rsync and Scp command in Linux

How to use Scp command in Linux Operating System.

With the scp (secure copy) command you can easily copy from and to a remote computer or between remote computers.

root@manish.bhadnari#] scp <Source> <destibation>



How to use rsynce command in Linux Operating System.

rsync is a program that behaves in much the same way that scp does, but has many more options and uses the rsync remote-update protocol to greatly speed up file transfers when the destination file already exists.

The rsync remote-update protocol allows rsync to transfer just the differences between two sets of files across the network link, using an efficient checksum-search algorithm described in the technical report that accompanies this package.



@ How to Install rsync command in Linux.

#yum install rsync


@Comman rsync command options

    --delete : delete files that don't exist on sender (system)
    -v : Verbose (try -vv for more detailed information)
    -e "ssh options" : specify the ssh as remote shell
    -a : archive mode
    -r : recurse into directories
    -z : compress file data


For more details for rsync read mention link:

http://linux.about.com/library/cmd/blcmdl1_rsync.htm

How to configure rssh on RHEL 5.5

Linux Configure rssh Chroot Jail To Lock Users To Their Home Directories Only

If you want to chroot users, then use rssh support chrooting option. It is used to set the directory where the root of the chroot jail will be located. This is a security feature.

A chroot on Linux or Unix OS is an operation that changes the root directory. It affects only the current process and its children. If your default home directory is /home/manish normal user can access files in /etc, /sbin or /bin directory. This allows an attacker to install programs / backdoor via your web server in /tmp. chroot allows to restrict file system access and locks down user to their own directory.

First download the rssh rpm (rssh-2.3.3-1.fc16.x86_64.rpm)

Configuring rssh chroot

chroot directory : /users

root@mansh.bhandari#] wget -c

Another url is wget http://dag.wieers.com/rpm/packages/rssh/rssh-2.3.2-1.2.el5.rf.x86_64.rpm

ftp://ftp.univie.ac.at/systems/linux/fedora/releases/16/Everything/x86_64/os/Packages/rssh-2.3.3-1.fc16.x86_64.rpm

root@mansh.bhandari#] rpm -ivh rssh-2.3.3-1.fc16.x86_64.rpm

root@mansh.bhandari#] mkdir /users

root@mansh.bhandari#] mkdir -p /users/{dev,etc,lib,usr,bin}

root@mansh.bhandari#] mkdir -p /users/usr/bin

root@mansh.bhandari#] mkdir -p /users/usr/libexec/openssh/

root@mansh.bhandari#] mkdir -p /users/libexec/openssh

Create /users/dev/null:

root@mansh.bhandari#] mknod -m 666 /users/dev/null c 1 3

Copy required /etc/ configuration files, as described above to your jail directory /users/etc:

root@mansh.bhandari#] cd /users/etc

root@mansh.bhandari#] cp /etc/ld.so.cache .

root@mansh.bhandari#] cp /etc/ld.so.conf .

root@mansh.bhandari#] cp /etc/nsswitch.conf .

root@mansh.bhandari#] cp /etc/passwd .

root@mansh.bhandari#] cp /etc/group .

root@mansh.bhandari#] cp /etc/hosts .

root@mansh.bhandari#] cp /etc/resolve.conf .

Open /usres/group and /users/passwd file and remove root and all other accounts.

Copy required binary files, as described above to your jail directory /users/bin and other locations:

root@mansh.bhandari#] cd /users/usr/bin

root@mansh.bhandari#] cp /usr/bin/scp .

root@mansh.bhandari#] cp /usr/bin/rssh .

root@mansh.bhandari#] cp /usr/bin/sftp .

root@mansh.bhandari#] cd /users/usr/libexec/openssh/

root@mansh.bhandari#] cp /usr/libexec/openssh/sftp-server .

or

root@manish.bhandari#] cp /usr/lib/openssh/sftp-server . (not found)

root@manish.bhandari#] cd /users/usr/libexec/

root@manish.bhandari#] cp /usr/libexec/rssh_chroot_helper .

OR
root@manish.bhandari#] cp /usr/lib/rssh/rssh_chroot_helper (not found)

root@manish.bhandari#] cd /users/bin/

root@manish.bhandari#] cp /bin/sh .
OR
root@manish.bhandari#] cp /bin/bash .

Copy all shared library files

The library files that any of these binary files need can be found by using the ldd / strace command. For example, running ldd against /usr/bin/sftp provides the following output:

ldd /usr/bin/sftp

Output:

linux-gate.so.1 =>  (0×00456000)

libresolv.so.2 => /lib/libresolv.so.2 (0x0050e000)

libcrypto.so.6 => /lib/libcrypto.so.6 (0x0013e000)

libutil.so.1 => /lib/libutil.so.1 (0x008ba000)

libz.so.1 => /usr/lib/libz.so.1 (0×00110000)

libnsl.so.1 => /lib/libnsl.so.1 (0x0080e000)

libcrypt.so.1 => /lib/libcrypt.so.1 (0x00a8c000)

libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0×00656000)

libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0×00271000)

libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0×00304000)

libcom_err.so.2 => /lib/libcom_err.so.2 (0×00777000)

libdl.so.2 => /lib/libdl.so.2 (0×00123000)

libnss3.so => /usr/lib/libnss3.so (0×00569000)

libc.so.6 => /lib/libc.so.6 (0x00b6c000)

libkrb5support.so.0 => /usr/lib/libkrb5support.so.0 (0×00127000)

libkeyutils.so.1 => /lib/libkeyutils.so.1 (0×00130000)

/lib/ld-linux.so.2 (0×00525000)

libplc4.so => /usr/lib/libplc4.so (0x008c9000)

libplds4.so => /usr/lib/libplds4.so (0×00133000)

libnspr4.so => /usr/lib/libnspr4.so (0x00d04000)

libpthread.so.0 => /lib/libpthread.so.0 (0x0032a000)

libselinux.so.1 => /lib/libselinux.so.1 (0×00341000)

libsepol.so.1 => /lib/libsepol.so.1 (0×00964000)

You need to copy all those libraries to /lib and other appropriate location. However, I recommend using this automated script called l2chroot:

root@manish.bhandari#] cd /sbin

root@manish.bhandari#] wget -O l2chroot http://www.cyberciti.biz/files/lighttpd/l2chroot.txt

root@manish.bhandari#] chmod +x l2chroot

Open l2chroot and set BASE variable to point to chroot directory (jail) location:

BASE=”/users”

Now copy all shared library files

root@manish.bhandari#] l2chroot /usr/bin/scp

root@manish.bhandari#] l2chroot /usr/bin/rssh

root@manish.bhandari#] l2chroot /usr/bin/sftp

root@manish.bhandari#] l2chroot /usr/libexec/openssh/sftp-server
OR
root@manish.bhandari#] l2chroot /usr/lib/openssh/sftp-server (not found)

root@manish.bhandari#] l2chroot /usr/libexec/rssh_chroot_helper
OR
root@manish.bhandari#] l2chroot /usr/lib/rssh/rssh_chroot_helper

root@manish.bhandari#] l2chroot /bin/sh
OR
root@manish.bhandari#]l2chroot /bin/bash

Modify syslogd configuration

root@mansh.bhandari#] vi /etc/sysconfig/syslog

Find line that read as follows:
SYSLOGD_OPTIONS=”-m 0″
Append -a /users/dev/log
SYSLOGD_OPTIONS=”-m 0 -a /users/dev/log”
Save and close the file. Restart syslog:

root@manish.bhandari#] /etc/init.d/syslog restart

Set chroot path

Open configuration file /etc/rssh.conf:


root@manish.bhandari#] vi /etc/rssh.conf


Set chrootpath to /users


chrootpath=/users


user=manish:022:00010:”/users”
Save and close the file. If sshd is not running start it:


root@manish.bhandari#] /etc/init.d/sshd restart

Set chroot path:

root@manish.bhandari3] vim /etc/rssh.conf

chrootpath=/users

Subsystem sftp internal-sftp

root@manish.bhandari#] /etc/init.d/sshd restart

Add user to jail

root@manish.bhandari#] useradd -m -d /users/manish -s /usr/bin/rssh manish

root@manish.bhandari#] passwd manish

Now vivek can login using sftp or copy files using scp:

root@manish.bhandari#] sftp manish@192.168.100.xx

manish@192.168.100.x password

sftp>

sftp> ls

sftp > pwd

Remote working directory : /users/manish

sftp > cd /tmp

Couldn't canonicalise: No such file or directory

User manish is allowed to login to server to trasfer files, but not allowed to browse entier file system.

http://pensacola-tech.com/pensacola/2010/05/05/configure-rssh/

                                                                                                                                 Manish Bhandari