常用JS加密编码算法代码

function URLEncode(Str){
if(Str==null||Str=="")
return "";
var newStr="";
function toCase(sStr){
return sStr.toString(16).toUpperCase();
}
for(var i=0,icode,len=Str.length;i<len;i++){
icode=Str.charCodeAt(i);
if( icode<0x10)
newStr+="%0"+icode.toString(16).toUpperCase();
else if(icode<0x80){
if(icode==0x20)
newStr+="+";
else if((icode>=0x30&&icode<=0x39)||(icode>=0x41&&icode<=0x5A)||(icode>=0x61&&icode<=0x7A))
newStr+=Str.charAt(i);
else
newStr+="%"+toCase(icode);
}
else if(icode<0x800){
newStr+="%"+toCase(0xC0+(icode>>6));
newStr+="%"+toCase(0x80+icode%0x40);
}
else{
newStr+="%"+toCase(0xE0+(icode>>12));
newStr+="%"+toCase(0x80+(icode>>6)%0x40);
newStr+="%"+toCase(0x80+icode%0x40);
}
}
return newStr;
}

var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64DecodeChars = new Array(
-1,-1,
-1,62,63,
52,53,54,55,56,57,58,59,60,61,1,2,3,4,5,6,7,8,9,10,11,12,13,14,
15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
41,42,43,44,45,46,47,48,49,50,51,-1);
function base64encode(str) {
var out,i,len;
var c1,c2,c3;
len = str.length;
i = 0;
out = "";
while(i < len) {
c1 = str.charCodeAt(i++) & 0xff;
if(i == len)
{
out += base64EncodeChars.charAt(c1 >> 2);
out += base64EncodeChars.charAt((c1 & 0x3) << 4);
out += "==";
break;
}
c2 = str.charCodeAt(i++);
if(i == len)
{
out += base64EncodeChars.charAt(c1 >> 2);
out += base64EncodeChars.charAt(((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4));
out += base64EncodeChars.charAt((c2 & 0xF) << 2);
out += "=";
break;
}
c3 = str.charCodeAt(i++);
out += base64EncodeChars.charAt(c1 >> 2);
out += base64EncodeChars.charAt(((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4));
out += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6));
out += base64EncodeChars.charAt(c3 & 0x3F);
}
return out;
}
function base64decode(str) {
var c1,c3,c4;
var i,len,out;
len = str.length;
i = 0;
out = "";
while(i < len) {
/* c1 */
do {
c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
} while(i < len && c1 == -1);
if(c1 == -1)
break;
/* c2 */
do {
c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
} while(i < len && c2 == -1);
if(c2 == -1)
break;
out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
/* c3 */
do {
c3 = str.charCodeAt(i++) & 0xff;
if(c3 == 61)
return out;
c3 = base64DecodeChars[c3];
} while(i < len && c3 == -1);
if(c3 == -1)
break;
out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
/* c4 */
do {
c4 = str.charCodeAt(i++) & 0xff;
if(c4 == 61)
return out;
c4 = base64DecodeChars[c4];
} while(i < len && c4 == -1);
if(c4 == -1)
break;
out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
}
return out;
}
function utf16to8(str) {
var out,c;
out = "";
len = str.length;
for(i = 0; i < len; i++) {
c = str.charCodeAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
out += str.charAt(i);
} else if (c > 0x07FF) {
out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
} else {
out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
}
}
return out;
}
function utf8to16(str) {
var out,c;
var char2,char3;
out = "";
len = str.length;
i = 0;
while(i < len) {
c = str.charCodeAt(i++);
switch(c >> 4)
{
case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
// 0xxxxxxx
out += str.charAt(i-1);
break;
case 12: case 13:
// 110x xxxx 10xx xxxx
char2 = str.charCodeAt(i++);
out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
break;
case 14:
// 1110 xxxx 10xx xxxx 10xx xxxx
char2 = str.charCodeAt(i++);
char3 = str.charCodeAt(i++);
out += String.fromCharCode(((c & 0x0F) << 12) |
((char2 & 0x3F) << 6) |
((char3 & 0x3F) << 0));
break;
}
}
return out;
}
function doit() {
var f = document.f
f.output.value = base64encode(utf16to8(f.source.value))
f.decode.value = utf8to16(base64decode(f.output.value))
}