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Diffstat (limited to 'security/ssh/DESCR')
| -rw-r--r-- | security/ssh/DESCR | 98 |
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diff --git a/security/ssh/DESCR b/security/ssh/DESCR new file mode 100644 index 00000000000..5c76294d0b0 --- /dev/null +++ b/security/ssh/DESCR @@ -0,0 +1,98 @@ +SSH (Secure Shell) is a program to log into another computer over a +network, to execute commands in a remote machine, and to move files +from one machine to another. It provides strong authentication and +secure communications over insecure channels. It is intended as a +replacement for rlogin, rsh, rcp, and rdist. + +FEATURES + + o Strong authentication. Closes several security holes (e.g., IP, + routing, and DNS spoofing). New authentication methods: .rhosts + together with RSA based host authentication, and pure RSA + authentication. + + o Improved privacy. All communications are automatically and + transparently encrypted. RSA is used for key exchange, and a + conventional cipher (normally IDEA, Blowfish, or triple-DES) for + encrypting the session. Encryption is started before + authentication, and no passwords or other information is + transmitted in the clear. Encryption is also used to protect + against spoofed packets. + + o Secure X11 sessions. The program automatically sets DISPLAY on + the server machine, and forwards any X11 connections over the + secure channel. Fake Xauthority information is automatically + generated and forwarded to the remote machine; the local client + automatically examines incoming X11 connections and replaces the + fake authorization data with the real data (never telling the + remote machine the real information). + + o Arbitrary TCP/IP ports can be redirected through the encrypted channel + in both directions (e.g., for e-cash transactions). + + o No retraining needed for normal users; everything happens + automatically, and old .rhosts files will work with strong + authentication if administration installs host key files. + + o Never trusts the network. Minimal trust on the remote side of + the connection. Minimal trust on domain name servers. Pure RSA + authentication never trusts anything but the private key. + + o Client RSA-authenticates the server machine in the beginning of + every connection to prevent trojan horses (by routing or DNS + spoofing) and man-in-the-middle attacks, and the server + RSA-authenticates the client machine before accepting .rhosts or + /etc/hosts.equiv authentication (to prevent DNS, routing, or + IP-spoofing). + + o Host authentication key distribution can be centrally by the + administration, automatically when the first connection is made + to a machine (the key obtained on the first connection will be + recorded and used for authentication in the future), or manually + by each user for his/her own use. The central and per-user host + key repositories are both used and complement each other. Host + keys can be generated centrally or automatically when the software + is installed. Host authentication keys are typically 1024 bits. + + o Any user can create any number of user authentication RSA keys for + his/her own use. Each user has a file which lists the RSA public + keys for which proof of possession of the corresponding private + key is accepted as authentication. User authentication keys are + typically 1024 bits. + + o The server program has its own server RSA key which is + automatically regenerated every hour. This key is never saved in + any file. Exchanged session keys are encrypted using both the + server key and the server host key. The purpose of the separate + server key is to make it impossible to decipher a captured session by + breaking into the server machine at a later time; one hour from + the connection even the server machine cannot decipher the session + key. The key regeneration interval is configurable. The server + key is normally 768 bits. + + o An authentication agent, running in the user's laptop or local + workstation, can be used to hold the user's RSA authentication + keys. Ssh automatically forwards the connection to the + authentication agent over any connections, and there is no need to + store the RSA authentication keys on any machine in the network + (except the user's own local machine). The authentication + protocols never reveal the keys; they can only be used to verify + that the user's agent has a certain key. Eventually the agent + could rely on a smart card to perform all authentication + computations. + + o The software can be installed and used (with restricted + functionality) even without root privileges. + + o The client is customizable in system-wide and per-user + configuration files. Most aspects of the client's operation can + be configured. Different options can be specified on a per-host basis. + + o Automatically executes conventional rsh (after displaying a + warning) if the server machine is not running sshd. + + o Optional compression of all data with gzip (including forwarded X11 + and TCP/IP port data), which may result in significant speedups on + slow connections. + + o Complete replacement for rlogin, rsh, and rcp. |