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Diffstat (limited to 'sys/boot/forth/check-password.4th')
| -rw-r--r-- | sys/boot/forth/check-password.4th | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/sys/boot/forth/check-password.4th b/sys/boot/forth/check-password.4th new file mode 100644 index 0000000..0a1fa5d --- /dev/null +++ b/sys/boot/forth/check-password.4th @@ -0,0 +1,156 @@ +\ Copyright (c) 2006-2011 Devin Teske <devinteske@hotmail.com> +\ All rights reserved. +\ +\ Redistribution and use in source and binary forms, with or without +\ modification, are permitted provided that the following conditions +\ are met: +\ 1. Redistributions of source code must retain the above copyright +\ notice, this list of conditions and the following disclaimer. +\ 2. Redistributions in binary form must reproduce the above copyright +\ notice, this list of conditions and the following disclaimer in the +\ documentation and/or other materials provided with the distribution. +\ +\ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +\ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +\ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +\ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +\ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +\ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +\ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +\ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +\ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +\ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +\ SUCH DAMAGE. +\ +\ $FreeBSD$ + +marker task-check-password.4th + +include /boot/screen.4th + +13 constant enter_key \ The decimal ASCII value for Enter key +8 constant bs_key \ The decimal ASCII value for Backspace key +16 constant readmax \ Maximum number of characters for the password + +variable readX \ Current X offset (column)(used by read) +variable read-start \ Starting X offset (column)(used by read) + +create readval 16 allot \ input obtained (maximum 16 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 + + \ Echo an asterisk (unless Backspace/Enter) + dup bs_key <> if ( and ) dup enter_key <> if + ." *" \ Echo an asterisk + then then + + exit \ Exit from the function + then then + + \ Always allow Backspace and Enter + dup bs_key = if exit then + dup enter_key = if exit then + + then + 50 ms \ Sleep for 50 milliseconds (see loader(8)) + again +; + +: read ( -- String prompt ) + + 0 25 at-xy \ Move the cursor to the bottom-left + dup 1+ read-start ! \ Store X offset after the prompt + read-start @ readX ! \ copy value to the current X offset + 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. + + \ If the key that was entered was not Enter, advance + dup enter_key <> if + readX @ 1+ readX ! \ Advance the column + readlen @ 1+ readlen ! \ Increment input length + then + + \ Handle backspacing + dup bs_key = if + readX @ 2 - readX ! \ Set new cursor position + readlen @ 2 - readlen ! \ Decrement input length + + \ Don't move behind starting position + readX @ read-start @ < if + read-start @ readX ! + then + readlen @ 0< if + 0 readlen ! + then + + \ Reposition cursor and erase character + readX @ 25 at-xy 1 spaces readX @ 25 at-xy + then + + dup enter_key = if + drop \ Clean up stack cruft + 10 emit \ Echo new line + exit + then + + \ If not Backspace or Enter, store the character + dup bs_key <> if ( and ) dup enter_key <> if + + \ store the character in our buffer + dup readval readlen @ 1- + c! + + then then + + drop \ drop the last key that was entered + + again \ Enter was not pressed; repeat +; + +: check-password ( -- ) + + \ Exit if a password was not set + s" password" getenv dup -1 = if + drop exit + then + + begin \ Loop as long as it takes to get the right password + + s" Password: " \ Output a prompt for a password + read \ Read the user's input until Enter + + 2dup readval readlen @ compare 0= if + 2drop exit \ Correct password + then + + \ Bad Password + 3000 ms + ." loader: incorrect password" 10 emit + + again \ Not the right password; repeat +; |
