Coldfusion Captcha
In these days, sending spam messages programs are building up and they are now the big challenge for website developers. That’s why some websites prevent this bots by the way of installing captcha program in their site. For coldfusion developer, I’ll describe how to prevent spam bots. Here is coding:
Captcha.cfc
<cfcomponent name=”Captcha” hint=”Writes the captcha to a file”>
<cfscript>
instance = StructNew();
</cfscript>
<!——————————————- PUBLIC ——————————————->
<cffunction name=”init” hint=”Constructor” access=”public” returntype=”Captcha” output=”false”>
<cfscript>
return this;
</cfscript>
</cffunction>
<cffunction name=”captchaToFile” hint=”Writes the captcha to the designated file path” access=”public” returntype=”void” output=”false”>
<cfargument name=”filePath” hint=”The absolute path to the file the CAPTCHA is to be written to” type=”string” required=”Yes”>
<cfargument name=”text” hint=”The text to display” type=”string” required=”Yes”>
<cfargument name=”width” hint=”The width of the image” type=”numeric” required=”true”>
<cfargument name=”height” hint=”The height of the image” type=”numeric” required=”true”>
<cfargument name=”fontsize” hint=”The font size the text” type=”numeric” required=”true”>
<cfargument name=”leftOffset” hint=”The number of pixels of padding to put to the left of the text” type=”numeric” required=”true”>
<cfargument name=”topOffset” hint=”The number of pixels of padding to put to the top of the text” type=”numeric” required=”true”>
<cfargument name=”shearXRange” hint=”The amount to shear the font on the X axis” type=”numeric” required=”true”>
<cfargument name=”shearYRange” hint=”The amount to shear the font on the Y axis” type=”numeric” required=”true”>
<cfscript>
var fileOutputStream = createObject(“java”, “java.io.FileOutputStream”).init(arguments.filePath);
writeToStream(fileOutputStream,
arguments.text,
arguments.width,
arguments.height,
arguments.fontsize,
arguments.leftOffset,
arguments.topOffset,
arguments.shearXRange,
arguments.shearYRange);
fileOutputStream.flush();
fileOutputStream.close();
</cfscript>
</cffunction>
<cffunction name=”captchaToBinary” hint=”Returns the captcha as binary data for use in the cfcontent ‘variable’ attribute” access=”public” returntype=”any” output=”false”>
<cfargument name=”text” hint=”The text to display” type=”string” required=”Yes”>
<cfargument name=”width” hint=”The width of the image” type=”numeric” required=”true”>
<cfargument name=”height” hint=”The height of the image” type=”numeric” required=”true”>
<cfargument name=”fontsize” hint=”The font size the text” type=”numeric” required=”true”>
<cfargument name=”leftOffset” hint=”The number of pixels of padding to put to the left of the text” type=”numeric” required=”true”>
<cfargument name=”topOffset” hint=”The number of pixels of padding to put to the top of the text” type=”numeric” required=”true”>
<cfargument name=”shearXRange” hint=”The amount to shear the font on the X axis” type=”numeric” required=”true”>
<cfargument name=”shearYRange” hint=”The amount to shear the font on the Y axis” type=”numeric” required=”true”>
<cfscript>
var byteOutputstream = createObject(“java”, “java.io.ByteArrayOutputStream”).init();
writeToStream(byteOutputstream,
arguments.text,
arguments.width,
arguments.height,
arguments.fontsize,
arguments.leftOffset,
arguments.topOffset,
arguments.shearXRange,
arguments.shearYRange);
return byteOutputstream.toByteArray();
</cfscript>
</cffunction>
<!——————————————- PACKAGE ——————————————->
<!——————————————- PRIVATE ——————————————->
<cffunction name=”writeToStream” hint=”Writes to a outputStream” access=”private” returntype=”void” output=”false”>
<cfargument name=”outputStream” hint=”Gimme a java.io.OutputStream” type=”any” required=”Yes”>
<cfargument name=”text” hint=”The text to display” type=”string” required=”Yes”>
<cfargument name=”width” hint=”The width of the image” type=”numeric” required=”true”>
<cfargument name=”height” hint=”The height of the image” type=”numeric” required=”true”>
<cfargument name=”fontsize” hint=”The font size the text” type=”numeric” required=”true”>
<cfargument name=”LeftOffset” hint=”The number of pixels of padding to put to the left of the text” type=”numeric” required=”true”>
<cfargument name=”TopOffset” hint=”The number of pixels of padding to put to the top of the text” type=”numeric” required=”true”>
<cfargument name=”shearXRange” hint=”The amount to shear the font on the X axis” type=”numeric” required=”true”>
<cfargument name=”shearYRange” hint=”The amount to shear the font on the Y axis” type=”numeric” required=”true”>
<cfscript>
/* variables */
var counter = 0; var characters = 0; var top = 0;
var len = 0; var size = 0; var left = 0;
var response = 0; var char = 0; var encoder = 0;
var encoderParam = 0;
/* utils */
var staticArrays = createObject(“java”, “java.util.Arrays”);
var staticCollections = createObject(“java”, “java.util.Collections”);
/* prep image */
var dimension = createObject(“java”, “java.awt.Dimension”).init(width, height);
var imageType = createObject(“java”, “java.awt.image.BufferedImage”).TYPE_INT_RGB;
var bufferedImage = createObject(“java”, “java.awt.image.BufferedImage”).init(JavaCast(“int”, dimension.getWidth()), JavaCast(“int”, dimension.getHeight()), imageType);
var graphics = bufferedImage.createGraphics();
/* get the fonts */
var allFonts = staticArrays.asList(createObject(“java”, “java.awt.GraphicsEnvironment”).getLocalGraphicsEnvironment().getAllFonts());
/* drawing graphics here */
/* background */
var startColor = createRandomLightGreyScaleColor();
var endColor = createRandomLightGreyScaleColor();
var gradientPaint = createObject(“java”, “java.awt.GradientPaint”).init(getRandomPointOnBorder(dimension),
startColor,
getRandomPointOnBorder(dimension),
endColor);
var background = createObject(“java”, “java.awt.Rectangle”).init(dimension);
graphics.setPaint(gradientPaint);
graphics.fill(background);
/* draw some lines */
len = randRange(10, 20);
for(counter = 1; counter lte len; counter = counter + 1)
{
drawRandomLine(graphics, dimension);
}
/* draw the text in random font characters */
characters = text.toCharArray();
len = ArrayLen(characters);
size = fontsize;
top = topOffset;
left = Leftoffset;
staticCollections.shuffle(allFonts);
for(counter = 1; counter lte len; counter = counter + 1)
{
char = characters[counter];
setNewFont(graphics, allFonts, size, arguments.shearXRange, arguments.shearYRange);
graphics.setColor(createRandomDarkGreyScaleColor());
//if cannot display, find a font that can
while(NOT graphics.getFont().canDisplay(char))
{
setNewFont(graphics, allFonts, size, arguments.shearXRange, arguments.shearYRange);
}
graphics.drawString(JavaCast(“string”, char), JavaCast(“int”, left), JavaCast(“int”, top));
left = left + (2 * graphics.getFontMetrics().charWidth(char));
}
/* draw a few more lines */
len = randRange(2, round(max(min(width, height) / 20, 3))); //draw more lines the bigger it is.
for(counter = 1; counter lte len; counter = counter + 1)
{
drawRandomLine(graphics, dimension);
}
encoder = createObject(“java”, “com.sun.image.codec.jpeg.JPEGCodec”).createJPEGEncoder(arguments.outputstream);
encoderParam = encoder.getDefaultJPEGEncodeParam(bufferedImage);
encoderParam.setQuality(JavaCast(“float”, 0.80), false);
encoder.setJPEGEncodeParam(encoderParam);
encoder.encode(bufferedImage);
</cfscript>
</cffunction>
<cffunction name=”createRandomLightGreyScaleColor” hint=”Creates a random greyscale java.awt.colour” access=”private” returntype=”any” output=”false”>
<cfscript>
var shade = JavaCast(“int”, RandRange(255, 160));
var color = createObject(“java”, “java.awt.Color”).init(shade, shade, shade);
return color;
</cfscript>
</cffunction>
<cffunction name=”createRandomDarkGreyScaleColor” hint=”Returns a dark greyscale java.awt.color” access=”private” returntype=”any” output=”false”>
<cfscript>
var shade = JavaCast(“int”, RandRange(0, 100));
var color = createObject(“java”, “java.awt.Color”).init(shade, shade, shade);
return color;
</cfscript>
</cffunction>
<cffunction name=”getRandomPointOnBorder” hint=”Gets a random java.awt.Point on the border” access=”private” returntype=”any” output=”false”>
<cfargument name=”dimension” hint=”The dimension object” type=”any” required=”Yes”>
<cfscript>
var point = createObject(“java”, “java.awt.Point”);
var height = Javacast(“int”, arguments.dimension.getHeight());
var width = JavaCast(“int”, arguments.dimension.getWidth());
var choice = randrange(1,4);
switch (choice)
{
case 1: //left side
point.setLocation(JavaCast(“int”, 0), JavaCast(“int”, RandRange(0, height)));
break;
case 2: //top side
point.setLocation(JavaCast(“int”, RandRange(0, width)), JavaCast(“int”, 0));
break;
case 3: //right side
point.setLocation(width, RandRange(0, height));
break;
case 4: //bottom side
point.setLocation(RandRange(0, width), height);
break;
}
return point;
</cfscript>
</cffunction>
<cffunction name=”setNewFont” hint=”Sets a new font in the graphics lib” access=”private” returntype=”void” output=”false”>
<cfargument name=”graphics” hint=”The graphics” type=”any” required=”Yes”>
<cfargument name=”fontCollection” hint=”The current font collection” type=”any” required=”Yes”>
<cfargument name=”size” hint=”The size of the font” type=”numeric” required=”Yes”>
<cfargument name=”shearXRange” hint=”The shear x range” type=”numeric” required=”Yes”>
<cfargument name=”shearYRange” hint=”The shear y range” type=”numeric” required=”Yes”>
<cfscript>
var font = 0;
var staticCollections = createObject(“java”, “java.util.Collections”);
staticCollections.rotate(arguments.fontCollection, 1);
//apply transform twice, just for fun
font = arguments.fontCollection[1].deriveFont(JavaCast(“float”, arguments.size)).deriveFont(getRandomTransformation(arguments.shearXRange, arguments.shearYRange)).deriveFont(getRandomTransformation(arguments.shearXRange, arguments.shearYRange));
arguments.graphics.setFont(font);
</cfscript>
</cffunction>
<cffunction name=”getRandomTransformation” hint=”Gets a random transformation” access=”private” returntype=”any” output=”false”>
<cfargument name=”shearXRange” hint=”The shear x range” type=”numeric” required=”Yes”>
<cfargument name=”shearYRange” hint=”The shear y range” type=”numeric” required=”Yes”>
<cfscript>
//create a slightly random affine transform
var transformation = createObject(“java”, “java.awt.geom.AffineTransform”).init();
var shearx = RandRange(-1 * arguments.shearXRange, arguments.shearXRange) / 100;
var sheary = RandRange(-1 * arguments.shearYRange, arguments.shearYRange) / 100;
transformation.shear(shearx, sheary);
return transformation;
</cfscript>
</cffunction>
<cffunction name=”drawRandomLine” hint=”draws a random line” access=”private” returntype=”void” output=”false”>
<cfargument name=”graphics” hint=”The graphics” type=”any” required=”Yes”>
<cfargument name=”dimension” hint=”The dimension object” type=”any” required=”Yes”>
<cfscript>
var point1 = getRandomPointOnBorder(arguments.dimension);
var point2 = getRandomPointOnBorder(arguments.dimension);
var staticColor = createObject(“java”, “java.awt.Color”);
arguments.graphics.setColor(staticColor.white);
arguments.graphics.drawLine(
JavaCast(“int”, point1.getX()),
JavaCast(“int”, point1.getY()),
JavaCast(“int”, point2.getX()),
JavaCast(“int”, point2.getY()));
</cfscript>
</cffunction>
</cfcomponent>
To include your CFM file in like that:
It make “random text and print it onto Captcha Image”
<cfset ststring=structNew()>
<cfloop index=”i” from=”1″ to=”6″ step=”1″>
<cfset a = randrange(48,122)>
<cfif (#a# gt 57 and #a# lt 65) or (#a# gt 90 and #a# lt 97)>
<cfset ststring["#i#"]=”E”>
<cfelse>
<cfset ststring["#i#"]=#chr(a)#>
</cfif>
</cfloop>
<cfset randtext_captcha=”#ststring[1]##ststring[2]##ststring[3]##ststring[4]##ststring[5]##ststring[6]#”>
<cfscript>
captcha = createObject(“component”, “Captcha”).init();
captcha.captchaToFile(expandPath(“captcha.jpg”),”#randtext_captcha#”,400,50,30,10,35,45,60);
</cfscript>
<img src=”captcha.jpg”>
How? It’s kinda easy, isn’t it?
Big Credit: http://www.compoundtheory.com/
