官方有一个MD5类,之前还不知道,昨天还把别人写的MD5类转成AS3的,看看这个代码:

package com.adobe.crypto ...{
import com.adobe.utils.IntUtil;

/**//**
* The MD5 Message-Digest Algorithm
*
* Implementation based on algorithm description at
* http://www.faqs.org/rfcs/rfc1321.html
*/
public class MD5 ...{

/**//**
* Performs the MD5 hash algorithm on a string.
*
* @param s The string to hash
* @return A string containing the hash value of s
* @langversion ActionScript 3.0
* @playerversion Flash 8.5
* @tiptext
*/
public static function hash( s:String ):String ...{
// initialize the md buffers
var a:int = 1732584193;
var b:int = -271733879;
var c:int = -1732584194;
var d:int = 271733878;
// variables to store previous values
var aa:int;
var bb:int;
var cc:int;
var dd:int;
// create the blocks from the string and
// save the length as a local var to reduce
// lookup in the loop below
var x:Array = createBlocks( s );
var len:int = x.length;
// loop over all of the blocks
for ( var i:int = 0; i < len; i += 16) ...{
// save previous values
aa = a;
bb = b;
cc = c;
dd = d;
// Round 1
a = ff( a, b, c, d, x[i+ 0], 7, -680876936 ); // 1
d = ff( d, a, b, c, x[i+ 1], 12, -389564586 ); // 2
c = ff( c, d, a, b, x[i+ 2], 17, 606105819 ); // 3
b = ff( b, c, d, a, x[i+ 3], 22, -1044525330 ); // 4
a = ff( a, b, c, d, x[i+ 4], 7, -176418897 ); // 5
d = ff( d, a, b, c, x[i+ 5], 12, 1200080426 ); // 6
c = ff( c, d, a, b, x[i+ 6], 17, -1473231341 ); // 7
b = ff( b, c, d, a, x[i+ 7], 22, -45705983 ); // 8
a = ff( a, b, c, d, x[i+ 8], 7, 1770035416 ); // 9
d = ff( d, a, b, c, x[i+ 9], 12, -1958414417 ); // 10
c = ff( c, d, a, b, x[i+10], 17, -42063 ); // 11
b = ff( b, c, d, a, x[i+11], 22, -1990404162 ); // 12
a = ff( a, b, c, d, x[i+12], 7, 1804603682 ); // 13
d = ff( d, a, b, c, x[i+13], 12, -40341101 ); // 14
c = ff( c, d, a, b, x[i+14], 17, -1502002290 ); // 15
b = ff( b, c, d, a, x[i+15], 22, 1236535329 ); // 16
// Round 2
a = gg( a, b, c, d, x[i+ 1], 5, -165796510 ); // 17
d = gg( d, a, b, c, x[i+ 6], 9, -1069501632 ); // 18
c = gg( c, d, a, b, x[i+11], 14, 643717713 ); // 19
b = gg( b, c, d, a, x[i+ 0], 20, -373897302 ); // 20
a = gg( a, b, c, d, x[i+ 5], 5, -701558691 ); // 21
d = gg( d, a, b, c, x[i+10], 9, 38016083 ); // 22
c = gg( c, d, a, b, x[i+15], 14, -660478335 ); // 23
b = gg( b, c, d, a, x[i+ 4], 20, -405537848 ); // 24
a = gg( a, b, c, d, x[i+ 9], 5, 568446438 ); // 25
d = gg( d, a, b, c, x[i+14], 9, -1019803690 ); // 26
c = gg( c, d, a, b, x[i+ 3], 14, -187363961 ); // 27
b = gg( b, c, d, a, x[i+ 8], 20, 1163531501 ); // 28
a = gg( a, b, c, d, x[i+13], 5, -1444681467 ); // 29
d = gg( d, a, b, c, x[i+ 2], 9, -51403784 ); // 30
c = gg( c, d, a, b, x[i+ 7], 14, 1735328473 ); // 31
b = gg( b, c, d, a, x[i+12], 20, -1926607734 ); // 32
// Round 3
a = hh( a, b, c, d, x[i+ 5], 4, -378558 ); // 33
d = hh( d, a, b, c, x[i+ 8], 11, -2022574463 ); // 34
c = hh( c, d, a, b, x[i+11], 16, 1839030562 ); // 35
b = hh( b, c, d, a, x[i+14], 23, -35309556 ); // 36
a = hh( a, b, c, d, x[i+ 1], 4, -1530992060 ); // 37
d = hh( d, a, b, c, x[i+ 4], 11, 1272893353 ); // 38
c = hh( c, d, a, b, x[i+ 7], 16, -155497632 ); // 39
b = hh( b, c, d, a, x[i+10], 23, -1094730640 ); // 40
a = hh( a, b, c, d, x[i+13], 4, 681279174 ); // 41
d = hh( d, a, b, c, x[i+ 0], 11, -358537222 ); // 42
c = hh( c, d, a, b, x[i+ 3], 16, -722521979 ); // 43
b = hh( b, c, d, a, x[i+ 6], 23, 76029189 ); // 44
a = hh( a, b, c, d, x[i+ 9], 4, -640364487 ); // 45
d = hh( d, a, b, c, x[i+12], 11, -421815835 ); // 46
c = hh( c, d, a, b, x[i+15], 16, 530742520 ); // 47
b = hh( b, c, d, a, x[i+ 2], 23, -995338651 ); // 48
// Round 4
a = ii( a, b, c, d, x[i+ 0], 6, -198630844 ); // 49
d = ii( d, a, b, c, x[i+ 7], 10, 1126891415 ); // 50
c = ii( c, d, a, b, x[i+14], 15, -1416354905 ); // 51
b = ii( b, c, d, a, x[i+ 5], 21, -57434055 ); // 52
a = ii( a, b, c, d, x[i+12], 6, 1700485571 ); // 53
d = ii( d, a, b, c, x[i+ 3], 10, -1894986606 ); // 54
c = ii( c, d, a, b, x[i+10], 15, -1051523 ); // 55
b = ii( b, c, d, a, x[i+ 1], 21, -2054922799 ); // 56
a = ii( a, b, c, d, x[i+ 8], 6, 1873313359 ); // 57
d = ii( d, a, b, c, x[i+15], 10, -30611744 ); // 58
c = ii( c, d, a, b, x[i+ 6], 15, -1560198380 ); // 59
b = ii( b, c, d, a, x[i+13], 21, 1309151649 ); // 60
a = ii( a, b, c, d, x[i+ 4], 6, -145523070 ); // 61
d = ii( d, a, b, c, x[i+11], 10, -1120210379 ); // 62
c = ii( c, d, a, b, x[i+ 2], 15, 718787259 ); // 63
b = ii( b, c, d, a, x[i+ 9], 21, -343485551 ); // 64
a += aa;
b += bb;
c += cc;
d += dd;
}
// Finish up by concatening the buffers with their hex output
return IntUtil.toHex( a ) + IntUtil.toHex( b ) + IntUtil.toHex( c ) + IntUtil.toHex( d );
}

/**//**
* Auxiliary function f as defined in RFC
*/
private static function f( x:int, y:int, z:int ):int ...{
return ( x & y ) | ( (~x) & z );
}

/**//**
* Auxiliary function g as defined in RFC
*/
private static function g( x:int, y:int, z:int ):int ...{
return ( x & z ) | ( y & (~z) );
}

/**//**
* Auxiliary function h as defined in RFC
*/
private static function h( x:int, y:int, z:int ):int ...{
return x ^ y ^ z;
}

/**//**
* Auxiliary function i as defined in RFC
*/
private static function i( x:int, y:int, z:int ):int ...{
return y ^ ( x | (~z) );
}

/**//**
* A generic transformation function. The logic of ff, gg, hh, and
* ii are all the same, minus the function used, so pull that logic
* out and simplify the method bodies for the transoformation functions.
*/
private static function transform( func:Function, a:int, b:int, c:int, d:int, x:int, s:int, t:int):int ...{
var tmp:int = a + int( func( b, c, d ) ) + x + t;
return IntUtil.rol( tmp, s ) + b;
}

/**//**
* ff transformation function
*/
private static function ff ( a:int, b:int, c:int, d:int, x:int, s:int, t:int ):int ...{
return transform( f, a, b, c, d, x, s, t );
}

/**//**
* gg transformation function
*/
private static function gg ( a:int, b:int, c:int, d:int, x:int, s:int, t:int ):int ...{
return transform( g, a, b, c, d, x, s, t );
}

/**//**
* hh transformation function
*/
private static function hh ( a:int, b:int, c:int, d:int, x:int, s:int, t:int ):int ...{
return transform( h, a, b, c, d, x, s, t );
}

/**//**
* ii transformation function
*/
private static function ii ( a:int, b:int, c:int, d:int, x:int, s:int, t:int ):int ...{
return transform( i, a, b, c, d, x, s, t );
}

/**//**
* Converts a string to a sequence of 16-word blocks
* that we'll do the processing on. Appends padding
* and length in the process.
*
* @param s The string to split into blocks
* @return An array containing the blocks that s was
* split into.
*/
private static function createBlocks( s:String ):Array ...{
var blocks:Array = new Array();
var len:int = s.length * 8;
var mask:int = 0xFF; // ignore hi byte of characters > 0xFF
for( var i:int = 0; i < len; i += 8 ) ...{
blocks[ i >> 5 ] |= ( s.charCodeAt( i / 8 ) & mask ) << ( i % 32 );
}
// append padding and length
blocks[ len >> 5 ] |= 0x80 << ( len % 32 );
blocks[ ( ( ( len + 64 ) >>> 9 ) << 4 ) + 14 ] = len;
return blocks;
}
}
}


package com.adobe.utils ...{
import flash.utils.Endian;

/**//**
* Contains reusable methods for operations pertaining
* to int values.
*/
public class IntUtil ...{

/**//**
* Rotates x left n bits
*
* @langversion ActionScript 3.0
* @playerversion Flash 8.5
* @tiptext
*/
public static function rol ( x:int, n:int ):int ...{
return ( x << n ) | ( x >>> ( 32 - n ) );
}

/**//** String for quick lookup of a hex character based on index */
private static var hexChars:String = "0123456789abcdef";

/**//**
* Outputs the hex value of a int, allowing the developer to specify
* the endinaness in the process. Hex output is lowercase.
*
* @param n The int value to output as hex
* @param bigEndian Flag to output the int as big or little endian
* @return A string of length 8 corresponding to the
* hex representation of n ( minus the leading "0x" )
* @langversion ActionScript 3.0
* @playerversion Flash 8.5
* @tiptext
*/
public static function toHex( n:int, bigEndian:Boolean = false ):String ...{
var s:String = "";

if ( bigEndian ) ...{
for ( var i:int = 0; i < 4; i++ ) ...{
s += hexChars.charAt( ( n >> ( ( 3 - i ) * 8 + 4 ) ) & 0xF )
+ hexChars.charAt( ( n >> ( ( 3 - i ) * 8 ) ) & 0xF );
}
} else ...{
for ( var x:int = 0; x < 4; x++ ) ...{
s += hexChars.charAt( ( n >> ( x * 8 + 4 ) ) & 0xF )
+ hexChars.charAt( ( n >> ( x * 8 ) ) & 0xF );
}
}
return s;
}
}
}
本文介绍了一种基于ActionScript 3.0的MD5消息摘要算法实现,该实现遵循了RFC 1321标准,并详细展示了核心逻辑及辅助函数。
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