Blame - ssh-rand-helper.8 - platform/external/openssh

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Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	1	.\" $Id: ssh-rand-helper.8,v 1.2 2003/11/21 12:48:56 djm Exp $
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	2	.\"
				3	.\" Copyright (c) 2002 Damien Miller. All rights reserved.
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				25	.Dd April 14, 2002
				26	.Dt SSH-RAND-HELPER 8
				27	.Os
				28	.Sh NAME
				29	.Nm ssh-rand-helper
				30	.Nd Random number gatherer for OpenSSH
				31	.Sh SYNOPSIS
				32	.Nm ssh-rand-hlper
				33	.Op Fl vxXh
				34	.Op Fl b Ar bytes
				35	.Sh DESCRIPTION
				36	.Nm
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	37	is a small helper program used by
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	38	.Xr ssh 1 ,
				39	.Xr ssh-add 1 ,
				40	.Xr ssh-agent 1 ,
				41	.Xr ssh-keygen 1 ,
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	42	.Xr ssh-keyscan 1
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	43	and
				44	.Xr sshd 8
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	45	to gather random numbers of cryptographic quality if the
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	46	.Xr openssl 4
				47	library has not been configured to provide them itself.
				48	.Pp
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	49	Normally
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	50	.Nm
				51	will generate a strong random seed and provide it to the calling
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	52	program via standard output. If standard output is a tty,
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	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 .
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	60	The output of each of the commands listed will be hashed and used to
				61	generate a random seed for the calling program.
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	62	.Nm
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	63	will also store seed files in
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	64	.Pa ~/.ssh/prng_seed
				65	between executions.
				66	.Pp
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	67	Alternately,
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	68	.Nm
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	69	may be configured at build time to collect random numbers from a
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	70	EGD/PRNGd server via a unix domain or localhost tcp socket.
				71	.Pp
Damien Miller	a8e06ce	2003-11-21 23:48:55 +1100	[diff] [blame]	72	This program is not intended to be run by the end-user, so the few
Damien Miller	32e4818	2002-04-14 19:27:12 +1000	[diff] [blame]	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.
				85	.Fl h
				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