xref: /freebsd/stand/forth/check-password.4th.8 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
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25.Dd June 24, 2018
26.Dt CHECK-PASSWORD.4TH 8
27.Os
28.Sh NAME
29.Nm check-password.4th
30.Nd FreeBSD password-checking boot module
31.Sh DESCRIPTION
32The file that goes by the name of
33.Nm
34is a set of commands designed to do one or more of the following:
35.Pp
36.Dl o Prevent booting without password
37.Dl o Prevent modification of boot options without password
38.Dl o Provide a password to mount geli(8) encrypted root disk(s)
39.Pp
40The commands of
41.Nm
42by themselves are not enough for most uses.
43Please refer to the
44examples below for the most common situations, and to
45.Xr loader 8
46for additional commands.
47.Pp
48Before using any of the commands provided in
49.Nm ,
50it must be included
51through the command:
52.Pp
53.Dl include check-password.4th
54.Pp
55This line is present in
56.Pa /boot/loader.4th
57file, so it is not needed (and should not be re-issued) in a normal setup.
58.Pp
59The commands provided by it are:
60.Pp
61.Bl -tag -width disable-module_module -compact -offset indent
62.It Ic check-password
63Multi-purpose function that can protect the interactive boot menu,
64prevent boot without password, or prompt for geli(8) passphrase
65.Pq depending on Xr loader.conf 5 settings .
66.Pp
67First checks
68.Va bootlock_password
69and if-set, the user cannot continue until the correct password is entered.
70.Pp
71Next, checks
72.Va geom_eli_passphrase_prompt
73and if set to
74.Li YES
75.Pq case-insensitive
76prompts the user to enter their GELI password for later mounting of the root
77device(s) during boot.
78.Pp
79Last, checks
80.Va password
81and if-set, tries to
82.Ic autoboot
83and only prompts for password on failure or user-interrupt.
84See
85.Xr loader.conf 5
86for additional information.
87.El
88.Pp
89The environment variables that effect its behavior are:
90.Bl -tag -width bootlock_password -offset indent
91.It Va bootlock_password
92Sets the bootlock password (up to 255 characters long) that is required by
93.Ic check-password
94to be entered before the system is allowed to boot.
95.It Va geom_eli_passphrase_prompt
96Selects whether loader(8) will prompt for GELI credentials, handing-off to the
97kernel for later mounting of
98.Xr geli 8
99encrypted root device(s).
100.It Va password
101Sets the password (up to 255 characters long) that is required by
102.Ic check-password
103before the user is allowed to visit the boot menu.
104.El
105.Sh FILES
106.Bl -tag -width /boot/check-password.4th -compact
107.It Pa /boot/loader
108The
109.Xr loader 8 .
110.It Pa /boot/check-password.4th
111.Nm
112itself.
113.It Pa /boot/loader.rc
114.Xr loader 8
115bootstrapping script.
116.El
117.Sh EXAMPLES
118Standard i386
119.Pa /boot/loader.rc :
120.Pp
121.Bd -literal -offset indent -compact
122include /boot/loader.4th
123check-password
124.Ed
125.Pp
126Set a password in
127.Xr loader.conf 5
128to prevent modification of boot options:
129.Pp
130.Bd -literal -offset indent -compact
131password="abc123"
132.Ed
133.Pp
134Set a password in
135.Xr loader.conf 5
136to prevent booting without password:
137.Pp
138.Bd -literal -offset indent -compact
139bootlock_password="boot"
140.Ed
141.Pp
142Add the following to
143.Xr loader.conf 5
144to generate a prompt at boot to collect GELI credentials for mounting
145.Xr geli 8
146encrypted root device(s):
147.Pp
148.Bd -literal -offset indent -compact
149geom_eli_passphrase_prompt="YES"
150.Ed
151.Sh SEE ALSO
152.Xr loader.conf 5 ,
153.Xr loader 8 ,
154.Xr loader.4th 8
155.Sh HISTORY
156The
157.Nm
158set of commands first appeared in
159.Fx 9.0 .
160.Sh AUTHORS
161The
162.Nm
163set of commands was written by
164.An -nosplit
165.An Devin Teske Aq dteske@FreeBSD.org .
166