SSH/SCP/RCP
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BACKGROUND
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What is a shell?
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An interface for users to interact with the machine/kernel
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Examples: MS-DOS, bash, csh, etc...
rlogin (remote login)
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A utility released as part of the BSD Unix operating system 1983.
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Allows users to log in to another host via a network
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Important security issues - sends all information, including passwords,
unencrypted. Thus, it is very insecure and is extremely vulnerable to
malicious attacks over a network
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Typically configured to not ask for a password, due to an assumed trusted
network
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Uses TCP port 514
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SSH
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Because rlogin is insecure over an untrusted network, SSH was
created to replace it in 1995
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Uses a secure, encrypted channel for communication
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Authentication is done using public-key cryptography
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Typically uses TCP port 22
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Many implementations for Windows, Mac, and Unix
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Allows commands to be executed remotely
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Supports tunneling of TCP ports and X11 (GUI) connections
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SSH USAGE
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Example: Login to 'willow.mcsr.olemiss.edu' as user 'student’
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> ssh bob@host.example.com
Example: Run the 'date' command as user 'student' on
'willow.mcsr.olemiss.edu’
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> ssh bob@host.example.com date
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SCP AND RCP
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commands copy files from one machine to another using a similar notation to cp
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SCP is the secure version from the ssh package
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Usage:
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scp [-r] [[user@]host1:]file1
Example: Copy local file 'file1' to 'willow.mcsr.olemiss.edu‘
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scp file1 student@willow.mcsr.olemiss.edu:/users/student/file1
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RCP is the non-secure version
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Usage:
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rcp [-r] [[user@]host1:]file1
Example: Copy local file 'file1' to 'willow.mcsr.olemiss.edu‘
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rcp file1 student@willow.mcsr.olemiss.edu:/users/student/file1
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