[gssapi-openssh.git] / openssh / 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
826f3a39	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
0b90ac93	30	.Nd random number gatherer for OpenSSH
826f3a39	31	.Sh SYNOPSIS
	32	.Nm ssh-rand-hlper
	33	.Op Fl vxXh
	34	.Op Fl b Ar bytes
	35	.Sh DESCRIPTION
	36	.Nm
540d72c3	37	is a small helper program used by
826f3a39	38	.Xr ssh 1 ,
	39	.Xr ssh-add 1 ,
	40	.Xr ssh-agent 1 ,
	41	.Xr ssh-keygen 1 ,
540d72c3	42	.Xr ssh-keyscan 1
826f3a39	43	and
826f3a39	44	.Xr sshd 8
540d72c3	45	to gather random numbers of cryptographic quality if the
826f3a39	46	.Xr openssl 4
	47	library has not been configured to provide them itself.
	48	.Pp
540d72c3	49	Normally
826f3a39	50	.Nm
826f3a39	51	will generate a strong random seed and provide it to the calling
540d72c3	52	program via standard output. If standard output is a tty,
826f3a39	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 .
540d72c3	60	The output of each of the commands listed will be hashed and used to
540d72c3	61	generate a random seed for the calling program.
826f3a39	62	.Nm
540d72c3	63	will also store seed files in
826f3a39	64	.Pa ~/.ssh/prng_seed
	65	between executions.
	66	.Pp
540d72c3	67	Alternately,
826f3a39	68	.Nm
540d72c3	69	may be configured at build time to collect random numbers from a
826f3a39	70	EGD/PRNGd server via a unix domain or localhost tcp socket.
826f3a39	71	.Pp
540d72c3	72	This program is not intended to be run by the end-user, so the few
826f3a39	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.
0b90ac93	85	.It Fl h
826f3a39	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