diff options
author | Colin Watson <cjwatson@debian.org> | 2008-07-22 14:59:59 +0000 |
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committer | Colin Watson <cjwatson@debian.org> | 2008-07-22 14:59:59 +0000 |
commit | ef94e5613d37bcbf880f21ee6094e4b1c7683a4c (patch) | |
tree | eebe1697910d248823033b5d14354c7f5ee8b471 /ssh-agent.0 | |
parent | 8f42e9b75a55401fa9dfdf14d49fbe5396c6ce92 (diff) | |
parent | 70847d299887abb96f8703ca99db6d817b78960e (diff) |
Import OpenSSH 5.1p1.
Diffstat (limited to 'ssh-agent.0')
-rw-r--r-- | ssh-agent.0 | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/ssh-agent.0 b/ssh-agent.0 new file mode 100644 index 000000000..90348a6b2 --- /dev/null +++ b/ssh-agent.0 | |||
@@ -0,0 +1,117 @@ | |||
1 | SSH-AGENT(1) OpenBSD Reference Manual SSH-AGENT(1) | ||
2 | |||
3 | NAME | ||
4 | ssh-agent - authentication agent | ||
5 | |||
6 | SYNOPSIS | ||
7 | ssh-agent [-c | -s] [-d] [-a bind_address] [-t life] [command [arg ...]] | ||
8 | ssh-agent [-c | -s] -k | ||
9 | |||
10 | DESCRIPTION | ||
11 | ssh-agent is a program to hold private keys used for public key authenti- | ||
12 | cation (RSA, DSA). The idea is that ssh-agent is started in the begin- | ||
13 | ning of an X-session or a login session, and all other windows or pro- | ||
14 | grams are started as clients to the ssh-agent program. Through use of | ||
15 | environment variables the agent can be located and automatically used for | ||
16 | authentication when logging in to other machines using ssh(1). | ||
17 | |||
18 | The options are as follows: | ||
19 | |||
20 | -a bind_address | ||
21 | Bind the agent to the unix-domain socket bind_address. The de- | ||
22 | fault is /tmp/ssh-XXXXXXXXXX/agent.<ppid>. | ||
23 | |||
24 | -c Generate C-shell commands on stdout. This is the default if | ||
25 | SHELL looks like it's a csh style of shell. | ||
26 | |||
27 | -d Debug mode. When this option is specified ssh-agent will not | ||
28 | fork. | ||
29 | |||
30 | -k Kill the current agent (given by the SSH_AGENT_PID environment | ||
31 | variable). | ||
32 | |||
33 | -s Generate Bourne shell commands on stdout. This is the default if | ||
34 | SHELL does not look like it's a csh style of shell. | ||
35 | |||
36 | -t life | ||
37 | Set a default value for the maximum lifetime of identities added | ||
38 | to the agent. The lifetime may be specified in seconds or in a | ||
39 | time format specified in sshd_config(5). A lifetime specified | ||
40 | for an identity with ssh-add(1) overrides this value. Without | ||
41 | this option the default maximum lifetime is forever. | ||
42 | |||
43 | If a commandline is given, this is executed as a subprocess of the agent. | ||
44 | When the command dies, so does the agent. | ||
45 | |||
46 | The agent initially does not have any private keys. Keys are added using | ||
47 | ssh-add(1). When executed without arguments, ssh-add(1) adds the files | ||
48 | ~/.ssh/id_rsa, ~/.ssh/id_dsa and ~/.ssh/identity. If the identity has a | ||
49 | passphrase, ssh-add(1) asks for the passphrase (using a small X11 appli- | ||
50 | cation if running under X11, or from the terminal if running without X). | ||
51 | It then sends the identity to the agent. Several identities can be | ||
52 | stored in the agent; the agent can automatically use any of these identi- | ||
53 | ties. ssh-add -l displays the identities currently held by the agent. | ||
54 | |||
55 | The idea is that the agent is run in the user's local PC, laptop, or ter- | ||
56 | minal. Authentication data need not be stored on any other machine, and | ||
57 | authentication passphrases never go over the network. However, the con- | ||
58 | nection to the agent is forwarded over SSH remote logins, and the user | ||
59 | can thus use the privileges given by the identities anywhere in the net- | ||
60 | work in a secure way. | ||
61 | |||
62 | There are two main ways to get an agent set up: The first is that the | ||
63 | agent starts a new subcommand into which some environment variables are | ||
64 | exported, eg ssh-agent xterm &. The second is that the agent prints the | ||
65 | needed shell commands (either sh(1) or csh(1) syntax can be generated) | ||
66 | which can be evalled in the calling shell, eg eval `ssh-agent -s` for | ||
67 | Bourne-type shells such as sh(1) or ksh(1) and eval `ssh-agent -c` for | ||
68 | csh(1) and derivatives. | ||
69 | |||
70 | Later ssh(1) looks at these variables and uses them to establish a con- | ||
71 | nection to the agent. | ||
72 | |||
73 | The agent will never send a private key over its request channel. In- | ||
74 | stead, operations that require a private key will be performed by the | ||
75 | agent, and the result will be returned to the requester. This way, pri- | ||
76 | vate keys are not exposed to clients using the agent. | ||
77 | |||
78 | A unix-domain socket is created and the name of this socket is stored in | ||
79 | the SSH_AUTH_SOCK environment variable. The socket is made accessible | ||
80 | only to the current user. This method is easily abused by root or anoth- | ||
81 | er instance of the same user. | ||
82 | |||
83 | The SSH_AGENT_PID environment variable holds the agent's process ID. | ||
84 | |||
85 | The agent exits automatically when the command given on the command line | ||
86 | terminates. | ||
87 | |||
88 | FILES | ||
89 | ~/.ssh/identity | ||
90 | Contains the protocol version 1 RSA authentication identity of | ||
91 | the user. | ||
92 | |||
93 | ~/.ssh/id_dsa | ||
94 | Contains the protocol version 2 DSA authentication identity of | ||
95 | the user. | ||
96 | |||
97 | ~/.ssh/id_rsa | ||
98 | Contains the protocol version 2 RSA authentication identity of | ||
99 | the user. | ||
100 | |||
101 | /tmp/ssh-XXXXXXXXXX/agent.<ppid> | ||
102 | Unix-domain sockets used to contain the connection to the authen- | ||
103 | tication agent. These sockets should only be readable by the | ||
104 | owner. The sockets should get automatically removed when the | ||
105 | agent exits. | ||
106 | |||
107 | SEE ALSO | ||
108 | ssh(1), ssh-add(1), ssh-keygen(1), sshd(8) | ||
109 | |||
110 | AUTHORS | ||
111 | OpenSSH is a derivative of the original and free ssh 1.2.12 release by | ||
112 | Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo | ||
113 | de Raadt and Dug Song removed many bugs, re-added newer features and cre- | ||
114 | ated OpenSSH. Markus Friedl contributed the support for SSH protocol | ||
115 | versions 1.5 and 2.0. | ||
116 | |||
117 | OpenBSD 4.4 June 5, 2007 2 | ||