Darren Tucker | 26dc3e6 | 2007-02-19 22:09:06 +1100 | [diff] [blame] | 1 | .\" $OpenBSD: ssh-keygen.1,v 1.74 2007/01/12 20:20:41 jmc Exp $ |
Ben Lindstrom | 36579d3 | 2001-01-29 07:39:26 +0000 | [diff] [blame] | 2 | .\" |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 3 | .\" -*- nroff -*- |
| 4 | .\" |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 5 | .\" Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 6 | .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 7 | .\" All rights reserved |
| 8 | .\" |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 9 | .\" As far as I am concerned, the code I have written for this software |
| 10 | .\" can be used freely for any purpose. Any derived versions of this |
| 11 | .\" software must be clearly marked as such, and if the derived work is |
| 12 | .\" incompatible with the protocol description in the RFC file, it must be |
| 13 | .\" called by a name other than "ssh" or "Secure Shell". |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 14 | .\" |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 15 | .\" |
Ben Lindstrom | 92a2e38 | 2001-03-05 06:59:27 +0000 | [diff] [blame] | 16 | .\" Copyright (c) 1999,2000 Markus Friedl. All rights reserved. |
| 17 | .\" Copyright (c) 1999 Aaron Campbell. All rights reserved. |
| 18 | .\" Copyright (c) 1999 Theo de Raadt. All rights reserved. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 19 | .\" |
| 20 | .\" Redistribution and use in source and binary forms, with or without |
| 21 | .\" modification, are permitted provided that the following conditions |
| 22 | .\" are met: |
| 23 | .\" 1. Redistributions of source code must retain the above copyright |
| 24 | .\" notice, this list of conditions and the following disclaimer. |
| 25 | .\" 2. Redistributions in binary form must reproduce the above copyright |
| 26 | .\" notice, this list of conditions and the following disclaimer in the |
| 27 | .\" documentation and/or other materials provided with the distribution. |
| 28 | .\" |
| 29 | .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 30 | .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 31 | .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 32 | .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 33 | .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 34 | .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 35 | .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 36 | .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 37 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 38 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 39 | .\" |
| 40 | .Dd September 25, 1999 |
| 41 | .Dt SSH-KEYGEN 1 |
| 42 | .Os |
| 43 | .Sh NAME |
| 44 | .Nm ssh-keygen |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 45 | .Nd authentication key generation, management and conversion |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 46 | .Sh SYNOPSIS |
| 47 | .Nm ssh-keygen |
Damien Miller | 495dca3 | 2003-04-01 21:42:14 +1000 | [diff] [blame] | 48 | .Bk -words |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 49 | .Op Fl q |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 50 | .Op Fl b Ar bits |
Damien Miller | 55fafa0 | 2002-02-19 15:22:07 +1100 | [diff] [blame] | 51 | .Fl t Ar type |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 52 | .Op Fl N Ar new_passphrase |
| 53 | .Op Fl C Ar comment |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 54 | .Op Fl f Ar output_keyfile |
Damien Miller | 495dca3 | 2003-04-01 21:42:14 +1000 | [diff] [blame] | 55 | .Ek |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 56 | .Nm ssh-keygen |
| 57 | .Fl p |
| 58 | .Op Fl P Ar old_passphrase |
| 59 | .Op Fl N Ar new_passphrase |
Damien Miller | 10f6f6b | 1999-11-17 17:29:08 +1100 | [diff] [blame] | 60 | .Op Fl f Ar keyfile |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 61 | .Nm ssh-keygen |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 62 | .Fl i |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 63 | .Op Fl f Ar input_keyfile |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 64 | .Nm ssh-keygen |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 65 | .Fl e |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 66 | .Op Fl f Ar input_keyfile |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 67 | .Nm ssh-keygen |
| 68 | .Fl y |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 69 | .Op Fl f Ar input_keyfile |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 70 | .Nm ssh-keygen |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 71 | .Fl c |
| 72 | .Op Fl P Ar passphrase |
| 73 | .Op Fl C Ar comment |
Damien Miller | 10f6f6b | 1999-11-17 17:29:08 +1100 | [diff] [blame] | 74 | .Op Fl f Ar keyfile |
| 75 | .Nm ssh-keygen |
| 76 | .Fl l |
Ben Lindstrom | 8fd372b | 2001-03-12 03:02:17 +0000 | [diff] [blame] | 77 | .Op Fl f Ar input_keyfile |
| 78 | .Nm ssh-keygen |
| 79 | .Fl B |
Damien Miller | 1a425f3 | 2000-09-02 10:08:09 +1100 | [diff] [blame] | 80 | .Op Fl f Ar input_keyfile |
Ben Lindstrom | a1ec4a9 | 2001-08-06 21:51:34 +0000 | [diff] [blame] | 81 | .Nm ssh-keygen |
| 82 | .Fl D Ar reader |
| 83 | .Nm ssh-keygen |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 84 | .Fl F Ar hostname |
| 85 | .Op Fl f Ar known_hosts_file |
| 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 |
Ben Lindstrom | a1ec4a9 | 2001-08-06 21:51:34 +0000 | [diff] [blame] | 93 | .Fl U Ar reader |
| 94 | .Op Fl f Ar input_keyfile |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 95 | .Nm ssh-keygen |
| 96 | .Fl r Ar hostname |
| 97 | .Op Fl f Ar input_keyfile |
| 98 | .Op Fl g |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 99 | .Nm ssh-keygen |
| 100 | .Fl G Ar output_file |
Darren Tucker | 06930c7 | 2003-12-31 11:34:51 +1100 | [diff] [blame] | 101 | .Op Fl v |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 102 | .Op Fl b Ar bits |
| 103 | .Op Fl M Ar memory |
| 104 | .Op Fl S Ar start_point |
| 105 | .Nm ssh-keygen |
| 106 | .Fl T Ar output_file |
| 107 | .Fl f Ar input_file |
Darren Tucker | 06930c7 | 2003-12-31 11:34:51 +1100 | [diff] [blame] | 108 | .Op Fl v |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 109 | .Op Fl a Ar num_trials |
| 110 | .Op Fl W Ar generator |
Damien Miller | 22c7726 | 2000-04-13 12:26:34 +1000 | [diff] [blame] | 111 | .Sh DESCRIPTION |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 112 | .Nm |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 113 | generates, manages and converts authentication keys for |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 114 | .Xr ssh 1 . |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 115 | .Nm |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 116 | can create RSA keys for use by SSH protocol version 1 and RSA or DSA |
Damien Miller | fbf486b | 2003-05-23 18:44:23 +1000 | [diff] [blame] | 117 | keys for use by SSH protocol version 2. |
| 118 | The type of key to be generated is specified with the |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 119 | .Fl t |
Damien Miller | a41c8b1 | 2002-01-22 23:05:08 +1100 | [diff] [blame] | 120 | option. |
Damien Miller | f14be5c | 2005-11-05 15:15:49 +1100 | [diff] [blame] | 121 | If invoked without any arguments, |
| 122 | .Nm |
Damien Miller | 83d0d39 | 2005-11-05 15:16:27 +1100 | [diff] [blame] | 123 | will generate an RSA key for use in SSH protocol 2 connections. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 124 | .Pp |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 125 | .Nm |
| 126 | is also used to generate groups for use in Diffie-Hellman group |
| 127 | exchange (DH-GEX). |
| 128 | See the |
| 129 | .Sx MODULI GENERATION |
| 130 | section for details. |
| 131 | .Pp |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 132 | Normally each user wishing to use SSH |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 133 | with RSA or DSA authentication runs this once to create the authentication |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 134 | key in |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 135 | .Pa ~/.ssh/identity , |
| 136 | .Pa ~/.ssh/id_dsa |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 137 | or |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 138 | .Pa ~/.ssh/id_rsa . |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 139 | Additionally, the system administrator may use this to generate host keys, |
| 140 | as seen in |
| 141 | .Pa /etc/rc . |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 142 | .Pp |
| 143 | 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] | 144 | to store the private key. |
| 145 | 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] | 146 | .Dq .pub |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 147 | appended. |
| 148 | The program also asks for a passphrase. |
| 149 | The passphrase may be empty to indicate no passphrase |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 150 | (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] | 151 | arbitrary length. |
Ben Lindstrom | 4e366d5 | 2001-12-06 16:43:21 +0000 | [diff] [blame] | 152 | A passphrase is similar to a password, except it can be a phrase with a |
| 153 | series of words, punctuation, numbers, whitespace, or any string of |
| 154 | characters you want. |
| 155 | Good passphrases are 10-30 characters long, are |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 156 | not simple sentences or otherwise easily guessable (English |
Ben Lindstrom | 2a097a4 | 2001-06-09 01:13:40 +0000 | [diff] [blame] | 157 | 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] | 158 | passphrases), and contain a mix of upper and lowercase letters, |
| 159 | numbers, and non-alphanumeric characters. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 160 | The passphrase can be changed later by using the |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 161 | .Fl p |
| 162 | option. |
| 163 | .Pp |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 164 | There is no way to recover a lost passphrase. |
| 165 | If the passphrase is |
Ben Lindstrom | 594e203 | 2001-09-12 18:35:30 +0000 | [diff] [blame] | 166 | lost or forgotten, a new key must be generated and copied to the |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 167 | corresponding public key to other machines. |
| 168 | .Pp |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 169 | For RSA1 keys, |
| 170 | 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] | 171 | convenience to the user to help identify the key. |
| 172 | The comment can tell what the key is for, or whatever is useful. |
| 173 | The comment is initialized to |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 174 | .Dq user@host |
| 175 | when the key is created, but can be changed using the |
| 176 | .Fl c |
| 177 | option. |
| 178 | .Pp |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 179 | After a key is generated, instructions below detail where the keys |
| 180 | should be placed to be activated. |
| 181 | .Pp |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 182 | The options are as follows: |
| 183 | .Bl -tag -width Ds |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 184 | .It Fl a Ar trials |
| 185 | Specifies the number of primality tests to perform when screening DH-GEX |
| 186 | candidates using the |
| 187 | .Fl T |
| 188 | command. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 189 | .It Fl B |
| 190 | Show the bubblebabble digest of specified private or public key file. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 191 | .It Fl b Ar bits |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 192 | Specifies the number of bits in the key to create. |
Darren Tucker | 9f64733 | 2005-11-28 16:41:46 +1100 | [diff] [blame] | 193 | 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] | 194 | Generally, 2048 bits is considered sufficient. |
Darren Tucker | 9f64733 | 2005-11-28 16:41:46 +1100 | [diff] [blame] | 195 | DSA keys must be exactly 1024 bits as specified by FIPS 186-2. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 196 | .It Fl C Ar comment |
| 197 | Provides a new comment. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 198 | .It Fl c |
| 199 | Requests changing the comment in the private and public key files. |
Damien Miller | eb5fec6 | 2001-11-12 10:52:44 +1100 | [diff] [blame] | 200 | This operation is only supported for RSA1 keys. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 201 | The program will prompt for the file containing the private keys, for |
Ben Lindstrom | aafff9c | 2001-05-06 03:01:02 +0000 | [diff] [blame] | 202 | the passphrase if the key has one, and for the new comment. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 203 | .It Fl D Ar reader |
| 204 | Download the RSA public key stored in the smartcard in |
| 205 | .Ar reader . |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 206 | .It Fl e |
Ben Lindstrom | 46c264f | 2001-04-24 16:56:58 +0000 | [diff] [blame] | 207 | This option will read a private or public OpenSSH key file and |
Damien Miller | c0367fb | 2007-01-05 16:25:46 +1100 | [diff] [blame] | 208 | print the key in |
| 209 | RFC 4716 SSH Public Key File Format |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 210 | to stdout. |
| 211 | This option allows exporting keys for use by several commercial |
| 212 | SSH implementations. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 213 | .It Fl F Ar hostname |
| 214 | Search for the specified |
| 215 | .Ar hostname |
| 216 | in a |
| 217 | .Pa known_hosts |
| 218 | file, listing any occurrences found. |
| 219 | This option is useful to find hashed host names or addresses and may also be |
| 220 | used in conjunction with the |
| 221 | .Fl H |
| 222 | option to print found keys in a hashed format. |
| 223 | .It Fl f Ar filename |
| 224 | Specifies the filename of the key file. |
| 225 | .It Fl G Ar output_file |
| 226 | Generate candidate primes for DH-GEX. |
| 227 | These primes must be screened for |
| 228 | safety (using the |
| 229 | .Fl T |
| 230 | option) before use. |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 231 | .It Fl g |
Darren Tucker | 0b42e6d | 2004-08-13 21:22:40 +1000 | [diff] [blame] | 232 | Use generic DNS format when printing fingerprint resource records using the |
Darren Tucker | 6e37037 | 2004-08-13 21:23:25 +1000 | [diff] [blame] | 233 | .Fl r |
Darren Tucker | 0b42e6d | 2004-08-13 21:22:40 +1000 | [diff] [blame] | 234 | command. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 235 | .It Fl H |
| 236 | Hash a |
| 237 | .Pa known_hosts |
Darren Tucker | da1adbc | 2005-03-14 23:15:58 +1100 | [diff] [blame] | 238 | file. |
| 239 | This replaces all hostnames and addresses with hashed representations |
| 240 | within the specified file; the original content is moved to a file with |
| 241 | a .old suffix. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 242 | These hashes may be used normally by |
| 243 | .Nm ssh |
| 244 | and |
| 245 | .Nm sshd , |
| 246 | but they do not reveal identifying information should the file's contents |
| 247 | be disclosed. |
| 248 | This option will not modify existing hashed hostnames and is therefore safe |
| 249 | to use on files that mix hashed and non-hashed names. |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 250 | .It Fl i |
| 251 | This option will read an unencrypted private (or public) key file |
| 252 | in SSH2-compatible format and print an OpenSSH compatible private |
| 253 | (or public) key to stdout. |
| 254 | .Nm |
Ben Lindstrom | 2857d9c | 2001-04-22 17:19:46 +0000 | [diff] [blame] | 255 | also reads the |
Darren Tucker | 26dc3e6 | 2007-02-19 22:09:06 +1100 | [diff] [blame] | 256 | RFC 4716 SSH Public Key File Format. |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 257 | This option allows importing keys from several commercial |
| 258 | SSH implementations. |
Damien Miller | 10f6f6b | 1999-11-17 17:29:08 +1100 | [diff] [blame] | 259 | .It Fl l |
Damien Miller | eb5fec6 | 2001-11-12 10:52:44 +1100 | [diff] [blame] | 260 | Show fingerprint of specified public key file. |
| 261 | Private RSA1 keys are also supported. |
| 262 | For RSA and DSA keys |
| 263 | .Nm |
| 264 | tries to find the matching public key file and prints its fingerprint. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 265 | .It Fl M Ar memory |
| 266 | Specify the amount of memory to use (in megabytes) when generating |
| 267 | candidate moduli for DH-GEX. |
| 268 | .It Fl N Ar new_passphrase |
| 269 | Provides the new passphrase. |
| 270 | .It Fl P Ar passphrase |
| 271 | Provides the (old) passphrase. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 272 | .It Fl p |
| 273 | Requests changing the passphrase of a private key file instead of |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 274 | creating a new private key. |
| 275 | The program will prompt for the file |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 276 | containing the private key, for the old passphrase, and twice for the |
| 277 | new passphrase. |
| 278 | .It Fl q |
| 279 | Silence |
| 280 | .Nm ssh-keygen . |
| 281 | Used by |
| 282 | .Pa /etc/rc |
| 283 | when creating a new key. |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 284 | .It Fl R Ar hostname |
| 285 | Removes all keys belonging to |
| 286 | .Ar hostname |
Damien Miller | 4c9c6fd | 2005-03-02 12:03:43 +1100 | [diff] [blame] | 287 | from a |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 288 | .Pa known_hosts |
| 289 | file. |
Damien Miller | 4c9c6fd | 2005-03-02 12:03:43 +1100 | [diff] [blame] | 290 | This option is useful to delete hashed hosts (see the |
Damien Miller | 4b42d7f | 2005-03-01 21:48:35 +1100 | [diff] [blame] | 291 | .Fl H |
| 292 | option above). |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 293 | .It Fl r Ar hostname |
| 294 | Print the SSHFP fingerprint resource record named |
| 295 | .Ar hostname |
| 296 | for the specified public key file. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 297 | .It Fl S Ar start |
| 298 | Specify start point (in hex) when generating candidate moduli for DH-GEX. |
| 299 | .It Fl T Ar output_file |
| 300 | Test DH group exchange candidate primes (generated using the |
| 301 | .Fl G |
| 302 | option) for safety. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 303 | .It Fl t Ar type |
| 304 | Specifies the type of key to create. |
| 305 | The possible values are |
| 306 | .Dq rsa1 |
| 307 | for protocol version 1 and |
| 308 | .Dq rsa |
| 309 | or |
| 310 | .Dq dsa |
| 311 | for protocol version 2. |
Ben Lindstrom | a1ec4a9 | 2001-08-06 21:51:34 +0000 | [diff] [blame] | 312 | .It Fl U Ar reader |
| 313 | Upload an existing RSA private key into the smartcard in |
| 314 | .Ar reader . |
Darren Tucker | 06930c7 | 2003-12-31 11:34:51 +1100 | [diff] [blame] | 315 | .It Fl v |
| 316 | Verbose mode. |
| 317 | Causes |
| 318 | .Nm |
| 319 | to print debugging messages about its progress. |
| 320 | This is helpful for debugging moduli generation. |
| 321 | Multiple |
| 322 | .Fl v |
| 323 | options increase the verbosity. |
| 324 | The maximum is 3. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 325 | .It Fl W Ar generator |
| 326 | Specify desired generator when testing candidate moduli for DH-GEX. |
| 327 | .It Fl y |
| 328 | This option will read a private |
| 329 | OpenSSH format file and print an OpenSSH public key to stdout. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 330 | .El |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 331 | .Sh MODULI GENERATION |
| 332 | .Nm |
| 333 | may be used to generate groups for the Diffie-Hellman Group Exchange |
| 334 | (DH-GEX) protocol. |
| 335 | Generating these groups is a two-step process: first, candidate |
| 336 | primes are generated using a fast, but memory intensive process. |
| 337 | These candidate primes are then tested for suitability (a CPU-intensive |
| 338 | process). |
| 339 | .Pp |
| 340 | Generation of primes is performed using the |
| 341 | .Fl G |
| 342 | option. |
| 343 | The desired length of the primes may be specified by the |
| 344 | .Fl b |
| 345 | option. |
| 346 | For example: |
| 347 | .Pp |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 348 | .Dl # ssh-keygen -G moduli-2048.candidates -b 2048 |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 349 | .Pp |
| 350 | By default, the search for primes begins at a random point in the |
| 351 | desired length range. |
| 352 | This may be overridden using the |
| 353 | .Fl S |
| 354 | option, which specifies a different start point (in hex). |
| 355 | .Pp |
| 356 | Once a set of candidates have been generated, they must be tested for |
| 357 | suitability. |
| 358 | This may be performed using the |
| 359 | .Fl T |
| 360 | option. |
| 361 | In this mode |
| 362 | .Nm |
| 363 | will read candidates from standard input (or a file specified using the |
| 364 | .Fl f |
| 365 | option). |
| 366 | For example: |
| 367 | .Pp |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 368 | .Dl # ssh-keygen -T moduli-2048 -f moduli-2048.candidates |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 369 | .Pp |
| 370 | By default, each candidate will be subjected to 100 primality tests. |
| 371 | This may be overridden using the |
| 372 | .Fl a |
| 373 | option. |
| 374 | The DH generator value will be chosen automatically for the |
| 375 | prime under consideration. |
| 376 | If a specific generator is desired, it may be requested using the |
| 377 | .Fl W |
| 378 | option. |
Damien Miller | 265d309 | 2005-03-02 12:05:06 +1100 | [diff] [blame] | 379 | Valid generator values are 2, 3, and 5. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 380 | .Pp |
| 381 | Screened DH groups may be installed in |
| 382 | .Pa /etc/moduli . |
| 383 | It is important that this file contains moduli of a range of bit lengths and |
| 384 | that both ends of a connection share common moduli. |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 385 | .Sh FILES |
| 386 | .Bl -tag -width Ds |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 387 | .It Pa ~/.ssh/identity |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 388 | Contains the protocol version 1 RSA authentication identity of the user. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 389 | This file should not be readable by anyone but the user. |
| 390 | It is possible to |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 391 | specify a passphrase when generating the key; that passphrase will be |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 392 | used to encrypt the private part of this file using 3DES. |
| 393 | This file is not automatically accessed by |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 394 | .Nm |
| 395 | but it is offered as the default file for the private key. |
Ben Lindstrom | bda98b0 | 2001-07-04 03:35:24 +0000 | [diff] [blame] | 396 | .Xr ssh 1 |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 397 | will read this file when a login attempt is made. |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 398 | .It Pa ~/.ssh/identity.pub |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 399 | Contains the protocol version 1 RSA public key for authentication. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 400 | The contents of this file should be added to |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 401 | .Pa ~/.ssh/authorized_keys |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 402 | on all machines |
Ben Lindstrom | 594e203 | 2001-09-12 18:35:30 +0000 | [diff] [blame] | 403 | where the user wishes to log in using RSA authentication. |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 404 | There is no need to keep the contents of this file secret. |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 405 | .It Pa ~/.ssh/id_dsa |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 406 | Contains the protocol version 2 DSA authentication identity of the user. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 407 | This file should not be readable by anyone but the user. |
| 408 | It is possible to |
| 409 | specify a passphrase when generating the key; that passphrase will be |
| 410 | used to encrypt the private part of this file using 3DES. |
| 411 | This file is not automatically accessed by |
| 412 | .Nm |
| 413 | but it is offered as the default file for the private key. |
Ben Lindstrom | bda98b0 | 2001-07-04 03:35:24 +0000 | [diff] [blame] | 414 | .Xr ssh 1 |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 415 | will read this file when a login attempt is made. |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 416 | .It Pa ~/.ssh/id_dsa.pub |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 417 | Contains the protocol version 2 DSA public key for authentication. |
| 418 | The contents of this file should be added to |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 419 | .Pa ~/.ssh/authorized_keys |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 420 | on all machines |
Ben Lindstrom | 594e203 | 2001-09-12 18:35:30 +0000 | [diff] [blame] | 421 | where the user wishes to log in using public key authentication. |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 422 | There is no need to keep the contents of this file secret. |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 423 | .It Pa ~/.ssh/id_rsa |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 424 | Contains the protocol version 2 RSA authentication identity of the user. |
| 425 | This file should not be readable by anyone but the user. |
| 426 | It is possible to |
| 427 | specify a passphrase when generating the key; that passphrase will be |
| 428 | used to encrypt the private part of this file using 3DES. |
| 429 | This file is not automatically accessed by |
| 430 | .Nm |
| 431 | but it is offered as the default file for the private key. |
Ben Lindstrom | bda98b0 | 2001-07-04 03:35:24 +0000 | [diff] [blame] | 432 | .Xr ssh 1 |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 433 | will read this file when a login attempt is made. |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 434 | .It Pa ~/.ssh/id_rsa.pub |
Ben Lindstrom | 18a82ac | 2001-04-11 15:59:35 +0000 | [diff] [blame] | 435 | Contains the protocol version 2 RSA public key for authentication. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 436 | The contents of this file should be added to |
Damien Miller | 167ea5d | 2005-05-26 12:04:02 +1000 | [diff] [blame] | 437 | .Pa ~/.ssh/authorized_keys |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 438 | on all machines |
Ben Lindstrom | 594e203 | 2001-09-12 18:35:30 +0000 | [diff] [blame] | 439 | where the user wishes to log in using public key authentication. |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 440 | There is no need to keep the contents of this file secret. |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 441 | .It Pa /etc/moduli |
| 442 | Contains Diffie-Hellman groups used for DH-GEX. |
| 443 | The file format is described in |
| 444 | .Xr moduli 5 . |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 445 | .El |
Damien Miller | 32aa144 | 1999-10-29 09:15:49 +1000 | [diff] [blame] | 446 | .Sh SEE ALSO |
| 447 | .Xr ssh 1 , |
| 448 | .Xr ssh-add 1 , |
Damien Miller | 2e8b1c8 | 1999-11-15 23:33:56 +1100 | [diff] [blame] | 449 | .Xr ssh-agent 1 , |
Darren Tucker | 019cefe | 2003-08-02 22:40:07 +1000 | [diff] [blame] | 450 | .Xr moduli 5 , |
Ben Lindstrom | 77788dc | 2001-02-10 23:10:33 +0000 | [diff] [blame] | 451 | .Xr sshd 8 |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 452 | .Rs |
Damien Miller | c0367fb | 2007-01-05 16:25:46 +1100 | [diff] [blame] | 453 | .%R RFC 4716 |
| 454 | .%T "The Secure Shell (SSH) Public Key File Format" |
| 455 | .%D 2006 |
Ben Lindstrom | 5a70782 | 2001-04-22 17:15:46 +0000 | [diff] [blame] | 456 | .Re |
Damien Miller | f1ce505 | 2003-06-11 22:04:39 +1000 | [diff] [blame] | 457 | .Sh AUTHORS |
| 458 | OpenSSH is a derivative of the original and free |
| 459 | ssh 1.2.12 release by Tatu Ylonen. |
| 460 | Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, |
| 461 | Theo de Raadt and Dug Song |
| 462 | removed many bugs, re-added newer features and |
| 463 | created OpenSSH. |
| 464 | Markus Friedl contributed the support for SSH |
| 465 | protocol versions 1.5 and 2.0. |