.TH SSH 1.SH NAMEssh, sshserve \- secure login from/to Brazil or Plan 9.SH SYNOPSIS.B ssh[.B \-v][.B \-r][.B \-u.I user].I hostname[.I command[.I arguments...]].PP.B scp[host:]file [host:]file.br.B scp[host:]file ... [host:]dir.PP.B sshserve.I address.SH DESCRIPTION.I Sshallows authenticated login over an encrypted channel to hosts thatsupport the ssh protocol (see the RFC listed below for encryption andauthentication details)..LP.I Sshtakes the host name of the machine to connect to as its mandatory argument.It may be specified as a domain name or an IP address.Normally, login is attempted using the user name from /dev/user.The.B \-v(verbose) flag gives feedback during the connection and authentication proces. The.B \-rflag strips carriage returns. The.B \-uflag allows login under a different name..LPIf no command is specified, an interactive shell is started on the remotehost.Otherwise, the command is executed with its arguments..LPSsh establishes a connection with an ssh daemon on the remote host.The daemon sends to ssh its RSA public host key and session key.Using these, ssh sends a session key which, presumably, only thedaemon can decipher.  After this, both sides start encrypting theirdata with this session key.  The encryption algorithm preferred byPlan9 ssh for data transfer is RC4, with triple-DES (which isn'treally triple DES but a somewhat doubtful variation on it) asbackup.  (All ssh implementations are required to be able to do 3DES.).LPWhen the daemon's host key has been received,.I sshlooks it up in $home/lib/keyring and in /sys/lib/ssh/keyring.  Ifthe key is found there, and it matches the received key,.I sshis satisfied.  If not,.sshreports this and offers to add the key to $home/lib/keyring..LPOver the encrypted channel,.I sshattempts to convince the daemon to accept the call.  It may prompt forthe password on the remote host \- note that this password will be sentover the.I encryptedchannel.  This is safe, provided one is indeed connected to the intendedhost..LPThe preferred way to authenticate the user, however, is thechallenge/response system used by.I netkey ..I Sshusers on other systems than Plan 9 should enable \s-2TIS_A\s0uthentication..LPWhen the connection is established, the command given in the remainingarguments, or the shell, is started up on the remote host..sp 1.I Scpuses.I sshto copy files from one host to another.  A remote file is identified bya host name, a colon and a file name (no spaces)..I Scpcan copy files from remote hosts and to remote hosts..sp 1.I Sshserveis the server that services.I sshcalls from remote hosts.  On Plan9 and Brazil, it always requires eithera response to a challenge (netkey), or a password.  The password isprotected by encryption as it travels from the remote host to.I sshserve ..SH FILES.TF /sys/lib/ssh/hostkey.public.TP.B /sys/lib/ssh/hostkey.publicPublic key for the host on which the program runs..TP.B /sys/lib/ssh/hostkey.secretSecret key for the host on which the program runs.  This file mustbe owned and be readable by bootes only..TP.B /sys/lib/ssh/keyringSystem keyring file containing public keys for remote ssh clients and servers..TP.B /usr/\fIuser\fP/lib/keyringPersonal keyring file containing public keys for remote ssh clients andservers..SH SOURCE.B /sys/src/cmd/ssh.SH "SEE ALSO".IR /sys/src/cmd/ssh/RFC*.IR Auth(6).SH BUGSThis program was written (and partially copied) by Sape Mullender.