diff options
author | Colin Watson <cjwatson@debian.org> | 2005-05-30 21:44:32 +0000 |
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committer | Colin Watson <cjwatson@debian.org> | 2005-05-30 21:44:32 +0000 |
commit | a55bd782aa819b7f5ae716de000f19f4f531850e (patch) | |
tree | 12638b19bc0ed9c8d48541d460693ab0fbb58e89 /ssh-agent.0 | |
parent | fe9489f7e522f780f3fa5c2f28208124d193398c (diff) | |
parent | 5d05471f6657646d1d6500c7c43134462c407ee6 (diff) |
Import OpenSSH 4.1p1.
Diffstat (limited to 'ssh-agent.0')
-rw-r--r-- | ssh-agent.0 | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/ssh-agent.0 b/ssh-agent.0 new file mode 100644 index 000000000..34da0a941 --- /dev/null +++ b/ssh-agent.0 @@ -0,0 +1,118 @@ +SSH-AGENT(1) OpenBSD Reference Manual SSH-AGENT(1) + +NAME + ssh-agent - authentication agent + +SYNOPSIS + ssh-agent [-a bind_address] [-c | -s] [-t life] [-d] [command [args ...]] + ssh-agent [-c | -s] -k + +DESCRIPTION + ssh-agent is a program to hold private keys used for public key authenti- + cation (RSA, DSA). The idea is that ssh-agent is started in the begin- + ning of an X-session or a login session, and all other windows or pro- + grams are started as clients to the ssh-agent program. Through use of + environment variables the agent can be located and automatically used for + authentication when logging in to other machines using ssh(1). + + The options are as follows: + + -a bind_address + Bind the agent to the unix-domain socket bind_address. The de- + fault is /tmp/ssh-XXXXXXXX/agent.<ppid>. + + -c Generate C-shell commands on stdout. This is the default if + SHELL looks like it's a csh style of shell. + + -s Generate Bourne shell commands on stdout. This is the default if + SHELL does not look like it's a csh style of shell. + + -k Kill the current agent (given by the SSH_AGENT_PID environment + variable). + + -t life + Set a default value for the maximum lifetime of identities added + to the agent. The lifetime may be specified in seconds or in a + time format specified in sshd(8). A lifetime specified for an + identity with ssh-add(1) overrides this value. Without this op- + tion the default maximum lifetime is forever. + + -d Debug mode. When this option is specified ssh-agent will not + fork. + + If a commandline is given, this is executed as a subprocess of the agent. + When the command dies, so does the agent. + + The agent initially does not have any private keys. Keys are added using + ssh-add(1). When executed without arguments, ssh-add(1) adds the files + $HOME/.ssh/id_rsa, $HOME/.ssh/id_dsa and $HOME/.ssh/identity. If the + identity has a passphrase, ssh-add(1) asks for the passphrase (using a + small X11 application if running under X11, or from the terminal if run- + ning without X). It then sends the identity to the agent. Several iden- + tities can be stored in the agent; the agent can automatically use any of + these identities. ssh-add -l displays the identities currently held by + the agent. + + The idea is that the agent is run in the user's local PC, laptop, or ter- + minal. Authentication data need not be stored on any other machine, and + authentication passphrases never go over the network. However, the con- + nection to the agent is forwarded over SSH remote logins, and the user + can thus use the privileges given by the identities anywhere in the net- + work in a secure way. + + There are two main ways to get an agent set up: The first is that the + agent starts a new subcommand into which some environment variables are + exported, eg ssh-agent xterm &. The second is that the agent prints the + needed shell commands (either sh(1) or csh(1) syntax can be generated) + which can be evalled in the calling shell, eg eval `ssh-agent -s` for + Bourne-type shells such as sh(1) or ksh(1) and eval `ssh-agent -c` for + csh(1) and derivatives. + + Later ssh(1) looks at these variables and uses them to establish a con- + nection to the agent. + + The agent will never send a private key over its request channel. In- + stead, operations that require a private key will be performed by the + agent, and the result will be returned to the requester. This way, pri- + vate keys are not exposed to clients using the agent. + + A unix-domain socket is created and the name of this socket is stored in + the SSH_AUTH_SOCK environment variable. The socket is made accessible + only to the current user. This method is easily abused by root or anoth- + er instance of the same user. + + The SSH_AGENT_PID environment variable holds the agent's process ID. + + The agent exits automatically when the command given on the command line + terminates. + +FILES + $HOME/.ssh/identity + Contains the protocol version 1 RSA authentication identity of + the user. + + $HOME/.ssh/id_dsa + Contains the protocol version 2 DSA authentication identity of + the user. + + $HOME/.ssh/id_rsa + Contains the protocol version 2 RSA authentication identity of + the user. + + /tmp/ssh-XXXXXXXX/agent.<ppid> + Unix-domain sockets used to contain the connection to the authen- + tication agent. These sockets should only be readable by the + owner. The sockets should get automatically removed when the + agent exits. + +SEE ALSO + ssh(1), ssh-add(1), ssh-keygen(1), sshd(8) + +AUTHORS + OpenSSH is a derivative of the original and free ssh 1.2.12 release by + Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo + de Raadt and Dug Song removed many bugs, re-added newer features and cre- + ated OpenSSH. Markus Friedl contributed the support for SSH protocol + versions 1.5 and 2.0. + +OpenBSD 3.7 September 25, 1999 2 |