The document provides an overview of the ELF (Executable and Linkable Format) file format used by most Unix operating systems. It discusses how ELF files contain sections and segments that provide information to linkers and loaders. Specifically, it explains that sections contain code and data and are used by linkers to connect pieces at compile time, while segments define memory permissions and locations and are used by loaders to map the binary into memory at runtime. It also gives examples of common sections like .text, .data, .rodata, and describes how dynamic linking with the PLT and GOT tables allows functions to be resolved at load time.
The document discusses the ELF file format and dynamic linking process. It describes the ELF header, program header table, and segments that make up an ELF file. The dynamic linker loads segments into memory, resolves symbols using hash tables, and initializes shared libraries and the main executable in the correct order. Symbol resolution involves determining the symbol hash, searching hash buckets in each library, and comparing names.
Program Structure in GNU/Linux (ELF Format)Varun Mahajan
The document discusses the processing of a user program in a GNU/Linux system. It describes the steps of preprocessing, compilation, assembly and linking. It then explains the ELF format used in object files, including the ELF header, program header table, section header table, and common sections like .text, .data, .bss, .symtab, and .strtab. Key details covered in each section include type of code or data, addresses, sizes, and other attributes.
The document discusses the process from compiling source code to executing a program. It covers preprocessing, compilation, assembly, linking, and the ELF file format. Preprocessing handles macros and conditionals. Compilation translates to assembly code. Assembly generates machine code. Linking combines object files and resolves symbols statically or dynamically using libraries. The ELF file format organizes machine code and data into sections in the executable.
FISL XIV - The ELF File Format and the Linux LoaderJohn Tortugo
These are the slides used in a lecture I gave in the XIV International Board on Free Software. In this lecture I gave a brief overview of the ELF specification (the ELF specification is a document describing the format of executable, shared libraries and relocatable objects files used in Linux and many others operating systems) and the Linux dynamic loader (which is a program that acts together with the OS to create and initialize a program address space among others tasks).
The document discusses how the Linux dynamic loader and LD_PRELOAD environment variable can be exploited to intercept and modify the behavior of shared library functions at runtime. It provides examples of how this technique could be used to implement a man-in-the-middle attack on OpenSSH authentication, log passwords, and extend the functionality of system programs like 'cat'. While powerful for debugging, this approach also has security disadvantages as it requires access to the executable and works only on exported symbols.
A hands-on introduction to the ELF Object file formatrety61
In our 6th semester we developed miASMa - a 2 pass Macro Assembler for an x86 machine. miASMa generates Relocatable Object Files that conforming to the ELF Format.
ELF (Executable and Linkable Format) is the standard file format for executable files, object code, and shared libraries in Linux. An ELF file contains an ELF header, program header table, and section header table. It supports relocatable object files (.o files), shared object files (.so files), and executable files. The file contains various sections like .text, .data, .bss, .rel, .symtab, and .strtab that contain code, initialized data, uninitialized data, relocation information, symbols, and strings respectively.
This PPT discusses the concept of Dynamic Linker as in Linux and its porting to Solaris ARM platform. It starts from the very basics of linking process
The document discusses the ELF file format and dynamic linking process. It describes the ELF header, program header table, and segments that make up an ELF file. The dynamic linker loads segments into memory, resolves symbols using hash tables, and initializes shared libraries and the main executable in the correct order. Symbol resolution involves determining the symbol hash, searching hash buckets in each library, and comparing names.
Program Structure in GNU/Linux (ELF Format)Varun Mahajan
The document discusses the processing of a user program in a GNU/Linux system. It describes the steps of preprocessing, compilation, assembly and linking. It then explains the ELF format used in object files, including the ELF header, program header table, section header table, and common sections like .text, .data, .bss, .symtab, and .strtab. Key details covered in each section include type of code or data, addresses, sizes, and other attributes.
The document discusses the process from compiling source code to executing a program. It covers preprocessing, compilation, assembly, linking, and the ELF file format. Preprocessing handles macros and conditionals. Compilation translates to assembly code. Assembly generates machine code. Linking combines object files and resolves symbols statically or dynamically using libraries. The ELF file format organizes machine code and data into sections in the executable.
FISL XIV - The ELF File Format and the Linux LoaderJohn Tortugo
These are the slides used in a lecture I gave in the XIV International Board on Free Software. In this lecture I gave a brief overview of the ELF specification (the ELF specification is a document describing the format of executable, shared libraries and relocatable objects files used in Linux and many others operating systems) and the Linux dynamic loader (which is a program that acts together with the OS to create and initialize a program address space among others tasks).
The document discusses how the Linux dynamic loader and LD_PRELOAD environment variable can be exploited to intercept and modify the behavior of shared library functions at runtime. It provides examples of how this technique could be used to implement a man-in-the-middle attack on OpenSSH authentication, log passwords, and extend the functionality of system programs like 'cat'. While powerful for debugging, this approach also has security disadvantages as it requires access to the executable and works only on exported symbols.
A hands-on introduction to the ELF Object file formatrety61
In our 6th semester we developed miASMa - a 2 pass Macro Assembler for an x86 machine. miASMa generates Relocatable Object Files that conforming to the ELF Format.
ELF (Executable and Linkable Format) is the standard file format for executable files, object code, and shared libraries in Linux. An ELF file contains an ELF header, program header table, and section header table. It supports relocatable object files (.o files), shared object files (.so files), and executable files. The file contains various sections like .text, .data, .bss, .rel, .symtab, and .strtab that contain code, initialized data, uninitialized data, relocation information, symbols, and strings respectively.
This PPT discusses the concept of Dynamic Linker as in Linux and its porting to Solaris ARM platform. It starts from the very basics of linking process
The document discusses linkers and loaders, describing their functions in combining object files into executable files. It covers the ELF format, static vs dynamic linking, and how executable files are run using static or dynamic linkers. Key points include how static linkers resolve symbols and perform relocation, while dynamic linkers use shared libraries and handle relocation at runtime via the dynamic linker.
This document contains information about Lex, Yacc, Flex, and Bison. It provides definitions and descriptions of each tool. Lex is a lexical analyzer generator that reads input specifying a lexical analyzer and outputs C code implementing a lexer. Yacc is a parser generator that takes a grammar description and snippets of C code as input and outputs a shift-reduce parser in C. Flex is a tool similar to Lex for generating scanners based on regular expressions. Bison is compatible with Yacc and can be used to develop language parsers.
This seminar presentation provides an overview of YACC (Yet Another Compiler Compiler). It discusses what compilers do, the structure of compilers including scanners, parsers, semantic routines, code generators and optimizers. It then reviews parsers and how YACC works by taking a grammar specification and generating C code for a parser. YACC declarations and commands are also summarized.
The document discusses different types of loaders and their functions. It explains that a loader takes object code as input and prepares it for execution by performing allocation of memory, linking of symbolic references, relocation of addresses, and loading the machine code into memory. It describes various types of loaders like compile-and-go, absolute, bootstrap, and relocating loaders. A relocating loader is able to load a program into memory wherever there is space, unlike an absolute loader which loads programs at fixed addresses.
The document discusses loaders, which are system software programs that perform the loading function of placing a program into memory for execution. There are several types of loaders: compile-and-go loaders directly place assembled code into memory; absolute loaders place code at specified addresses; relocating loaders allow code to be loaded at different addresses and combine programs. Relocating loaders output object code, symbol tables, and relocation information to perform allocation, relocation, linking, and loading separately from assembly. Direct-linking loaders provide more flexibility by allowing multiple program and data segments with intersegment references.
This document provides an introduction to using Lex and Yacc to build compilers. Lex is used to generate a lexical analyzer from input patterns, which converts strings to tokens. Yacc generates a parser from a grammar, which analyzes tokens to build a syntax tree. The document describes building a calculator as an example, which can be converted to a compiler by changing the code generation. It also discusses additional Lex and Yacc features like strings, reserved words, debugging, recursion, and attributes.
The document discusses ANSI C macros and the C preprocessor. It explains that the preprocessor allows constants and macros to be defined which makes writing C programs easier. Key points covered include:
1. How the preprocessor works by modifying the source code before compiling based on directives.
2. Common directives like #define, #include, #ifdef and macros with and without arguments.
3. How macros replace symbols and can be defined in terms of other macros.
4. The use of header files and standard library header files.
5. Other directives like #undef, #if and predefined macros like __DATE__ and __FILE__.
Loaders are system software programs that perform the loading function of placing programs into memory for execution. The fundamental processes of loaders include allocation of memory space, linking of object programs, relocation to allow loading at different addresses, and loading the object program into memory. There are different types of loaders such as compile-and-go loaders, absolute loaders, and linking loaders. Compile-and-go loaders directly place assembled code into memory locations for execution, while absolute loaders place machine code onto cards to later load into memory. Linking loaders allow for multiple program segments and external references between segments through the use of symbol tables and relocation information.
This is the fourteenth (and last for now) set of slides from a Perl programming course that I held some years ago.
I want to share it with everyone looking for intransitive Perl-knowledge.
A table of content for all presentations can be found at i-can.eu.
The source code for the examples and the presentations in ODP format are on https://github.com/kberov/PerlProgrammingCourse
The document discusses the Portable Executable (PE) file format used in Windows operating systems. It describes the basic structure of a PE file which includes sections for executable code, data, resources, exports, imports, and debugging. It also explains the DOS header and stub, the PE file header containing signatures and metadata, and the image and optional headers containing addresses and alignments. Sections are described as containing code, data, resources, and other essential information.
The document discusses Perl programming and is divided into 5 modules: 1) Introduction to Perl, 2) Regular Expressions, 3) File Handling, 4) Connecting to Databases, and 5) Introduction to Perl Programming. It provides an overview of Perl variables, data types, operators, and basic programming structures. It also covers installing Perl, Perl modules, and interacting with files and databases.
This document discusses linking in the MS-DOS operating system. It describes how linking involves combining various pieces of code and data into a single file that can be loaded into memory and executed. The document outlines the role of linkers in automatically performing linking. It also provides details on the object module format and record types in MS-DOS, and describes how a linker would be designed for MS-DOS, including its invocation command format, linking and relocation processes, and use of data structures.
This document provides an introduction to Yacc and Lex, which are parser and lexer generator tools. Yacc is used to describe the grammar of a language and automatically generate a parser. The user provides grammar rules in BNF format. Lex is used to generate a lexer (also called a tokenizer) that recognizes tokens in the input based on regular expressions. It returns tokens to the parser. The document gives examples of Yacc and Lex grammar files and explains how they are compiled and used to build a parser for an input language.
loader and linker are both system software which capable of loads the object code, assembled by an assembler, (loader) and link a different kind of block of a huge program. both software works at the bottom of the operation (i.e. closer to the hardware). in fact, both have machine dependent and independent features.
Assemblers translate assembly language into machine code object files. Linkers merge object files and library routines into executable files by resolving references and assigning memory locations. Loaders bring executables into memory and start program execution by initializing registers and jumping to the main routine.
This document discusses low-level input/output in C programming. It explains that low-level I/O provides direct access to files and devices using functions like open(), close(), read(), write(), and lseek(). These functions take a file descriptor as a parameter and allow accessing files sequentially or randomly. The document also covers error handling using errno values and differentiates between high-level and low-level I/O.
Before 1975 writing a compiler was a very time-consuming process. Then Lesk [1975] and Johnson published papers on lex and YACC. These utilities/components greatly simplify compiler writing. We’ve used flex and bison to compile the code.
Description of all types of Loaders from System programming subjects.
eg. Compile-Go Loader
General Loader
Absolute Loader
Relocating Loader
Practical Relocating Loader
Linking Loader
Linker Vs. Loader
general relocatable loader
The document provides an overview of yacc (Yet Another Compiler Compiler), which is a tool that parses a stream of tokens according to a user-specified grammar. It describes the structure of a yacc file, which includes definitions, rules, and code sections. It also discusses how yacc interacts with lex to generate tokens, and how values can be returned from lex to yacc using the yylval variable. An example calculator program is provided to demonstrate how yacc can be used to parse arithmetic expressions by defining grammar rules and associating actions with parsing steps.
The document discusses the "Hello World" program in C and assembly languages. It provides the C code, compiles and runs it using GCC and LLVM, and examines the output assembly code, object file and executable using various Linux tools like objdump, readelf, nm, and strace. It explains concepts like sections, segments, symbol tables, relocation records, and the role of linker and loader.
The document discusses linkers and loaders, describing their functions in combining object files into executable files. It covers the ELF format, static vs dynamic linking, and how executable files are run using static or dynamic linkers. Key points include how static linkers resolve symbols and perform relocation, while dynamic linkers use shared libraries and handle relocation at runtime via the dynamic linker.
This document contains information about Lex, Yacc, Flex, and Bison. It provides definitions and descriptions of each tool. Lex is a lexical analyzer generator that reads input specifying a lexical analyzer and outputs C code implementing a lexer. Yacc is a parser generator that takes a grammar description and snippets of C code as input and outputs a shift-reduce parser in C. Flex is a tool similar to Lex for generating scanners based on regular expressions. Bison is compatible with Yacc and can be used to develop language parsers.
This seminar presentation provides an overview of YACC (Yet Another Compiler Compiler). It discusses what compilers do, the structure of compilers including scanners, parsers, semantic routines, code generators and optimizers. It then reviews parsers and how YACC works by taking a grammar specification and generating C code for a parser. YACC declarations and commands are also summarized.
The document discusses different types of loaders and their functions. It explains that a loader takes object code as input and prepares it for execution by performing allocation of memory, linking of symbolic references, relocation of addresses, and loading the machine code into memory. It describes various types of loaders like compile-and-go, absolute, bootstrap, and relocating loaders. A relocating loader is able to load a program into memory wherever there is space, unlike an absolute loader which loads programs at fixed addresses.
The document discusses loaders, which are system software programs that perform the loading function of placing a program into memory for execution. There are several types of loaders: compile-and-go loaders directly place assembled code into memory; absolute loaders place code at specified addresses; relocating loaders allow code to be loaded at different addresses and combine programs. Relocating loaders output object code, symbol tables, and relocation information to perform allocation, relocation, linking, and loading separately from assembly. Direct-linking loaders provide more flexibility by allowing multiple program and data segments with intersegment references.
This document provides an introduction to using Lex and Yacc to build compilers. Lex is used to generate a lexical analyzer from input patterns, which converts strings to tokens. Yacc generates a parser from a grammar, which analyzes tokens to build a syntax tree. The document describes building a calculator as an example, which can be converted to a compiler by changing the code generation. It also discusses additional Lex and Yacc features like strings, reserved words, debugging, recursion, and attributes.
The document discusses ANSI C macros and the C preprocessor. It explains that the preprocessor allows constants and macros to be defined which makes writing C programs easier. Key points covered include:
1. How the preprocessor works by modifying the source code before compiling based on directives.
2. Common directives like #define, #include, #ifdef and macros with and without arguments.
3. How macros replace symbols and can be defined in terms of other macros.
4. The use of header files and standard library header files.
5. Other directives like #undef, #if and predefined macros like __DATE__ and __FILE__.
Loaders are system software programs that perform the loading function of placing programs into memory for execution. The fundamental processes of loaders include allocation of memory space, linking of object programs, relocation to allow loading at different addresses, and loading the object program into memory. There are different types of loaders such as compile-and-go loaders, absolute loaders, and linking loaders. Compile-and-go loaders directly place assembled code into memory locations for execution, while absolute loaders place machine code onto cards to later load into memory. Linking loaders allow for multiple program segments and external references between segments through the use of symbol tables and relocation information.
This is the fourteenth (and last for now) set of slides from a Perl programming course that I held some years ago.
I want to share it with everyone looking for intransitive Perl-knowledge.
A table of content for all presentations can be found at i-can.eu.
The source code for the examples and the presentations in ODP format are on https://github.com/kberov/PerlProgrammingCourse
The document discusses the Portable Executable (PE) file format used in Windows operating systems. It describes the basic structure of a PE file which includes sections for executable code, data, resources, exports, imports, and debugging. It also explains the DOS header and stub, the PE file header containing signatures and metadata, and the image and optional headers containing addresses and alignments. Sections are described as containing code, data, resources, and other essential information.
The document discusses Perl programming and is divided into 5 modules: 1) Introduction to Perl, 2) Regular Expressions, 3) File Handling, 4) Connecting to Databases, and 5) Introduction to Perl Programming. It provides an overview of Perl variables, data types, operators, and basic programming structures. It also covers installing Perl, Perl modules, and interacting with files and databases.
This document discusses linking in the MS-DOS operating system. It describes how linking involves combining various pieces of code and data into a single file that can be loaded into memory and executed. The document outlines the role of linkers in automatically performing linking. It also provides details on the object module format and record types in MS-DOS, and describes how a linker would be designed for MS-DOS, including its invocation command format, linking and relocation processes, and use of data structures.
This document provides an introduction to Yacc and Lex, which are parser and lexer generator tools. Yacc is used to describe the grammar of a language and automatically generate a parser. The user provides grammar rules in BNF format. Lex is used to generate a lexer (also called a tokenizer) that recognizes tokens in the input based on regular expressions. It returns tokens to the parser. The document gives examples of Yacc and Lex grammar files and explains how they are compiled and used to build a parser for an input language.
loader and linker are both system software which capable of loads the object code, assembled by an assembler, (loader) and link a different kind of block of a huge program. both software works at the bottom of the operation (i.e. closer to the hardware). in fact, both have machine dependent and independent features.
Assemblers translate assembly language into machine code object files. Linkers merge object files and library routines into executable files by resolving references and assigning memory locations. Loaders bring executables into memory and start program execution by initializing registers and jumping to the main routine.
This document discusses low-level input/output in C programming. It explains that low-level I/O provides direct access to files and devices using functions like open(), close(), read(), write(), and lseek(). These functions take a file descriptor as a parameter and allow accessing files sequentially or randomly. The document also covers error handling using errno values and differentiates between high-level and low-level I/O.
Before 1975 writing a compiler was a very time-consuming process. Then Lesk [1975] and Johnson published papers on lex and YACC. These utilities/components greatly simplify compiler writing. We’ve used flex and bison to compile the code.
Description of all types of Loaders from System programming subjects.
eg. Compile-Go Loader
General Loader
Absolute Loader
Relocating Loader
Practical Relocating Loader
Linking Loader
Linker Vs. Loader
general relocatable loader
The document provides an overview of yacc (Yet Another Compiler Compiler), which is a tool that parses a stream of tokens according to a user-specified grammar. It describes the structure of a yacc file, which includes definitions, rules, and code sections. It also discusses how yacc interacts with lex to generate tokens, and how values can be returned from lex to yacc using the yylval variable. An example calculator program is provided to demonstrate how yacc can be used to parse arithmetic expressions by defining grammar rules and associating actions with parsing steps.
The document discusses the "Hello World" program in C and assembly languages. It provides the C code, compiles and runs it using GCC and LLVM, and examines the output assembly code, object file and executable using various Linux tools like objdump, readelf, nm, and strace. It explains concepts like sections, segments, symbol tables, relocation records, and the role of linker and loader.
1. Embedded C requires compilers to create executable files that can be downloaded and run on microcontrollers, while C compilers typically generate code for operating systems on desktop computers.
2. Embedded systems often have real-time constraints and limited memory and other resources that require more optimization, unlike most desktop applications.
3. Programming for embedded systems focuses on optimally using limited resources and satisfying timing requirements using basic C constructs and function libraries.
1. Embedded C requires compilers to create files that can be downloaded and run on microcontrollers, while C compilers typically generate OS-dependent executables for desktop computers.
2. Embedded systems often have real-time constraints and limited memory/power that are usually not concerns for desktop applications.
3. Programming for embedded systems requires optimally using limited resources and satisfying real-time constraints, which is done using the basic C syntax and function libraries but with an embedded/hardware-oriented mindset.
The document provides an introduction to assembly language programming. It explains that assembly language uses mnemonics to represent machine instructions, making programs more readable compared to machine code. An assembler is needed to translate assembly code into executable object code. Assembly language provides direct access to hardware and can be faster than high-level languages, though it is more difficult to program and maintain.
The document provides an overview of the Analog Devices Blackfin processor BF532. Some key points:
- The BF532 is a high-performance embedded processor designed for audio, video, automotive and other applications. It combines a 32-bit RISC instruction set with dual 16-bit MAC units and 8-bit video processing.
- It features a maximum clock speed of 600MHz, two 16-bit MACs, two 40-bit ALUs, four 8-bit video ALUs, and 148KB of on-chip memory. It supports interfaces like SPI, parallel ports, UART and has peripherals like timers and DMA.
- The document discusses the Blackfin architecture
HES2011 - James Oakley and Sergey bratus-Exploiting-the-Hard-Working-DWARFHackito Ergo Sum
The document describes how DWARF bytecode, included in GCC-compiled binaries to support exception handling, can be exploited to insert trojan payloads. DWARF bytecode interpreters are included in the standard C++ runtime and are Turing-complete, allowing the bytecode to perform arbitrary computations by influencing program flow. A demonstration shows how DWARF bytecode can be used to hijack exceptions and execute malicious payloads without requiring native code.
Design of 32 Bit Processor Using 8051 and Leon3 (Progress Report)Talal Khaliq
This document outlines the design and development of a general purpose processor over a one year period. It will involve starting with an open source 8-bit 8051 processor, implementing it on an FPGA, and adding custom peripherals. It will then move to a more advanced 32-bit Leon3 processor, using software tools to simulate and synthesize it on an FPGA. The goal is to explore processor architecture and obtain a synthesizable core to add further components for improved functionality. Milestones include understanding the 8051 architecture, adding a peripheral, and setting up the Leon3 toolchain and memory management unit.
This document provides a user guide for the Wishbone serializer core, which establishes a transparent Wishbone bridge between two FPGAs using high-speed serial transceivers. The core supports simultaneous communication between a master on one FPGA and a slave on the other FPGA. It contains a Wishbone control logic block, asynchronous FIFOs to handle the two clock domains, and uses an Aurora 8B/10B core for serial transmission. The guide describes the files and architecture of the core.
This document discusses bypassing address space layout randomization (ASLR) protections to execute shellcode on the stack. It begins with an overview of stack-based buffer overflows and modern protections like non-executable stacks. It then describes using return-oriented programming (ROP) techniques like ret2libc to hijack control flow and call library functions like system() to spawn a shell. Specifically, it outlines overwriting a return address to call mprotect() to make the stack executable, then jumping to shellcode on the stack. The document provides example exploit code and steps to find needed addresses in memory.
The document discusses bypassing address space layout randomization (ASLR) on Linux. It begins with a refresher on buffer overflows and modern protections like ASLR and DEP. It then explores finding fixed addresses in the .text section that are not subject to ASLR to redirect execution, such as calls and jumps to registers. The document shows searching binaries for these instruction sequences and checking register values to leverage them for exploiting a vulnerable program while ASLR is enabled.
Defcon 22 - Stitching numbers - generating rop payloads from in memory numbersAlexandre Moneger
The document discusses generating return-oriented programming (ROP) payloads using numbers found in memory. It proposes a technique called "number stitching" which involves representing shellcode as increasing numeric deltas, finding numbers in memory to build those values, and using them to reconstruct the shellcode on a controlled stack. This solves the problem of finding long byte sequences or gadgets, by instead stitching together smaller numbers available in memory. The document outlines solving the "coin change problem" to efficiently find combinations of numbers that sum to each shellcode chunk value.
The document discusses various techniques for debugging Linux kernel modules and device drivers, including:
1) Using printk statements to output debugging messages from within the kernel.
2) Examining the interaction between kernel and userspace using strace to see system calls.
3) Adding entries to /proc filesystem for additional output.
4) Enabling kernel debugging with kgdb or hardware debuggers.
5) Common error types like kernel panics and oops messages that indicate issues.
Troubleshooting Linux Kernel Modules And Device DriversSatpal Parmar
The document discusses various techniques for debugging Linux kernel modules and device drivers, including:
1) Using printk statements to output debug messages from kernel space.
2) Watching system calls with strace to debug interactions between user and kernel space.
3) Adding /proc file system entries and write functions to dynamically modify driver values at runtime.
4) Enabling source-level debugging with tools like kgdb to debug at the level of C source code.
First Steps Developing Embedded Applications using Heterogeneous Multi-core P...Toradex
Read our blog for the latest on demystifying the development of embedded systems using Heterogeneous Multicore Processing architecture powered SoCs! This might provide you with the jump start you need for your development. https://www.toradex.com/blog/first-steps-developing-embedded-applications-using-heterogeneous-multicore-processors
The document discusses embedded systems and ARM processors. It provides examples of common devices that use ARM processors, such as smartphones, tablets, smartwatches and fitness trackers. It then explains some key aspects of computer architecture, assembly language, and how programs are executed on a processor at the machine code level. This includes details on memory organization, registers, the fetch-decode-execute cycle, and pipelining. An example of calculating the sum of an array in C and at the assembly level is also provided.
The document discusses assembly language programming. It begins by explaining that assembly language is a low-level programming language useful for embedded systems and device drivers due to its close correspondence to machine code and ability to optimize for speed and size. The document then provides details on memory organization, addressing modes, interrupts, and an example program to test the program status word register in assembly language.
This document discusses firmware development for ARM processors. It covers the toolchain used, including RealView compilers and linkers. It discusses the embedded development process from simple "hello world" programs to standalone applications. Key topics covered include retargeting the C library, memory mapping, scatter loading, and ordering code and data through linker directives.
Similar to 06 - ELF format, knowing your friend (20)
Quick talk on how to leverage scapy-ssl_tls to perform TLS 1.3 testing. Covers which area of the stack are less vulnerable with TLS 1.3 as opposed to 1.2.
BSides LV 2016 - Beyond the tip of the iceberg - fuzzing binary protocols for...Alexandre Moneger
This presentation shows that code coverage guided fuzzing is possible in the context of network daemon fuzzing.
Some fuzzers are blackbox while others are protocol aware. Even ones which are made protocol aware, fuzzer writers typically model the protocol specification and implement packet awareness logic in the fuzzer. Unfortunately, just because the fuzzer is protocol aware, it does not guarantee that sufficient code paths have been reached.
The presentation deals with specific scenarios where the target protocol is completely unknown (proprietary) and no source code or protocol specs are accessible. The tool developed builds a feedback loop between the client and the server components using the concept of "gate functions". A gate function triggers monitoring. The pintool component tracks the binary code coverage for all the functions untill it reaches an exit gate. By instrumenting such gated functions, the tool is able to measure code coverage during packet processing.
This document summarizes a presentation about pentesting custom TLS stacks. It discusses using the scapy-ssl_tls tool to craft and analyze TLS packets in order to evaluate the security of custom TLS implementations. The presentation covers TLS protocol basics, features of scapy-ssl_tls like packet parsing and crypto hooks, and techniques for analyzing areas like supported versions/ciphers, the TLS state machine, Diffie-Hellman parameters, side channels, fragmentation, and more. It aims to provide a way to efficiently reproduce TLS attacks and help test responses to vulnerabilities.
This document discusses the importance of instrumentation for effective fuzzing. It notes that while fuzzing may seem simple, it actually requires significant effort, target code adaptation, and input corpus minimization. Instrumentation is key to determining code coverage, finding new paths, and prioritizing inputs that lead to crashes or new code coverage. The document provides examples of instrumentation techniques using binary rewriting and hardware features and discusses how to set up fuzzing when source code is available versus when it is not. It also outlines some current gaps in fuzzing techniques.
This document discusses padding oracle attacks against RSA encryption. It begins with an overview of textbook RSA and how padding like PKCS#1 v1.5 addresses issues like predictability and malleability. It then explains what a padding oracle is and how the Bleichenbacher attack allows decrypting ciphertexts by querying a padding oracle repeatedly. The document demonstrates generating faulty padding, sending requests to a padding oracle, and using the responses to conduct the Bleichenbacher attack and recover the plaintext. It emphasizes that padding oracles are a real vulnerability and outlines approaches to mitigate risks.
The document discusses buffer overflow attacks and techniques for exploiting them on a vulnerable C program called "ch3". It describes how the program can be compiled without protections, how to determine the offset needed to overwrite the return address, and how to craft an exploit by placing shellcode and the address of the buffer in the input to redirect execution and gain a shell. Variations for dealing with small buffers or unpredictable addresses are also covered.
The document discusses various return-oriented programming (ROP) countermeasures, including position independent code (PIE) which randomizes the base address of all segments, making it difficult to predict gadget addresses and rely on bruteforcing. PIE imposes around a 25% performance overhead but is not widely used. Full RELRO prevents PLT/GOT overwrites but does not prevent GOT dereferencing. Stack pivot and return detection are difficult to implement outside of research. For exploitation concerns, PIE is the best available option.
Return oriented programming (ROP) allows an attacker to bypass address space layout randomization (ASLR) and data execution prevention (DEP). It works by identifying small "gadgets" in a program's code that end with a return instruction. These gadgets can be stitched together to perform operations or redirect execution flow. First, gadgets are found in the program using tools like ROPeMe or objdump. Useful gadgets include those that load registers from memory or call functions indirectly. The gadgets can then be chained to build ROP payloads that copy shellcode into memory and pivot the stack to execute it.
Buffer overflow exploitation without operating system protections is a well understood subject. But how does one achieve the same results with all protections enabled (N/X, ASLR, …). Hint: re-use what the vulnerable binary offers you.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
artificial intelligence and data science contents.pptxGauravCar
What is artificial intelligence? Artificial intelligence is the ability of a computer or computer-controlled robot to perform tasks that are commonly associated with the intellectual processes characteristic of humans, such as the ability to reason.
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Artificial intelligence (AI) | Definitio
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.