1\ Copyright (c) 2006-2015 Devin Teske <dteske@FreeBSD.org>
2\ All rights reserved.
3\ 
4\ Redistribution and use in source and binary forms, with or without
5\ modification, are permitted provided that the following conditions
6\ are met:
7\ 1. Redistributions of source code must retain the above copyright
8\    notice, this list of conditions and the following disclaimer.
9\ 2. Redistributions in binary form must reproduce the above copyright
10\    notice, this list of conditions and the following disclaimer in the
11\    documentation and/or other materials provided with the distribution.
12\ 
13\ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14\ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15\ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16\ ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17\ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18\ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19\ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20\ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21\ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22\ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23\ SUCH DAMAGE.
24\ 
25
26marker task-check-password.4th
27
28include /boot/screen.4th
29
30vocabulary password-processing
31only forth also password-processing definitions
32
3313  constant enter_key       \ The decimal ASCII value for Enter key
348   constant bs_key          \ The decimal ASCII value for Backspace key
3521  constant ctrl_u          \ The decimal ASCII value for Ctrl-U sequence
36255 constant readmax         \ Maximum number of characters for the password
37
38variable read-tick           \ Twiddle position (used by read)
39variable read-start          \ Starting X offset (column)(used by read)
40
41create readval readmax allot \ input obtained (up to readmax characters)
42variable readlen             \ input length
43
44\ This function blocks program flow (loops forever) until a key is pressed.
45\ The key that was pressed is added to the top of the stack in the form of its
46\ decimal ASCII representation. Note: the stack cannot be empty when this
47\ function starts or an underflow exception will occur. Simplest way to prevent
48\ this is to pass 0 as a stack parameter (ie. `0 sgetkey'). This function is
49\ called by the read function. You need not call it directly. NOTE: arrow keys
50\ show as 0 on the stack
51\ 
52: sgetkey ( -- )
53
54	begin \ Loop forever
55		key? if \ Was a key pressed? (see loader(8))
56			drop \ Remove stack-cruft
57			key  \ Get the key that was pressed
58
59			\ Check key pressed (see loader(8)) and input limit
60			dup 0<> if ( and ) readlen @ readmax < if
61				\ Spin the twiddle and then exit this function
62				read-tick @ dup 1+ 4 mod read-tick !
63				2 spaces
64				dup 0 = if ( 1 ) ." /" else
65				dup 1 = if ( 2 ) ." -" else
66				dup 2 = if ( 3 ) ." \" else
67				dup 3 = if ( 4 ) ." |" else
68					1 spaces
69				then then then then drop
70				read-start @ 25 at-xy
71				exit
72			then then
73
74			\ Always allow Backspace, Enter, and Ctrl-U
75			dup bs_key = if exit then
76			dup enter_key = if exit then
77			dup ctrl_u = if exit then
78		then
79		50 ms \ Sleep for 50 milliseconds (see loader(8))
80	again
81;
82
83: cfill ( c c-addr/u -- )
84	begin dup 0> while
85		-rot 2dup c! 1+ rot 1-
86	repeat 2drop drop
87;
88
89: read-reset ( -- )
90	0 readlen !
91	0 readval readmax cfill
92;
93
94: read ( c-addr/u -- ) \ Expects string prompt as stack input
95
96	0 25 at-xy           \ Move the cursor to the bottom-left
97	dup 1+ read-start !  \ Store X offset after the prompt
98	0 readlen !          \ Initialize the read length
99	type                 \ Print the prompt
100
101	begin \ Loop forever
102
103		0 sgetkey \ Block here, waiting for a key to be pressed
104
105		\ We are not going to echo the password to the screen (for
106		\ security reasons). If Enter is pressed, we process the
107		\ password, otherwise augment the key to a string.
108
109		dup enter_key = if
110			drop     \ Clean up stack cruft
111			3 spaces \ Erase the twiddle
112			10 emit  \ Echo new line
113			exit
114		else dup ctrl_u = if
115			3 spaces read-start @ 25 at-xy \ Erase the twiddle
116			0 readlen ! \ Reset input to NULL
117		else dup bs_key = if
118			readlen @ 1 - dup readlen ! \ Decrement input length
119			dup 0< if drop 0 dup readlen ! then \ Don't go negative
120			0= if 3 spaces read-start @ 25 at-xy then \ Twiddle
121		else dup \ Store the character
122			\ NB: sgetkey prevents overflow by way of blocking
123			\     at readmax except for Backspace or Enter
124			readlen @ 1+ dup readlen ! 1- readval + c!
125		then then then
126
127		drop \ last key pressed
128	again \ Enter was not pressed; repeat
129;
130
131only forth definitions also password-processing also support-functions
132
133: check-password ( -- )
134
135	\ Do not allow the user to proceed beyond this point if a boot-lock
136	\ password has been set (preventing even boot from proceeding)
137	s" bootlock_password" getenv dup -1 <> if
138		dup readmax > if drop readmax then
139		begin
140			s" Boot Password: " read ( prompt -- )
141			2dup readval readlen @ compare 0<>
142		while
143			3000 ms ." loader: incorrect password" 10 emit
144		repeat
145		2drop read-reset
146	else drop then
147
148	\ Prompt for GEOM ELI (geli(8)) passphrase if enabled
149	s" geom_eli_passphrase_prompt" getenv dup -1 <> if
150		s" YES" compare-insensitive 0= if
151			s" GELI Passphrase: " read ( prompt -- )
152			readval readlen @ s" kern.geom.eli.passphrase" setenv
153			read-reset
154		then
155	else drop then
156
157	\ Exit if a password was not set
158	s" password" getenv -1 = if exit else drop then
159
160	\ We should prevent the user from visiting the menu or dropping to the
161	\ interactive loader(8) prompt, but still allow the machine to boot...
162
163	any_conf_read? if load_kernel load_modules then
164	0 autoboot
165
166	\ Only reached if autoboot fails for any reason (including if/when
167	\ the user aborts/escapes the countdown sequence leading to boot).
168
169	s" password" getenv dup readmax > if drop readmax then
170	begin
171		s" Password: " read ( prompt -- )
172		2dup readval readlen @ compare 0= if \ Correct password?
173			2drop read-reset exit
174		then
175		3000 ms ." loader: incorrect password" 10 emit
176	again
177;
178
179only forth definitions
180