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Diffstat (limited to 'crypto/openssh/ssh-agent.0')
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diff --git a/crypto/openssh/ssh-agent.0 b/crypto/openssh/ssh-agent.0 new file mode 100644 index 0000000..e5f0f73 --- /dev/null +++ b/crypto/openssh/ssh-agent.0 @@ -0,0 +1,123 @@ +SSH-AGENT(1) OpenBSD Reference Manual SSH-AGENT(1) + +NAME + ssh-agent - authentication agent + +SYNOPSIS + ssh-agent [-c | -s] [-d] [-a bind_address] [-t life] [command [arg ...]] + ssh-agent [-c | -s] -k + +DESCRIPTION + ssh-agent is a program to hold private keys used for public key + authentication (RSA, DSA, ECDSA). The idea is that ssh-agent is started + in the beginning of an X-session or a login session, and all other + windows or programs 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 + default is $TMPDIR/ssh-XXXXXXXXXX/agent.<ppid>. + + -c Generate C-shell commands on stdout. This is the default if + SHELL looks like it's a csh style of shell. + + -d Debug mode. When this option is specified ssh-agent will not + fork. + + -k Kill the current agent (given by the SSH_AGENT_PID environment + variable). + + -s Generate Bourne shell commands on stdout. This is the default if + SHELL does not look like it's a csh style of shell. + + -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_config(5). A lifetime specified + for an identity with ssh-add(1) overrides this value. Without + this option the default maximum lifetime is forever. + + 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 + ~/.ssh/id_rsa, ~/.ssh/id_dsa, ~/.ssh/id_ecdsa and ~/.ssh/identity. If + the identity has a passphrase, ssh-add(1) asks for the passphrase on the + terminal if it has one or from a small X11 program if running under X11. + If neither of these is the case then the authentication will fail. It + then sends the identity to the agent. Several identities 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 + terminal. Authentication data need not be stored on any other machine, + and authentication passphrases never go over the network. However, the + connection to the agent is forwarded over SSH remote logins, and the user + can thus use the privileges given by the identities anywhere in the + network 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 evaluated 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 + connection to the agent. + + The agent will never send a private key over its request channel. + Instead, operations that require a private key will be performed by the + agent, and the result will be returned to the requester. This way, + private 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 + another 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 + ~/.ssh/identity + Contains the protocol version 1 RSA authentication identity of + the user. + + ~/.ssh/id_dsa + Contains the protocol version 2 DSA authentication identity of + the user. + + ~/.ssh/id_ecdsa + Contains the protocol version 2 ECDSA authentication identity of + the user. + + ~/.ssh/id_rsa + Contains the protocol version 2 RSA authentication identity of + the user. + + $TMPDIR/ssh-XXXXXXXXXX/agent.<ppid> + UNIX-domain sockets used to contain the connection to the + authentication 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 + created OpenSSH. Markus Friedl contributed the support for SSH protocol + versions 1.5 and 2.0. + +OpenBSD 5.4 November 21, 2010 OpenBSD 5.4 |