javascript实现的DES加密示例

//
//THISSOFTWAREISPROVIDED"ASIS"AND
//ANYEXPRESSORIMPLIEDWARRANTIES,INCLUDING,BUTNOTLIMITEDTO,THE
//IMPLIEDWARRANTIESOFMERCHANTABILITYANDFITNESSFORAPARTICULARPURPOSE
//AREDISCLAIMED.INNOEVENTSHALLTHEAUTHORORCONTRIBUTORSBELIABLE
//FORANYDIRECT,INDIRECT,INCIDENTAL,SPECIAL,EXEMPLARY,ORCONSEQUENTIAL
//DAMAGES(INCLUDING,BUTNOTLIMITEDTO,PROCUREMENTOFSUBSTITUTEGOODS
//ORSERVICES;LOSSOFUSE,DATA,ORPROFITS;ORBUSINESSINTERRUPTION)
//HOWEVERCAUSEDANDONANYTHEORYOFLIABILITY,WHETHERINCONTRACT,STRICT
//LIABILITY,ORTORT(INCLUDINGNEGLIGENCEOROTHERWISE)ARISINGINANYWAY
//OUTOFTHEUSEOFTHISSOFTWARE,EVENIFADVISEDOFTHEPOSSIBILITYOF
//SUCHDAMAGE.

//des
//thistakesthekey,themessage,andwhethertoencryptordecrypt
functiondes(key,message,encrypt,mode,iv,padding){
//declaringthislocallyspeedsthingsupabit
varspfunction1=newArray(0x1010400,0,0x10000,0x1010404,0x1010004,0x10404,0x4,0x10000,0x400,0x1010400,0x1010404,0x400,0x1000404,0x1010004,0x1000000,0x4,0x404,0x1000400,0x1000400,0x10400,0x10400,0x1010000,0x1010000,0x1000404,0x10004,0x1000004,0x1000004,0x10004,0,0x404,0x10404,0x1000000,0x10000,0x1010404,0x4,0x1010000,0x1010400,0x1000000,0x1000000,0x400,0x1010004,0x10000,0x10400,0x1000004,0x400,0x4,0x1000404,0x10404,0x1010404,0x10004,0x1010000,0x1000404,0x1000004,0x404,0x10404,0x1010400,0x404,0x1000400,0x1000400,0,0x10004,0x10400,0,0x1010004);
varspfunction2=newArray(-0x7fef7fe0,-0x7fff8000,0x8000,0x108020,0x100000,0x20,-0x7fefffe0,-0x7fff7fe0,-0x7fffffe0,-0x7fef7fe0,-0x7fef8000,-0x80000000,-0x7fff8000,0x100000,0x20,-0x7fefffe0,0x108000,0x100020,-0x7fff7fe0,0,-0x80000000,0x8000,0x108020,-0x7ff00000,0x100020,-0x7fffffe0,0,0x108000,0x8020,-0x7fef8000,-0x7ff00000,0x8020,0,0x108020,-0x7fefffe0,0x100000,-0x7fff7fe0,-0x7ff00000,-0x7fef8000,0x8000,-0x7ff00000,-0x7fff8000,0x20,-0x7fef7fe0,0x108020,0x20,0x8000,-0x80000000,0x8020,-0x7fef8000,0x100000,-0x7fffffe0,0x100020,-0x7fff7fe0,-0x7fffffe0,0x100020,0x108000,0,-0x7fff8000,0x8020,-0x80000000,-0x7fefffe0,-0x7fef7fe0,0x108000);
varspfunction3=newArray(0x208,0x8020200,0,0x8020008,0x8000200,0,0x20208,0x8000200,0x20008,0x8000008,0x8000008,0x20000,0x8020208,0x20008,0x8020000,0x208,0x8000000,0x8,0x8020200,0x200,0x20200,0x8020000,0x8020008,0x20208,0x8000208,0x20200,0x20000,0x8000208,0x8,0x8020208,0x200,0x8000000,0x8020200,0x8000000,0x20008,0x208,0x20000,0x8020200,0x8000200,0,0x200,0x20008,0x8020208,0x8000200,0x8000008,0x200,0,0x8020008,0x8000208,0x20000,0x8000000,0x8020208,0x8,0x20208,0x20200,0x8000008,0x8020000,0x8000208,0x208,0x8020000,0x20208,0x8,0x8020008,0x20200);
varspfunction4=newArray(0x802001,0x2081,0x2081,0x80,0x802080,0x800081,0x800001,0x2001,0,0x802000,0x802000,0x802081,0x81,0,0x800080,0x800001,0x1,0x2000,0x800000,0x802001,0x80,0x800000,0x2001,0x2080,0x800081,0x1,0x2080,0x800080,0x2000,0x802080,0x802081,0x81,0x800080,0x800001,0x802000,0x802081,0x81,0,0,0x802000,0x2080,0x800080,0x800081,0x1,0x802001,0x2081,0x2081,0x80,0x802081,0x81,0x1,0x2000,0x800001,0x2001,0x802080,0x800081,0x2001,0x2080,0x800000,0x802001,0x80,0x800000,0x2000,0x802080);
varspfunction5=newArray(0x100,0x2080100,0x2080000,0x42000100,0x80000,0x100,0x40000000,0x2080000,0x40080100,0x80000,0x2000100,0x40080100,0x42000100,0x42080000,0x80100,0x40000000,0x2000000,0x40080000,0x40080000,0,0x40000100,0x42080100,0x42080100,0x2000100,0x42080000,0x40000100,0,0x42000000,0x2080100,0x2000000,0x42000000,0x80100,0x80000,0x42000100,0x100,0x2000000,0x40000000,0x2080000,0x42000100,0x40080100,0x2000100,0x40000000,0x42080000,0x2080100,0x40080100,0x100,0x2000000,0x42080000,0x42080100,0x80100,0x42000000,0x42080100,0x2080000,0,0x40080000,0x42000000,0x80100,0x2000100,0x40000100,0x80000,0,0x40080000,0x2080100,0x40000100);
varspfunction6=newArray(0x20000010,0x20400000,0x4000,0x20404010,0x20400000,0x10,0x20404010,0x400000,0x20004000,0x404010,0x400000,0x20000010,0x400010,0x20004000,0x20000000,0x4010,0,0x400010,0x20004010,0x4000,0x404000,0x20004010,0x10,0x20400010,0x20400010,0,0x404010,0x20404000,0x4010,0x404000,0x20404000,0x20000000,0x20004000,0x10,0x20400010,0x404000,0x20404010,0x400000,0x4010,0x20000010,0x400000,0x20004000,0x20000000,0x4010,0x20000010,0x20404010,0x404000,0x20400000,0x404010,0x20404000,0,0x20400010,0x10,0x4000,0x20400000,0x404010,0x4000,0x400010,0x20004010,0,0x20404000,0x20000000,0x400010,0x20004010);
varspfunction7=newArray(0x200000,0x4200002,0x4000802,0,0x800,0x4000802,0x200802,0x4200800,0x4200802,0x200000,0,0x4000002,0x2,0x4000000,0x4200002,0x802,0x4000800,0x200802,0x200002,0x4000800,0x4000002,0x4200000,0x4200800,0x200002,0x4200000,0x800,0x802,0x4200802,0x200800,0x2,0x4000000,0x200800,0x4000000,0x200800,0x200000,0x4000802,0x4000802,0x4200002,0x4200002,0x2,0x200002,0x4000000,0x4000800,0x200000,0x4200800,0x802,0x200802,0x4200800,0x802,0x4000002,0x4200802,0x4200000,0x200800,0,0x2,0x4200802,0,0x200802,0x4200000,0x800,0x4000002,0x4000800,0x800,0x200002);
varspfunction8=newArray(0x10001040,0x1000,0x40000,0x10041040,0x10000000,0x10001040,0x40,0x10000000,0x40040,0x10040000,0x10041040,0x41000,0x10041000,0x41040,0x1000,0x40,0x10040000,0x10000040,0x10001000,0x1040,0x41000,0x40040,0x10040040,0x10041000,0x1040,0,0,0x10040040,0x10000040,0x10001000,0x41040,0x40000,0x41040,0x40000,0x10041000,0x1000,0x40,0x10040040,0x1000,0x41040,0x10001000,0x40,0x10000040,0x10040000,0x10040040,0x10000000,0x40000,0x10001040,0,0x10041040,0x40040,0x10000040,0x10040000,0x10001000,0x10001040,0,0x10041040,0x41000,0x41000,0x1040,0x1040,0x40040,0x10000000,0x10041000);

//createthe16or48subkeyswewillneed
varkeys=des_createKeys(key);
varm=0,i,j,temp,temp2,right1,right2,left,right,looping;
varcbcleft,cbcleft2,cbcright,cbcright2
varendloop,loopinc;
varlen=message.length;
varchunk=0;
//setuptheloopsforsingleandtripledes
variterations=keys.length==32?3:9;//singleortripledes
if(iterations==3){looping=encrypt?newArray(0,32,2):newArray(30,-2,-2);}
else{looping=encrypt?newArray(0,32,2,62,30,-2,64,96,2):newArray(94,62,-2,32,64,2,30,-2,-2);}

//padthemessagedependingonthepaddingparameter
if(padding==2)message+="";//padthemessagewithspaces
elseif(padding==1){temp=8-(len%8);message+=String.fromCharCode(temp,temp,temp,temp,temp,temp,temp,temp);if(temp==8)len+=8;}//PKCS7padding
elseif(!padding)message+="\0\0\0\0\0\0\0\0";//padthemessageoutwithnullbytes

//storetheresulthere
result="";
tempresult="";

if(mode==1){//CBCmode
cbcleft=(iv.charCodeAt(m++)<<24)|(iv.charCodeAt(m++)<<16)|(iv.charCodeAt(m++)<<8)|iv.charCodeAt(m++);
cbcright=(iv.charCodeAt(m++)<<24)|(iv.charCodeAt(m++)<<16)|(iv.charCodeAt(m++)<<8)|iv.charCodeAt(m++);
m=0;
}

//loopthrougheach64bitchunkofthemessage
while(m<len){
left=(message.charCodeAt(m++)<<24)|(message.charCodeAt(m++)<<16)|(message.charCodeAt(m++)<<8)|message.charCodeAt(m++);
right=(message.charCodeAt(m++)<<24)|(message.charCodeAt(m++)<<16)|(message.charCodeAt(m++)<<8)|message.charCodeAt(m++);

//forCipherBlockChainingmode,xorthemessagewiththepreviousresult
if(mode==1){if(encrypt){left^=cbcleft;right^=cbcright;}else{cbcleft2=cbcleft;cbcright2=cbcright;cbcleft=left;cbcright=right;}}

//firsteach64butchunkofthemessagemustbepermutedaccordingtoIP
temp=((left>>>4)^right)&0x0f0f0f0f;right^=temp;left^=(temp<<4);
temp=((left>>>16)^right)&0x0000ffff;right^=temp;left^=(temp<<16);
temp=((right>>>2)^left)&0x33333333;left^=temp;right^=(temp<<2);
temp=((right>>>8)^left)&0x00ff00ff;left^=temp;right^=(temp<<8);
temp=((left>>>1)^right)&0x55555555;right^=temp;left^=(temp<<1);

left=((left<<1)|(left>>>31));
right=((right<<1)|(right>>>31));

//dothiseither1or3timesforeachchunkofthemessage
for(j=0;j<iterations;j+=3){
endloop=looping[j+1];
loopinc=looping[j+2];
//nowgothroughandperformtheencryptionordecryption
for(i=looping[j];i!=endloop;i+=loopinc){//forefficiency
right1=right^keys[i];
right2=((right>>>4)|(right<<28))^keys[i+1];
//theresultisattainedbypassingthesebytesthroughtheSselectionfunctions
temp=left;
left=right;
right=temp^(spfunction2[(right1>>>24)&0x3f]|spfunction4[(right1>>>16)&0x3f]
|spfunction6[(right1>>>8)&0x3f]|spfunction8[right1&0x3f]
|spfunction1[(right2>>>24)&0x3f]|spfunction3[(right2>>>16)&0x3f]
|spfunction5[(right2>>>8)&0x3f]|spfunction7[right2&0x3f]);
}
temp=left;left=right;right=temp;//unreverseleftandright
}//foreither1or3iterations

//movetheneachonebittotheright
left=((left>>>1)|(left<<31));
right=((right>>>1)|(right<<31));

//nowperformIP-1,whichisIPintheoppositedirection
temp=((left>>>1)^right)&0x55555555;right^=temp;left^=(temp<<1);
temp=((right>>>8)^left)&0x00ff00ff;left^=temp;right^=(temp<<8);
temp=((right>>>2)^left)&0x33333333;left^=temp;right^=(temp<<2);
temp=((left>>>16)^right)&0x0000ffff;right^=temp;left^=(temp<<16);
temp=((left>>>4)^right)&0x0f0f0f0f;right^=temp;left^=(temp<<4);

//forCipherBlockChainingmode,xorthemessagewiththepreviousresult
if(mode==1){if(encrypt){cbcleft=left;cbcright=right;}else{left^=cbcleft2;right^=cbcright2;}}
tempresult+=String.fromCharCode((left>>>24),((left>>>16)&0xff),((left>>>8)&0xff),(left&0xff),(right>>>24),((right>>>16)&0xff),((right>>>8)&0xff),(right&0xff));

chunk+=8;
if(chunk==512){result+=tempresult;tempresult="";chunk=0;}
}//forevery8characters,or64bitsinthemessage

//returntheresultasanarray
returnresult+tempresult;
}//endofdes



//des_createKeys
//thistakesasinputa64bitkey(eventhoughonly56bitsareused)
//asanarrayof2integers,andreturns1648bitkeys
functiondes_createKeys(key){
//declaringthislocallyspeedsthingsupabit
pc2bytes0=newArray(0,0x4,0x20000000,0x20000004,0x10000,0x10004,0x20010000,0x20010004,0x200,0x204,0x20000200,0x20000204,0x10200,0x10204,0x20010200,0x20010204);
pc2bytes1=newArray(0,0x1,0x100000,0x100001,0x4000000,0x4000001,0x4100000,0x4100001,0x100,0x101,0x100100,0x100101,0x4000100,0x4000101,0x4100100,0x4100101);
pc2bytes2=newArray(0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808,0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808);
pc2bytes3=newArray(0,0x200000,0x8000000,0x8200000,0x2000,0x202000,0x8002000,0x8202000,0x20000,0x220000,0x8020000,0x8220000,0x22000,0x222000,0x8022000,0x8222000);
pc2bytes4=newArray(0,0x40000,0x10,0x40010,0,0x40000,0x10,0x40010,0x1000,0x41000,0x1010,0x41010,0x1000,0x41000,0x1010,0x41010);
pc2bytes5=newArray(0,0x400,0x20,0x420,0,0x400,0x20,0x420,0x2000000,0x2000400,0x2000020,0x2000420,0x2000000,0x2000400,0x2000020,0x2000420);
pc2bytes6=newArray(0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002,0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002);
pc2bytes7=newArray(0,0x10000,0x800,0x10800,0x20000000,0x20010000,0x20000800,0x20010800,0x20000,0x30000,0x20800,0x30800,0x20020000,0x20030000,0x20020800,0x20030800);
pc2bytes8=newArray(0,0x40000,0,0x40000,0x2,0x40002,0x2,0x40002,0x2000000,0x2040000,0x2000000,0x2040000,0x2000002,0x2040002,0x2000002,0x2040002);
pc2bytes9=newArray(0,0x10000000,0x8,0x10000008,0,0x10000000,0x8,0x10000008,0x400,0x10000400,0x408,0x10000408,0x400,0x10000400,0x408,0x10000408);
pc2bytes10=newArray(0,0x20,0,0x20,0x100000,0x100020,0x100000,0x100020,0x2000,0x2020,0x2000,0x2020,0x102000,0x102020,0x102000,0x102020);
pc2bytes11=newArray(0,0x1000000,0x200,0x1000200,0x200000,0x1200000,0x200200,0x1200200,0x4000000,0x5000000,0x4000200,0x5000200,0x4200000,0x5200000,0x4200200,0x5200200);
pc2bytes12=newArray(0,0x1000,0x8000000,0x8001000,0x80000,0x81000,0x8080000,0x8081000,0x10,0x1010,0x8000010,0x8001010,0x80010,0x81010,0x8080010,0x8081010);
pc2bytes13=newArray(0,0x4,0x100,0x104,0,0x4,0x100,0x104,0x1,0x5,0x101,0x105,0x1,0x5,0x101,0x105);

//howmanyiterations(1fordes,3fortripledes)
variterations=key.length>8?3:1;//changedbyPaul16/6/2007touseTripleDESfor9+bytekeys
//storesthereturnkeys
varkeys=newArray(32*iterations);
//nowdefinetheleftshiftswhichneedtobedone
varshifts=newArray(0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0);
//othervariables
varlefttemp,righttemp,m=0,n=0,temp;

for(varj=0;j<iterations;j++){//either1or3iterations
left=(key.charCodeAt(m++)<<24)|(key.charCodeAt(m++)<<16)|(key.charCodeAt(m++)<<8)|key.charCodeAt(m++);
right=(key.charCodeAt(m++)<<24)|(key.charCodeAt(m++)<<16)|(key.charCodeAt(m++)<<8)|key.charCodeAt(m++);

temp=((left>>>4)^right)&0x0f0f0f0f;right^=temp;left^=(temp<<4);
temp=((right>>>-16)^left)&0x0000ffff;left^=temp;right^=(temp<<-16);
temp=((left>>>2)^right)&0x33333333;right^=temp;left^=(temp<<2);
temp=((right>>>-16)^left)&0x0000ffff;left^=temp;right^=(temp<<-16);
temp=((left>>>1)^right)&0x55555555;right^=temp;left^=(temp<<1);
temp=((right>>>8)^left)&0x00ff00ff;left^=temp;right^=(temp<<8);
temp=((left>>>1)^right)&0x55555555;right^=temp;left^=(temp<<1);

//therightsideneedstobeshiftedandtogetthelastfourbitsoftheleftside
temp=(left<<8)|((right>>>20)&0x000000f0);
//leftneedstobeputupsidedown
left=(right<<24)|((right<<8)&0xff0000)|((right>>>8)&0xff00)|((right>>>24)&0xf0);
right=temp;

//nowgothroughandperformtheseshiftsontheleftandrightkeys
for(vari=0;i<shifts.length;i++){
//shiftthekeyseitheroneortwobitstotheleft
if(shifts[i]){left=(left<<2)|(left>>>26);right=(right<<2)|(right>>>26);}
else{left=(left<<1)|(left>>>27);right=(right<<1)|(right>>>27);}
left&=-0xf;right&=-0xf;

//nowapplyPC-2,insuchawaythatEiseasierwhenencryptingordecrypting
//thisconversionwilllooklikePC-2exceptonlythelast6bitsofeachbyteareused
//ratherthan48consecutivebitsandtheorderoflineswillbeaccordingto
//howtheSselectionfunctionswillbeapplied:S2,S4,S6,S8,S1,S3,S5,S7
lefttemp=pc2bytes0[left>>>28]|pc2bytes1[(left>>>24)&0xf]
|pc2bytes2[(left>>>20)&0xf]|pc2bytes3[(left>>>16)&0xf]
|pc2bytes4[(left>>>12)&0xf]|pc2bytes5[(left>>>8)&0xf]
|pc2bytes6[(left>>>4)&0xf];
righttemp=pc2bytes7[right>>>28]|pc2bytes8[(right>>>24)&0xf]
|pc2bytes9[(right>>>20)&0xf]|pc2bytes10[(right>>>16)&0xf]
|pc2bytes11[(right>>>12)&0xf]|pc2bytes12[(right>>>8)&0xf]
|pc2bytes13[(right>>>4)&0xf];
temp=((righttemp>>>16)^lefttemp)&0x0000ffff;
keys[n++]=lefttemp^temp;keys[n++]=righttemp^(temp<<16);
}
}//foreachiterations
//returnthekeyswe"vecreated
returnkeys;
}//endofdes_createKeys



//////////////////////////////TEST//////////////////////////////
functionstringToHex(s){
varr="0x";
varhexes=newArray("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f");
for(vari=0;i<s.length;i++){r+=hexes[s.charCodeAt(i)>>4]+hexes[s.charCodeAt(i)&0xf];}
returnr;
}

functionhexToString(h){
varr="";
for(vari=(h.substr(0,2)=="0x")?2:0;i<h.length;i+=2){r+=String.fromCharCode(parseInt(h.substr(i,2),16));}
returnr;
}

varkey="thisisa24bytekey!!";
varmessage="Thisisatestmessage";
varciphertext=des(key,message,1,0);
document.writeln("DESTest:"+stringToHex(ciphertext));