Asp verification code generation

<% @ Language = "javascript" %>
<%
/*
* Copyright (c) 2006 Hardway Hou
* Distributed under the BSD License
* Too red from PNGlet http://www.elf.org/pnglets/
*/
Var ASCII = new Array (36 );
ASCII [0] = "1110000111110111101111011110111101111011110111101111011110111101111011110111101111011110111110000111 ";
ASCII [1] = "1111011111110001111111110111111111011111111101111111110111111111011111111101111111110111111100000111 ";
ASCII [2] = "1110000111110111101111011110111111111011111111011111111011111111011111111011111111011110111100000011 ";
ASCII [3] = "1110000111110111101111011110111111110111111100111111111101111111111011110111101111011110111110000111 ";
ASCII [4] = "1111101111111110111111110011111110101111110110111111011011111100000011111110111111111011111111000011 ";
ASCII [5] = "1100000011110111111111011111111101000111110011101111111110111111111011110111101111011110111110000111 ";
ASCII [6] = "1111000111111011101111011111111101111111110100011111001110111101111011110111101111011110111110000111 ";
ASCII [7] = "1100000011110111011111011101111111101111111110111111110111111111011111111101111111110111111111011111 ";
ASCII [8] = "1110000111110111101111011110111101111011111000011111101101111101111011110111101111011110111110000111 ";
ASCII [9] = "1110001111110111011111011110111101111011110111001111100010111111111011111111101111011101111110001111 ";
ASCII [10] = "1111011111111101111111101011111110101111111010111111101011111100000111110111011111011101111000100011 ";
ASCII [11] = "1000000111110111101111011110111101110111110000111111011101111101111011110111101111011110111000000111 ";
ASCII [12] = "1110000011110111101110111110111011111111101111111110111111111011111111101111101111011101111110001111 ";
ASCII [13] = "0000001111110111011111011110111101111011110111101111011110111101111011110111101111011101110000001111 ";
ASCII [14] = "1000000111110111101111011011111101101111110000111111011011111101101111110111111111011110111000000111 ";
ASCII [15] = "1000000111110111101111011011111101101111110000111111011011111101101111110111111111011111111000111111 ";
ASCII [16] = "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 ";

Var FONT_WIDTH = 10;
Var FONT_HEIGHT = 10;

// Note.
// Assume all the strings are formed by BYTE.
// That is, a single character is a BYTE.
// It will be converted to real BYTE at output phase.

// Using index color, depth 8
Var WIDTH = 160;
Var HEIGHT = 40;
Var DEPTH = 8;
Var MAP = new Array (WIDTH + 1) * HEIGHT );

Function B4 (B ){
Return String. fromCharCode (B> 24) & 0xFF, (B> 16) & 0xFF, (B> 8) & 0xFF, B & 0xFF );
}
Function B2 (B ){
Return String. fromCharCode (B> 8) & 0xFF, B & 0xFF );
}
Function B1 (B ){
Return String. fromCharCode (B & 0xFF );
}

Var CRC_TABLE = new Array (256 );
// Make crc table
Function CRC32_Init (){
Var n = 0, k = 0;
Var c;
For (n = 0; n <256; n ++ ){
C = n;
For (k = 0; k <8; k ++ ){
If (c & 1)
C = 0xedb88320 ^ (c >>> 1 );
Else
C = c >>> 1;
  }
CRC_TABLE [n] = c;
 }
}
CRC32_Init ();

Function CRC32 (str ){
Var c = 0 xFFFFFFFF;
Var n = 0;
For (n = 0; n <str. length; n ++ ){
C = CRC_TABLE [(c ^ str. charCodeAt (n) & 0xFF] ^ (c >>> 8 );
 }
Return c ^ 0 xFFFFFFFF;
}

Function png_signature (){
Return [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a];
}

Function png_chunk (type, str ){
Var ary = [], I = 0;
Var crc;
 
Crc = CRC32 (type + str );
Str = B4 (str. length) + type + str;
Str = str + B4 (crc );
 
For (I = 0; I <str. length; I ++)
Ary. push (str. charCodeAt (I ));
Return ary;
}

Function png_IHDR (){
Return png_chunk ("IHDR", B4 (WIDTH) + B4 (HEIGHT) + B1 (DEPTH) + B1 (3) + B1 (0) + B1 (0) + B1 (0 ));
}

Function png_PLTE (){
Return png_chunk ("PLTE ",
B1 (255) + B1 (255) + B1 (255) // 0
+ B1 (224) + B1 (224) + B1 (224) // 1
+ B1 (192) + B1 (192) + B1 (192) // 2
+ B1 (160) + B1 (160) + B1 (160) // 3
+ B1 (128) + B1 (128) + B1 (128) // 4
+ B1 (96) + B1 (96) + B1 (96) // 5
+ B1 (64) + B1 (64) + B1 (64) // 6
+ B1 (32) + B1 (32) + B1 (32) // 7
+ B1 (0) + B1 (0) + B1 (0) // 8
);
}

Function png_IDAT (){
Var h = HEIGHT
Var strip = WIDTH + 1;
Var x, y;
  
Var data = ""
For (y = 0; y Data = data + String. fromCharCode (MAP [x + y * strip]);
Var LEN = data. length;
Var NLEN = LEN ^ 0 xFFFFFFFF;
 
// Calculate Simple Adler-32 checksum
Var BASE = 65521, NMAX = 5552;
Var s1 = 1, s2 = 0, n = NMAX;
Var I;
For (I = 0; I <LEN; I ++ ){
S1 + = data. charCodeAt (I );
S2 + = s1;
If (n --) = 0 ){
S1 % = BASE;
S2 % = BASE;
N = NMAX;
  }
 }
S1 % = BASE;
S2 % = BASE;
 
Return png_chunk ("IDAT", B1 (0x78) + B1 (0xDA) + B1 (0x01) +/* uncompressd lz77 */
String. fromCharCode (LEN) & 0xFF, (LEN> 8) & 0xFF, (NLEN) & 0xFF, (NLEN> 8) & 0xFF) +
Data + B4 (s2 <16) | s1 ));
}

Function png_IEND (){
Return png_chunk ("IEND ","");
}

Function png_output (){
Var dat = [], I = 0
Var str = "";
Dat = dat. concat (png_signature (), png_IHDR (), png_PLTE (), png_IDAT (), png_IEND ());
If (dat. length % 2 = 1) dat. push (0); // Fill data to make it 2-byte aligned
For (I = 0; I <dat. length-1; I + = 2 ){
Response. binaryWrite (String. fromCharCode (dat [I] + (dat [I + 1] <8 )));
 }
}

Function Map_Init (){
Var x, y;
Var strip = WIDTH + 1;
For (x = 0; x <strip; x ++) for (y = 0; y <HEIGHT; y ++ ){
If (x = 0)
MAP [x + y * strip] = 0; // scanline indicator
Else
MAP [x + y * strip] = 8; // bgcolor
 }
}

Function putPixel (x, y, c ){
MAP [x + 1 + y * (WIDTH + 1)] = c;
}
Function getPixel (x, y, c ){
Return MAP [x + 1 + y * (WIDTH + 1)];
}

Function putChar (ox, oy, ch ){
Var x, y;
Oy + = Math. floor (Math. random () * 5-5.5 );
For (y = 0; y <FONT_HEIGHT; y ++ ){
Ox + = Math. floor (Math. random () * 2 + 0.5)-1;
For (x = 0; x <FONT_WIDTH; x ++ ){
Var c = 1-parseInt (ASCII [ch]. charAt (x + y * FONT_WIDTH ));
If (c> 0 ){
C = 0;
// Double size, bold and random italic
PutPixel (ox + x * 3, oy + y * 2, c );
PutPixel (ox + x * 3 + 1, oy + y * 2, c );
PutPixel (ox + x * 3 + 2, oy + y * 2, c );
PutPixel (ox + x * 3, oy + y * 2 + 1, c );
PutPixel (ox + x * 3 + 1, oy + y * 2 + 1, c );
PutPixel (ox + x * 3 + 2, oy + y * 2 + 1, c );
   }
  }
 }
}
Function putNoise (n, c ){
Var I, x, y;
For (I = 0; I <n; I ++ ){
X = Math. floor (Math. random () * WIDTH );
Y = Math. floor (Math. random () * HEIGHT );
PutPixel (x, y, c );
 }
}
Function smooth (){
Var x, y;
Var c0, c1, c2, c3, c4; // center, up, right, down, left
For (x = 0; x <WIDTH; x ++) for (y = 0; y <HEIGHT; y ++ ){
C0 = getPixel (x, y );
C1 = (y> 0 )? GetPixel (x, Y-1): c0;
C2 = (x <WIDTH )? GetPixel (x + 1, y): c0;
C3 = (y <HEIGHT )? GetPixel (x, y + 1): c0;
C4 = (x> 0 )? GetPixel (X-1, y): c0;
PutPixel (x, y, Math. floor (c0*6 + c1 + c2 + c3 + c4)/10 + 0.5 ));
 }
}

// MD5
Var v1 = 0; var v2 = ""; var v3 = 8; function hex_md5 (s) {return binl2hex (f2 (f8 (s), s. length * v3);} function b64_md5 (s) {return binl2b64 (f2 (f8 (s), s. length * v3);} function str_md5 (s) {return binl2str (f2 (f8 (s), s. length * v3);} function hex_hmac_md5 (key, data) {return binl2hex (f9 (key, data);} function b64_hmac_md5 (key, data) {return binl2b64 (f9 (key, data);} function str_hmac_md5 (key, data) {return binl2str (f9 (key, data);} func Tion f1 () {return hex_md5 ("abc") = "900150983cd24fb0d6963f7d28e17f72";} function f2 (x, len) {x [len> 5] | = 0x80 <(len) % 32); x [(len + 64) >>> 9) <4) + 14] = len; var a = 1732584193; var B =-271733879; var c =-1732584194; var d = 271733878; for (var I = 0; I <x. length; I + = 16) {var olda = a; var oldb = B; var oldc = c; var oldd = d; a = f4 (a, B, c, d, x [I + 0], 7,-680876936); d = f4 (d, a, B, c, x [I + 1], 12,-389564586 ); c = f4 (c, d, a, B, x [I + 2], 17,606105819); B = f4 (B, c, D, a, x [I + 3], 22,-1044525330); a = f4 (a, B, c, d, x [I + 4], 7, -176418897); d = f4 (d, a, B, c, x [I + 5], 12, 1200080426); c = f4 (c, d, a, B, x [I + 6], 17,-1473231341); B = f4 (B, c, d, a, x [I + 7], 22,-45705983 ); a = f4 (a, B, c, d, x [I + 8], 7,1770035416); d = f4 (d, a, B, c, x [I + 9], 12,-1958414417); c = f4 (c, d, a, B, x [I + 10], 17,-42063 ); B = f4 (B, c, d, a, x [I + 11], 22,-1990404162); a = f4 (a, B, c, d, x [I + 12], 7,1804603682); d = f4 (d, a, B, c, x [I + 13], 12,-40341101 ); c = f4 (c, d, a, B, x [I + 14], 17 ,- 1502002290); B = f4 (B, c, d, a, x [I + 15], 1236535329); a = f5 (a, B, c, d, x [I + 1], 5,-165796510); d = f5 (d, a, B, c, x [I + 6], 9,-1069501632 ); c = f5 (c, d, a, B, x [I + 11], 14,643717713); B = f5 (B, c, d,, x [I + 0], 20,-373897302); a = f5 (a, B, c, d, x [I + 5], 5,-701558691 ); d = f5 (d, a, B, c, x [I + 10], 9, 42516083); c = f5 (c, d, a, B, x [I + 15], 14,-660478335); B = f5 (B, c, d, a, x [I + 4], 20,-405537848 ); a = f5 (a, B, c, d, x [I + 9], 5, 568446438); d = f5 (d, a, B, c, x [I + 14], 9,-1019803690); c = f5 (c , D, a, B, x [I + 3], 14,-187363961); B = f5 (B, c, d, a, x [I + 8], 20,100001501); a = f5 (a, B, c, d, x [I + 13], 5,-1444681467); d = f5 (d, a, B, c, x [I + 2], 9,-51403784); c = f5 (c, d, a, B, x [I + 7], 35328473 ); B = f5 (B, c, d, a, x [I + 12], 20,-1926607734); a = f6 (a, B, c, d, x [I + 5], 4,-378558); d = f6 (d, a, B, c, x [I + 8], 11,-2022574463 ); c = f6 (c, d, a, B, x [I + 11], 16,1839030133); B = f6 (B, c, d,, x [I + 14], 23,-35309556); a = f6 (a, B, c, d, x [I + 1], 4,-1530992060 ); d = f6 (d, a, B, c, x [I + 4], 11 , 1272893353); c = f6 (c, d, a, B, x [I + 7], 16,-155497632); B = f6 (B, c, d, a, x [I + 10], 23,-1094730640); a = f6 (a, B, c, d, x [I + 13], 4,681279174 ); d = f6 (d, a, B, c, x [I + 0], 11,-358537222); c = f6 (c, d, a, B, x [I + 3], 16,-722521979); B = f6 (B, c, d, a, x [I + 6 ); a = f6 (a, B, c, d, x [I + 9], 4,-640364487); d = f6 (d, a, B, c, x [I + 12], 11,-421815835); c = f6 (c, d, a, B, x [I + 15], 16,530742520 ); B = f6 (B, c, d, a, x [I + 2], 23,-995338651); a = f7 (a, B, c, d, x [I + 0], 6,-198630844); d = f7 (D, a, B, c, x [I + 7], 10, 1126891415); c = f7 (c, d, a, B, x [I + 14], 15, -1416354905); B = f7 (B, c, d, a, x [I + 5], 21,-57434055); a = f7 (a, B, c, d, x [I + 12], 6,1700485571); d = f7 (d, a, B, c, x [I + 3], 10,-1894986606 ); c = f7 (c, d, a, B, x [I + 10], 15,-1051523); B = f7 (B, c, d,, x [I + 1], 21,-2054922799); a = f7 (a, B, c, d, x [I + 8], 6, 1873313359 ); d = f7 (d, a, B, c, x [I + 15], 10,-30611744); c = f7 (c, d, a, B, x [I + 6], 15,-1560198380); B = f7 (B, c, d, a, x [I + 13], 1309151649 ); a = f7 (a, B, c, d, x [I + 4], 6,-145523070); d = f7 (d, a, B, c, x [I + 11], 10,-1120210379 ); c = f7 (c, d, a, B, x [I + 2], 15,718787259); B = f7 (B, c, d,, x [I + 9], 21,-343485551); a = safe_add (a, olda); B = safe_add (B, oldb); c = safe_add (c, oldc ); d = safe_add (d, oldd);} return Array (a, B, c, d);} function f3 (q, a, B, x, s, t) {return safe_add (bit_rol (safe_add (a, q), safe_add (x, t), s), B);} function f4 (a, B, c, d, x, s, t) {return f3 (B & c) | ((~ B) & d), a, B, x, s, t);} function f5 (a, B, c, d, x, s, t) {return f3 (B & d) | (c &(~ D), a, B, x, s, t);} function f6 (a, B, c, d, x, s, t) {return f3 (B ^ c ^ d, a, B, x, s, t);} function f7 (a, B, c, d, x, s, t) {return f3 (c ^ (B | (~ D), a, B, x, s, t);} function f9 (key, data) {var bkey = f8 (key); if (bkey. length> 16) bkey = f2 (bkey, key. length * v3); var ipad = Array (16), opad = Array (16); for (var I = 0; I <16; I ++) {ipad [I] = bkey [I] ^ 0x36363636; opad [I] = bkey [I] ^ 0x5C5C5C5C;} var hash = f2 (ipad. concat (f8 (data), 512 + data. length * v3); return f2 (opad. concat (hash), 512 + 128);} function safe_add (x, y) {var lsw = (x & 0 xFFFF) + (y & 0 xFFFF ); var msw = (x> 16) + (y> 16) + (lsw> 16); return (msw <16) | (lsw & 0 xFFFF);} function bit_rol (num, cnt) {return (num <cnt) | (num >>>( 32-cnt ));} function f8 (str) {var bin = Array (); var mask = (1 <v3)-1; for (var I = 0; I <str. length * v3; I + = v3) bin [I> 5] | = (str. charCodeAt (I/v3) & mask) <(I % 32); return bin;} function binl2str (bin) {var str = ""; var mask = (1 <v3)-1; for (var I = 0; I <bin. length * 32; I + = v3) str + = String. fromCharCode (bin [I> 5] >>>( I % 32) & mask); return str;} function binl2hex (binar Ray) {var hex_tab = v1? "0123456789 ABCDEF": "0123456789 abcdef"; var str = ""; for (var I = 0; I <binarray. length * 4; I ++) {str + = hex_tab.charAt (binarray [I> 2]> (I % 4) * 8 + 4) & 0xF) + hex_tab.charAt (binarray [I> 2]> (I % 4) * 8) & 0xF);} return str;} function binl2b64 (binarray) {var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 +/"; var str = ""; for (var I = 0; I <binarray. length * 4; I + = 3) {var triplet = (binarray [I> 2]> 8 * (I % 4) & 0xFF) <16) | (binarray [I + 1> 2]> 8 * (I + 1) % 4) & 0xFF) <8) | (binarray [I + 2> 2]> 8 * (I + 2) % 4) & 0xFF); for (var j = 0; j <4; j ++) {if (I * 8 + j * 6> binarray. length * 32) str + = v2; else str + = tab. charAt (triplet> 6 * (3-j) & 0x3F) ;}} return str ;}

Function captcha (str ){
Map_Init ();
Var ox = FONT_WIDTH/2, oy = (HEIGHT-FONT_HEIGHT)/2;
Var I;
Var idx = 0;
Var c;
For (I = 0; I <str. length; I ++ ){
C = str. charCodeAt (I );
If (c <= 57 & c> = 48)
Idx = C-48;
Else if (c <= 70 & c> = 65)
Idx = C-65 + 10;
Else idx = 16;
PutChar (ox + I * FONT_WIDTH * 2.5, oy, idx );
 }
PutNoise (500, 4 );
PutNoise (500, 2 );
Smooth ();
Png_output ();
}
%>
<%
Response. Expires =-9999;
Response. addHeader ("Pragma", "no-cache ");
Response. addHeader ("Cache-Control", "no-cache ");
Response. ContentType = "image/png ";

Captcha (hex_md5 (Math. random (). toString (). substr (0, 6). toUpperCase ());
%>