\ Copyright (c) 2006-2015 Devin Teske <dteske@FreeBSD.org>

\ All rights reserved.

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marker task-check-password.4th

include /boot/forth/screen.4th

vocabulary password-processing

only forth also password-processing definitions

13 constant enter_key \ The decimal ASCII value for Enter key

8 constant bs_key \ The decimal ASCII value for Backspace key

21 constant ctrl_u \ The decimal ASCII value for Ctrl-U sequence

255 constant readmax \ Maximum number of characters for the password

variable read-tick \ Twiddle position (used by read)

variable read-start \ Starting X offset (column)(used by read)

create readval readmax allot \ input obtained (up to readmax characters)

variable readlen \ input length

\ This function blocks program flow (loops forever) until a key is pressed.

\ The key that was pressed is added to the top of the stack in the form of its

\ decimal ASCII representation. Note: the stack cannot be empty when this

\ function starts or an underflow exception will occur. Simplest way to prevent

\ this is to pass 0 as a stack parameter (ie. `0 sgetkey'). This function is

\ called by the read function. You need not call it directly. NOTE: arrow keys

\ show as 0 on the stack

\

: sgetkey ( -- )

begin \ Loop forever

key? if \ Was a key pressed? (see loader(8))

drop \ Remove stack-cruft

key \ Get the key that was pressed

\ Check key pressed (see loader(8)) and input limit

dup 0<> if ( and ) readlen @ readmax < if

\ Spin the twiddle and then exit this function

read-tick @ dup 1+ 4 mod read-tick !

2 spaces

dup 0 = if ( 1 ) ." /" else

dup 1 = if ( 2 ) ." -" else

dup 2 = if ( 3 ) ." \" else

dup 3 = if ( 4 ) ." |" else

1 spaces

then then then then drop

read-start @ 25 at-xy

exit

then then

\ Always allow Backspace, Enter, and Ctrl-U

dup bs_key = if exit then

dup enter_key = if exit then

dup ctrl_u = if exit then

then

50 ms \ Sleep for 50 milliseconds (see loader(8))

again

;

: cfill ( c c-addr/u -- )

begin dup 0> while

-rot 2dup c! 1+ rot 1-

repeat 2drop drop

;

: read-reset ( -- )

0 readlen !

0 readval readmax cfill

;

: read ( c-addr/u -- ) \ Expects string prompt as stack input

0 25 at-xy \ Move the cursor to the bottom-left

dup 1+ read-start ! \ Store X offset after the prompt

0 readlen ! \ Initialize the read length

type \ Print the prompt

begin \ Loop forever

0 sgetkey \ Block here, waiting for a key to be pressed

\ We are not going to echo the password to the screen (for

\ security reasons). If Enter is pressed, we process the

\ password, otherwise augment the key to a string.

dup enter_key = if

drop \ Clean up stack cruft

3 spaces \ Erase the twiddle

10 emit \ Echo new line

exit

else dup ctrl_u = if

3 spaces read-start @ 25 at-xy \ Erase the twiddle

0 readlen ! \ Reset input to NULL

else dup bs_key = if

readlen @ 1 - dup readlen ! \ Decrement input length

dup 0< if drop 0 dup readlen ! then \ Don't go negative

0= if 3 spaces read-start @ 25 at-xy then \ Twiddle

else dup \ Store the character

\ NB: sgetkey prevents overflow by way of blocking

\ at readmax except for Backspace or Enter

readlen @ 1+ dup readlen ! 1- readval + c!

then then then

drop \ last key pressed

again \ Enter was not pressed; repeat

;

only forth definitions also password-processing

: check-password ( -- )

\ Do not allow the user to proceed beyond this point if a boot-lock

\ password has been set (preventing even boot from proceeding)

s" bootlock_password" getenv dup -1 <> if

dup readmax > if drop readmax then

begin

s" Boot Password: " read ( prompt -- )

2dup readval readlen @ compare 0<>

while

3000 ms ." loader: incorrect password" 10 emit

repeat

2drop read-reset

else drop then

\ Prompt for GEOM ELI (geli(8)) passphrase if enabled

s" geom_eli_passphrase_prompt" getenv dup -1 <> if

s" YES" compare-insensitive 0= if

s" GELI Passphrase: " read ( prompt -- )

readval readlen @ s" kern.geom.eli.passphrase" setenv

read-reset

then

else drop then

\ Exit if a password was not set

s" password" getenv -1 = if exit else drop then

\ We should prevent the user from visiting the menu or dropping to the

\ interactive loader(8) prompt, but still allow the machine to boot...

0 autoboot

\ Only reached if autoboot fails for any reason (including if/when

\ the user aborts/escapes the countdown sequence leading to boot).

s" password" getenv dup readmax > if drop readmax then

begin

s" Password: " read ( prompt -- )

2dup readval readlen @ compare 0= if \ Correct password?

2drop read-reset exit

then

3000 ms ." loader: incorrect password" 10 emit

again

;

only forth definitions