to implement ‘Jump if Lesser
than’ functionality to instruction stored in any of the registers.
Misc: This category includes various miscellaneous instructions like taking an explicit input
and storing it onto the stack, printing a result, incrementing IP, sleep and also the default
instruction for an invalid opcode.
1.7 Run( ) Function
The main component of the processor is the execution unit. In different processor
architectures the opcodes are differently delivered to the execution unit where it is finally
executed and the different components are triggered.
In our implementation this unit is implemented by the RUN( ) function. The run function
begins with fetching the next instruction, which is then decoded by looking up from a switch
table and is then as per the case particular operation is performed. And the values of the
different components get altered. This component is the backbone of the architecture and
performs all the functions.
It has a special variable called OPCODE which holds the instruction to be executed next, the
data type for OPCODE is unsigned char.
1.8 Other Design Specifics
The processor has been design with a motivation of slowing down reversing, and as a
common practice there are many packing routines which might be coded on the architectures,
however for such programs dynamically more memory has to be allocated, which is
implemented in this architecture via instruction 0xC9.
In real world stack implementation we are able to read a particular value from the stack by
giving an offset to the ESP or EBP without having changed the ESP, similarly our
architecture supports the instructions to perform this action.