常用JS加密编码算法代码第2/2页

一：utf8编码函数

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;
}

二：base64编码,解码函数

var base64encodechars = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64decodechars = new array(
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 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, -1, -1, -1, -1, -1,
-1, 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, -1, -1, -1, -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, c2, 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, i, len, 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, i, len, 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))
}

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