php中base64和js中base64可互相加解密

<?php 

$str='云+社区'; 

echo $encode\_str= base64\_encode($str); 

echo '
'; 

echo base64\_decode($encode\_str); 

?>

<script type="text/javascript"> 
    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; 
    } 
     
    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 str_decode(str){ 
            return utf8to16(base64decode(str)); 
    } 
    function str_encode(str){ 
        return base64encode(utf16to8(str)); 
    } 
     
    var str='云+社区'; 
    var encode_str=str_encode(str); 
    document.write(encode_str); 
    document.write('<br />'); 
    var decode_str=str_decode(encode_str); 
    document.write(decode_str);
    
    </script>