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Taint Checking
Taint checking is a feature in some computer programming languages, such as Perl, Ruby or Ballerina designed to increase security by preventing malicious users from executing commands on a host computer. Taint checks highlight specific security risks primarily associated with web sites which are attacked using techniques such as SQL injection or buffer overflow attack approaches. Overview The concept behind taint checking is that any variable that can be modified by an outside user (for example a variable set by a field in a web form) poses a potential security risk. If that variable is used in an expression that sets a second variable, that second variable is now also suspicious. The taint checking tool can then proceed variable by variable forming a list of variables which are potentially influenced by outside input. If any of these variables is used to execute dangerous commands (such as direct commands to a SQL database or the host computer operating system), the taint check ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms (usually in a chosen programming language, commonly referred to as coding). The source code of a program is written in one or more languages that are intelligible to programmers, rather than machine code, which is directly executed by the central processing unit. The purpose of programming is to find a sequence of instructions that will automate the performance of a task (which can be as complex as an operating system) on a computer, often for solving a given problem. Proficient programming thus usually requires expertise in several different subjects, including knowledge of the application domain, specialized algori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-interference (security)
Noninterference is a strict multilevel security policy model, first described by Goguen and Meseguer in 1982, and amplified further in 1984. Introduction In simple terms, a computer is modeled as a machine with inputs and outputs. Inputs and outputs are classified as either ''low'' (low sensitivity, not highly classified) or ''high'' (sensitive, not to be viewed by uncleared individuals). A computer has the noninterference property if and only if any sequence of low inputs will produce the same low outputs, regardless of what the high level inputs are. That is, if a low (uncleared) user is working on the machine, it will respond in exactly the same manner (on the low outputs) whether or not a high (cleared) user is working with sensitive data. The low user will not be able to acquire any information about the activities (if any) of the high user. Formal expression Let M be a memory configuration, and let M_\text and M_H be the projection of the memory M to the low and high parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaScript
JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side for Web page, webpage behavior, often incorporating third-party Library (computing), libraries. All major Web browser, web browsers have a dedicated JavaScript engine to execute the Source code, code on User (computing), users' devices. JavaScript is a High-level programming language, high-level, often Just-in-time compilation, just-in-time compiled language that conforms to the ECMAScript standard. It has dynamic typing, Prototype-based programming, prototype-based object-oriented programming, object-orientation, and first-class functions. It is Programming paradigm, multi-paradigm, supporting Event-driven programming, event-driven, functional programming, functional, and imperative programming, imperative programming paradigm, programmin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Netscape
Netscape Communications Corporation (originally Mosaic Communications Corporation) was an American independent computer services company with headquarters in Mountain View, California and then Dulles, Virginia. Its Netscape web browser was once dominant but lost to Internet Explorer and other competitors in the so-called first browser war, with its market share falling from more than 90 percent in the mid-1990s to less than 1 percent in 2006. An early Netscape employee Brendan Eich created the JavaScript programming language, the most widely used language for client-side scripting of web pages and a founding engineer of Netscape Lou Montulli created HTTP cookies. The company also developed SSL which was used for securing online communications before its successor TLS took over. Netscape stock traded from 1995 until 1999 when the company was acquired by AOL in a pooling-of-interests transaction ultimately worth US$10 billion. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Setuid
The Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ... access rights flags setuid and setgid (short for ''set user identity'' and ''set group identity'') allow users to run an executable with the file system permissions of the executable's owner or group respectively and to change behaviour in directories. They are often used to allow users on a computer system to run programs with temporarily elevated privileges in order to perform a specific task. While the assumed user id or group id privileges provided are not always elevated, at a minimum they are specific. The flags setuid and setgid are needed for tasks that require different privileges than what the user is normally granted, such as the ability to alter system files or databases to change their login password. Some of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perl DBI
In computing, the Perl DBI (Perl Database Interface) offers a standardized way for programmers using the Perl programming language to embed database communication within their programs. The latest DBI module for Perl from CPAN can run on a range of operating systems. History In September 1992, Buzz Moschetti, creator of interperl, observed that several bespoke compiled extensions of perl (at the time, perl version 4 or more commonly perl4) featuring connectivity to popular SQL-based databases had emerged, namely Interbase, Informix, Oracle, and Sybase. He engaged the authors of these bespoke versions with the idea of creating a common interface layer to the databases separate from the specifics of the underlying implementations. Tim Bunce took the lead and began specifying what would become the DBI module in 1994 upon the release of perl5 which eliminated the need for bespoke compilation in favor of dynamic, invocation time loading of libraries (modules). the Perl communit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prepared Statement
In database management systems (DBMS), a prepared statement, parameterized statement, or parameterized query is a feature used to pre-compile SQL code, separating it from data. Benefits of prepared statements are: * efficiency, because they can be used repeatedly without re-compiling * security, by reducing or eliminating SQL injection attacks A prepared statement takes the form of a pre-compiled template into which constant values are substituted during each execution, and typically use SQL DML statements such as INSERT, SELECT, or UPDATE. A common workflow for prepared statements is: # Prepare: The application creates the statement template and sends it to the DBMS. Certain values are left unspecified, called ''parameters'', ''placeholders'' or ''bind variables'' (labelled "?" below): #: # Compile: The DBMS compiles (parses, optimizes and translates) the statement template, and stores the result without executing it. # Execute: The application supplies (or ''binds'') val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
String Literal
A string literal (computer programming), literal or anonymous string is a String (computer science), string value in the source code of a computer program. Modern Computer programming, programming languages commonly use a quoted sequence of characters, formally "#Bracketed delimiters, bracketed delimiters", as in x = "foo", where "foo" is a string Literal (computer programming), literal with value foo. Methods such as #Escape sequences, escape sequences can be used to avoid the problem of #Delimiter collision, delimiter collision (issues with brackets) and allow the delimiters to be embedded in a string. There are many alternate notations for specifying string literals especially in complicated cases. The exact notation depends on the programming language in question. Nevertheless, there are general guidelines that most modern programming languages follow. Syntax Bracketed delimiters Most modern programming languages use delimiter#Bracket delimiters, bracket delimiters (also ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Flow (information Theory)
Information flow in an information theoretical context is the transfer of information from a variable x to a variable y in a given process. Not all flows may be desirable; for example, a system should not leak any confidential information (partially or not) to public observers--as it is a violation of privacy on an individual level, or might cause major loss on a corporate level. Introduction Securing the data manipulated by computing systems has been a challenge in the past years. Several methods to limit the information disclosure exist today, such as access control lists, firewalls, and cryptography. However, although these methods do impose limits on the information that is released by a system, they provide no guarantees about information ''propagation''.Andrei Sabelfeld and Andrew C. Myers. Language-Based Information-Flow Security. IEEE Journal on Selected Areas in Communications, 21(1), Jan. 2003. For example, access control lists of file systems prevent unauthorized fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a ''host machine'', and each virtual machine is called a ''guest machine''. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances (usually called ''containers'') must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Languages
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming language is usually split into the two components of syntax (form) and semantics (meaning), which are usually defined by a formal language. Some languages are defined by a specification document (for example, the C programming language is specified by an ISO Standard) while other languages (such as Perl) have a dominant implementation that is treated as a reference. Some languages have both, with the basic language defined by a standard and extensions taken from the dominant implementation being common. Programming language theory is the subfield of computer science that studies the design, implementation, analysis, characterization, and classification of programming languages. Definitions There are many considerations when defining w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable (programming)
In computer programming, a variable is an abstract storage location paired with an associated symbolic name, which contains some known or unknown quantity of information referred to as a ''value''; or in simpler terms, a variable is a named container for a particular set of bits or type of data (like integer, float, string etc...). A variable can eventually be associated with or identified by a memory address. The variable name is the usual way to reference the stored value, in addition to referring to the variable itself, depending on the context. This separation of name and content allows the name to be used independently of the exact information it represents. The identifier in computer source code can be bound to a value during run time, and the value of the variable may thus change during the course of program execution. Variables in programming may not directly correspond to the concept of variables in mathematics. The latter is abstract, having no reference to a physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
