1 \ Copyright (c) 2006-2015 Devin Teske <dteske@FreeBSD.org>
4 \ Redistribution and use in source and binary forms, with or without
5 \ modification, are permitted provided that the following conditions
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8 \ notice, this list of conditions and the following disclaimer.
9 \ 2. Redistributions in binary form must reproduce the above copyright
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27 marker task-check-password.4th
29 include /boot/screen.4th
31 13 constant enter_key \ The decimal ASCII value for Enter key
32 8 constant bs_key \ The decimal ASCII value for Backspace key
33 21 constant ctrl_u \ The decimal ASCII value for Ctrl-U sequence
34 255 constant readmax \ Maximum number of characters for the password
36 variable read-tick \ Twiddle position (used by read)
37 variable read-start \ Starting X offset (column)(used by read)
39 create readval readmax allot \ input obtained (up to readmax characters)
40 variable readlen \ input length
42 \ This function blocks program flow (loops forever) until a key is pressed.
43 \ The key that was pressed is added to the top of the stack in the form of its
44 \ decimal ASCII representation. Note: the stack cannot be empty when this
45 \ function starts or an underflow exception will occur. Simplest way to prevent
46 \ this is to pass 0 as a stack parameter (ie. `0 sgetkey'). This function is
47 \ called by the read function. You need not call it directly. NOTE: arrow keys
48 \ show as 0 on the stack
53 key? if \ Was a key pressed? (see loader(8))
54 drop \ Remove stack-cruft
55 key \ Get the key that was pressed
57 \ Check key pressed (see loader(8)) and input limit
58 dup 0<> if ( and ) readlen @ readmax < if
59 \ Spin the twiddle and then exit this function
60 read-tick @ dup 1+ 4 mod read-tick !
62 dup 0 = if ( 1 ) ." /" else
63 dup 1 = if ( 2 ) ." -" else
64 dup 2 = if ( 3 ) ." \" else
65 dup 3 = if ( 4 ) ." |" else
67 then then then then drop
72 \ Always allow Backspace, Enter, and Ctrl-U
73 dup bs_key = if exit then
74 dup enter_key = if exit then
75 dup ctrl_u = if exit then
77 50 ms \ Sleep for 50 milliseconds (see loader(8))
81 : read ( c-addr/u -- ) \ Expects string prompt as stack input
83 0 25 at-xy \ Move the cursor to the bottom-left
84 dup 1+ read-start ! \ Store X offset after the prompt
85 0 readlen ! \ Initialize the read length
86 type \ Print the prompt
90 0 sgetkey \ Block here, waiting for a key to be pressed
92 \ We are not going to echo the password to the screen (for
93 \ security reasons). If Enter is pressed, we process the
94 \ password, otherwise augment the key to a string.
97 drop \ Clean up stack cruft
98 3 spaces \ Erase the twiddle
99 10 emit \ Echo new line
102 3 spaces read-start @ 25 at-xy \ Erase the twiddle
103 0 readlen ! \ Reset input to NULL
105 readlen @ 1 - dup readlen ! \ Decrement input length
106 dup 0< if drop 0 dup readlen ! then \ Don't go negative
107 0= if 3 spaces read-start @ 25 at-xy then \ Twiddle
108 else dup \ Store the character
109 \ NB: sgetkey prevents overflow by way of blocking
110 \ at readmax except for Backspace or Enter
111 readlen @ 1+ dup readlen ! 1- readval + c!
114 drop \ last key pressed
115 again \ Enter was not pressed; repeat
118 : check-password ( -- )
120 \ Do not allow the user to proceed beyond this point if a boot-lock
121 \ password has been set (preventing even boot from proceeding)
122 s" bootlock_password" getenv dup -1 <> if
123 dup readmax > if drop readmax then
125 s" Boot Password: " read ( prompt -- )
126 2dup readval readlen @ compare 0<>
128 3000 ms ." loader: incorrect password" 10 emit
132 drop ( -1 ) \ getenv cruft
135 \ Exit if a password was not set
136 s" password" getenv -1 = if exit else drop then
138 \ We should prevent the user from visiting the menu or dropping to the
139 \ interactive loader(8) prompt, but still allow the machine to boot...
143 \ Only reached if autoboot fails for any reason (including if/when
144 \ the user aborts/escapes the countdown sequence leading to boot).
146 s" password" getenv dup readmax > if drop readmax then
148 s" Password: " read ( prompt -- )
149 2dup readval readlen @ compare 0= if
150 2drop exit \ Correct password
152 3000 ms ." loader: incorrect password" 10 emit