source: cprs/trunk/BDK32/Source/Hash.pas@ 896

{ **************************************************************
        Package: XWB - Kernel RPCBroker
        Date Created: Sept 18, 1997 (Version 1.1)
        Site Name: Oakland, OI Field Office, Dept of Veteran Affairs
        Developers: Wally Fort, Joel Ivey
        Description: Encryption and decryption functions.
        Current Release: Version 1.1 Patch 40 (January 7, 2005))
*************************************************************** }

unit Hash;


interface

uses SysUtils, Classes;


{function and procedure prototypes}
function Decrypt(EncryptedText: string): string;
function Encrypt(NormalText: string): string;

const
  maxKeys = 20;
  CipherPad: array[0..maxKeys - 1] of string = (

    'wkEo-ZJt!dG)49K{nX1BS$vH<&:Myf*>Ae0jQW=;|#PsO`''%+rmb[gpqN,l6/hFC@DcUa ]z~R}"V\iIxu?872.(TYL5_3',
    'rKv`R;M/9BqAF%&tSs#Vh)dO1DZP> *fX''u[.4lY=-mg_ci802N7LTG<]!CWo:3?{+,5Q}(@jaExn$~p\IyHwzU"|k6Jeb',
    '\pV(ZJk"WQmCn!Y,y@1d+~8s?[lNMxgHEt=uw|X:qSLjAI*}6zoF{T3#;ca)/h5%`P4$r]G''9e2if_>UDKb7<v0&- RBO.',
    'depjt3g4W)qD0V~NJar\B "?OYhcu[<Ms%Z`RIL_6:]AX-zG.#}$@vk7/5x&*m;(yb2Fn+l''PwUof1K{9,|EQi>H=CT8S!',
    'NZW:1}K$byP;jk)7''`x90B|cq@iSsEnu,(l-hf.&Y_?J#R]+voQXU8mrV[!p4tg~OMez CAaGFD6H53%L/dT2<*>"{\wI=',
    'vCiJ<oZ9|phXVNn)m K`t/SI%]A5qOWe\&?;jT~M!fz1l>[D_0xR32c*4.P"G{r7}E8wUgyudF+6-:B=$(sY,LkbHa#''@Q',
    'hvMX,''4Ty;[a8/{6l~F_V"}qLI\!@x(D7bRmUH]W15J%N0BYPkrs&9:$)Zj>u|zwQ=ieC-oGA.#?tfdcO3gp`S+En K2*<',
    'jd!W5[];4''<C$/&x|rZ(k{>?ghBzIFN}fAK"#`p_TqtD*1E37XGVs@0nmSe+Y6Qyo-aUu%i8c=H2vJ\) R:MLb.9,wlO~P',
    '2ThtjEM+!=xXb)7,ZV{*ci3"8@_l-HS69L>]\AUF/Q%:qD?1~m(yvO0e''<#o$p4dnIzKP|`NrkaGg.ufCRB[; sJYwW}5&',
    'vB\5/zl-9y:Pj|=(R''7QJI *&CTX"p0]_3.idcuOefVU#omwNZ`$Fs?L+1Sk<,b)hM4A6[Y%aDrg@~KqEW8t>H};n!2xG{',
    'sFz0Bo@_HfnK>LR}qWXV+D6`Y28=4Cm~G/7-5A\b9!a#rP.l&M$hc3ijQk;),TvUd<[:I"u1''NZSOw]*gxtE{eJp|y (?%',
    'M@,D}|LJyGO8`$*ZqH .j>c~h<d=fimszv[#-53F!+a;NC''6T91IV?(0x&/{B)w"]Q\YUWprk4:ol%g2nE7teRKbAPuS_X',
    '.mjY#_0*H<B=Q+FML6]s;r2:e8R}[ic&KA 1w{)vV5d,$u"~xD/Pg?IyfthO@CzWp%!`N4Z''3-(o|J9XUE7k\TlqSb>anG',
    'xVa1'']_GU<X`|\NgM?LS9{"jT%s$}y[nvtlefB2RKJW~(/cIDCPow4,>#zm+:5b@06O3Ap8=*7ZFY!H-uEQk; .q)i&rhd',
    'I]Jz7AG@QX."%3Lq>METUo{Pp_ |a6<0dYVSv8:b)~W9NK`(r''4fs&wim\kReC2hg=HOj$1B*/nxt,;c#y+![?lFuZ-5D}',
    'Rr(Ge6F Hx>q$m&C%M~Tn,:"o''tX/*yP.{lZ!YkiVhuw_<KE5a[;}W0gjsz3]@7cI2\QN?f#4p|vb1OUBD9)=-LJA+d`S8',
    'I~k>y|m};d)-7DZ"Fe/Y<B:xwojR,Vh]O0Sc[`$sg8GXE!1&Qrzp._W%TNK(=J 3i*2abuHA4C''?Mv\Pq{n#56LftUl@9+',
    '~A*>9 WidFN,1KsmwQ)GJM{I4:C%}#Ep(?HB/r;t.&U8o|l[''Lg"2hRDyZ5`nbf]qjc0!zS-TkYO<_=76a\X@$Pe3+xVvu',
    'yYgjf"5VdHc#uA,W1i+v''6|@pr{n;DJ!8(btPGaQM.LT3oe?NB/&9>Z`-}02*%x<7lsqz4OS ~E$\R]KI[:UwC_=h)kXmF',
    '5:iar.{YU7mBZR@-K|2 "+~`M%8sq4JhPo<_X\Sg3WC;Tuxz,fvEQ1p9=w}FAI&j/keD0c?)LN6OHV]lGy''$*>nd[(tb!#');

implementation

uses mfunstr {for Translate function};


function Encrypt(normalText: string): string;
var
  associatorIndex, identifierIndex: integer;
begin
  Randomize;
  associatorIndex := random(MaxKeys);
  repeat
    identifierIndex := Random(MaxKeys);
  until associatorIndex <> identifierIndex; {make sure indexes are different}

  Result := chr(AssociatorIndex+32) +
            Translate(NormalText, CipherPad[AssociatorIndex],
                      CipherPad[IdentifierIndex]) +
            chr(identifierIndex+32);
end;



function Decrypt(EncryptedText: string): string;
var
  AssociatorIndex, IdentifierIndex: integer;
begin
  IdentifierIndex := Ord(EncryptedText[1])-32;
  AssociatorIndex := Ord(EncryptedText[Length(EncryptedText)])-32;
  Result := Translate(copy(EncryptedText,2,Length(EncryptedText)-2),
                      CipherPad[AssociatorIndex],
                      CipherPad[IdentifierIndex]);
end;

end.