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Xhost
In the X Window System, programs run as X clients, and as such they connect to the X display server, possibly via a computer network. Since the network may be accessible to other users, a method for forbidding access to programs run by users different from the one who is logged in is necessary. There are five standard access control mechanisms that control whether a client application can connect to an X display server. They can be grouped in three categories: # access based on host # access based on cookie # access based on user Additionally, like every other network connection, tunneling can be used. Host-based access The host-based access method consists in specifying a set of hosts that are authorized to connect to the X display server. This system has inferior security, as it allows every user who has access to such a host to connect to the display. The xhost program and three X Window System core protocol requests are used to activate this mechanism and to display and ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Window System Core Protocol
The X Window System core protocolRobert W. Scheifler and James Gettys: ''X Window System: Core and extension protocols, X version 11, releases 6 and 6.1'', Digital Press 1996, RFC 1013Grant EdwardsAn Introduction to X11 User Interfaces is the base protocol of the X Window System, which is a networked windowing system for bitmap displays used to build graphical user interfaces on Unix, Unix-like, and other operating systems. The X Window System is based on a client–server model: a single server controls the input/output hardware, such as the screen, the keyboard, and the mouse; all application programs act as clients, interacting with the user and with the other clients via the server. This interaction is regulated by the X Window System core protocol. Other protocols related to the X Window System exist, both built at the top of the X Window System core protocol or as separate protocols. In the X Window System core protocol, only four kinds of packets are sent, asynchro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Window System
The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at version 11 (hence "X11") since September 1987. The X.Org Foundation leads the X project, with the current reference implementation, X.Org Server, available as free and open-source software under the MIT License and similar permissive licenses. Purpose and abilities X is an architecture-independent system for remote graphical user interfaces and input device capabilities. Each person using a networked computer terminal, terminal has the ability to interact with the display with any type of user input device. In its standard distribution it is a complete, albeit simple, display and interface solution which delivers a standard widget toolkit, toolkit and protocol stack for building graphical user interfaces on most Unix-like operating syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Window System Protocols And Architecture
In computing, the X Window System (commonly: X11, or X) is a network-transparent windowing system for bitmap displays. This article details the protocols and technical structure of X11. Client–server model and network transparency X uses a client–server model. An ''X server'' program runs on a computer with a graphical display and communicates with various ''client programs''. The X server acts as a go-between for the user and the client programs, accepting requests on TCP port 6000 plus the display number for graphical output (windows) from the client programs and displaying them to the user (display), and receiving user input (keyboard, mouse) and transmitting it to the client programs. In X, the server runs on the user's computer, while the clients may run on remote machines. This terminology reverses the common notion of client–server systems, where the ''client'' normally runs on the user's local computer and the server runs on the remote computer. The X Window ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSSAPI
The Generic Security Service Application Programming Interface (GSSAPI, also GSS-API) is an application programming interface for programs to access security services. The GSSAPI is an IETF standard that addresses the problem of many similar but incompatible security services in use . Operation The GSSAPI, by itself, does not provide any security. Instead, security-service vendors provide GSSAPI ''implementations'' - usually in the form of libraries installed with their security software. These libraries present a GSSAPI-compatible interface to application writers who can write their application to use only the vendor-independent GSSAPI. If the security implementation ever needs replacing, the application need not be rewritten. The definitive feature of GSSAPI applications is the exchange of opaque messages (''tokens'') which hide the implementation detail from the higher-level application. The client and server sides of the application are written to convey the tokens given t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secure Shell
The Secure Shell Protocol (SSH Protocol) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH was designed for Unix-like operating systems as a replacement for Telnet and unsecured remote Unix shell protocols, such as the Berkeley Remote Shell (rsh) and the related rlogin and rexec protocols, which all use insecure, plaintext methods of authentication, like passwords. Since mechanisms like Telnet and Remote Shell are designed to access and operate remote computers, sending the authentication tokens (e.g. username and password) for this access to these computers across a public network in an unsecured way poses a great risk of 3rd parties obtaining the password and achieving the same level of access to the remote system as the telnet user. Secure Shell mitigates this risk through the use of encryption mechanisms that are intended to hide th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerberos (protocol)
Kerberos () is a computer-network authentication protocol that works on the basis of ''tickets'' to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. Its designers aimed it primarily at a client–server model, and it provides mutual authentication—both the user and the server verify each other's identity. Kerberos protocol messages are protected against eavesdropping and replay attacks. Kerberos builds on symmetric-key cryptography and requires a trusted third party, and optionally may use public-key cryptography during certain phases of authentication.RFC 4556, abstract. Kerberos uses UDP port 88 by default. The protocol was named after the character '' Kerberos'' (or ''Cerberus'') from Greek mythology, the ferocious three-headed guard dog of Hades. History and development The Massachusetts Institute of Technology (MIT) developed Kerberos in 1988 to protect network services provided by Project Athena. Its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SunOS
SunOS is a Unix-branded operating system developed by Sun Microsystems for their workstation and server computer systems from 1982 until the mid-1990s. The ''SunOS'' name is usually only used to refer to versions 1.0 to 4.1.4, which were based on BSD, while versions 5.0 and later are based on UNIX System V Release 4 and are marketed under the brand name '' Solaris''. History SunOS 1 only supported the Sun-2 series systems, including Sun-1 systems upgraded with Sun-2 ( 68010) CPU boards. SunOS 2 supported Sun-2 and Sun-3 ( 68020) series systems. SunOS 4 supported Sun-2 (until release 4.0.3), Sun-3 (until 4.1.1), Sun386i (4.0, 4.0.1 and 4.0.2 only) and Sun-4 ( SPARC) architectures. Although SunOS 4 was intended to be the first release to fully support Sun's new SPARC processor, there was also a SunOS 3.2 release with preliminary support for Sun-4 systems. SunOS 4.1.2 introduced support for Sun's first sun4m-architecture multiprocessor machines (t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Network Computing Remote Procedure Call
__NOTOC__ Open Network Computing (ONC) Remote Procedure Call (RPC), commonly known as Sun RPC is a remote procedure call system. ONC was originally developed by Sun Microsystems in the 1980s as part of their Network File System project. ONC is based on calling conventions used in Unix and the C programming language. It serializes data using the External Data Representation (XDR), which has also found some use to encode and decode data in files that are to be accessed on more than one platform. ONC then delivers the XDR payload using either UDP or TCP. Access to RPC services on a machine are provided via a '' port mapper'' that listens for queries on a well-known port (number 111) over UDP and TCP. ONC RPC version 2 was first described in published in April 1988. In June 1988 it was updated by . Later it was updated by , published in August 1995. , published in May 2009, is the current version. All these documents describe only version 2 and version 1 was not covered by any R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desktop Communication Protocol
Desktop Communication Protocol (DCOP) was an inter-process communication (IPC) daemon by KDE used in K Desktop Environment 3. The design goal for the protocol was to allow applications to interoperate, and share complex tasks. Essentially, DCOP was a ‘remote control’ system, which allowed applications or scripts to enlist the help of other applications. DCOP is built on top of the X11 Inter-Client Exchange protocol. DCOP continues to be used by the K Desktop Environment 3-fork Trinity Desktop Environment. DCOP was replaced by D-Bus, a message bus system heavily influenced by the DCOP and standardized by freedesktop.org, in KDE Software Compilation 4 and later. DCOP model DCOP implements the client–server model, where each application using DCOP is a client and communicates with other clients through the DCOP server. DCOP server functions like a traffic director, dispatching messages/calls to the proper destinations. All clients are peers of each other. Two types of acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secure Copy
Secure copy protocol (SCP) is a means of securely transferring computer files between a local host and a remote server (computing), host or between two remote hosts. It is based on the Secure Shell (SSH) protocol. "SCP" commonly refers to both the Secure Copy Protocol and the program itself. According to OpenSSH developers in April 2019, SCP is outdated, inflexible and not readily fixed; they recommend the use of more modern protocols like SSH File Transfer Protocol, SFTP and rsync for file transfer. As of OpenSSH version 9.0, scp client therefore uses SFTP for file transfers by default instead of the legacy SCP/RCP protocol. Secure Copy Protocol The SCP is a network protocol, based on the BSD rcp (Unix), RCP protocol, which supports file transfers between hosts on a network. SCP uses Secure Shell (SSH) for data transfer and uses the same mechanisms for authentication, thereby ensuring the Information security#Authenticity, authenticity and confidentiality of the data in trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secret Key
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key's security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the practice of the same key being used for both encryption and decryption. Asymmetric cryptography Asymmetric cryptography has separate keys for encrypting and decrypting. These keys are known as the public and private keys, respectively. Purpose Since the key pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Program
A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangible components. A ''computer program'' in its human-readable form is called source code. Source code needs another computer program to Execution (computing), execute because computers can only execute their native machine instructions. Therefore, source code may be Translator (computing), translated to machine instructions using a compiler written for the language. (Assembly language programs are translated using an Assembler (computing), assembler.) The resulting file is called an executable. Alternatively, source code may execute within an interpreter (computing), interpreter written for the language. If the executable is requested for execution, then the operating system Loader (computing), loads it into Random-access memory, memory and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
