PHP captcha without graphics ?

[VanDerSaAr]

Hello!

 

I want to place captcha on the registration page of my own forum in PHP, but my free hoster does not support any graphic library. Now I can not to change my hoster.

 

So, I tried to search text capcha and found those several examples:

 

1) http://textcaptcha.com

Probably, it uses WordNet and Prolog. This captcha is remote and require to sign up on the site. I do not like such program, because, imho, secure captcha must be local.

 

2) http://www.smiffysplace.com/textcaptcha_example.php

This captcha is local, but, I guess, it can be overcame easily, if database of questions and answers will be known. That's why, I do not like this captcha too.

 

So, what PHP local captcha without graphics can you recommend to use?

[Davie33]

Hi don't know if this is any good to you but here you go any way.

http://www.xaprb.com/blog/2006/01/28/captchas-done-better/

Its not captcha but help abit.

[VanDerSaAr]

Hi don't know if this is any good to you but here you go any way.

http://www.xaprb.com/blog/2006/01/28/captchas-done-better/

Its not captcha but help abit.

<?php
$captchas = Array();

# Create a single entry
$captchas[] = array(
    "question" => "What color is the sky?",
    "answer" => "blue",
    "options" => array("blue", "red", "orange"));

# Create as many as desired by copy-and-paste...
?>

Yes, it can be temporary solution of problem, but those variants of answers will be bruteforced by spamer, and captcha will be ovecame.

[scootstah]

Use Recaptcha. You don't need the graphic libraries to use it.

[VanDerSaAr]

Use Recaptcha. You don't need the graphic libraries to use it.

Google's ReCaptcha is remote. I want local captcha.

[scootstah]

You're not going to get captcha without GD, sorry. The whole idea of captcha is supposed to be hard for computers to read, but easy for humans to read. As OCR software gets better and better, this is slowly turning the other way around. But, if you have straight up text on your website it's not really going to do anything for you.

 

There are a number of other solutions like answering questions or solving math problems.

 

You could maybe randomly generate a little colored box and ask what color it is. Although, that might not work for color blind people.

[VanDerSaAr]

You're not going to get captcha without GD, sorry. The whole idea of captcha is supposed to be hard for computers to read, but easy for humans to read. As OCR software gets better and better, this is slowly turning the other way around. But, if you have straight up text on your website it's not really going to do anything for you.

 

There are a number of other solutions like answering questions or solving math problems.

 

You could maybe randomly generate a little colored box and ask what color it is. Although, that might not work for color blind people.

I will not surrender.

 

I will try to write my own open source text captcha.

[Christian F.]

Math problems are the one thing computers can do a lot better than humans, every time. So it's even less useful than a CAPTCHA test.

Reading comprehension, on the other hand, is something which computers cannot simulate. At least not without a proper AI. Sure, hardcoded questions can be collected and made a database out of, but that requires human intervention specific for said site.

 

So if you really want to secure your page, do something that requires actually intelligence to solve.

[floridaflatlander]

You're not going to get captcha without GD, sorry.

 

As a note I saw a web site one time that had a question like "What is the second word in the sentence at the top of the page?" or something like that.

 

I also had a pic of a manual captchua I did (just one) and it worked, the numbers were 4321 on a jpg with some lines through it and if you're a small site that may be all you'll need. But the question above worked very good.

[Jessica]

If the math problem is

"What is one plus three"

Is that still effective as a captcha?

 

What's the one PHP Freaks uses? Isn't it a text based one? I haven't had to do it in a while

[scootstah]

If the math problem is

"What is one plus three"

Is that still effective as a captcha?

 

The text can be parsed into "1 + 3", which is then easily solvable.

 

Some people work 9-5 cracking CAPTCHA's, this kind of stuff is trivial.

[Mahngiel]

There's the 'select the [random] image' where a few images are randomly picked from a database and order.

[PFMaBiSmAd]

There's the 'select the [random] image' where a few images are randomly picked from a database and order.

 

Because each actual image is static, you can get a 'signature' for them (filename, filesize, and/or actual binary data of the image) that lets you map the question to the correct image.

 

You would need to dynamically alter the images each time they are output, varying the size/color/name... so that any one actual image has a random signature each time it is used.

[scootstah]

There's the 'select the [random] image' where a few images are randomly picked from a database and order.

 

Because each actual image is static, you can get a 'signature' for them (filename, filesize, and/or actual binary data of the image) that lets you map the question to the correct image.

 

You would need to dynamically alter the images each time they are output, varying the size/color/name... so that any one actual image has a random signature each time it is used.

 

And even then, if enough effort was exerted, you could probably write something that could trace the images and choose that way. Even if you change colors or size, the outline would be roughly the same.

[Mahngiel]

And even then, if enough effort was exerted, ...

 

... You could crack windows

... you could "land a man" on the moon

... you could run for president

 

:ahem:

 

There's a way to break everything with enough effort.  Captcha / verification codes / and the like are only a menial way to slow down the enemy.  There is no de facto fool-proof way to stop the baddies - all you can do is through enough shit in their way.

[floridaflatlander]

There is no de facto fool-proof way to stop the baddies - all you can do is through enough shit in their way.

 

 

change enough to some 

[VanDerSaAr]

I will not surrender.

 

I will try to write my own open source text captcha.

I wrote my own open source text captcha.

 

ConsoleCaptcha ©

Version: 1.0 (2012-08-27)

 

Author: VanDerSaAr

License: MIT

 

ConsoleCaptcha generates text based images with symbols, which enough easily can be read by humans, but difficulty can be read by OCR systems or other robots. It does not require any graphic library (GD, etc), any database of questions, etc. It does not use much resources and more faster. It can be used with telnet, ssh, etc.

 

 

See examples:

 

1) standart size, small font, medium deviation:

http://cryptbb.site40.net/reg.php?v=1

 

2) huge size, small font, large deviation:

http://cryptbb.site40.net/reg.php?v=2

 

3) standart size, smallest font, medium deviation:

http://cryptbb.site40.net/reg.php?v=3

 

 

<?php

/*=============================================================================================

ConsoleCaptcha (c)
Version: 1.0 (2012-08-27)

Author: VanDerSaAr
See example: http://cryptbb.site40.net/reg.php?v=1

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

License: MIT

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

-----------------------------------------------------------------------------------------------

How to use ConsoleCaptcha v1.0:

<code>
<?php
include("console-captcha-v1.php");
echo ConsoleCaptchaV1(
  "EFHLN", # random captcha text = string of 1..30 symbols from EFHLNTXZ + space
  4,    # defined font size              = 1..24 pixels
  21,   # defined canvas height          = 13..100 symbols
  120,  # minimal canvas width           = 0..600 symbols
  
  12,   # minimal strike line height     = 12..min_canvas_width
  50,   # minimal strike line width      = 50..100 symbols
  30,   # maximal add strike line height = 0..50 symbols
  15,   # maximal inverval between strike lines = 0..25 symbols
  
  10,   # minimal letter size            = 10..canvas_height-3
  100,  # maximal letter size            = min_letter_size..canvas_height-3
  0,    # minimal interval between letters = 0..100 symbols
  4,    # maximal interval between letters = min_interval_letter..100
  
  10);  # maximal deviation of letter from vertical line = 0..30 degrees
?>
</code>

To check captcha you can use hashes, sessions, etc.

*///===========================================================================================

function ConsoleCaptchaV1(
  $CaptchaText, // = "EFHLN" # random captcha text = 1..30 symbols from EFHLNTXZ + space
  $FontSize,          // = 4    # defined font size              = 1..24
  $CanvasHeight,      // = 21   # defined canvas height          = 13..100
  $MinCanvasWidth,    // = 120  # minimal canvas width           = 0..600
  $MinStrikeHeight,   // = 12   # minimal strike line height     = 12..$MinCanvasWidth
  $MinStrikeLength,   // = 50   # minimal strike line width      = 50..100
  $AddStrikeLength,   // = 30   # maximal add strike line height = 30..50
  $MaxStrikeInterval, // = 15   # maximal inverval between strike lines = 15..25
  $MinLetterSize,     // = 10   # minimal symbol size            = 10..$CanvasHeight-3
  $MaxLetterSize,     // = 100  # maximal symbol size            = 100..$CanvasHeight-3
  $MinLetterInterval, // = 0    # minimal interval between minimal symbol size = 0..100
  $MaxLetterInterval, // = 4    # maximal interval between minimal symbol size = 4..100
  $MaxLetterAngle     // = 10   # maximal deviation of symbol from vertical line = 0..30
  ) {

#==============================================================================================  

function FuncAngleX($FuncX, $FuncAngle, $FuncSize) { # func (origin x, pos angle, pos length)

  if (($FuncAngle >= (M_PI / 2)) and ($FuncAngle < (3 * M_PI / 2))) { # if angle = PI/2 .. 3*PI/2
  
    $FuncX = $FuncX - round($FuncSize * cos($FuncAngle)); # set position x

  } else { # if (($FuncAngle >= (M_PI / 2)) and ($FuncAngle < (3 * M_PI / 2))) # if angle = 0..PI/2 + 3*PI/2..2*PI

    if ($FuncAngle < (M_PI / 2)) { # if angle = 0 .. PI/2
      $FuncX = $FuncX + round($FuncSize * cos(M_PI - $FuncAngle)); # set position x
    } else { # if ($FuncAngle < (M_PI / 2)) # if angle = 3*PI/2 .. 2*PI
      $FuncX = $FuncX + round($FuncSize * cos($FuncAngle - M_PI)); # set position x
} # if ($FuncAngle < (M_PI / 2)) else

  } # if (($FuncAngle >= (M_PI / 2)) and ($FuncAngle < (3 * M_PI / 2))) else
  
  return $FuncX; # return position x    
  
} # function FuncAngleX ($FuncX, $FuncAngle, $FuncSize)

#----------------------------------------------------------------------------------------------

function FuncPointPos($FuncOriginX, $FuncOriginY, $FuncRatio, $FuncSize1, $FuncAngle1,
$FuncSize2, $FuncAngle2) { # func (origin x, y; factor y; positions length, angle of degrees)

  $FuncA = ($FuncAngle1 / 180) * M_PI; # set position1 angle
  
  if ($FuncA > (2 * M_PI)) { # if angle more 2*PI
    $FuncA = $FuncA - (2 * M_PI); # decrease angle
  } # if ($FuncA > (2 * M_PI))
  if ($FuncA < 0) { # if angle less 0
    $FuncA = $FuncA + (2 * M_PI); # increase angle
  } # if ($FuncA < 0)
  
  $FuncX1 = FuncAngleX($FuncOriginX, $FuncA, $FuncSize1); # set position1 x
  $FuncY1 = $FuncOriginY + round(($FuncSize1 * sin($FuncA)) / $FuncRatio); # set position1 y

  $FuncA = ($FuncAngle2 / 180) * M_PI; # set position2 angle
  
  if ($FuncA > (2 * M_PI)) { # if angle more 2*PI
    $FuncA = $FuncA - (2 * M_PI); # decrease angle
  } # if ($FuncA > (2 * M_PI))
  if ($FuncA < 0) { # if angle less 0
    $FuncA = $FuncA + (2 * M_PI); # increase angle
  } # if ($FuncA < 0)
  
  $FuncX2 = FuncAngleX($FuncOriginX, $FuncA, $FuncSize2); # set position2 x
  $FuncY2 = $FuncOriginY + round(($FuncSize2 * sin($FuncA)) / $FuncRatio); # set position2 y
  
  return array ($FuncX1, $FuncY1, $FuncX2, $FuncY2); # return positions x1, y1, x2, y2
  
} # function FuncPointPos()

#==============================================================================================  

  $NeedDebug = false; # if need to print tech info
  
  #$FontSize = 4; // 4 # get font size // debug
  if ($FontSize < 1) {$FontSize = 1;} # if value less min value then set min value
  if ($FontSize > 24) {$FontSize = 24;} # if value more max value then set max value
  
  #$CanvasHeight = 21; // 21 # get canvas height // debug
  if ($CanvasHeight < 13) {$CanvasHeight = 13;} # if value less min value then set min value
  if ($CanvasHeight > 100) {$CanvasHeight = 100;} # if value more max value then set max value

  #$MinCanvasWidth = 120; // 120 # get minimal canvas width // debug
  if ($MinCanvasWidth < 0) {$MinCanvasWidth = 0;} # if value less min value then set min value
  if ($MinCanvasWidth > 600) {$MinCanvasWidth = 600;} # if value more max value then set max value

  #$MinStrikeHeight = 12; // 12 # get minimal strike line height // debug
  if ($MinStrikeHeight < 12) {$MinStrikeHeight = 12;} # if value less min value then set min value
  if ($MinStrikeHeight > $CanvasHeight) {$MinStrikeHeight = $CanvasHeight;} # if value more max value then set max value
  
  #$MinStrikeLength = 50; // 50 # get minimal strike line length // debug
  if ($MinStrikeLength < 50) {$MinStrikeLength = 50;} # if value less min value then set min value
  if ($MinStrikeLength > 100) {$MinStrikeLength = 100;} # if value more max value then set max value

  #$AddStrikeLength = 30; // 30 # get maximal add strike line height // debug
  if ($AddStrikeLength < 0) {$AddStrikeLength = 0;} # if value less min value then set min value
  if ($AddStrikeLength > 50) {$AddStrikeLength = 50;} # if value more max value then set max value

  #$MaxStrikeInterval = 15; // 15 # get maximal inverval between strike lines // debug
  if ($MaxStrikeInterval < 0) {$MaxStrikeInterval = 0;} # if value less min value then set min value
  if ($MaxStrikeInterval > 25) {$MaxStrikeInterval = 25;} # if value more max value then set max value
  
  #$MinLetterSize = 10; // 10 # get minimal symbol size // debug
  if ($MinLetterSize < 10) {$MinLetterSize = 10;} # if value less min value then set min value
  if ($MinLetterSize > $CanvasHeight - 3) {$MinLetterSize = $CanvasHeight - 3;} # if value more max value then set max value
  
  #$MaxLetterSize = 100; // 100 # get maximal symbol size // debug
  if ($MaxLetterSize < $MinLetterSize) {$MaxLetterSize = $MinLetterSize;} # if value less min value then set min value
  if ($MaxLetterSize > $CanvasHeight - 3) {$MaxLetterSize = $CanvasHeight - 3;} # if value more max value then set max value

  #$MinLetterInterval = 0; // 0 # get minimal interval between minimal symbol size // debug
  if ($MinLetterInterval < 0) {$MinLetterInterval = 0;} # if value less min value then set min value
  if ($MinLetterInterval > 100) {$MinLetterInterval = 100;} # if value more max value then set max value
  
  #$MaxLetterInterval = 4; // 4 # get maximal interval between minimal symbol size // debug
  if ($MaxLetterInterval < $MinLetterInterval) {$MaxLetterInterval = $MinLetterInterval;} # if value less min value then set min value
  if ($MaxLetterInterval > 100) {$MaxLetterInterval = 100;} # if value more max value then set max value

  #$MaxLetterAngle = 10; // 10 # get maximal deviation of symbol from vertical line // debug
  if ($MaxLetterAngle < 0) {$MaxLetterAngle = 0;} # if value less min value then set min value
  if ($MaxLetterAngle > 30) {$MaxLetterAngle = 30;} # if value more max value then set max value

#----------------------------------------------------------------------------------------------  
  
  if ($FontSize < 3) { # if letters too small
    $CanvasBackChars = " "; # set canvas background chars
  } else { # if ($FontSize < 3)
    $CanvasBackChars = ".,' "; # set canvas background chars  
  } # if ($FontSize < 3) else

  $CanvasFrontChars = "#@&"; # set canvas front chars  
  $DrawChar = "*"; # set temp draw char
  $SpaceChar = " "; # set temp space char
  $Ratio = "1.73"; # set ratio between width and height of symbols

  for ($For1 = 1; $For1 <= $CanvasHeight; $For1++) { # cycle lines of canvas
  
    if ($NeedDebug === true) { # if need to debug
      $Line[$For1] = sprintf('%1$02d', $For1); # set line number
} else { # if ($NeedDebug === true) # if not need to debug
  $Line[$For1] = $SpaceChar; # set space
} # if ($NeedDebug === true) else

  } # for ($For1 = 1; $For1 <= $CanvasHeight; $For1++)

  $DrawCount = 0; # clear draw lines count
  $OriginX = 2; # set start symbol position

  $PointX1 = array(); # assign array of x1 point of draw line
  $PointY1 = array(); # assign array of y1 point of draw line
  $PointX2 = array(); # assign array of x2 point of draw line
  $PointY2 = array(); # assign array of y2 point of draw line
  
  for ($For1 = (strlen($CaptchaText) - 1); $For1 >= 0; $For1--) { # cycle symbols of captcha text
  
    if (strpos('EFHLNTXZ ', $CaptchaText[$For1]) === false) { # if captcha symbol is unknown and not space
  $CaptchaText = substr_replace($CaptchaText, "", $For1, 1); # delete symbol
} # if (strpos('EFHLNTXZ ', $CaptchaText[$For1]) === false)

  } # for ($For1 = (strlen($CaptchaText) - 1); $For1 >= 0; $For1--)
  
  if (strlen($CaptchaText) > 30) { # if length of captcha text more value
    $CaptchaText = substr($CaptchaText, 0, 30); # cut captcha text from right side
  } # if (strlen($CaptchaText) > 30)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

for ($For1 = 0; $For1 < strlen($CaptchaText); $For1++) { # cycle symbols of captcha

  $OriginX = $OriginX + rand($MinLetterInterval, $MaxLetterInterval); # increase origin x plus random interval

  $MainSize = rand($MinLetterSize, $MaxLetterSize); # randomize letter size
  #$MainSize = 7; # debug

  $DeltaA = rand(0, $MaxLetterAngle * 2) - $MaxLetterAngle; # randomize angle delta
  #$DeltaA = 0; # debug

  $OriginY = rand(ceil($MainSize / 2) + 2, $CanvasHeight - ceil($MainSize / 2) - 1); # randomize origin y = 08..14
  
  $OriginX = $OriginX + ceil($MainSize / 2) + 1; # increase origin x plus half letter size
  
#----------------------------------------------------------------------------------------------  

if (strpos('EFHLN', $CaptchaText[$For1]) !== false) { # left column begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize, 300 + $DeltaA, $MainSize, 60 + $DeltaA);
} # left column end

if (strpos('EFTZ', $CaptchaText[$For1]) !== false) { # top row begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize, 300 + $DeltaA, $MainSize, 240 + $DeltaA);
} # top row end

if (strpos('EFH', $CaptchaText[$For1]) !== false) { # middle row begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize / 2.1, 0 + $DeltaA, $MainSize / 2.1, 180 + $DeltaA);
} # middle row end	
  
if (strpos('ELZ', $CaptchaText[$For1]) !== false) { # bottom row begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize, 60 + $DeltaA, $MainSize, 120 + $DeltaA);
} # # bottom row end
  
if (strpos('HN', $CaptchaText[$For1]) !== false) { # right column begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize, 240 + $DeltaA, $MainSize, 120 + $DeltaA);
} # right column end

if (strpos('T', $CaptchaText[$For1]) !== false) { # middle column begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize / 1.2, 270 + $DeltaA, $MainSize / 1.2, 90 + $DeltaA);
} # middle column end

if (strpos('NX', $CaptchaText[$For1]) !== false) { # diagonal \ begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize, 300 + $DeltaA, $MainSize, 120 + $DeltaA);
} # diagonal \ end

if (strpos('XZ', $CaptchaText[$For1]) !== false) { # diagonal / begin
  $DrawCount = $DrawCount + 1; # increase line count
  list ($PointX1[$DrawCount], $PointY1[$DrawCount], $PointX2[$DrawCount], $PointY2[$DrawCount]) =
  FuncPointPos($OriginX, $OriginY, $Ratio, $MainSize, 240 + $DeltaA, $MainSize, 60 + $DeltaA);
} # diagonal / begin

#----------------------------------------------------------------------------------------------  
  
  $OriginX = $OriginX + ceil($MainSize / 2) + 1; # increase origin x plus half letter size
  
} # for ($For1 = 0; $For1 < strlen($CaptchaText); $For1++)

#==============================================================================================

$OriginX = $OriginX + 2; # increase origin x
$MarginX = 0; # clear margin x

if ($OriginX < $MinCanvasWidth) { # if origin x less minimal canvas width
  $MarginX = rand(0, $MinCanvasWidth - $OriginX); # randomize margin x
  $OriginX = $MinCanvasWidth; # set margin x
} # if ($OriginX < $MinCanvasWidth)

for ($For1 = 1; $For1 <= $DrawCount; $For1++) { # cycle draw lines
  $PointX1[$For1] = $PointX1[$For1] + $MarginX; # shift position x1 of draw line point
  $PointX2[$For1] = $PointX2[$For1] + $MarginX; # shift position x2 of draw line point
} # for ($For1 = 1; $For1 <= $DrawCount; $For1++)

#----------------------------------------------------------------------------------------------
  
$DotX1 = 1; # clear dot x1

while ($DotX1 < $OriginX) { # while dot x1 less right side of canvas

  $DotX2 = $DotX1 + $MinStrikeLength + rand(0, $AddStrikeLength); # set dot x2
  
  if ($DotX2 >= ($OriginX - $MinStrikeLength)) { # if dot x2 near right side
    $DotX2 = $OriginX; # set origin x to dot x2
  } # if ($DotX2 >= ($OriginX - $MinStrikeLength))

  if ($DotX1 != 1) { # if it is not left side
  
    if (($DotX2 - $DotX1) > ($MinStrikeLength + $AddStrikeLength)) { # if x1 x2 delta more strike line length
      $DotX1 = $DotX2 - ($MinStrikeLength + $AddStrikeLength); # set dot x1
    } # if (($DotX2 - $DotX1) > ($MinStrikeLength + $AddStrikeLength))

  } # if ($DotX1 != 1)

#----------------------------------------------------------------------------------------------
  
  if (($MinStrikeHeight * 2) > $CanvasHeight) { # if canvas height less doubled minimal strike line height
  
    if (rand(0, 1) == 1) { # if 50%/50%
  $DotY1 = rand(1, $CanvasHeight - $MinStrikeHeight + 1); # randomize left position of strike line
} else { # if (rand(0, 1) == 1)
  $DotY1 = rand($MinStrikeHeight, $CanvasHeight); # randomize left position of strike line
} # if (rand(0, 1) == 1) else

  } else { # if (($MinStrikeHeight * 2) > $CanvasHeight)
  
    $DotY1 = rand(1, $CanvasHeight); # randomize left position of strike line

  } # if (($MinStrikeHeight * 2) > $CanvasHeight) else

  if (($DotY1 - $MinStrikeHeight + 1) < 1) { # if left position of strike line near top of canvas  
$DotY2 = rand($DotY1 + $MinStrikeHeight - 1, $CanvasHeight); # randomize right position of strike line 	
  } else { # if (($DotY1 - $MinStrikeHeight + 1) < 1)  
  
    if (($DotY1 + $MinStrikeHeight - 1) > $CanvasHeight) { # if left position of strike line near bottom of canvas	
  $DotY2 = rand(1, $DotY1 - $MinStrikeHeight + 1); # randomize right position of strike line 	  
} else { # if (($DotY1 + $MinStrikeHeight - 1) > $CanvasHeight)

      if (rand(0, 1) == 1) { # if 50%/50%
    $DotY2 = rand($DotY1 + $MinStrikeHeight - 1, $CanvasHeight); # randomize right position of strike line 
  } else { # if (rand(0, 1) == 1)
    $DotY2 = rand(1, $DotY1 - $MinStrikeHeight + 1); # randomize right position of strike line 
  } # if (rand(0, 1) == 1) else
  
} # if (($DotY1 + $MinStrikeHeight - 1) > $CanvasHeight) else			
  } # if (($DotY1 - $MinStrikeHeight + 1) < 1) else

#----------------------------------------------------------------------------------------------
  
  $DrawCount = $DrawCount + 1; # increase draw line count
  $PointX1[$DrawCount] = $DotX1; # set point x1
  $PointY1[$DrawCount] = $DotY1; # set point y1
  $PointX2[$DrawCount] = $DotX2; # set point x2
  $PointY2[$DrawCount] = $DotY2; # set point y2
  
  $DotX1 = $DotX2 + rand(0, $MaxStrikeInterval); # increase dot x1
  
} # while ($DotX1 < $OriginX)

#==============================================================================================

// draw lines on canvas

for ($For1 = 1; $For1 <= $DrawCount; $For1++) { # cycle draw lines
  $DotX1 = $PointX1[$For1]; # get dot x1
  $DotY1 = $PointY1[$For1]; # get dot y1
  $DotX2 = $PointX2[$For1]; # get dot x2
  $DotY2 = $PointY2[$For1]; # get dot y2
  
  if ($NeedDebug == true) { # if need to debug
    echo 'DotX1=' . $DotX1 . ', DotY1=' . $DotY1 . ';'
. ' DotX2=' . $DotX2 . ', DotY2=' . $DotY2 . ': '; # print coordinates
  } # if ($NeedDebug == true)

  if ($DotX1 < $DotX2) { # if need to debug
    $FromX = $DotX1; # set left position x
  } else { # if ($DotX1 < $DotX2)
    $FromX = $DotX2; # set right position x
  } # if ($DotX1 < $DotX2) else
  if ($DotY1 < $DotY2) { # if need to debug
    $FromY = $DotY1; # set top position y
  } else { # if ($DotY1 < $DotY2)
    $FromY = $DotY2; # set bottom position y
  } # if ($DotY1 < $DotY2) else
  
  if ($NeedDebug == true) { # if need to debug
    echo 'FromX=' . $FromX . ', FromY=' . $FromY . '; '; # print coordinates
  } # if ($NeedDebug == true)
  
  $DeltaX = abs($DotX1 - $DotX2); # set delta x
  $DeltaY = abs($DotY1 - $DotY2); # set delta y

  if ($NeedDebug == true) { # if need to debug then print coordinates
    echo 'DeltaX=' . $DeltaX . ', DeltaY=' . $DeltaY . '.<BR>'; # print coodinates
  } # if ($NeedDebug == true)

#----------------------------------------------------------------------------------------------
  
  if ($DeltaX > $DeltaY) { # if width of letter more height
  
    for ($For2 = 0; $For2 <= $DeltaX; $For2++) { # cycle points of width
  if ($DotX1 >= $DotX2) { # if position x1 more or equal position x2
  
    if ($DotY1 < $DotY2) { # if position y1 less position y2
      $TmpInt = round($DeltaY * (($DeltaX - $For2) / $DeltaX)); # set y coodinate
	} else { # if ($DotY1 < $DotY2)
	  $TmpInt = round($DeltaY * ($For2 / $DeltaX)); # set y coodinate
	} # if ($DotY1 < $DotY2) else

  } else { # if ($DotX1 >= $DotX2)
  
    if ($DotY1 >= $DotY2) { # if position y1 more position y2
      $TmpInt = round($DeltaY * (($DeltaX - $For2) / $DeltaX)); # set y coodinate
	} else { # if ($DotY1 >= $DotY2)
	  $TmpInt = round($DeltaY * ($For2 / $DeltaX)); # set y coodinate
	} # if ($DotY1 >= $DotY2) else

  } # if ($DotX1 >= $DotX2) else

      if ($NeedDebug == true) { # if need to debug
	    echo 'Y' . $For2 . '=' . $TmpInt . ', '; # print y coodinate
      }	# if ($NeedDebug == true)
  
  $Line[$FromY + $TmpInt][$FromX + $For2 - 1] = $DrawChar; # draw char on canvas 
    } # for ($For2 = 0; $For2 <= $DeltaX; $For2++) 

  } else { # if ($DeltaX > $DeltaY)  
  
    for ($For2 = 0; $For2 <= $DeltaY; $For2++) { # cycle points of height
  if ($DotY1 >= $DotY2) { # if position y1 more or equal position y2
  
    if ($DotX1 < $DotX2) { # if position x1 less position x2
      $TmpInt = round($DeltaX * (($DeltaY - $For2) / $DeltaY)); # set x coodinate
	} else { # if ($DotX1 < $DotX2)
	  $TmpInt = round($DeltaX * ($For2 / $DeltaY)); # set x coodinate
	} # if ($DotX1 < $DotX2) else

  } else { # if ($DotY1 >= $DotY2)
  
    if ($DotX1 >= $DotX2) { # if position x1 more or equal position x2
      $TmpInt = round($DeltaX * (($DeltaY - $For2) / $DeltaY)); # set x coodinate
	} else { # if ($DotX1 >= $DotX2)
	  $TmpInt = round($DeltaX * ($For2 / $DeltaY)); # set x coodinate
	} # if ($DotX1 >= $DotX2) else

  } # if ($DotY1 >= $DotY2) else

      if ($NeedDebug == true) { # if need to debug
  	    echo 'X' . $For2 . '=' . $TmpInt . ', '; # print x coodinate
      } # if ($NeedDebug == true)
  
  $Line[$FromY + $For2][$FromX + $TmpInt - 1] = $DrawChar; # draw char on canvas
    } # for ($For2 = 0; $For2 <= $DeltaY; $For2++)	

  } # if ($DeltaX > $DeltaY) else
  
#----------------------------------------------------------------------------------------------
  
  if ($NeedDebug == true) { # if need to debug
    echo '<BR>'; # print line break
  } # if ($NeedDebug == true) 
} # for ($For1 = 1; $For1 <= $DrawCount; $For1++)

#==============================================================================================

  $FuncString = ""; # clear canvas line

  for ($For1 = 1; $For1 <= $CanvasHeight; $For1++) { # cycle draw lines
    $TmpString = $Line[$For1]; # set draw line
$TmpInt = strlen($TmpString); # set length of draw line

    if ($TmpInt < $OriginX) { # if length of draw line less right side of canvas
  for ($For2 = $TmpInt; $For2 < $OriginX; $For2++) { # cycle symbols of draw line
    $TmpString = $TmpString . $SpaceChar; # add space to draw line
  }	# for ($For2 = $TmpInt; $For2 < $OriginX; $For2++)
} # if ($TmpInt < $OriginX)

$TmpInt = strlen($CanvasBackChars) - 1; # set length of background string of symbols

    for ($For2 = 0; $For2 < $OriginX; $For2++) { # cycle symbols of draw line
      if ($TmpString[$For2] == $SpaceChar) { # if symbol is space char
    $TmpString[$For2] = $CanvasBackChars[rand(0, $TmpInt)]; # randomize space char
  } # if ($TmpString[$For2] == $SpaceChar)
} # for ($For2 = 0; $For2 < $OriginX; $For2++)

$TmpInt = strlen($CanvasFrontChars) - 1; # set length of front string of symbols

for ($For2 = 0; $For2 < $OriginX; $For2++) { # cycle symbols of draw line
      if ($TmpString[$For2] == $DrawChar) { # if symbol is draw char
    $TmpString[$For2] = $CanvasFrontChars[rand(0, $TmpInt)]; # randomize draw char
  } # if ($TmpString[$For2] == $DrawChar)
    } # for ($For2 = 0; $For2 < $OriginX; $For2++)

$TmpString = str_replace(" ", " ", $TmpString); # change spaces to idents
$FuncString = $FuncString . $TmpString . '<BR>'; # add draw line to canvas line
  } # for ($For1 = 1; $For1 <= $CanvasHeight; $For1++)

  return '<SPAN STYLE="font-family: Lucida Console, Terminal, Courier; font-size: ' . $FontSize . '">'
  . $FuncString . '</SPAN>'; # return canvas line
} # function ShowCaptcha($CaptchaText)

#==============================================================================================

?>

 

 

If ConsoleCaptcha was usefull for you, please comment here.

18909_.zip

[xyph]

I doubt any OCR software would have issues with that CAPTCHA.

 

Neat idea though.

[Christian F.]

I think you need to re-examine your solution... This was even less useful than the worst picture-based CAPTCHA I've seen.

 

Opera 12.01 on Xubuntu 8.04, btw.

[Jessica]

That's weird, I also looked at it and they all worked fine for me. I agree with xyph but still they didn't look anything like what Christian posted.

[Christian F.]

My guess is that both of you are using Windows, and thus has the same font that the OP relies upon for the formatting.

[VanDerSaAr]

I think you need to re-examine your solution... This was even less useful than the worst picture-based CAPTCHA I've seen.

 

Opera 12.01 on Xubuntu 8.04, btw.

 

return '<SPAN STYLE="[b]font-family: Lucida Console, Terminal, Courier;[/b] font-size: ' . $FontSize . '">'
. $FuncString . '</SPAN>'; # return canvas line

 

Do you have any of those fonts?

[xyph]

How it displays could vary from system to system, because it relies on client-side rendering to be visible.

 

If you don't have Lucida Console, Terminal or Courier fonts installed, it will flat out break. Using <pre> tags might help with this, but it still depends on the font the browser decides to use for that tag.

[Jessica]

You should add monospace to the end of the list.

http://en.wikipedia.org/wiki/Font_family_%28HTML%29#Generic_font_families

 

[VanDerSaAr]

My guess is that both of you are using Windows, and thus has the same font that the OP relies upon for the formatting.

Yes, I am on Windows 7.

 

What console font in your operation system? I can add this font name in my forum right now.