ssh-agent(1) User Commands ssh-agent(1)NAMEssh-agent - authentication agent
SYNOPSISssh-agent [-a bind_address] [-c | -s ] [-d]
[command [args]...]
ssh-agent [-c | -s] -k
DESCRIPTIONssh-agent is a program to hold private keys used for public key authen‐
tication (RSA, DSA). ssh-agent is often started at the beginning of a
login session. 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). See the System Administration Guide:
Security Services.
If a command line 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), which sends the identity to the agent. Several iden‐
tities can be stored in the agent; the agent can automatically use any
of these identities. Use the -l option in ssh-add(1) to display the
identities currently held by the agent.
The agent is run in the user's local host. Authentication data need not
be stored on any other machine, and authentication passphrases never go
over the network. However, if the connection to the agent is forwarded
over SSH remote logins, the user can use the privileges given by the
identities anywhere in the network in a secure way.
There are two main ways to get an agent setup. Either you let the agent
start a new subcommand into which some environment variables are
exported, or you let the agent print the needed shell commands (either
sh(1) or csh(1) syntax can be generated) which can be evalled in the
calling shell. Later, use ssh(1) to look at these variables and use
them to establish a connection to the agent.
A unix-domain socket is created (/tmp/ssh-XXXXXXXX/agent.pid) and the
name of this socket is stored in the SSH_AUTH_SOCK environment vari‐
able. 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 PID.
The agent exits automatically when the command given on the command
line terminates.
OPTIONS
The following options are supported:
-a bind_address Binds the agent to the unix-domain socket
bind_address. The default is /tmp/ssh-
XXXXXXXX/agent.pid.
-c Generates C-shell commands on stdout. This is the
default if SHELL indicates that it is a csh style of
shell.
-d Debug mode. When this option is specified, ssh-agent
will not fork.
-k Kills the current agent (given by the SSH_AGENT_PID
environment variable).
-s Generates Bourne shell commands on stdout. This is
the default if SHELL does not indicate that it is a
csh style of shell.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
1 An error occurred.
FILES
/tmp/ssh-XXXXXXXX/agent.pid
Unix-domain sockets used to contain the connection to the authenti‐
cation agent. These sockets should only be readable by the owner.
The sockets are removed when the agent exits.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWsshu │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOssh(1), ssh-add(1), ssh-keygen(1), sshd(1M), attributes(5)
System Administration Guide: Security Services
SunOS 5.10 17 Nov 2008 ssh-agent(1)
