JavaScript DHTML/Security/Playfair Encryption
Playfair Encryption in JavaScript
<source lang="html4strict">
<html>
<head> <title>Playfair Encryption</title> <script>
var MCarr=new Array( "*","|",".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---", ".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--..","-----",".----","..---","...--","....-", ".....","-....","--...","---..","----." ); var ABC012arr="*|ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; function DoMorseDecrypt(x) {mess="";apos=0;bpos=0; while(bpos<x.length) {
bpos=x.indexOf(" ",apos);if(bpos<0){bpos=x.length};
dits=x.substring(apos,bpos);apos=bpos+1;let="";
for(j=0;j<MCarr.length;j++){ if(dits==MCarr[j]){let=ABC012arr.charAt(j)} };
if(let==""){let="*"};
mess+=let;
}; return mess; }; function DoMorseEncrypt(x) {mess=""; for(i=0;i<x.length;i++) { let=x.charAt(i).toUpperCase(); for(j=0;j<MCarr.length;j++){ if(let==ABC012arr.charAt(j)){mess+=MCarr[j]} }; mess+=" "; }; mess=mess.substring(0,mess.length-1); return mess; };
function DoReverse(x){y="";for(i=0;i<x.length;i++){y+=x.charAt(x.length-1-i);};return y};
function DoCaeserEncrypt(x,shf) { abc="abcdefghijklmnopqrstuvwxyz"; ABC="ABCDEFGHIJKLMNOPQRSTUVWXYZ"; r1="";r2="";shf=eval(shf); for(i=0;i<x.length;i++){let=x.charAt(i);pos=ABC.indexOf(let);if(pos>=0){r1+=ABC.charAt( (pos+shf)%26 )}else{r1+=let};}; for(i=0;i<r1.length;i++){let=r1.charAt(i);pos=abc.indexOf(let);if(pos>=0){r2+=abc.charAt( (pos+shf)%26 )}else{r2+=let};}; return r2; }; function DoCaeserDecrypt(x,shf) {return DoCaeserEncrypt(x,26-shf);};
function MakeCipherABC(abc,key1) { abc=abc.toUpperCase();key1=key1.toUpperCase(); cyabc=key1+abc; for(i=0;i<abc.length;i++){let=cyabc.charAt(i);pos=cyabc.indexOf(let,i+1); while(pos>-1){cyabc=cyabc.substring(0,pos)+cyabc.substring(pos+1,cyabc.length);pos=cyabc.indexOf(let,i+1);};}; return cyabc; }
function DoVigenere(et,key1,key2,abc,dir,vigtype,altluabc) {dt="";et=et.toUpperCase();key1=key1.toUpperCase();key2=key2.toUpperCase();abc=abc.toUpperCase();dir=dir.toUpperCase(); pos=et.indexOf(" "); while(pos>-1){et=et.substring(0,pos)+et.substring(pos+1,et.length);pos=et.indexOf(" ");}; cyabc=MakeCipherABC(abc,key1); key1=cyabc; lu=cyabc; if(vigtype=="N"){lu=abc}; if(vigtype=="K"){lu=cyabc}; if(vigtype=="A"){lu=altluabc}; for(i=0;i<et.length;i++) {let=et.charAt(i);letinabc=abc.indexOf(let); if(letinabc<0){dt+=let;et=et.substring(0,i)+et.substring(i+1,et.length);i--} else{ if(dir=="E"){dt+=lu.charAt((key1.indexOf(let)+key1.length+key1.indexOf(key2.charAt(i%key2.length)))%key1.length);}; if(dir=="D"){dt+=lu.charAt((key1.indexOf(let)+key1.length-key1.indexOf(key2.charAt(i%key2.length)))%key1.length);};}; }; return dt;}; function DoFreqCnt(x,abc) {var i,abc,pos,freqs;
pos=x.indexOf(" ");while(pos>-1){x=x.substring(0,pos)+x.substring(pos+1,x.length);pos=x.indexOf(" ");};
x=x.toUpperCase();freqs="";
letarr=new Array("");
for(i=0;i<abc.length;i++){letarr[i]=0;};
for(i=0;i<x.length;i++){letarr[abc.indexOf(x.charAt(i))]++};
for(i=0;i<abc.length;i++){freqs+=abc.charAt(i)+":"+letarr[i]+"/"+x.length+"="+letarr[i]/x.length+"\n";};
return freqs;
} function DoRowColumnTranspose(et,rowcol,jump,startrow) {dt="";if((et=="")||(rowcol=="")||(jump=="")||(startrow=="")){dt="You must supply all values";return dt;} maxrow=eval(rowcol.substring(0,rowcol.indexOf(","))); maxcol=eval(rowcol.substring(rowcol.indexOf(",")+1,rowcol.length)); jump=eval(jump);startrow=eval(startrow); if(startrow>maxrow){dt="Start Row must be <= Max Rows";return dt;} lin=new Array(""); for(i=0;i<maxrow;i++){lin[i]=et.substring(maxcol*i,maxcol*(i+1))}; row=startrow-1;col=maxcol-1;//starting point for(i=0;i<(maxrow*maxcol);i++) {dt+=lin[row].charAt(col);
row=row+jump;
while(row>=maxrow){row-=maxrow;col-=1;};
while(col<=-1){col+=maxcol;row-=1;};
while(row<=-1){row+=maxrow;col-=1;};
while(col>=maxcol){col-=maxcol;row-=1;};
}; return dt;};
function DoModTranspose(et,startlet,jumpinc,modulus) {dt="";if((et=="")||(startlet=="")||(jumpinc=="")||(modulus=="")){dt="You must supply all values";return dt;} startlet=eval(startlet)-1;jumpinc=eval(jumpinc);modulus=eval(modulus); if(startlet>modulus){dt="startlet must be <= maxchar";return dt;} et=escape(et); pos=et.indexOf("%0D"); while(pos>-1){et=et.substring(0,pos)+et.substring(pos+3,et.length);pos=et.indexOf("%0D");}; pos=et.indexOf("%0A"); while(pos>-1){et=et.substring(0,pos)+et.substring(pos+3,et.length);pos=et.indexOf("%0A");}; et=unescape(et); for(i=0;i<(modulus);i++){dt+=et.charAt((startlet+jumpinc*i)%modulus);}; return dt;};
function DoAsciiHex(x,dir) {hex="0123456789ABCDEF";almostAscii=" !"#$%&"+"""+"()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ["+"\\"+"]^_`abcdefghijklmnopqrstuvwxyz{|}";r=""; if(dir=="A2H") {for(i=0;i<x.length;i++){let=x.charAt(i);pos=almostAscii.indexOf(let)+32;h16=Math.floor(pos/16);h1=pos%16;r+=hex.charAt(h16)+hex.charAt(h1);};}; if(dir=="H2A") {for(i=0;i<x.length;i++){let1=x.charAt(2*i);let2=x.charAt(2*i+1);val=hex.indexOf(let1)*16+hex.indexOf(let2);r+=almostAscii.charAt(val-32);};}; return r; };
function DoSubstitute(x,orig,sub,dir) { x=x.toUpperCase();r=""; if(dir=="e") {for(i=0;i<x.length;i++){let=x.charAt(i);pos=orig.indexOf(let);if(pos>-1){r+=sub.charAt(pos)}else{r+=let}}}; if(dir=="d") {for(i=0;i<x.length;i++){let=x.charAt(i);pos=sub.indexOf(let);if(pos>-1){r+=orig.charAt(pos)}else{r+=let}}}; return r; }; function SwitchEm(x,a,b) { posA=x.indexOf(a); posB=x.indexOf(b); r1=x.substring(0,posA)+b+x.substring(posA+1,x.length); r2=r1.substring(0,posB)+a+r1.substring(posB+1,r1.length); return r2; };
function MakePlayfairSquare(abc,key1)
{
cyabc=MakeCipherABC(abc,key1);
row = new Array();for(i=0;i<5;i++){row[i]=""};
for(i=0;i<5;i++){for(j=0;j<5;j++)row[i]+=cyabc.charAt(5*i+j);};
sqr="";for(i=0;i<5;i++){sqr+=row[i]+"\n"};
return sqr;
};
function DoPlayfair(et,abc,key1,dir,dup) { et=et.toUpperCase();abc=abc.toUpperCase();key1=key1.toUpperCase(); pos=et.indexOf(" "); while(pos>-1){et=et.substring(0,pos)+et.substring(pos+1,et.length);pos=et.indexOf(" ");}; pos=et.indexOf("?"); while(pos>-1){et=et.substring(0,pos)+et.substring(pos+1,et.length);pos=et.indexOf("?");}; for(i=0;i<et.length;i=i+2) {let1=et.charAt(i);let2=et.charAt(i+1);if(let1==let2){et=et.substring(0,i+1)+"X"+et.substring(i+1,et.length)};}; if( (et.length%2)==1 ){et+="X"} if(dup!=""){ pos=et.indexOf(dup); while(pos>-1){et=et.substring(0,pos)+"I"+et.substring(pos+1,et.length);pos=et.indexOf(dup);}; }; cyabc=MakeCipherABC(abc,key1) row=new Array();for(i=0;i<5;i++){row[i]=""}; for(i=0;i<5;i++){for(j=0;j<5;j++)row[i]+=cyabc.charAt(5*i+j);}; shf=1;if(dir=="E"){shf=1};if(dir=="D"){shf=4}; dt=""; for(i=0;i<et.length;i=i+2) { pos1=cyabc.indexOf(et.charAt(i));pos2=cyabc.indexOf(et.charAt(i+1)); x1=pos1%5;y1=Math.floor(pos1/5);x2=pos2%5;y2=Math.floor(pos2/5); if(y1==y2){x1=(x1+shf)%5;x2=(x2+shf)%5} else if(x1==x2){y1=(y1+shf)%5;y2=(y2+shf)%5} else{temp=x1;x1=x2;x2=temp}; dt+=row[y1].charAt(x1)+row[y2].charAt(x2) ; };
return dt; };
</script> </head> <body> <form name="PlayfairForm">
Playfair Encryption |
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Insert Alphabet:
<input type="button" value="no Q" onClick="ABC.value="ABCDEFGHIJKLMNOPRSTUVWXYZ";DupLet.value="Q"">
<input type="button" value="no J" onClick="ABC.value="ABCDEFGHIKLMNOPQRSTUVWXYZ";DupLet.value="J"">
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<textarea rows="16" name="Original" cols="36"></textarea> |
<textarea rows="16" name="Encrypted" cols="36"></textarea> |
<textarea rows="16" name="Decrypted" cols="36"></textarea> |
Original Message |
Encrypted Message<input type="button" value="Decrypt" onClick="Decrypted.value=DoPlayfair(Encrypted.value,ABC.value,Key1.value,"D",DupLet.value)"> |
Decrypted Message<input type="reset" value="Reset"> |
</form> </body>
</html>
</source>
