Password cracking linux and Solaris 10 permissions and Linux Intro

PRESENTATION COVERING THREE TOPICS AS FOLLOWS

PERMISSIONS IN SOLARIS 10CRACKING THE LINUX

PASSWORDAN INTRODUCTION TO LINUX

04/08/23

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Prepared by :

Rohit Kumar Jaiswal, Sarafat Ansari, Vaibhav Singh

PERMISSIONS IN SOLARIS 10

Overview of the topics View file and directory permissions Determine file or directory access Change the permissions Modify the default permissions

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-rwxrwxr-x 1 rvdheij rvdheij 5224 Dec 30 03:22 hello-rw-rw-r-- 1 rvdheij rvdheij 221 Dec 30 03:59 hello.c-rw-rw-r-- 1 rvdheij rvdheij 1514 Dec 30 03:59 hello.sdrwxrwxr-x 7 rvdheij rvdheij 1024 Dec 31 14:52 posixuft

Permissions

Owner

Group

Viewing Permission CategoriesTo view the permissions for files and directories, perform the ls –l command. e.g.$ ls –l

As the left picture shows that the first three letters after the dash shows the permission for the owner, second three shows permissions for the group and the last three shows the permissions for other.

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This figure shows the information displayed for the sarafat file.r = Readable, w = Writable, x = Executable, - = Denied

The example is :

$ ls -l <file name>-rw-r--r-- 1 user1 staff 1319 Mar 15 11:23 sarafat

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The first field of information displayed by the ls –l command is the file type.The file type typically specifies whether it is a file or a directory. A file is represented by a hyphen (-). A directory is represented by the letter d.

Permission Types --• The owner permissions• The group permissions• The other permissions

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Viewing Permission Categories

Permissions Description -rwx------ This file has read, write, and execute permissions set for the file owner only. Permissions for group and other are denied.dr-xr-x--- This directory has read and execute permissions set for the directory owner and the group only.-rwxr-xr-x This file has read, write, and execute permissions set for the file owner. Read and execute permissions are set for the group and other.

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Octal Digits for Permission Sets—Shows the octal numbers that represent a combined set of permissions.

Octal Value Permission Sets Binary 7 r w x 111 (4+2+1) 6 rw- 110 (4+2+0) 5 r-x 101 (4+0+1) 4 r-- 100 (4+0+0) 3 -wx 011 (0+2+1) 2 -w- 010 (0+2+0) 1 --x 001 (0+0+1) 0 --- 000 (0+0+0) 7

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Octal Mode Permissions644 rw-r--r--751 rwxr-x--x775 rwxrwxr-x777 rwxrwxrwx

Combined Values and PermissionsShows the permission sets for the three-digit octal numbers.

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ACL (Access Control List)

ACLs can provide greater control over file access permissions and provide better file security for the file owner, file group, other, specific users, and specific groups.

ACL Commands and their descriptions

getfacl filename(s) Displays ACL entries on files.setfacloptions filename(s)Sets, adds, modifies, and deletes ACL entries on files.setfacl -m acl_entries Creates or modifies ACL entries on files.setfacl -s acl_entries Removes old ACL entries on files and replaces them with new ACL entries.setfacl -d acl_entries Deletes one or more ACL entries on files. 9

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Determining if a File Has an ACL

There are two ways to determine if a file has an ACL:

• Use the getfacl command.• Use the ls -l command.Using the ls -l command on any file that has an ACL displays a plus (+) sign at the end of the permission mode field; for example:# ls -l file.txt-rwxr-----+ 1 user1 class 167 Apr 18 11:13 file.txt

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EXAMPLESConfiguring or Modifying an ACL : - The following example shows you how to add a new ACL entry to a file with existing ACL entries:$ setfacl -m u:userb:7 file2$ getfacl file2# file: file2# owner: userc# group: sysadminuser::rwuser:usera:rwx #effective:r--user:userb:rwx #effective:r--group::r-- #effective:r--mask:r--other:r-- 11

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EXAMPLESubstituting an ACL to replace the entire ACL on a file, you must specify at least the basic set of user, group, other, and mask permissions and file names; for example:

$ setfacl -s u::rwx,g::rw-,o:r--,m:rw-,u:usera:rwx file1$ getfacl file1# file: file1# owner: userc# group: sysadminuser::rwxuser:usera:rwx #effective:rwgroup::rw- #effective:rwmask:rwother:r—

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Cracking the Linux PasswordSteps:Here are the few steps that you can follow to crack the password of the root in Linux[1] –

•Start your linux computer •When it shows a prompt performing the grub loading process•Press a•It will take you to the another screen press a button again.•You are now on a another prompt in the end of the already written line type single linux•You will now get a # prompt. Type the passwd command to change the password of the root.•Sh-3.00 # passwd root

Changing password for user root•Type you root new password•Sh-3.00 # confirm the root password•You will get a message saying that your root password has been updated successfully.•Restart the computer •Now you can login using your root user and the newly set password.

[1] If you want to crack the passw

ord using this method you m

ust know

the grub password should not be set.

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An Introduction to Linux

What is Linux?

Linux stands for Linux not unix. It means that even though it has been developed out of or using the same source code of Unix but it has not got anything to do with Unix.

Features :

•A fully-networked 32/64-Bit Unix-like Operating System •X Windows is the GUI of Linux•Can run with the multiple Operating Systems •Runs on multiple platforms •Open Source Code available to be modified•Multiuser Operating System

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Copyright (c) NIIT Lahurabir

1. Linus Torvalds, one of the Student of the Helsinki University created it with ssistance from programmers around the world.

2. First posted on Internet in 19913. Linux 1.0 in 1994; 2.2 in 19994. Today used on 7-10 million computers with

1000’s of programmers working to enhance it.15

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Ho

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Open Source Software

Open source is a freeware Licensed under GPL based softwares and that is how it is growing its popularity among people. Open source softwares can be downloaded even modified using the same source code. It helps the developers in many ways such as:

People improve, adapt it and fix bugs. And this can happen at a speed that, compared to conventional software development, seems astonishing.

How do you get it?

Download it from the Internet from a “Distribution” (i.e. RedHat, OpenSuse, Mandriva, Mandrake, Debian, Ubuntu, Gentoo and many more)

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Why is it significant?Linux kernel

•X Windows system and GUI•Web, e-mail, FTP servers

Installation & configuration support•3rd party apps•Supports the file having .rpm (Redhat Package Manager) extension •Open Office is provided the linux for free•Moziila is the default web-browser for Linux •Hardware support

Powerful•Runs on multiple hardware platforms•Users like its speed and stability•No requirement for latest hardware

It’s “free”•Licensed under GPL•Vendors are distributors who package Linux

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Linux File System

Linux files are stored in a single rooted, hierarchical file systemData files are stored in directories (folders)Directories may be nested as deep as needed

Linux File

System Basics

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Files are named bynaming each

containing directorystarting at the root

This is known as the pathname

/etc/passwd

/home/neale/b

NAMING THE FILES AND DIRECTORIES

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Some Special File Names

•Some file names are special:/ The root directory (not to be confused with the root user). The current directory.. The parent (previous) directory~ My home directory

Examples:•./a same as a•../jane/x go up one level then look in directory jane for x

Some Special File Names/home - all users’ home directories are stored here/bin, /usr/bin - system commands/sbin, /usr/sbin - commands used by sysadmins /etc - all sorts of configuration files/var - logs, spool directories etc./dev - device files/proc - special system files 20

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Some Very Basic Commands in Linux :•pwd - print (display) the working directory•cd <dir> - change the current working directory to dir •ls - list the files in the current working directory•ls -l - list the files in the current working directory in long format

File Commands :•cp <fromfile> <tofile>

Copy from the <fromfile> to the <tofile> •mv <fromfile> <tofile>

Move/rename the <fromfile> to the <tofile>•rm <file>

Remove the file named <file>•mkdir <newdir>

Make a new directory called <newdir>•rmdir <dir>

Remove an (empty) directory

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THANK YOU

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