[openssh.git] / ssh-rand-helper.8

.\" $Id$
.\"
.\" Copyright (c) 2002 Damien Miller.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd April 14, 2002
.Dt SSH-RAND-HELPER 8
.Os
.Sh NAME
.Nm ssh-rand-helper
.Nd random number gatherer for OpenSSH
.Sh SYNOPSIS
.Nm ssh-rand-hlper
.Op Fl vxXh
.Op Fl b Ar bytes
.Sh DESCRIPTION
.Nm
is a small helper program used by
.Xr ssh 1 ,
.Xr ssh-add 1 ,
.Xr ssh-agent 1 ,
.Xr ssh-keygen 1 ,
.Xr ssh-keyscan 1
and
.Xr sshd 8
to gather random numbers of cryptographic quality if the
.Xr openssl 4
library has not been configured to provide them itself.
.Pp
Normally
.Nm
will generate a strong random seed and provide it to the calling
program via standard output. If standard output is a tty,
.Nm
will instead print the seed in hexidecimal format unless told otherwise.
.Pp
.Nm
will by default gather random numbers from the system commands listed
in
.Pa /etc/ssh/ssh_prng_cmds .
The output of each of the commands listed will be hashed and used to
generate a random seed for the calling program.
.Nm
will also store seed files in
.Pa ~/.ssh/prng_seed
between executions.
.Pp
Alternately,
.Nm
may be configured at build time to collect random numbers from a
EGD/PRNGd server via a unix domain or localhost tcp socket.
.Pp
This program is not intended to be run by the end-user, so the few
commandline options are for debugging purposes only.
.Bl -tag -width Ds
.It Fl b Ar bytes
Specify the number of random bytes to include in the output.
.It Fl x
Output a hexidecimal instead of a binary seed.
.It Fl X
Force output of a binary seed, even if standard output is a tty
.It Fl v
Turn on debugging message. Multiple
.Fl v
options will increase the debugging level.
.It Fl h
Display a summary of options.
.El
.Sh AUTHORS
Damien Miller <djm@mindrot.org>
.Sh SEE ALSO
.Xr ssh 1 ,
.Xr ssh-add 1 ,
.Xr ssh-keygen 1 ,
.Xr sshd 8
Commit	Line	Data
f6e6303d	1	.\" $Id$
	2	.\"
	3	.\" Copyright (c) 2002 Damien Miller. All rights reserved.
	4	.\"
	5	.\" Redistribution and use in source and binary forms, with or without
	6	.\" modification, are permitted provided that the following conditions
	7	.\" are met:
	8	.\" 1. Redistributions of source code must retain the above copyright
	9	.\" notice, this list of conditions and the following disclaimer.
	10	.\" 2. Redistributions in binary form must reproduce the above copyright
	11	.\" notice, this list of conditions and the following disclaimer in the
	12	.\" documentation and/or other materials provided with the distribution.
	13	.\"
	14	.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	15	.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	16	.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	17	.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	18	.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	19	.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	20	.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	21	.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	23	.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	.\"
	25	.Dd April 14, 2002
	26	.Dt SSH-RAND-HELPER 8
	27	.Os
	28	.Sh NAME
	29	.Nm ssh-rand-helper
ed9b5e5f	30	.Nd random number gatherer for OpenSSH
f6e6303d	31	.Sh SYNOPSIS
	32	.Nm ssh-rand-hlper
	33	.Op Fl vxXh
	34	.Op Fl b Ar bytes
	35	.Sh DESCRIPTION
	36	.Nm
aff51935	37	is a small helper program used by
f6e6303d	38	.Xr ssh 1 ,
	39	.Xr ssh-add 1 ,
	40	.Xr ssh-agent 1 ,
	41	.Xr ssh-keygen 1 ,
aff51935	42	.Xr ssh-keyscan 1
f6e6303d	43	and
f6e6303d	44	.Xr sshd 8
aff51935	45	to gather random numbers of cryptographic quality if the
f6e6303d	46	.Xr openssl 4
	47	library has not been configured to provide them itself.
	48	.Pp
aff51935	49	Normally
f6e6303d	50	.Nm
f6e6303d	51	will generate a strong random seed and provide it to the calling
aff51935	52	program via standard output. If standard output is a tty,
f6e6303d	53	.Nm
	54	will instead print the seed in hexidecimal format unless told otherwise.
	55	.Pp
	56	.Nm
	57	will by default gather random numbers from the system commands listed
	58	in
	59	.Pa /etc/ssh/ssh_prng_cmds .
aff51935	60	The output of each of the commands listed will be hashed and used to
aff51935	61	generate a random seed for the calling program.
f6e6303d	62	.Nm
aff51935	63	will also store seed files in
f6e6303d	64	.Pa ~/.ssh/prng_seed
	65	between executions.
	66	.Pp
aff51935	67	Alternately,
f6e6303d	68	.Nm
aff51935	69	may be configured at build time to collect random numbers from a
f6e6303d	70	EGD/PRNGd server via a unix domain or localhost tcp socket.
f6e6303d	71	.Pp
aff51935	72	This program is not intended to be run by the end-user, so the few
f6e6303d	73	commandline options are for debugging purposes only.
	74	.Bl -tag -width Ds
	75	.It Fl b Ar bytes
	76	Specify the number of random bytes to include in the output.
	77	.It Fl x
	78	Output a hexidecimal instead of a binary seed.
	79	.It Fl X
	80	Force output of a binary seed, even if standard output is a tty
	81	.It Fl v
	82	Turn on debugging message. Multiple
	83	.Fl v
	84	options will increase the debugging level.
ed9b5e5f	85	.It Fl h
f6e6303d	86	Display a summary of options.
	87	.El
	88	.Sh AUTHORS
	89	Damien Miller <djm@mindrot.org>
	90	.Sh SEE ALSO
	91	.Xr ssh 1 ,
	92	.Xr ssh-add 1 ,
	93	.Xr ssh-keygen 1 ,
	94	.Xr sshd 8