javascript实现的DES加密示例

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　　//des

　　//this takes the key, the message, and whether to encrypt or decrypt

　　function des (key, message, encrypt, mode, iv, padding) {

　　//declaring this locally speeds things up a bit

　　var spfunction1 = new Array (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);

　　var spfunction2 = new Array (-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);

　　var spfunction3 = new Array (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);

　　var spfunction4 = new Array (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);

　　var spfunction5 = new Array (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);

　　var spfunction6 = new Array (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);

　　var spfunction7 = new Array (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);

　　var spfunction8 = new Array (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);

　　//create the 16 or 48 subkeys we will need

　　var keys = des_createKeys (key);

　　var m=0, i, j, temp, temp2, right1, right2, left, right, looping;

　　var cbcleft, cbcleft2, cbcright, cbcright2

　　var endloop, loopinc;

　　var len = message.length;

　　var chunk = 0;

　　//set up the loops for single and triple des

　　var iterations = keys.length == 32 ? 3 : 9; //single or triple des

　　if (iterations == 3) {looping = encrypt ? new Array (0, 32, 2) : new Array (30, -2, -2);}

　　else {looping = encrypt ? new Array (0, 32, 2, 62, 30, -2, 64, 96, 2) : new Array (94, 62, -2, 32, 64, 2, 30, -2, -2);}

　　//pad the message depending on the padding parameter

　　if (padding == 2) message += " "; //pad the message with spaces

　　else if (padding == 1) {temp = 8-(len%8); message += String.fromCharCode (temp,temp,temp,temp,temp,temp,temp,temp); if (temp==8) len+=8;} //PKCS7 padding

　　else if (!padding) message += "\0\0\0\0\0\0\0\0"; //pad the message out with null bytes

　　//store the result here

　　result = "";

　　tempresult = "";

　　if (mode == 1) { //CBC mode

　　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;

　　}

　　//loop through each 64 bit chunk of the message

　　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++);

　　//for Cipher Block Chaining mode, xor the message with the previous result

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

　　//first each 64 but chunk of the message must be permuted according to IP

　　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));

　　//do this either 1 or 3 times for each chunk of the message

　　for (j=0; j<iterations; j+=3) {

　　endloop = looping[j+1];

　　loopinc = looping[j+2];

　　//now go through and perform the encryption or decryption

　　for (i=looping[j]; i!=endloop; i+=loopinc) { //for efficiency

　　right1 = right ^ keys[i];

　　right2 = ((right >>> 4) | (right << 28)) ^ keys[i+1];

　　//the result is attained by passing these bytes through the S selection functions

　　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; //unreverse left and right

　　} //for either 1 or 3 iterations

　　//move then each one bit to the right

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

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

　　//now perform IP-1, which is IP in the opposite direction

　　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);

　　//for Cipher Block Chaining mode, xor the message with the previous result

　　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;}

　　} //for every 8 characters, or 64 bits in the message

　　//return the result as an array

　　return result + tempresult;

　　} //end of des

　　//des_createKeys

　　//this takes as input a 64 bit key (even though only 56 bits are used)

　　//as an array of 2 integers, and returns 16 48 bit keys

　　function des_createKeys (key) {

　　//declaring this locally speeds things up a bit

　　pc2bytes0 = new Array (0,0x4,0x20000000,0x20000004,0x10000,0x10004,0x20010000,0x20010004,0x200,0x204,0x20000200,0x20000204,0x10200,0x10204,0x20010200,0x20010204);

　　pc2bytes1 = new Array (0,0x1,0x100000,0x100001,0x4000000,0x4000001,0x4100000,0x4100001,0x100,0x101,0x100100,0x100101,0x4000100,0x4000101,0x4100100,0x4100101);

　　pc2bytes2 = new Array (0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808,0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808);

　　pc2bytes3 = new Array (0,0x200000,0x8000000,0x8200000,0x2000,0x202000,0x8002000,0x8202000,0x20000,0x220000,0x8020000,0x8220000,0x22000,0x222000,0x8022000,0x8222000);

　　pc2bytes4 = new Array (0,0x40000,0x10,0x40010,0,0x40000,0x10,0x40010,0x1000,0x41000,0x1010,0x41010,0x1000,0x41000,0x1010,0x41010);

　　pc2bytes5 = new Array (0,0x400,0x20,0x420,0,0x400,0x20,0x420,0x2000000,0x2000400,0x2000020,0x2000420,0x2000000,0x2000400,0x2000020,0x2000420);

　　pc2bytes6 = new Array (0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002,0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002);

　　pc2bytes7 = new Array (0,0x10000,0x800,0x10800,0x20000000,0x20010000,0x20000800,0x20010800,0x20000,0x30000,0x20800,0x30800,0x20020000,0x20030000,0x20020800,0x20030800);

　　pc2bytes8 = new Array (0,0x40000,0,0x40000,0x2,0x40002,0x2,0x40002,0x2000000,0x2040000,0x2000000,0x2040000,0x2000002,0x2040002,0x2000002,0x2040002);

　　pc2bytes9 = new Array (0,0x10000000,0x8,0x10000008,0,0x10000000,0x8,0x10000008,0x400,0x10000400,0x408,0x10000408,0x400,0x10000400,0x408,0x10000408);

　　pc2bytes10 = new Array (0,0x20,0,0x20,0x100000,0x100020,0x100000,0x100020,0x2000,0x2020,0x2000,0x2020,0x102000,0x102020,0x102000,0x102020);

　　pc2bytes11 = new Array (0,0x1000000,0x200,0x1000200,0x200000,0x1200000,0x200200,0x1200200,0x4000000,0x5000000,0x4000200,0x5000200,0x4200000,0x5200000,0x4200200,0x5200200);

　　pc2bytes12 = new Array (0,0x1000,0x8000000,0x8001000,0x80000,0x81000,0x8080000,0x8081000,0x10,0x1010,0x8000010,0x8001010,0x80010,0x81010,0x8080010,0x8081010);

　　pc2bytes13 = new Array (0,0x4,0x100,0x104,0,0x4,0x100,0x104,0x1,0x5,0x101,0x105,0x1,0x5,0x101,0x105);

　　//how many iterations (1 for des, 3 for triple des)

　　var iterations = key.length > 8 ? 3 : 1; //changed by Paul 16/6/2007 to use Triple DES for 9+ byte keys

　　//stores the return keys

　　var keys = new Array (32 * iterations);

　　//now define the left shifts which need to be done

　　var shifts = new Array (0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0);

　　//other variables

　　var lefttemp, righttemp, m=0, n=0, temp;

　　for (var j=0; j<iterations; j++) { //either 1 or 3 iterations

　　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);

　　//the right side needs to be shifted and to get the last four bits of the left side

　　temp = (left << 8) | ((right >>> 20) & 0x000000f0);

　　//left needs to be put upside down

　　left = (right << 24) | ((right << 8) & 0xff0000) | ((right >>> 8) & 0xff00) | ((right >>> 24) & 0xf0);

　　right = temp;

　　//now go through and perform these shifts on the left and right keys

　　for (var i=0; i < shifts.length; i++) {

　　//shift the keys either one or two bits to the left

　　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;

　　//now apply PC-2, in such a way that E is easier when encrypting or decrypting

　　//this conversion will look like PC-2 except only the last 6 bits of each byte are used

　　//rather than 48 consecutive bits and the order of lines will be according to

　　//how the S selection functions will be applied: 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);

　　}

　　} //for each iterations

　　//return the keys we've created

　　return keys;

　　} //end of des_createKeys

　　////////////////////////////// TEST //////////////////////////////

　　function stringToHex (s) {

　　var r = "0x";

　　var hexes = new Array ("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f");

　　for (var i=0; i<s.length; i++) {r += hexes [s.charCodeAt(i) >> 4] + hexes [s.charCodeAt(i) & 0xf];}

　　return r;

　　}

　　function hexToString (h) {

　　var r = "";

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

　　return r;

　　}

　　var key = "this is a 24 byte key !!";

　　var message = "This is a test message";

　　var ciphertext = des (key, message, 1, 0);

　　document.writeln ("DES Test: " + stringToHex (ciphertext));

　　var key = "this is a 24 byte key !!";

　　var message = "This is a test message";

　　var ciphertext = des (key, message, 1, 0);

　　document.writeln ("DES Test: " + stringToHex (ciphertext));

　　//encrypt using single DES (with an 8 byte key) in CBC mode

　　//with the given input vector and PKCS7 padding

　　des ("8bytekey", "This is the message.", 1, 1, "inputvec", 1);

　　//encrypt using triple DES (with a 24 byte key) in ECB mode

　　des ("this is a 24 byte key !!", "This is the message.", 1);

　　//decrypt using single DES in ECB mode

　　des ("8bytekey", "2384lf&*£90LSdsf", 0);