Damien Miller | 390d056 | 2011-10-18 16:05:19 +1100 | [diff] [blame] | 1 | .\" $OpenBSD: ssh-keygen.1,v 1.108 2011/10/16 11:02:46 dtucker Exp $ |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 2 | .\" |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 3 | .\" Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 4 | .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | .\" All rights reserved |
| 6 | .\" |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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". |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 12 | .\" |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 13 | .\" |
Ben Lindstrom | 92a2e38 | 2001-03-05 06:59:27 +0000 | [diff] [blame] | 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. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 17 | .\" |
| 18 | .\" Redistribution and use in source and binary forms, with or without |
| 19 | .\" modification, are permitted provided that the following conditions |
| 20 | .\" are met: |
| 21 | .\" 1. Redistributions of source code must retain the above copyright |
| 22 | .\" notice, this list of conditions and the following disclaimer. |
| 23 | .\" 2. Redistributions in binary form must reproduce the above copyright |
| 24 | .\" notice, this list of conditions and the following disclaimer in the |
| 25 | .\" documentation and/or other materials provided with the distribution. |
| 26 | .\" |
| 27 | .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 28 | .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 29 | .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 30 | .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 31 | .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 32 | .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 33 | .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 34 | .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 35 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 36 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 37 | .\" |
Damien Miller | 390d056 | 2011-10-18 16:05:19 +1100 | [diff] [blame] | 38 | .Dd $Mdocdate: October 16 2011 $ |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 39 | .Dt SSH-KEYGEN 1 |
| 40 | .Os |
| 41 | .Sh NAME |
| 42 | .Nm ssh-keygen |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 43 | .Nd authentication key generation, management and conversion |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 44 | .Sh SYNOPSIS |
Damien Miller | 495dca3 | 2003-04-01 21:42:14 +1000 | [diff] [blame] | 45 | .Bk -words |
Damien Miller | bad5e03 | 2010-07-16 13:59:59 +1000 | [diff] [blame] | 46 | .Nm ssh-keygen |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 47 | .Op Fl q |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 48 | .Op Fl b Ar bits |
Damien Miller | 55fafa0 | 2002-02-19 15:22:07 +1100 | [diff] [blame] | 49 | .Fl t Ar type |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 50 | .Op Fl N Ar new_passphrase |
| 51 | .Op Fl C Ar comment |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 52 | .Op Fl f Ar output_keyfile |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 53 | .Nm ssh-keygen |
| 54 | .Fl p |
| 55 | .Op Fl P Ar old_passphrase |
| 56 | .Op Fl N Ar new_passphrase |
Damien Miller | 10f6f6b | 1999-11-17 17:29:08 +1100 | [diff] [blame] | 57 | .Op Fl f Ar keyfile |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 58 | .Nm ssh-keygen |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 59 | .Fl i |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 60 | .Op Fl m Ar key_format |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 61 | .Op Fl f Ar input_keyfile |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 62 | .Nm ssh-keygen |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 63 | .Fl e |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 64 | .Op Fl m Ar key_format |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 65 | .Op Fl f Ar input_keyfile |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 66 | .Nm ssh-keygen |
| 67 | .Fl y |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 68 | .Op Fl f Ar input_keyfile |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 69 | .Nm ssh-keygen |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 70 | .Fl c |
| 71 | .Op Fl P Ar passphrase |
| 72 | .Op Fl C Ar comment |
Damien Miller | 10f6f6b | 1999-11-17 17:29:08 +1100 | [diff] [blame] | 73 | .Op Fl f Ar keyfile |
| 74 | .Nm ssh-keygen |
| 75 | .Fl l |
Ben Lindstrom | 8fd372b | 2001-03-12 03:02:17 +0000 | [diff] [blame] | 76 | .Op Fl f Ar input_keyfile |
| 77 | .Nm ssh-keygen |
| 78 | .Fl B |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 79 | .Op Fl f Ar input_keyfile |
Ben Lindstrom | a1ec4a9 | 2001-08-06 21:51:34 +0000 | [diff] [blame] | 80 | .Nm ssh-keygen |
Damien Miller | 048dc93 | 2010-02-12 09:22:04 +1100 | [diff] [blame] | 81 | .Fl D Ar pkcs11 |
Ben Lindstrom | a1ec4a9 | 2001-08-06 21:51:34 +0000 | [diff] [blame] | 82 | .Nm ssh-keygen |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 83 | .Fl F Ar hostname |
| 84 | .Op Fl f Ar known_hosts_file |
Damien Miller | 718ed50 | 2008-11-03 19:15:20 +1100 | [diff] [blame] | 85 | .Op Fl l |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 86 | .Nm ssh-keygen |
| 87 | .Fl H |
| 88 | .Op Fl f Ar known_hosts_file |
| 89 | .Nm ssh-keygen |
| 90 | .Fl R Ar hostname |
| 91 | .Op Fl f Ar known_hosts_file |
| 92 | .Nm ssh-keygen |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 93 | .Fl r Ar hostname |
| 94 | .Op Fl f Ar input_keyfile |
| 95 | .Op Fl g |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 96 | .Nm ssh-keygen |
| 97 | .Fl G Ar output_file |
Darren Tucker | 06930c7 | 2003-12-31 11:34:51 +1100 | [diff] [blame] | 98 | .Op Fl v |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 99 | .Op Fl b Ar bits |
| 100 | .Op Fl M Ar memory |
| 101 | .Op Fl S Ar start_point |
| 102 | .Nm ssh-keygen |
| 103 | .Fl T Ar output_file |
| 104 | .Fl f Ar input_file |
Darren Tucker | 06930c7 | 2003-12-31 11:34:51 +1100 | [diff] [blame] | 105 | .Op Fl v |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 106 | .Op Fl a Ar num_trials |
Damien Miller | 390d056 | 2011-10-18 16:05:19 +1100 | [diff] [blame] | 107 | .Op Fl K Ar checkpt |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 108 | .Op Fl W Ar generator |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 109 | .Nm ssh-keygen |
| 110 | .Fl s Ar ca_key |
| 111 | .Fl I Ar certificate_identity |
| 112 | .Op Fl h |
| 113 | .Op Fl n Ar principals |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 114 | .Op Fl O Ar option |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 115 | .Op Fl V Ar validity_interval |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 116 | .Op Fl z Ar serial_number |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 117 | .Ar |
Damien Miller | f2b70ca | 2010-03-05 07:39:35 +1100 | [diff] [blame] | 118 | .Nm ssh-keygen |
Damien Miller | f2b70ca | 2010-03-05 07:39:35 +1100 | [diff] [blame] | 119 | .Fl L |
| 120 | .Op Fl f Ar input_keyfile |
Damien Miller | 58f1baf | 2011-05-05 14:06:15 +1000 | [diff] [blame] | 121 | .Nm ssh-keygen |
| 122 | .Fl A |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 123 | .Ek |
Damien Miller | 22c7726 | 2000-04-13 12:26:34 +1000 | [diff] [blame] | 124 | .Sh DESCRIPTION |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 125 | .Nm |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 126 | generates, manages and converts authentication keys for |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 127 | .Xr ssh 1 . |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 128 | .Nm |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 129 | can create RSA keys for use by SSH protocol version 1 and DSA, ECDSA or RSA |
Damien Miller | fbf486b | 2003-05-23 18:44:23 +1000 | [diff] [blame] | 130 | keys for use by SSH protocol version 2. |
| 131 | The type of key to be generated is specified with the |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 132 | .Fl t |
Damien Miller | a41c8b1 | 2002-01-22 23:05:08 +1100 | [diff] [blame] | 133 | option. |
Damien Miller | f14be5c | 2005-11-05 15:15:49 +1100 | [diff] [blame] | 134 | If invoked without any arguments, |
| 135 | .Nm |
Damien Miller | 83d0d39 | 2005-11-05 15:16:27 +1100 | [diff] [blame] | 136 | will generate an RSA key for use in SSH protocol 2 connections. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 137 | .Pp |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 138 | .Nm |
| 139 | is also used to generate groups for use in Diffie-Hellman group |
| 140 | exchange (DH-GEX). |
| 141 | See the |
| 142 | .Sx MODULI GENERATION |
| 143 | section for details. |
| 144 | .Pp |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 145 | Normally each user wishing to use SSH |
Damien Miller | eb8b60e | 2010-08-31 22:41:14 +1000 | [diff] [blame] | 146 | with public key authentication runs this once to create the authentication |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 147 | key in |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 148 | .Pa ~/.ssh/identity , |
Damien Miller | eb8b60e | 2010-08-31 22:41:14 +1000 | [diff] [blame] | 149 | .Pa ~/.ssh/id_ecdsa , |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 150 | .Pa ~/.ssh/id_dsa |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 151 | or |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 152 | .Pa ~/.ssh/id_rsa . |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 153 | Additionally, the system administrator may use this to generate host keys, |
| 154 | as seen in |
| 155 | .Pa /etc/rc . |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 156 | .Pp |
| 157 | Normally this program generates the key and asks for a file in which |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 158 | to store the private key. |
| 159 | The public key is stored in a file with the same name but |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 160 | .Dq .pub |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 161 | appended. |
| 162 | The program also asks for a passphrase. |
| 163 | The passphrase may be empty to indicate no passphrase |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 164 | (host keys must have an empty passphrase), or it may be a string of |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 165 | arbitrary length. |
Ben Lindstrom | 4e366d5 | 2001-12-06 16:43:21 +0000 | [diff] [blame] | 166 | A passphrase is similar to a password, except it can be a phrase with a |
| 167 | series of words, punctuation, numbers, whitespace, or any string of |
| 168 | characters you want. |
| 169 | Good passphrases are 10-30 characters long, are |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 170 | not simple sentences or otherwise easily guessable (English |
Ben Lindstrom | 2a097a4 | 2001-06-09 01:13:40 +0000 | [diff] [blame] | 171 | prose has only 1-2 bits of entropy per character, and provides very bad |
Ben Lindstrom | 4e366d5 | 2001-12-06 16:43:21 +0000 | [diff] [blame] | 172 | passphrases), and contain a mix of upper and lowercase letters, |
| 173 | numbers, and non-alphanumeric characters. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 174 | The passphrase can be changed later by using the |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 175 | .Fl p |
| 176 | option. |
| 177 | .Pp |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 178 | There is no way to recover a lost passphrase. |
Damien Miller | 085c90f | 2011-05-05 14:15:33 +1000 | [diff] [blame] | 179 | If the passphrase is lost or forgotten, a new key must be generated |
| 180 | and the corresponding public key copied to other machines. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 181 | .Pp |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 182 | For RSA1 keys, |
| 183 | there is also a comment field in the key file that is only for |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 184 | convenience to the user to help identify the key. |
| 185 | The comment can tell what the key is for, or whatever is useful. |
| 186 | The comment is initialized to |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 187 | .Dq user@host |
| 188 | when the key is created, but can be changed using the |
| 189 | .Fl c |
| 190 | option. |
| 191 | .Pp |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 192 | After a key is generated, instructions below detail where the keys |
| 193 | should be placed to be activated. |
| 194 | .Pp |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 195 | The options are as follows: |
| 196 | .Bl -tag -width Ds |
Damien Miller | 58f1baf | 2011-05-05 14:06:15 +1000 | [diff] [blame] | 197 | .It Fl A |
| 198 | For each of the key types (rsa1, rsa, dsa and ecdsa) for which host keys |
| 199 | do not exist, generate the host keys with the default key file path, |
| 200 | an empty passphrase, default bits for the key type, and default comment. |
Damien Miller | 3ca1eb3 | 2011-05-05 14:13:50 +1000 | [diff] [blame] | 201 | This is used by |
Damien Miller | 58f1baf | 2011-05-05 14:06:15 +1000 | [diff] [blame] | 202 | .Pa /etc/rc |
| 203 | to generate new host keys. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 204 | .It Fl a Ar trials |
| 205 | Specifies the number of primality tests to perform when screening DH-GEX |
| 206 | candidates using the |
| 207 | .Fl T |
| 208 | command. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 209 | .It Fl B |
| 210 | Show the bubblebabble digest of specified private or public key file. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 211 | .It Fl b Ar bits |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 212 | Specifies the number of bits in the key to create. |
Darren Tucker | 9f64733 | 2005-11-28 16:41:46 +1100 | [diff] [blame] | 213 | For RSA keys, the minimum size is 768 bits and the default is 2048 bits. |
Damien Miller | ac7ef6a | 2005-06-16 13:19:06 +1000 | [diff] [blame] | 214 | Generally, 2048 bits is considered sufficient. |
Darren Tucker | 9f64733 | 2005-11-28 16:41:46 +1100 | [diff] [blame] | 215 | DSA keys must be exactly 1024 bits as specified by FIPS 186-2. |
Damien Miller | ad21032 | 2011-05-05 14:15:54 +1000 | [diff] [blame] | 216 | For ECDSA keys, the |
| 217 | .Fl b |
Damien Miller | 6232a16 | 2011-09-22 21:36:00 +1000 | [diff] [blame] | 218 | flag determines the key length by selecting from one of three elliptic |
Damien Miller | ad21032 | 2011-05-05 14:15:54 +1000 | [diff] [blame] | 219 | curve sizes: 256, 384 or 521 bits. |
| 220 | Attempting to use bit lengths other than these three values for ECDSA keys |
| 221 | will fail. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 222 | .It Fl C Ar comment |
| 223 | Provides a new comment. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 224 | .It Fl c |
| 225 | Requests changing the comment in the private and public key files. |
Damien Miller | eb5fec6 | 2001-11-12 10:52:44 +1100 | [diff] [blame] | 226 | This operation is only supported for RSA1 keys. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 227 | The program will prompt for the file containing the private keys, for |
Ben Lindstrom | aafff9c | 2001-05-06 03:01:02 +0000 | [diff] [blame] | 228 | the passphrase if the key has one, and for the new comment. |
Damien Miller | 7ea845e | 2010-02-12 09:21:02 +1100 | [diff] [blame] | 229 | .It Fl D Ar pkcs11 |
Damien Miller | a761844 | 2010-02-12 09:26:02 +1100 | [diff] [blame] | 230 | Download the RSA public keys provided by the PKCS#11 shared library |
| 231 | .Ar pkcs11 . |
Damien Miller | 757f34e | 2010-08-05 13:05:31 +1000 | [diff] [blame] | 232 | When used in combination with |
| 233 | .Fl s , |
| 234 | this option indicates that a CA key resides in a PKCS#11 token (see the |
| 235 | .Sx CERTIFICATES |
| 236 | section for details). |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 237 | .It Fl e |
Ben Lindstrom | 46c264f | 2001-04-24 16:56:58 +0000 | [diff] [blame] | 238 | This option will read a private or public OpenSSH key file and |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 239 | print to stdout the key in one of the formats specified by the |
| 240 | .Fl m |
| 241 | option. |
| 242 | The default export format is |
| 243 | .Dq RFC4716 . |
Damien Miller | ea72728 | 2010-07-02 13:35:34 +1000 | [diff] [blame] | 244 | This option allows exporting OpenSSH keys for use by other programs, including |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 245 | several commercial SSH implementations. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 246 | .It Fl F Ar hostname |
| 247 | Search for the specified |
| 248 | .Ar hostname |
| 249 | in a |
| 250 | .Pa known_hosts |
| 251 | file, listing any occurrences found. |
| 252 | This option is useful to find hashed host names or addresses and may also be |
| 253 | used in conjunction with the |
| 254 | .Fl H |
| 255 | option to print found keys in a hashed format. |
| 256 | .It Fl f Ar filename |
| 257 | Specifies the filename of the key file. |
| 258 | .It Fl G Ar output_file |
| 259 | Generate candidate primes for DH-GEX. |
| 260 | These primes must be screened for |
| 261 | safety (using the |
| 262 | .Fl T |
| 263 | option) before use. |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 264 | .It Fl g |
Darren Tucker | 0b42e6d | 2004-08-13 21:22:40 +1000 | [diff] [blame] | 265 | Use generic DNS format when printing fingerprint resource records using the |
Darren Tucker | 6e37037 | 2004-08-13 21:23:25 +1000 | [diff] [blame] | 266 | .Fl r |
Darren Tucker | 0b42e6d | 2004-08-13 21:22:40 +1000 | [diff] [blame] | 267 | command. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 268 | .It Fl H |
| 269 | Hash a |
| 270 | .Pa known_hosts |
Darren Tucker | da1adbc | 2005-03-14 23:15:58 +1100 | [diff] [blame] | 271 | file. |
| 272 | This replaces all hostnames and addresses with hashed representations |
| 273 | within the specified file; the original content is moved to a file with |
| 274 | a .old suffix. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 275 | These hashes may be used normally by |
| 276 | .Nm ssh |
| 277 | and |
| 278 | .Nm sshd , |
| 279 | but they do not reveal identifying information should the file's contents |
| 280 | be disclosed. |
| 281 | This option will not modify existing hashed hostnames and is therefore safe |
| 282 | to use on files that mix hashed and non-hashed names. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 283 | .It Fl h |
| 284 | When signing a key, create a host certificate instead of a user |
| 285 | certificate. |
| 286 | Please see the |
| 287 | .Sx CERTIFICATES |
| 288 | section for details. |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 289 | .It Fl I Ar certificate_identity |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 290 | Specify the key identity when signing a public key. |
| 291 | Please see the |
| 292 | .Sx CERTIFICATES |
| 293 | section for details. |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 294 | .It Fl i |
| 295 | This option will read an unencrypted private (or public) key file |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 296 | in the format specified by the |
| 297 | .Fl m |
| 298 | option and print an OpenSSH compatible private |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 299 | (or public) key to stdout. |
Damien Miller | 390d056 | 2011-10-18 16:05:19 +1100 | [diff] [blame] | 300 | .It Fl K Ar checkpt |
| 301 | Write the last line processed to the file |
| 302 | .Ar checkpt |
| 303 | while performing DH candidate screening using the |
| 304 | .Fl T |
| 305 | option. |
| 306 | This will be used to skip lines in the input file that have already been |
| 307 | processed if the job is restarted. |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 308 | This option allows importing keys from other software, including several |
| 309 | commercial SSH implementations. |
| 310 | The default import format is |
| 311 | .Dq RFC4716 . |
Damien Miller | f2b70ca | 2010-03-05 07:39:35 +1100 | [diff] [blame] | 312 | .It Fl L |
| 313 | Prints the contents of a certificate. |
Damien Miller | 10f6f6b | 1999-11-17 17:29:08 +1100 | [diff] [blame] | 314 | .It Fl l |
Darren Tucker | 35c4553 | 2008-06-13 04:43:15 +1000 | [diff] [blame] | 315 | Show fingerprint of specified public key file. |
Damien Miller | eb5fec6 | 2001-11-12 10:52:44 +1100 | [diff] [blame] | 316 | Private RSA1 keys are also supported. |
| 317 | For RSA and DSA keys |
| 318 | .Nm |
Darren Tucker | f09e825 | 2008-06-13 05:18:03 +1000 | [diff] [blame] | 319 | tries to find the matching public key file and prints its fingerprint. |
| 320 | If combined with |
| 321 | .Fl v , |
| 322 | an ASCII art representation of the key is supplied with the fingerprint. |
Damien Miller | ea72728 | 2010-07-02 13:35:34 +1000 | [diff] [blame] | 323 | .It Fl M Ar memory |
| 324 | Specify the amount of memory to use (in megabytes) when generating |
| 325 | candidate moduli for DH-GEX. |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 326 | .It Fl m Ar key_format |
| 327 | Specify a key format for the |
| 328 | .Fl i |
| 329 | (import) or |
| 330 | .Fl e |
Damien Miller | ea72728 | 2010-07-02 13:35:34 +1000 | [diff] [blame] | 331 | (export) conversion options. |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 332 | The supported key formats are: |
| 333 | .Dq RFC4716 |
Damien Miller | ea72728 | 2010-07-02 13:35:34 +1000 | [diff] [blame] | 334 | (RFC 4716/SSH2 public or private key), |
Damien Miller | 44b2504 | 2010-07-02 13:35:01 +1000 | [diff] [blame] | 335 | .Dq PKCS8 |
| 336 | (PEM PKCS8 public key) |
| 337 | or |
| 338 | .Dq PEM |
| 339 | (PEM public key). |
| 340 | The default conversion format is |
| 341 | .Dq RFC4716 . |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 342 | .It Fl N Ar new_passphrase |
| 343 | Provides the new passphrase. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 344 | .It Fl n Ar principals |
| 345 | Specify one or more principals (user or host names) to be included in |
| 346 | a certificate when signing a key. |
| 347 | Multiple principals may be specified, separated by commas. |
| 348 | Please see the |
| 349 | .Sx CERTIFICATES |
| 350 | section for details. |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 351 | .It Fl O Ar option |
| 352 | Specify a certificate option when signing a key. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 353 | This option may be specified multiple times. |
| 354 | Please see the |
| 355 | .Sx CERTIFICATES |
| 356 | section for details. |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 357 | The options that are valid for user certificates are: |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 358 | .Bl -tag -width Ds |
Damien Miller | c59e244 | 2010-03-22 05:50:31 +1100 | [diff] [blame] | 359 | .It Ic clear |
| 360 | Clear all enabled permissions. |
| 361 | This is useful for clearing the default set of permissions so permissions may |
| 362 | be added individually. |
| 363 | .It Ic force-command Ns = Ns Ar command |
| 364 | Forces the execution of |
| 365 | .Ar command |
| 366 | instead of any shell or command specified by the user when |
| 367 | the certificate is used for authentication. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 368 | .It Ic no-agent-forwarding |
| 369 | Disable |
| 370 | .Xr ssh-agent 1 |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 371 | forwarding (permitted by default). |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 372 | .It Ic no-port-forwarding |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 373 | Disable port forwarding (permitted by default). |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 374 | .It Ic no-pty |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 375 | Disable PTY allocation (permitted by default). |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 376 | .It Ic no-user-rc |
| 377 | Disable execution of |
| 378 | .Pa ~/.ssh/rc |
| 379 | by |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 380 | .Xr sshd 8 |
| 381 | (permitted by default). |
Damien Miller | c59e244 | 2010-03-22 05:50:31 +1100 | [diff] [blame] | 382 | .It Ic no-x11-forwarding |
| 383 | Disable X11 forwarding (permitted by default). |
Damien Miller | 081c976 | 2010-03-08 11:30:00 +1100 | [diff] [blame] | 384 | .It Ic permit-agent-forwarding |
| 385 | Allows |
| 386 | .Xr ssh-agent 1 |
| 387 | forwarding. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 388 | .It Ic permit-port-forwarding |
| 389 | Allows port forwarding. |
| 390 | .It Ic permit-pty |
| 391 | Allows PTY allocation. |
| 392 | .It Ic permit-user-rc |
| 393 | Allows execution of |
| 394 | .Pa ~/.ssh/rc |
| 395 | by |
| 396 | .Xr sshd 8 . |
Damien Miller | c59e244 | 2010-03-22 05:50:31 +1100 | [diff] [blame] | 397 | .It Ic permit-x11-forwarding |
| 398 | Allows X11 forwarding. |
| 399 | .It Ic source-address Ns = Ns Ar address_list |
Damien Miller | 77497e1 | 2010-03-22 05:50:51 +1100 | [diff] [blame] | 400 | Restrict the source addresses from which the certificate is considered valid. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 401 | The |
| 402 | .Ar address_list |
| 403 | is a comma-separated list of one or more address/netmask pairs in CIDR |
| 404 | format. |
| 405 | .El |
| 406 | .Pp |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 407 | At present, no options are valid for host keys. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 408 | .It Fl P Ar passphrase |
| 409 | Provides the (old) passphrase. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 410 | .It Fl p |
| 411 | Requests changing the passphrase of a private key file instead of |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 412 | creating a new private key. |
| 413 | The program will prompt for the file |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 414 | containing the private key, for the old passphrase, and twice for the |
| 415 | new passphrase. |
| 416 | .It Fl q |
| 417 | Silence |
| 418 | .Nm ssh-keygen . |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 419 | .It Fl R Ar hostname |
| 420 | Removes all keys belonging to |
| 421 | .Ar hostname |
Damien Miller | 4c9c6fd | 2005-03-02 12:03:43 +1100 | [diff] [blame] | 422 | from a |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 423 | .Pa known_hosts |
| 424 | file. |
Damien Miller | 4c9c6fd | 2005-03-02 12:03:43 +1100 | [diff] [blame] | 425 | This option is useful to delete hashed hosts (see the |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 426 | .Fl H |
| 427 | option above). |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 428 | .It Fl r Ar hostname |
| 429 | Print the SSHFP fingerprint resource record named |
| 430 | .Ar hostname |
| 431 | for the specified public key file. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 432 | .It Fl S Ar start |
| 433 | Specify start point (in hex) when generating candidate moduli for DH-GEX. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 434 | .It Fl s Ar ca_key |
| 435 | Certify (sign) a public key using the specified CA key. |
| 436 | Please see the |
| 437 | .Sx CERTIFICATES |
| 438 | section for details. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 439 | .It Fl T Ar output_file |
| 440 | Test DH group exchange candidate primes (generated using the |
| 441 | .Fl G |
| 442 | option) for safety. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 443 | .It Fl t Ar type |
| 444 | Specifies the type of key to create. |
| 445 | The possible values are |
| 446 | .Dq rsa1 |
| 447 | for protocol version 1 and |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 448 | .Dq dsa , |
| 449 | .Dq ecdsa |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 450 | or |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 451 | .Dq rsa |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 452 | for protocol version 2. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 453 | .It Fl V Ar validity_interval |
| 454 | Specify a validity interval when signing a certificate. |
| 455 | A validity interval may consist of a single time, indicating that the |
| 456 | certificate is valid beginning now and expiring at that time, or may consist |
| 457 | of two times separated by a colon to indicate an explicit time interval. |
| 458 | The start time may be specified as a date in YYYYMMDD format, a time |
| 459 | in YYYYMMDDHHMMSS format or a relative time (to the current time) consisting |
| 460 | of a minus sign followed by a relative time in the format described in the |
| 461 | .Sx TIME FORMATS |
| 462 | section of |
Damien Miller | 77497e1 | 2010-03-22 05:50:51 +1100 | [diff] [blame] | 463 | .Xr sshd_config 5 . |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 464 | The end time may be specified as a YYYYMMDD date, a YYYYMMDDHHMMSS time or |
| 465 | a relative time starting with a plus character. |
| 466 | .Pp |
| 467 | For example: |
| 468 | .Dq +52w1d |
| 469 | (valid from now to 52 weeks and one day from now), |
| 470 | .Dq -4w:+4w |
| 471 | (valid from four weeks ago to four weeks from now), |
| 472 | .Dq 20100101123000:20110101123000 |
| 473 | (valid from 12:30 PM, January 1st, 2010 to 12:30 PM, January 1st, 2011), |
| 474 | .Dq -1d:20110101 |
| 475 | (valid from yesterday to midnight, January 1st, 2011). |
Darren Tucker | 06930c7 | 2003-12-31 11:34:51 +1100 | [diff] [blame] | 476 | .It Fl v |
| 477 | Verbose mode. |
| 478 | Causes |
| 479 | .Nm |
| 480 | to print debugging messages about its progress. |
| 481 | This is helpful for debugging moduli generation. |
| 482 | Multiple |
| 483 | .Fl v |
| 484 | options increase the verbosity. |
| 485 | The maximum is 3. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 486 | .It Fl W Ar generator |
| 487 | Specify desired generator when testing candidate moduli for DH-GEX. |
| 488 | .It Fl y |
| 489 | This option will read a private |
| 490 | OpenSSH format file and print an OpenSSH public key to stdout. |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 491 | .It Fl z Ar serial_number |
| 492 | Specifies a serial number to be embedded in the certificate to distinguish |
| 493 | this certificate from others from the same CA. |
| 494 | The default serial number is zero. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 495 | .El |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 496 | .Sh MODULI GENERATION |
| 497 | .Nm |
| 498 | may be used to generate groups for the Diffie-Hellman Group Exchange |
| 499 | (DH-GEX) protocol. |
| 500 | Generating these groups is a two-step process: first, candidate |
| 501 | primes are generated using a fast, but memory intensive process. |
| 502 | These candidate primes are then tested for suitability (a CPU-intensive |
| 503 | process). |
| 504 | .Pp |
| 505 | Generation of primes is performed using the |
| 506 | .Fl G |
| 507 | option. |
| 508 | The desired length of the primes may be specified by the |
| 509 | .Fl b |
| 510 | option. |
| 511 | For example: |
| 512 | .Pp |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 513 | .Dl # ssh-keygen -G moduli-2048.candidates -b 2048 |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 514 | .Pp |
| 515 | By default, the search for primes begins at a random point in the |
| 516 | desired length range. |
| 517 | This may be overridden using the |
| 518 | .Fl S |
| 519 | option, which specifies a different start point (in hex). |
| 520 | .Pp |
| 521 | Once a set of candidates have been generated, they must be tested for |
| 522 | suitability. |
| 523 | This may be performed using the |
| 524 | .Fl T |
| 525 | option. |
| 526 | In this mode |
| 527 | .Nm |
| 528 | will read candidates from standard input (or a file specified using the |
| 529 | .Fl f |
| 530 | option). |
| 531 | For example: |
| 532 | .Pp |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 533 | .Dl # ssh-keygen -T moduli-2048 -f moduli-2048.candidates |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 534 | .Pp |
| 535 | By default, each candidate will be subjected to 100 primality tests. |
| 536 | This may be overridden using the |
| 537 | .Fl a |
| 538 | option. |
| 539 | The DH generator value will be chosen automatically for the |
| 540 | prime under consideration. |
| 541 | If a specific generator is desired, it may be requested using the |
| 542 | .Fl W |
| 543 | option. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 544 | Valid generator values are 2, 3, and 5. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 545 | .Pp |
| 546 | Screened DH groups may be installed in |
| 547 | .Pa /etc/moduli . |
| 548 | It is important that this file contains moduli of a range of bit lengths and |
| 549 | that both ends of a connection share common moduli. |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 550 | .Sh CERTIFICATES |
| 551 | .Nm |
| 552 | supports signing of keys to produce certificates that may be used for |
| 553 | user or host authentication. |
| 554 | Certificates consist of a public key, some identity information, zero or |
Damien Miller | 1f18142 | 2010-04-18 08:08:03 +1000 | [diff] [blame] | 555 | more principal (user or host) names and a set of options that |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 556 | are signed by a Certification Authority (CA) key. |
| 557 | Clients or servers may then trust only the CA key and verify its signature |
| 558 | on a certificate rather than trusting many user/host keys. |
| 559 | Note that OpenSSH certificates are a different, and much simpler, format to |
| 560 | the X.509 certificates used in |
| 561 | .Xr ssl 8 . |
| 562 | .Pp |
| 563 | .Nm |
| 564 | supports two types of certificates: user and host. |
| 565 | User certificates authenticate users to servers, whereas host certificates |
Damien Miller | 15f5b56 | 2010-03-03 10:25:21 +1100 | [diff] [blame] | 566 | authenticate server hosts to users. |
| 567 | To generate a user certificate: |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 568 | .Pp |
| 569 | .Dl $ ssh-keygen -s /path/to/ca_key -I key_id /path/to/user_key.pub |
| 570 | .Pp |
| 571 | The resultant certificate will be placed in |
Damien Miller | 1b61a28 | 2010-03-22 05:55:06 +1100 | [diff] [blame] | 572 | .Pa /path/to/user_key-cert.pub . |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 573 | A host certificate requires the |
| 574 | .Fl h |
| 575 | option: |
| 576 | .Pp |
| 577 | .Dl $ ssh-keygen -s /path/to/ca_key -I key_id -h /path/to/host_key.pub |
| 578 | .Pp |
| 579 | The host certificate will be output to |
Damien Miller | 1b61a28 | 2010-03-22 05:55:06 +1100 | [diff] [blame] | 580 | .Pa /path/to/host_key-cert.pub . |
Damien Miller | 757f34e | 2010-08-05 13:05:31 +1000 | [diff] [blame] | 581 | .Pp |
| 582 | It is possible to sign using a CA key stored in a PKCS#11 token by |
| 583 | providing the token library using |
| 584 | .Fl D |
| 585 | and identifying the CA key by providing its public half as an argument |
| 586 | to |
| 587 | .Fl s : |
| 588 | .Pp |
| 589 | .Dl $ ssh-keygen -s ca_key.pub -D libpkcs11.so -I key_id host_key.pub |
| 590 | .Pp |
| 591 | In all cases, |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 592 | .Ar key_id |
| 593 | is a "key identifier" that is logged by the server when the certificate |
| 594 | is used for authentication. |
| 595 | .Pp |
| 596 | Certificates may be limited to be valid for a set of principal (user/host) |
| 597 | names. |
| 598 | By default, generated certificates are valid for all users or hosts. |
| 599 | To generate a certificate for a specified set of principals: |
| 600 | .Pp |
| 601 | .Dl $ ssh-keygen -s ca_key -I key_id -n user1,user2 user_key.pub |
Damien Miller | 5a5d94b | 2010-03-22 05:57:49 +1100 | [diff] [blame] | 602 | .Dl "$ ssh-keygen -s ca_key -I key_id -h -n host.domain user_key.pub" |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 603 | .Pp |
| 604 | Additional limitations on the validity and use of user certificates may |
Damien Miller | 1f18142 | 2010-04-18 08:08:03 +1000 | [diff] [blame] | 605 | be specified through certificate options. |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 606 | A certificate option may disable features of the SSH session, may be |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 607 | valid only when presented from particular source addresses or may |
| 608 | force the use of a specific command. |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 609 | For a list of valid certificate options, see the documentation for the |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 610 | .Fl O |
| 611 | option above. |
| 612 | .Pp |
| 613 | Finally, certificates may be defined with a validity lifetime. |
| 614 | The |
| 615 | .Fl V |
| 616 | option allows specification of certificate start and end times. |
| 617 | A certificate that is presented at a time outside this range will not be |
| 618 | considered valid. |
| 619 | By default, certificates have a maximum validity interval. |
| 620 | .Pp |
| 621 | For certificates to be used for user or host authentication, the CA |
| 622 | public key must be trusted by |
| 623 | .Xr sshd 8 |
| 624 | or |
| 625 | .Xr ssh 1 . |
| 626 | Please refer to those manual pages for details. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 627 | .Sh FILES |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 628 | .Bl -tag -width Ds -compact |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 629 | .It Pa ~/.ssh/identity |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 630 | Contains the protocol version 1 RSA authentication identity of the user. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 631 | This file should not be readable by anyone but the user. |
| 632 | It is possible to |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 633 | specify a passphrase when generating the key; that passphrase will be |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 634 | used to encrypt the private part of this file using 3DES. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 635 | This file is not automatically accessed by |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 636 | .Nm |
| 637 | but it is offered as the default file for the private key. |
Ben Lindstrom | bda98b0 | 2001-07-04 03:35:24 +0000 | [diff] [blame] | 638 | .Xr ssh 1 |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 639 | will read this file when a login attempt is made. |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 640 | .Pp |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 641 | .It Pa ~/.ssh/identity.pub |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 642 | Contains the protocol version 1 RSA public key for authentication. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 643 | The contents of this file should be added to |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 644 | .Pa ~/.ssh/authorized_keys |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 645 | on all machines |
Ben Lindstrom | 594e203 | 2001-09-12 18:35:30 +0000 | [diff] [blame] | 646 | where the user wishes to log in using RSA authentication. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 647 | There is no need to keep the contents of this file secret. |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 648 | .Pp |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 649 | .It Pa ~/.ssh/id_dsa |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 650 | .It Pa ~/.ssh/id_ecdsa |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 651 | .It Pa ~/.ssh/id_rsa |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 652 | Contains the protocol version 2 DSA, ECDSA or RSA authentication identity of the user. |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 653 | This file should not be readable by anyone but the user. |
| 654 | It is possible to |
| 655 | specify a passphrase when generating the key; that passphrase will be |
Darren Tucker | 199ee6f | 2009-10-24 11:50:17 +1100 | [diff] [blame] | 656 | used to encrypt the private part of this file using 128-bit AES. |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 657 | This file is not automatically accessed by |
| 658 | .Nm |
| 659 | but it is offered as the default file for the private key. |
Ben Lindstrom | bda98b0 | 2001-07-04 03:35:24 +0000 | [diff] [blame] | 660 | .Xr ssh 1 |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 661 | will read this file when a login attempt is made. |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 662 | .Pp |
| 663 | .It Pa ~/.ssh/id_dsa.pub |
| 664 | .It Pa ~/.ssh/id_ecdsa.pub |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 665 | .It Pa ~/.ssh/id_rsa.pub |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 666 | Contains the protocol version 2 DSA, ECDSA or RSA public key for authentication. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 667 | The contents of this file should be added to |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 668 | .Pa ~/.ssh/authorized_keys |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 669 | on all machines |
Ben Lindstrom | 594e203 | 2001-09-12 18:35:30 +0000 | [diff] [blame] | 670 | where the user wishes to log in using public key authentication. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 671 | There is no need to keep the contents of this file secret. |
Damien Miller | 6186bbc | 2010-09-24 22:00:54 +1000 | [diff] [blame] | 672 | .Pp |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 673 | .It Pa /etc/moduli |
| 674 | Contains Diffie-Hellman groups used for DH-GEX. |
| 675 | The file format is described in |
| 676 | .Xr moduli 5 . |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 677 | .El |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 678 | .Sh SEE ALSO |
| 679 | .Xr ssh 1 , |
| 680 | .Xr ssh-add 1 , |
Damien Miller | 2e8b1c8 | 1999-11-15 23:33:56 +1100 | [diff] [blame] | 681 | .Xr ssh-agent 1 , |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 682 | .Xr moduli 5 , |
Ben Lindstrom | 77788dc | 2001-02-10 23:10:33 +0000 | [diff] [blame] | 683 | .Xr sshd 8 |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 684 | .Rs |
Damien Miller | c0367fb | 2007-01-05 16:25:46 +1100 | [diff] [blame] | 685 | .%R RFC 4716 |
| 686 | .%T "The Secure Shell (SSH) Public Key File Format" |
| 687 | .%D 2006 |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 688 | .Re |
Damien Miller | f1ce505 | 2003-06-11 22:04:39 +1000 | [diff] [blame] | 689 | .Sh AUTHORS |
| 690 | OpenSSH is a derivative of the original and free |
| 691 | ssh 1.2.12 release by Tatu Ylonen. |
| 692 | Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, |
| 693 | Theo de Raadt and Dug Song |
| 694 | removed many bugs, re-added newer features and |
| 695 | created OpenSSH. |
| 696 | Markus Friedl contributed the support for SSH |
| 697 | protocol versions 1.5 and 2.0. |