uniapp-base64加密解密（不会中⽂乱码）var _PADCHAR = "=",
_ALPHA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
_VERSION = "1.1";//Mr. Ruan fix to 1.1 to support asian char(utf8)
function _getbyte64( s, i ) {
// This is oddly fast, except on Chrome/V8.
// Minimal or no improvement in performance by using a
// object with properties mapping chars to value (eg. 'A': 0)
var idx = _ALPHA.indexOf( s.charAt( i ) );
if ( idx === -1 ) {
throw "Cannot decode base64";
}
return idx;
}
function _decode_chars(y, x){
while(y.length > 0){
var ch = y[0];
if(ch < 0x80) {
y.shift();
x.push(String.fromCharCode(ch));
}else if((ch & 0x80) == 0xc0){
if(y.length < 2) break;
ch = y.shift();
var ch1 = y.shift();
x.push(String.fromCharCode( ((ch & 0x1f) << 6) + (ch1 & 0x3f)));
}else{
if(y.length < 3) break;
ch = y.shift();
var ch1 = y.shift();
var ch2 = y.shift();
x.push(String.fromCharCode(((ch & 0x0f) << 12) + ((ch1 & 0x3f) << 6) + (ch2 & 0x3f)));
}
}
}
function _decode( s ) {
var pads = 0,
i,
b10,
imax = s.length,
x = [],
y = [];
s = String( s );
if ( imax === 0 ) {
return s;
}
if ( imax % 4 !== 0 ) {
throw "Cannot decode base64";
}
if ( s.charAt( imax - 1 ) === _PADCHAR ) {
pads = 1;
if ( s.charAt( imax - 2 ) === _PADCHAR ) {
pads = 2;
}
// either way, we want to ignore this last block
imax -= 4;
}
for ( i = 0; i < imax; i += 4 ) {
var ch1 = _getbyte64( s, i );
var ch2 = _getbyte64( s, i + 1);
var ch3 = _getbyte64( s, i + 2);
var ch4 = _getbyte64( s, i + 3);
b10 = ( _getbyte64( s, i ) << 18 ) | ( _getbyte64( s, i + 1 ) << 12 ) | ( _getbyte64( s, i + 2 ) << 6 ) | _getbyte64( s, i + 3 );
y.push(b10 >> 16);
y.push((b10 >> 8) & 0xff);
y.push(b10 & 0xff);
_decode_chars(y, x);
}
switch ( pads ) {
case 1:
b10 = ( _getbyte64( s, i ) << 18 ) | ( _getbyte64( s, i + 1 ) << 12 ) | ( _getbyte64( s, i + 2 ) << 6 );
y.push(b10 >> 16);
y.push((b10 >> 8) & 0xff);
break;
case 2:
b10 = ( _getbyte64( s, i ) << 18) | ( _getbyte64( s, i + 1 ) << 12 );
y.push(b10 >> 16);
break;
}
_decode_chars(y, x);
网页app
if(y.length > 0) throw "Cannot decode base64";
return x.join( "" );
}
function _get_chars(ch, y){
if(ch < 0x80) y.push(ch);
else if(ch < 0x800){
y.push(0xc0 + ((ch >> 6) & 0x1f));
y.push(0x80 + (ch & 0x3f));
}else{
y.push(0xe0 + ((ch >> 12) & 0xf));
y.push(0x80 + ((ch >> 6) & 0x3f));
y.push(0x80 + (ch & 0x3f));
}
}
function _encode( s ) {
if ( arguments.length !== 1 ) {
throw "SyntaxError: exactly one argument required";
}
s = String( s );
if ( s.length === 0 ) {
return s;
}
//s = _encode_utf8(s);
var i,
b10,
y = [],
x = [],
len = s.length;
i = 0;
while(i < len){
_get_chars(s.charCodeAt(i), y);
while(y.length >= 3){
var ch1 = y.shift();
var ch2 = y.shift();
var ch3 = y.shift();
b10 = ( ch1 << 16 ) | ( ch2 << 8 ) | ch3;
x.push( _ALPHA.charAt( b10 >> 18 ) );
x.push( _ALPHA.charAt( ( b10 >> 12 ) & 0x3F ) );
x.push( _ALPHA.charAt( ( b10 >> 6 ) & 0x3f ) );
x.push( _ALPHA.charAt( b10 & 0x3f ) );
}
i++;
}
switch ( y.length ) {
case 1:
var ch = y.shift();
b10 = ch << 16;
x.push( _ALPHA.charAt( b10 >> 18 ) + _ALPHA.charAt( ( b10 >> 12 ) & 0x3F ) + _PADCHAR + _PADCHAR );
break;
case 2:
var ch1 = y.shift();
var ch2 = y.shift();
b10 = ( ch1 << 16 ) | ( ch2 << 8 );
x.push( _ALPHA.charAt( b10 >> 18 ) + _ALPHA.charAt( ( b10 >> 12 ) & 0x3F ) + _ALPHA.charAt( ( b10 >> 6 ) & 0x3f ) + _PADCHAR );          break;
}
return x.join( "" );
}