javascript实现base64加密解密
<HTML><HEAD>
<TITLE>Base64</TITLE>
<script language=javascript>
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;
} while(i < len && c1 == -1);
if(c1 == -1)
break;
/* c2 */
do {
c2 = base64DecodeChars;
} 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;
} 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;
} 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))
}
</script>
</HEAD>
<BODY>
<H1>Base64</H1>
<FORM NAME="f">
原码<BR>
<TEXTAREA NAME="source" ROWS=4 COLS=60 WRAP="soft"></TEXTAREA><BR><BR>
Base64 encode<BR>
<TEXTAREA NAME="output" ROWS=4 COLS=60 WRAP="soft"></TEXTAREA><BR><BR>
Base64 decode<BR>
<TEXTAREA NAME="decode" ROWS=4 COLS=60 WRAP="soft"></TEXTAREA><BR><BR>
<INPUT TYPE=BUTTON VALUE="转换" >
</FORM>
</BODY>
JavaScript Base64/Hex Encoder/Decoder
<html><head>
<title>Base64 and Hex Encoding and Decoding</title>
<meta name="Description" c>
<meta name="Keywords" c>
<script language=javascript type="text/javascript">
<!--
var END_OF_INPUT = -1;
var base64Chars = new Array(
'A','B','C','D','E','F','G','H',
'I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X',
'Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n',
'o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3',
'4','5','6','7','8','9','+','/'
);
var reverseBase64Chars = new Array();
for (var i=0; i < base64Chars.length; i++){
reverseBase64Chars] = i;
}
var base64Str;
var base64Count;
function setBase64Str(str){
base64Str = str;
base64Count = 0;
}
function readBase64(){
if (!base64Str) return END_OF_INPUT;
if (base64Count >= base64Str.length) return END_OF_INPUT;
var c = base64Str.charCodeAt(base64Count) & 0xff;
base64Count++;
return c;
}
function encodeBase64(str){
setBase64Str(str);
var result = '';
var inBuffer = new Array(3);
var lineCount = 0;
var done = false;
while (!done && (inBuffer = readBase64()) != END_OF_INPUT){
inBuffer = readBase64();
inBuffer = readBase64();
result += (base64Chars[ inBuffer >> 2 ]);
if (inBuffer != END_OF_INPUT){
result += (base64Chars [(( inBuffer << 4 ) & 0x30) | (inBuffer >> 4) ]);
if (inBuffer != END_OF_INPUT){
result += (base64Chars [((inBuffer << 2) & 0x3c) | (inBuffer >> 6) ]);
result += (base64Chars & 0x3F]);
} else {
result += (base64Chars [((inBuffer << 2) & 0x3c)]);
result += ('=');
done = true;
}
} else {
result += (base64Chars [(( inBuffer << 4 ) & 0x30)]);
result += ('=');
result += ('=');
done = true;
}
lineCount += 4;
if (lineCount >= 76){
result += ('\n');
lineCount = 0;
}
}
return result;
}
function readReverseBase64(){
if (!base64Str) return END_OF_INPUT;
while (true){
if (base64Count >= base64Str.length) return END_OF_INPUT;
var nextCharacter = base64Str.charAt(base64Count);
base64Count++;
if (reverseBase64Chars){
return reverseBase64Chars;
}
if (nextCharacter == 'A') return 0;
}
}
function ntos(n){
n=n.toString(16);
if (n.length == 1) n="0"+n;
n="%"+n;
return unescape(n);
}
function decodeBase64(str){
setBase64Str(str);
var result = "";
var inBuffer = new Array(4);
var done = false;
while (!done && (inBuffer = readReverseBase64()) != END_OF_INPUT
&& (inBuffer = readReverseBase64()) != END_OF_INPUT){
inBuffer = readReverseBase64();
inBuffer = readReverseBase64();
result += ntos((((inBuffer << 2) & 0xff)| inBuffer >> 4));
if (inBuffer != END_OF_INPUT){
result +=ntos((((inBuffer << 4) & 0xff)| inBuffer >> 2));
if (inBuffer != END_OF_INPUT){
result +=ntos((((inBuffer << 6)& 0xff) | inBuffer));
} else {
done = true;
}
} else {
done = true;
}
}
return result;
}
var digitArray = new Array('0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f');
function toHex(n){
var result = ''
var start = true;
for (var i=32; i>0;){
i-=4;
var digit = (n>>i) & 0xf;
if (!start || digit != 0){
start = false;
result += digitArray;
}
}
return (result==''?'0':result);
}
function pad(str, len, pad){
var result = str;
for (var i=str.length; i<len; i++){
result = pad + result;
}
return result;
}
function encodeHex(str){
var result = "";
for (var i=0; i<str.length; i++){
result += pad(toHex(str.charCodeAt(i)&0xff),2,'0');
}
return result;
}
function decodeHex(str){
str = str.replace(new RegExp("s/[^0-9a-zA-Z]//g"));
var result = "";
var nextchar = "";
for (var i=0; i<str.length; i++){
nextchar += str.charAt(i);
if (nextchar.length == 2){
result += ntos(eval('0x'+nextchar));
nextchar = "";
}
}
return result;
}
//--></script>
</head>
<body>
<form name=code >
<textarea name=text style='width:100%;height:75%;'>Enter text to encode or decode here.</textarea>
<table>
<tr><td align=center>
<input value="Encode" type=button >
</td><td align=center>
Base 64
</td><td align=center>
<input value="Decode" type=button >
</td></tr>
<tr><td align=center>
<input value="Encode" type=button >
</td><td align=center>
Hex
</td><td align=center>
<input value="Decode" type=button >
</td></tr>
<tr><td align=center>
</td><td align=center>
<input type=reset value=Clear>
</td><td align=center>
</td></tr>
</table>
</form>
</body>
</html>
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