1*8dc9b10eSFernando Apesteguía.\" 2*8dc9b10eSFernando Apesteguía.\" SPDX-License-Identifier: BSD-2-Clause 3*8dc9b10eSFernando Apesteguía.\" 4*8dc9b10eSFernando Apesteguía.\" Copyright (c) 2023 Fernando Apesteguia <fernando.apesteguia@gmail.com> 5*8dc9b10eSFernando Apesteguía.\" 6*8dc9b10eSFernando Apesteguía.\" Redistribution and use in source and binary forms, with or without 7*8dc9b10eSFernando Apesteguía.\" modification, are permitted provided that the following conditions 8*8dc9b10eSFernando Apesteguía.\" are met: 9*8dc9b10eSFernando Apesteguía.\" 1. Redistributions of source code must retain the above copyright 10*8dc9b10eSFernando Apesteguía.\" notice, this list of conditions and the following disclaimer. 11*8dc9b10eSFernando Apesteguía.\" 2. Redistributions in binary form must reproduce the above copyright 12*8dc9b10eSFernando Apesteguía.\" notice, this list of conditions and the following disclaimer in the 13*8dc9b10eSFernando Apesteguía.\" documentation and/or other materials provided with the distribution. 14*8dc9b10eSFernando Apesteguía.\" 15*8dc9b10eSFernando Apesteguía.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16*8dc9b10eSFernando Apesteguía.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17*8dc9b10eSFernando Apesteguía.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18*8dc9b10eSFernando Apesteguía.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19*8dc9b10eSFernando Apesteguía.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20*8dc9b10eSFernando Apesteguía.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21*8dc9b10eSFernando Apesteguía.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22*8dc9b10eSFernando Apesteguía.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23*8dc9b10eSFernando Apesteguía.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24*8dc9b10eSFernando Apesteguía.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25*8dc9b10eSFernando Apesteguía.\" SUCH DAMAGE. 26*8dc9b10eSFernando Apesteguía.\" 27*8dc9b10eSFernando Apesteguía.Dd September 18, 2023 28*8dc9b10eSFernando Apesteguía.Dt SAVE-ENTROPY 8 29*8dc9b10eSFernando Apesteguía.Os 30*8dc9b10eSFernando Apesteguía.Sh NAME 31*8dc9b10eSFernando Apesteguía.Nm save-entropy 32*8dc9b10eSFernando Apesteguía.Nd Save bits of entropy to feed /dev/random at startup 33*8dc9b10eSFernando Apesteguía.Sh SYNOPSIS 34*8dc9b10eSFernando Apesteguía.Nm save-entropy 35*8dc9b10eSFernando Apesteguía.Sh DESCRIPTION 36*8dc9b10eSFernando ApesteguíaThe 37*8dc9b10eSFernando Apesteguía.Nm 38*8dc9b10eSFernando Apesteguíacommand is used to save entropy data from 39*8dc9b10eSFernando Apesteguía.Pa /dev/random 40*8dc9b10eSFernando Apesteguíato files in a specified output location. 41*8dc9b10eSFernando ApesteguíaThe files saved are used at startup to provide additional entropy for 42*8dc9b10eSFernando Apesteguía.Pa /dev/random . 43*8dc9b10eSFernando ApesteguíaThe output file will be different in every invocation until the maximum number 44*8dc9b10eSFernando Apesteguíaof different files is reached. 45*8dc9b10eSFernando Apesteguía(See 46*8dc9b10eSFernando Apesteguía.Em entropy_save_num 47*8dc9b10eSFernando Apesteguíafor details). 48*8dc9b10eSFernando ApesteguíaBy default this script is invoked via 49*8dc9b10eSFernando Apesteguía.Xr cron 8 50*8dc9b10eSFernando Apesteguíaevery eleven minutes approximately. 51*8dc9b10eSFernando Apesteguía.Pp 52*8dc9b10eSFernando ApesteguíaThis command does nothing if executed inside a 53*8dc9b10eSFernando Apesteguía.Xr jail 8 . 54*8dc9b10eSFernando Apesteguía.Pp 55*8dc9b10eSFernando ApesteguíaThree variables in 56*8dc9b10eSFernando Apesteguía.Pa /etc/rc.conf 57*8dc9b10eSFernando Apesteguíaregulate the behavior of the script: 58*8dc9b10eSFernando Apesteguía.Bl -tag -width Ds 59*8dc9b10eSFernando Apesteguía.It Va entropy_dir 60*8dc9b10eSFernando ApesteguíaSpecify the directory for saved entropy files. 61*8dc9b10eSFernando ApesteguíaDefaults to 62*8dc9b10eSFernando Apesteguía.Pa /var/db/entropy . 63*8dc9b10eSFernando ApesteguíaIf set to "NO" it disables caching entropy via 64*8dc9b10eSFernando Apesteguía.Xr cron 8 . 65*8dc9b10eSFernando ApesteguíaThis setting is shared with 66*8dc9b10eSFernando Apesteguía.Pa /etc/rc.d/random . 67*8dc9b10eSFernando Apesteguía.It Va entropy_save_sz 68*8dc9b10eSFernando ApesteguíaSize of the entropy cache files. 69*8dc9b10eSFernando ApesteguíaDefaults to 4096. 70*8dc9b10eSFernando Apesteguía.It Va entropy_save_num 71*8dc9b10eSFernando ApesteguíaNumber of entropy cache files to save. 72*8dc9b10eSFernando ApesteguíaDefaults to 8. 73*8dc9b10eSFernando Apesteguía.El 74*8dc9b10eSFernando Apesteguía.Sh FILES 75*8dc9b10eSFernando Apesteguía.Bl -tag -width Ds 76*8dc9b10eSFernando Apesteguía.It Pa /etc/rc.conf 77*8dc9b10eSFernando Apesteguía.El 78*8dc9b10eSFernando Apesteguía.Sh EXIT STATUS 79*8dc9b10eSFernando Apesteguía.Ex -std 80*8dc9b10eSFernando ApesteguíaErrors will be recorded in the system log. 81*8dc9b10eSFernando Apesteguía.Sh SEE ALSO 82*8dc9b10eSFernando Apesteguía.Xr syslog 3 , 83*8dc9b10eSFernando Apesteguía.Xr random 4 , 84*8dc9b10eSFernando Apesteguía.Xr rc.conf 5 , 85*8dc9b10eSFernando Apesteguía.Xr cron 8 86*8dc9b10eSFernando Apesteguía.Sh HISTORY 87*8dc9b10eSFernando ApesteguíaThe 88*8dc9b10eSFernando Apesteguía.Nm 89*8dc9b10eSFernando Apesteguíacommand first appeared in 90*8dc9b10eSFernando Apesteguía.Fx 5.0 . 91*8dc9b10eSFernando Apesteguía.Sh AUTHORS 92*8dc9b10eSFernando ApesteguíaThe 93*8dc9b10eSFernando Apesteguía.Nm 94*8dc9b10eSFernando Apesteguíacommand was originally written by 95*8dc9b10eSFernando Apesteguía.An Doug Barton <dougb@FreeBSD.org> . 96*8dc9b10eSFernando ApesteguíaThis manual page was written by 97*8dc9b10eSFernando Apesteguía.An Fernando Apesteguia <fernape@FreeBSD.org> . 98