Session Options/Connection/SSH1
From SecureCRT
The first version of the SSH protocol which provides a way to encrypt network traffic between a client and a server.
A data path or circuit between two computers over a phone line, network cable, or other means.
An algorithm used to encrypt data at varying levels of security. Examples include 3DES, AES, Blowfish, RC4, and Twofish.
A session is a set of options that are assigned to a connection to a remote machine in SecureCRT. These settings and options are saved under a session name and allowthe user to have different preferences for different hosts.
A computer program that provides services to other computer programs (called clients). Often the computer on which a server program runs is also called a server. The term host is often used as a synonym for server.
The concept of connecting a logical port on a local machine to a port on a remote machine over a secure (encrypted) channel. All requests for services sent to the local port are then forwarded across the secure channel to the corresponding port on the remote machine.
The process of verifying that an individual truly is who he or she claims to be. Supplying a password is a very common method of authentication. The most secure method of authentication supported in SecureCRT is public-key authentication. See also: identity file, public-private key pair.
A computer or application that uses services provided by a server.
Identity files are two files containing the public-private key pair used to connect to an SSH server using RSA or DSA authentication. The Identity file contains the public and private key pair and is used by SecureCRT. The Identity.pub file contains only the public key which is usually appended to the authorized_keys file.
Connection / SSH1
The SSH1 category of the Session Options
dialog allows you to configure your SSH1connection.
The SSH1 category only appears when you have selected
SSH1 as your Protocol.
SSH1 Overview
SSH1 provides secure communication over a nonsecure channel by encrypting the data channel using the cipher algorithm selected for the session by the user.
WARNING: Setting cipher
to None causes the data channel to be left
unencrypted and offers no security.
The cipher selected must also be supported by the destination SSH1 server. An error will be reported during a connection attempt if the chosen cipher is not supported by the server.
Port forwarding is another feature based on SSH security. See Port Forwarding with SSH to learn more about encrypting connections for other applications (such as IMAP) that are not secure by default.
SSH1 connection settings include hostname, port, username, cipher, and authentication.
Hostname
The hostname or IP address of the remote machine that provides the SSH1 service.
Port
The port number of the SSH1 service on the remote machine. For SSH1,
the default port is 22.
Firewall
If your connection involves a firewall, select your firewall from the list of firewalls that have been configured in the Global Options/Firewall dialog.
Username
The username used to log on to the remote machine.
Authentication
SecureCRT supports three types of authentication for connecting to SSH1 servers: password, RSA, and TIS.
Password authentication
transmits the user's password to the server to authenticate the connection.
The transmitted password is protected from network eavesdropping, due
to the cipher encryption of the data channel. For this reason, some SSH1
servers reject the use of password authentication if the cipher is set
to None.
RSA authentication uses a public/private key pair to authenticate the connection. The general mechanism behind RSA authentication is that the SSH1 server "challenges" the client to decrypt a message encoded using the user's public key stored on the server. Upon connecting, the SSH1 server generates a random value, encrypts the value using the user's public key and sends the encrypted challenge to the client. The client authenticates the connection by successfully decrypting the challenge using the user's private key. The security of the mechanism requires that no one but the owner have access to the private key. The private key is stored locally in an identity file. The first time you connect to an SSH1 server using RSA authentication, SecureCRT will prompt you for the location of this file. Also, prior to using RSA authentication, the public key must be made available to the SSH1 server.
TIS firewall authentication uses the TIS firewall server to provide a challenge phrase / response combination. SSH1 servers must be configured to offer TIS authentication.