xref: /openssh-portable/ssh-add.1 (revision fe2ec0b9)
1.\"	$OpenBSD: ssh-add.1,v 1.80 2020/06/26 05:04:07 djm Exp $
2.\"
3.\" Author: Tatu Ylonen <ylo@cs.hut.fi>
4.\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5.\"                    All rights reserved
6.\"
7.\" As far as I am concerned, the code I have written for this software
8.\" can be used freely for any purpose.  Any derived versions of this
9.\" software must be clearly marked as such, and if the derived work is
10.\" incompatible with the protocol description in the RFC file, it must be
11.\" called by a name other than "ssh" or "Secure Shell".
12.\"
13.\"
14.\" Copyright (c) 1999,2000 Markus Friedl.  All rights reserved.
15.\" Copyright (c) 1999 Aaron Campbell.  All rights reserved.
16.\" Copyright (c) 1999 Theo de Raadt.  All rights reserved.
17.\"
18.\" Redistribution and use in source and binary forms, with or without
19.\" modification, are permitted provided that the following conditions
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21.\" 1. Redistributions of source code must retain the above copyright
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23.\" 2. Redistributions in binary form must reproduce the above copyright
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25.\"    documentation and/or other materials provided with the distribution.
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27.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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29.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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32.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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38.Dd $Mdocdate: June 26 2020 $
39.Dt SSH-ADD 1
40.Os
41.Sh NAME
42.Nm ssh-add
43.Nd adds private key identities to the OpenSSH authentication agent
44.Sh SYNOPSIS
45.Nm ssh-add
46.Op Fl cDdKkLlqvXx
47.Op Fl E Ar fingerprint_hash
48.Op Fl S Ar provider
49.Op Fl t Ar life
50.Op Ar
51.Nm ssh-add
52.Fl s Ar pkcs11
53.Nm ssh-add
54.Fl e Ar pkcs11
55.Nm ssh-add
56.Fl T
57.Ar pubkey ...
58.Sh DESCRIPTION
59.Nm
60adds private key identities to the authentication agent,
61.Xr ssh-agent 1 .
62When run without arguments, it adds the files
63.Pa ~/.ssh/id_rsa ,
64.Pa ~/.ssh/id_dsa ,
65.Pa ~/.ssh/id_ecdsa ,
66.Pa ~/.ssh/id_ecdsa_sk ,
67.Pa ~/.ssh/id_ed25519 ,
68and
69.Pa ~/.ssh/id_ed25519_sk .
70After loading a private key,
71.Nm
72will try to load corresponding certificate information from the
73filename obtained by appending
74.Pa -cert.pub
75to the name of the private key file.
76Alternative file names can be given on the command line.
77.Pp
78If any file requires a passphrase,
79.Nm
80asks for the passphrase from the user.
81The passphrase is read from the user's tty.
82.Nm
83retries the last passphrase if multiple identity files are given.
84.Pp
85The authentication agent must be running and the
86.Ev SSH_AUTH_SOCK
87environment variable must contain the name of its socket for
88.Nm
89to work.
90.Pp
91The options are as follows:
92.Bl -tag -width Ds
93.It Fl c
94Indicates that added identities should be subject to confirmation before
95being used for authentication.
96Confirmation is performed by
97.Xr ssh-askpass 1 .
98Successful confirmation is signaled by a zero exit status from
99.Xr ssh-askpass 1 ,
100rather than text entered into the requester.
101.It Fl D
102Deletes all identities from the agent.
103.It Fl d
104Instead of adding identities, removes identities from the agent.
105If
106.Nm
107has been run without arguments, the keys for the default identities and
108their corresponding certificates will be removed.
109Otherwise, the argument list will be interpreted as a list of paths to
110public key files to specify keys and certificates to be removed from the agent.
111If no public key is found at a given path,
112.Nm
113will append
114.Pa .pub
115and retry.
116If the argument list consists of
117.Dq -
118then
119.Nm
120will read public keys to be removed from standard input.
121.It Fl E Ar fingerprint_hash
122Specifies the hash algorithm used when displaying key fingerprints.
123Valid options are:
124.Dq md5
125and
126.Dq sha256 .
127The default is
128.Dq sha256 .
129.It Fl e Ar pkcs11
130Remove keys provided by the PKCS#11 shared library
131.Ar pkcs11 .
132.It Fl K
133Load resident keys from a FIDO authenticator.
134.It Fl k
135When loading keys into or deleting keys from the agent, process plain private
136keys only and skip certificates.
137.It Fl L
138Lists public key parameters of all identities currently represented
139by the agent.
140.It Fl l
141Lists fingerprints of all identities currently represented by the agent.
142.It Fl q
143Be quiet after a successful operation.
144.It Fl S Ar provider
145Specifies a path to a library that will be used when adding
146FIDO authenticator-hosted keys, overriding the default of using the
147internal USB HID support.
148.It Fl s Ar pkcs11
149Add keys provided by the PKCS#11 shared library
150.Ar pkcs11 .
151.It Fl T Ar pubkey ...
152Tests whether the private keys that correspond to the specified
153.Ar pubkey
154files are usable by performing sign and verify operations on each.
155.It Fl t Ar life
156Set a maximum lifetime when adding identities to an agent.
157The lifetime may be specified in seconds or in a time format
158specified in
159.Xr sshd_config 5 .
160.It Fl v
161Verbose mode.
162Causes
163.Nm
164to print debugging messages about its progress.
165This is helpful in debugging problems.
166Multiple
167.Fl v
168options increase the verbosity.
169The maximum is 3.
170.It Fl X
171Unlock the agent.
172.It Fl x
173Lock the agent with a password.
174.El
175.Sh ENVIRONMENT
176.Bl -tag -width Ds
177.It Ev "DISPLAY" and "SSH_ASKPASS"
178If
179.Nm
180needs a passphrase, it will read the passphrase from the current
181terminal if it was run from a terminal.
182If
183.Nm
184does not have a terminal associated with it but
185.Ev DISPLAY
186and
187.Ev SSH_ASKPASS
188are set, it will execute the program specified by
189.Ev SSH_ASKPASS
190(by default
191.Dq ssh-askpass )
192and open an X11 window to read the passphrase.
193This is particularly useful when calling
194.Nm
195from a
196.Pa .xsession
197or related script.
198(Note that on some machines it
199may be necessary to redirect the input from
200.Pa /dev/null
201to make this work.)
202.It Ev SSH_AUTH_SOCK
203Identifies the path of a
204.Ux Ns -domain
205socket used to communicate with the agent.
206.It Ev SSH_SK_PROVIDER
207Specifies a path to a library that will be used when loading any
208FIDO authenticator-hosted keys, overriding the default of using
209the built-in USB HID support.
210.El
211.Sh FILES
212.Bl -tag -width Ds -compact
213.It Pa ~/.ssh/id_dsa
214.It Pa ~/.ssh/id_ecdsa
215.It Pa ~/.ssh/id_ecdsa_sk
216.It Pa ~/.ssh/id_ed25519
217.It Pa ~/.ssh/id_ed25519_sk
218.It Pa ~/.ssh/id_rsa
219Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
220authenticator-hosted Ed25519 or RSA authentication identity of the user.
221.El
222.Pp
223Identity files should not be readable by anyone but the user.
224Note that
225.Nm
226ignores identity files if they are accessible by others.
227.Sh EXIT STATUS
228Exit status is 0 on success, 1 if the specified command fails,
229and 2 if
230.Nm
231is unable to contact the authentication agent.
232.Sh SEE ALSO
233.Xr ssh 1 ,
234.Xr ssh-agent 1 ,
235.Xr ssh-askpass 1 ,
236.Xr ssh-keygen 1 ,
237.Xr sshd 8
238.Sh AUTHORS
239OpenSSH is a derivative of the original and free
240ssh 1.2.12 release by Tatu Ylonen.
241Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
242Theo de Raadt and Dug Song
243removed many bugs, re-added newer features and
244created OpenSSH.
245Markus Friedl contributed the support for SSH
246protocol versions 1.5 and 2.0.
247