| ssh-agent.0 (207311) | ssh-agent.0 (214979) |
|---|---|
| 1SSH-AGENT(1) OpenBSD Reference Manual SSH-AGENT(1) 2 3NAME 4 ssh-agent - authentication agent 5 6SYNOPSIS 7 ssh-agent [-c | -s] [-d] [-a bind_address] [-t life] [command [arg ...]] 8 ssh-agent [-c | -s] -k 9 10DESCRIPTION | 1SSH-AGENT(1) OpenBSD Reference Manual SSH-AGENT(1) 2 3NAME 4 ssh-agent - authentication agent 5 6SYNOPSIS 7 ssh-agent [-c | -s] [-d] [-a bind_address] [-t life] [command [arg ...]] 8 ssh-agent [-c | -s] -k 9 10DESCRIPTION |
| 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 | 11 ssh-agent is a program to hold private keys used for public key 12 authentication (RSA, DSA). The idea is that ssh-agent is started in the 13 beginning of an X-session or a login session, and all other windows or 14 programs 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 | 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. | 21 Bind the agent to the UNIX-domain socket bind_address. The 22 default 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 --- 14 unchanged lines hidden (view full) --- 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 on the terminal if it has 50 one or from a small X11 program if running under X11. If neither of 51 these is the case then the authentication will fail. It then sends the 52 identity to the agent. Several identities can be stored in the agent; | 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 --- 14 unchanged lines hidden (view full) --- 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 on the terminal if it has 50 one or from a small X11 program if running under X11. If neither of 51 these is the case then the authentication will fail. It then sends the 52 identity to the agent. Several identities can be stored in the agent; |
| 53 the agent can automatically use any of these identities. ssh-add -l dis- 54 plays the identities currently held by the agent. | 53 the agent can automatically use any of these identities. ssh-add -l 54 displays the identities currently held by the agent. |
| 55 | 55 |
| 56 The idea is that the agent is run in the user's local PC, laptop, or ter- 57 minal. Authentication data need not be stored on any other machine, and 58 authentication passphrases never go over the network. However, the con- 59 nection to the agent is forwarded over SSH remote logins, and the user 60 can thus use the privileges given by the identities anywhere in the net- 61 work in a secure way. | 56 The idea is that the agent is run in the user's local PC, laptop, or 57 terminal. Authentication data need not be stored on any other machine, 58 and authentication passphrases never go over the network. However, the 59 connection to the agent is forwarded over SSH remote logins, and the user 60 can thus use the privileges given by the identities anywhere in the 61 network in a secure way. |
| 62 63 There are two main ways to get an agent set up: The first is that the 64 agent starts a new subcommand into which some environment variables are 65 exported, eg ssh-agent xterm &. The second is that the agent prints the 66 needed shell commands (either sh(1) or csh(1) syntax can be generated) 67 which can be evaluated in the calling shell, eg eval `ssh-agent -s` for 68 Bourne-type shells such as sh(1) or ksh(1) and eval `ssh-agent -c` for 69 csh(1) and derivatives. 70 | 62 63 There are two main ways to get an agent set up: The first is that the 64 agent starts a new subcommand into which some environment variables are 65 exported, eg ssh-agent xterm &. The second is that the agent prints the 66 needed shell commands (either sh(1) or csh(1) syntax can be generated) 67 which can be evaluated in the calling shell, eg eval `ssh-agent -s` for 68 Bourne-type shells such as sh(1) or ksh(1) and eval `ssh-agent -c` for 69 csh(1) and derivatives. 70 |
| 71 Later ssh(1) looks at these variables and uses them to establish a con- 72 nection to the agent. | 71 Later ssh(1) looks at these variables and uses them to establish a 72 connection to the agent. |
| 73 | 73 |
| 74 The agent will never send a private key over its request channel. In- 75 stead, operations that require a private key will be performed by the 76 agent, and the result will be returned to the requester. This way, pri- 77 vate keys are not exposed to clients using the agent. | 74 The agent will never send a private key over its request channel. 75 Instead, operations that require a private key will be performed by the 76 agent, and the result will be returned to the requester. This way, 77 private keys are not exposed to clients using the agent. |
| 78 79 A UNIX-domain socket is created and the name of this socket is stored in 80 the SSH_AUTH_SOCK environment variable. The socket is made accessible | 78 79 A UNIX-domain socket is created and the name of this socket is stored in 80 the SSH_AUTH_SOCK environment variable. The socket is made accessible |
| 81 only to the current user. This method is easily abused by root or anoth- 82 er instance of the same user. | 81 only to the current user. This method is easily abused by root or 82 another instance of the same user. |
| 83 84 The SSH_AGENT_PID environment variable holds the agent's process ID. 85 86 The agent exits automatically when the command given on the command line 87 terminates. 88 89FILES 90 ~/.ssh/identity --- 4 unchanged lines hidden (view full) --- 95 Contains the protocol version 2 DSA authentication identity of 96 the user. 97 98 ~/.ssh/id_rsa 99 Contains the protocol version 2 RSA authentication identity of 100 the user. 101 102 /tmp/ssh-XXXXXXXXXX/agent.<ppid> | 83 84 The SSH_AGENT_PID environment variable holds the agent's process ID. 85 86 The agent exits automatically when the command given on the command line 87 terminates. 88 89FILES 90 ~/.ssh/identity --- 4 unchanged lines hidden (view full) --- 95 Contains the protocol version 2 DSA authentication identity of 96 the user. 97 98 ~/.ssh/id_rsa 99 Contains the protocol version 2 RSA authentication identity of 100 the user. 101 102 /tmp/ssh-XXXXXXXXXX/agent.<ppid> |
| 103 UNIX-domain sockets used to contain the connection to the authen- 104 tication agent. These sockets should only be readable by the 105 owner. The sockets should get automatically removed when the | 103 UNIX-domain sockets used to contain the connection to the 104 authentication agent. These sockets should only be readable by 105 the owner. The sockets should get automatically removed when the |
| 106 agent exits. 107 108SEE ALSO 109 ssh(1), ssh-add(1), ssh-keygen(1), sshd(8) 110 111AUTHORS 112 OpenSSH is a derivative of the original and free ssh 1.2.12 release by 113 Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo | 106 agent exits. 107 108SEE ALSO 109 ssh(1), ssh-add(1), ssh-keygen(1), sshd(8) 110 111AUTHORS 112 OpenSSH is a derivative of the original and free ssh 1.2.12 release by 113 Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo |
| 114 de Raadt and Dug Song removed many bugs, re-added newer features and cre- 115 ated OpenSSH. Markus Friedl contributed the support for SSH protocol | 114 de Raadt and Dug Song removed many bugs, re-added newer features and 115 created OpenSSH. Markus Friedl contributed the support for SSH protocol |
| 116 versions 1.5 and 2.0. 117 | 116 versions 1.5 and 2.0. 117 |
| 118OpenBSD 4.7 January 17, 2010 2 | 118OpenBSD 4.8 January 17, 2010 OpenBSD 4.8 |