unit AMD5;

interface

        ////////////////////////////////////////////
        //  文件名 : AMD5.pas                     //
        //   功能  : 与md5.asp计算结果相同        //
        //   作者  : 由ScriptBaby改编自md5.asp    //
        // 完成时间: 2004-07-21                   //
        ////////////////////////////////////////////

              //请转载者保留以上信息，谢谢//

uses
  SysUtils;

type
  arrlongword = array of longword;

type
  sMD5 = class
    class function RotateLeft(const lValue, Bits: longword): longword;
    class function MD5(const sMessage: string; const sType: boolean = false): string;
    class function ConvToWord(const sMessage: string): arrlongword; overload;
    class function ConvToWord(const sMessage: WideString): arrlongword; overload;
    class function WordToHex(const lValue: longword): string;
  end;

implementation

const
  BITS_TO_A_BYTE = 8;
  BYTES_TO_A_WORD = 4;
  BITS_TO_A_WORD = 32;

  cAA = $67452301;
  cBB = $EFCDAB89;
  cCC = $98BADCFE;
  cDD = $10325476;

  MODULUS_BITS = 512;
  CONGRUENT_BITS = 448;

{ sMD5 }

class function sMD5.ConvToWord(const sMessage: WideString): arrlongword;
var
  lMessageLength,      
  lNumberOfWords,      
  lBytePosition,
  lByteCount,          
  lWordCount: longword;
  lWordArray: arrlongword;

  { Function }
  function Asc(const t: WideChar): Smallint;
  var
    s: string;
    a: Smallint;
  begin
     s := t;

     a := Smallint(s[1]);
     case Length(s) of
       2:
       begin
         a := a shl 8;
         a := a + Smallint(s[2]);
       end
     else ;
     end;

     Result := a;
  end;