| 1 | .\" $Id: ssh-rand-helper.8,v 1.1.1.1 2003-02-05 19:02:40 zacheiss Exp $ |
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| 2 | .\" |
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| 3 | .\" Copyright (c) 2002 Damien Miller. All rights reserved. |
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| 4 | .\" |
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| 5 | .\" Redistribution and use in source and binary forms, with or without |
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| 6 | .\" modification, are permitted provided that the following conditions |
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| 7 | .\" are met: |
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| 8 | .\" 1. Redistributions of source code must retain the above copyright |
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| 9 | .\" notice, this list of conditions and the following disclaimer. |
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| 10 | .\" 2. Redistributions in binary form must reproduce the above copyright |
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| 11 | .\" notice, this list of conditions and the following disclaimer in the |
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| 12 | .\" documentation and/or other materials provided with the distribution. |
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| 13 | .\" |
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| 14 | .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 15 | .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 16 | .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 17 | .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 18 | .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 19 | .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 20 | .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 21 | .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 22 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 23 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 24 | .\" |
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| 25 | .Dd April 14, 2002 |
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| 26 | .Dt SSH-RAND-HELPER 8 |
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| 27 | .Os |
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| 28 | .Sh NAME |
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| 29 | .Nm ssh-rand-helper |
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| 30 | .Nd Random number gatherer for OpenSSH |
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| 31 | .Sh SYNOPSIS |
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| 32 | .Nm ssh-rand-hlper |
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| 33 | .Op Fl vxXh |
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| 34 | .Op Fl b Ar bytes |
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| 35 | .Sh DESCRIPTION |
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| 36 | .Nm |
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| 37 | is a small helper program used by |
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| 38 | .Xr ssh 1 , |
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| 39 | .Xr ssh-add 1 , |
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| 40 | .Xr ssh-agent 1 , |
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| 41 | .Xr ssh-keygen 1 , |
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| 42 | .Xr ssh-keyscan 1 |
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| 43 | and |
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| 44 | .Xr sshd 8 |
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| 45 | to gather random numbers of cryptographic quality if the |
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| 46 | .Xr openssl 4 |
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| 47 | library has not been configured to provide them itself. |
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| 48 | .Pp |
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| 49 | Normally |
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| 50 | .Nm |
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| 51 | will generate a strong random seed and provide it to the calling |
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| 52 | program via standard output. If standard output is a tty, |
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| 53 | .Nm |
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| 54 | will instead print the seed in hexidecimal format unless told otherwise. |
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| 55 | .Pp |
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| 56 | .Nm |
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| 57 | will by default gather random numbers from the system commands listed |
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| 58 | in |
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| 59 | .Pa /etc/ssh/ssh_prng_cmds . |
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| 60 | The output of each of the commands listed will be hashed and used to |
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| 61 | generate a random seed for the calling program. |
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| 62 | .Nm |
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| 63 | will also store seed files in |
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| 64 | .Pa ~/.ssh/prng_seed |
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| 65 | between executions. |
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| 66 | .Pp |
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| 67 | Alternately, |
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| 68 | .Nm |
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| 69 | may be configured at build time to collect random numbers from a |
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| 70 | EGD/PRNGd server via a unix domain or localhost tcp socket. |
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| 71 | .Pp |
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| 72 | This program is not intended to be run by the end-user, so the few |
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| 73 | commandline options are for debugging purposes only. |
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| 74 | .Bl -tag -width Ds |
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| 75 | .It Fl b Ar bytes |
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| 76 | Specify the number of random bytes to include in the output. |
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| 77 | .It Fl x |
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| 78 | Output a hexidecimal instead of a binary seed. |
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| 79 | .It Fl X |
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| 80 | Force output of a binary seed, even if standard output is a tty |
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| 81 | .It Fl v |
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| 82 | Turn on debugging message. Multiple |
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| 83 | .Fl v |
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| 84 | options will increase the debugging level. |
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| 85 | .Fl h |
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| 86 | Display a summary of options. |
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| 87 | .El |
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| 88 | .Sh AUTHORS |
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| 89 | Damien Miller <djm@mindrot.org> |
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| 90 | .Sh SEE ALSO |
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| 91 | .Xr ssh 1 , |
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| 92 | .Xr ssh-add 1 , |
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| 93 | .Xr ssh-keygen 1 , |
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| 94 | .Xr sshd 8 |
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