Thursday, 18 July 2013

Using Wine In Red Hat Linux

                              Using Wine In Red Hat Linux


Wine is a great tool for Linux users who want to install and run Windows applications under Linux. Tonight I decided to test Wine and therefore searched about downloading and installing Wine on my Red Hat Enterprise Linux. So its time for you to get ready for an eventful journey towards Wine.
The installation process is quite easy. Wine package is included in RHEL so all you need is to issue the following command:
  • yum install wine
Now just be patient till it get installed. Once you have it installed get an exe file to test Wine. So I downloaded Firefox8 and give it a try with Wine. Now open your terminal. Don’t try to run it from CLI mode. To run an exe issue the following command:
  • wine yourfilepath.exe( for example I issued wine /root/Desktop/Firefox\ Setup\ 8.0.exe
And what I see is that the installation process has begun. Wow! I am running exe files in Linux.
Running Windows Applications In Linux using Wine

Sunday, 14 July 2013

To Password Protect Folders with Folder Protector?




    Step 1. Select folders for protect
  • Copy Folder Protector (lockdir.exe) to the folder you want to protect or drag and drop the folder you want to protect in the operation window of Folder Protector for adding the folder to protect.
    step 2. Send Password to protect selected folder
  • Make settings in Settings window and then right-click on the folder and navigate to "Folder Protector" option to password protect it.
Protect
Step 3. Make settings to retrieve password.
  • a. Click on the ">>" Button on the right side of the main window.
    b. Type a password hint to help you remember your password.
  • Remember that anyone unprotected this folder will be able to see the password hint.
    c. Set an e-mail address to help you retrieve password. The program will remember this e-mail address if you click on "Save as default e-mail".
Step 4. Click "Protect" button to Protect folders

Part II. Unprotect a Folder

    Three different unprotection modes
  • Virtual Drive: Access your data in a virtual drive without extracting the data, which means the folder will be reprotected automatically as soon as you close the explorer window.
  • Temporary: Show a restore window on your taskbar after unprotection, which allows you restore protection easily.
  • Complete: Completely unprotect your folder. You need to run Folder Protector again and enter a new password to protect the folder if you wish to gain folder protection again.
  • Unprotect
    Temporary unprotection Window.
    Temporaray Unprotect

Saturday, 13 July 2013

RSA Algorithm Example


RSA Algorithm Example

  • Choose p = 3 and q = 11
  • Compute n = p * q = 3 * 11 = 33
  • Compute φ(n) = (p - 1) * (q - 1) = 2 * 10 = 20
  • Choose e such that 1 < e < φ(n) and e and n are coprime. Let e = 7
  • Compute a value for d such that (d * e) % φ(n) = 1. One solution is d = 3 [(3 * 7) % 20 = 1]
  • Public key is (e, n) => (7, 33)
  • Private key is (d, n) => (3, 33)
  • The encryption of m = 2 is c = 27 % 33 = 29
  • The decryption of c = 29 is m = 293 % 33 = 2

Friday, 12 July 2013

Cryptographic Algorithms


THE CRYPTOGRAPHY GUIDE



Cryptographic Algorithms

There are of course a wide range of cryptographic algorithms in use. The following are amongst the most well known:

DES
This is the 'Data Encryption Standard'. This is a cipher that operates on 64-bit blocks of data, using a 56-bit key. It is a 'private key' system. Further Details on the DES Algorithm
RSA
RSA is a public-key system designed by Rivest, Shamir, and Adleman. Further Details on the RSA Algorithm
HASH
A 'hash algorithm' is used for computing a condensed representation of a fixed length message/file. This is sometimes known as a 'message digest', or a 'fingerprint'..
MD5
MD5 is a 128 bit message digest function. It was developed by Ron Rivest. Further Details on the MD5 Algorithm

AES
This is the Advanced Encryption Standard (using the Rijndael block cipher) approved by NIST.
SHA-1
SHA-1 is a hashing algorithm similar in structure to MD5, but producing a digest of 160 bits (20 bytes).Because of the large digest size, it is less likely that two different messages will have the same SHA-1 message digest. For this reason SHA-1 is recommended in preference to MD5.
HMAC
HMAC is a hashing method that uses a key in conjunction with an algorithm such as MD5 or SHA-1. Thus one can refer to HMAC-MD5 and HMAC-SHA1

Wednesday, 10 July 2013

Windows XP Network configuration

Windows XP Professional

Windows XP TCP/IP configuration panel.
Click Start -> Control Panel -> Network Connections.
Alternately, click Start ->, and right-click My Network Places then select Properties.
The following procedure steps through the Windows XP Professional TCP/IP configuration process:
  1. On some installations the interface will be called Local Area Connection and on others it will be called Network Bridge. On our system it is called Network Bridge. Right-click on Network Bridge -> Properties.
    Network Bridge Configuration.
    Network Bridge Configuration.

  2.  The Network Bridge Configuration, or Local Area Connection, panel is used to set TCP/IP protocol settings. In This connection uses the following items: box, click on Internet Protocol (TCP/IP), then click on Properties.
    The default setting is DHCP-enabled operation (i.e.“Obtain an IP address automatically”).
    Internet Protocol (TCP/IP) Properties.
    Internet Protocol (TCP/IP) Properties.

    Many network administrators will want to use DHCP to configure all client TCP/IP protocol stack settings.
    If it is necessary to provide a fixed IP address, click on “Use the following IP address” and enter the IP Address, the subnet mask, and the default gateway address in the boxes provided.
  3. Click the Advanced button to proceed with TCP/IP configuration. This opens a panel in which it is possible to create additional IP addresses for this interface. The technical name for the additional addresses is IP aliases, and additionally this panel permits the setting of more default gateways (routers). In most cases where DHCP is used, it will not be necessary to create additional settings.
    Advanced Network Settings
    Advanced Network Settings

    Fixed settings may be required for DNS and WINS if these settings are not provided automatically via DHCP.
  4. Click the DNS tab to add DNS server settings. The example system uses manually configured DNS settings. When finished making changes, click the OK to commit the settings.
    DNS Configuration.
    DNS Configuration.

  5.  Click the WINS tab to add manual WINS server entries. This step demonstrates an example system that uses manually configured WINS settings. When finished making changes, click OK to commit the settings.
    WINS Configuration
    WINS Configuration

Network configuration in Linux




How to configure the network card in Red hat enterprise Linux 5 and Centos 5


You can configure network card by editing text files stored in 
/etc/sysconfig/network-scripts/ directory.

First change directory to /etc/sysconfig/network-scripts/:

# cd /etc/sysconfig/network-scripts/

You need to edit files as follows:

/etc/sysconfig/network-scripts/ifcfg-eth0 : First Ethernet card configuration file
/etc/sysconfig/network-scripts/ifcfg-eth1 : Second Ethernet card configuration file
To edit/create first NIC file, type command:
# vi ifcfg-eth0

modify as follows:


# Intel Corporation 82573E Gigabit Ethernet Controller (Copper)

DEVICE=eth0

BOOTPROTO=static

DHCPCLASS=

HWADDR=00:30:48:56:A6:2E

IPADDR=192.168.1.2

NETMASK=255.255.255.0

ONBOOT=yes


Save and close the file. Define default gateway (router IP) and hostname in 
/etc/sysconfig/network file:

# vi /etc/sysconfig/network

Append/modify configuration as follows:
NETWORKING=yes

HOSTNAME=server1.example.com

GATEWAY=192.168.1.1


Save and close the file. Restart networking:

# /etc/init.d/network restart

Make sure you have correct DNS server defined in /etc/resolv.conf file:

# vi /etc/resolv.conf
Setup DNS Server as follows:
nameserver XX.XX.XX.XX

nameserver XX.XX.XX.XX

Tuesday, 9 July 2013

OOPs Concepts



OOPs – Object Oriented Programming System
Object-oriented programming (OOP) is a programming paradigm that uses “Objects “and their interactions to design applications and computer programs.

There are different types of OOPs are used, they are
  1. Object
  2. Class
  3. Data Abstraction & Encapsulation
  4. Inheritance
  5. Polymorphism
  6. Dynamic Binding
  7. Message Passing

1) Object :Object is the basic unit of object-oriented programming. Objects are identified by its unique name. An object represents a particular instance of a class. There can be more than one instance of an object. Each instance of an object can hold its own relevant data.
An Object is a collection of data members and associated member functions also known as methods.
For example whenever a class name is created according to the class an object should be created without creating object can’t able to use class.
The class of Dog defines all possible dogs by listing the characteristics and behaviors they can have; the object Lassie is one particular dog, with particular versions of the characteristics. A Dog has fur; Lassie has brown-and-white fur.
2) Class :
Classes are data types based on which objects are created. Objects with similar properties and methods are grouped together to form a Class. Thus a Class represents a set of individual objects. Characteristics of an object are represented in a class as Properties. The actions that can be performed by objects become functions of the class and is referred to as Methods.
For example consider we have a Class of Cars under which Santro Xing, Alto and WaganR represents individual Objects. In this context each Car Object will have its own, Model, Year of Manufacture, Colour, Top Speed, Engine Power etc., which form Properties of the Car class and the associated actions i.e., object functions like Start, Move, Stop form the Methods of Car Class.No memory is allocated when a class is created. Memory is allocated only when an object is created, i.e., when an instance of a class is created.

3) Data abstraction & Encapsulation :The wrapping up of data and its functions into a single unit is called Encapsulation.
When using Data Encapsulation, data is not accessed directly, it is only accessible through the functions present inside the class.
Data Abstraction increases the power of programming language by creating user defined data types. Data Abstraction also represents the needed information in the program without presenting the details.
Abstraction refers to the act of representing essential features without including the background details or explanation between them.
For example, a class Car would be made up of an Engine, Gearbox, Steering objects, and many more components. To build the Car class, one does not need to know how the different components work internally, but only how to interface with them, i.e., send messages to them, receive messages from them, and perhaps make the different objects composing the class interact with each other.
4) Inheritance :
Inheritance is the process of forming a new class from an existing class or base class.
The base class is also known as parent class or super class, the new class that is formed is called derived class.
Derived class is also known as a child class or sub class. Inheritance helps in reducing the overall code size of the program, which is an important concept in object-oriented programming.
It is classifieds into different types, they are
  • Single level inheritance
  • Multi-level inheritance
  • Hybrid inheritance
  • Hierarchial inheritance
5) Polymorphism :
Polymorphism allows routines to use variables of different types at different times. An operator or function can be given different meanings or functions. Polymorphism refers to a single function or multi-functioning operator performing in different ways.
Poly a Greek term ability to take more than one form. Overloading is one type of Polymorphism. It allows an object to have different meanings, depending on its context. When an exiting operator or function begins to operate on new data type, or class, it is understood to be overloaded.
6) Dynamic binding :
It contains a concept of Inheritance and Polymorphism.
7) Message Passing :It refers to that establishing communication between one place to another.
 

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