[JavaScript] Base64, JavaScript와 Java 호환

* JavaScript로 암호화 -> Java로 복호화, 혹은 그 반대의 경우 쓸 수 있음

 

[JavaScript]

<script type="text/javascript">

var enc64List, dec64List;
 
function initBase64() {
    enc64List = new Array();
    dec64List = new Array();
    var i;
    for (i = 0; i < 26; i++) {
        enc64List[enc64List.length] = String.fromCharCode(65 + i);
    }
    for (i = 0; i < 26; i++) {
        enc64List[enc64List.length] = String.fromCharCode(97 + i);
    }
    for (i = 0; i < 10; i++) {
        enc64List[enc64List.length] = String.fromCharCode(48 + i);
    }
    enc64List[enc64List.length] = "+";
    enc64List[enc64List.length] = "/";
    for (i = 0; i < 128; i++) {
        dec64List[dec64List.length] = -1;
    }
    for (i = 0; i < 64; i++) {
        dec64List[enc64List[i].charCodeAt(0)] = i;
    }
}
 
function base64Encode(str) {
    initBase64();
    var c, d, e, end = 0;
    var u, v, w, x;
    var ptr = -1;
    var input = str.split("");
    var output = "";
    while(end == 0) {
        c = (typeof input[++ptr] != "undefined") ? input[ptr].charCodeAt(0) :
            ((end = 1) ? 0 : 0);
        d = (typeof input[++ptr] != "undefined") ? input[ptr].charCodeAt(0) :
            ((end += 1) ? 0 : 0);
        e = (typeof input[++ptr] != "undefined") ? input[ptr].charCodeAt(0) :
            ((end += 1) ? 0 : 0);
        u = enc64List[c >> 2];
        v = enc64List[(0x00000003 & c) << 4 | d >> 4];
        w = enc64List[(0x0000000F & d) << 2 | e >> 6];
        x = enc64List[e & 0x0000003F];
        if (end >= 1) {x = "=";}
        if (end == 2) {w = "=";}
        if (end < 3) {output += u + v + w + x;}
    }
    var formattedOutput = "";
    var lineLength = 76;
    while (output.length > lineLength) {
     formattedOutput += output.substring(0, lineLength) + "\n";
     output = output.substring(lineLength);
    }
    formattedOutput += output;
    return formattedOutput;
}
 
function base64Decode(str) {
    var c=0, d=0, e=0, f=0, i=0, n=0;
    var input = str.split("");
    var output = "";
    var ptr = 0;
    do {
        f = input[ptr++].charCodeAt(0);
        i = dec64List[f];
        if ( f >= 0 && f < 128 && i != -1 ) {
            if ( n % 4 == 0 ) {
                c = i << 2;
            } else if ( n % 4 == 1 ) {
                c = c | ( i >> 4 );
                d = ( i & 0x0000000F ) << 4;
            } else if ( n % 4 == 2 ) {
                d = d | ( i >> 2 );
                e = ( i & 0x00000003 ) << 6;
            } else {
                e = e | i;
            }
            n++;
            if ( n % 4 == 0 ) {
                output += String.fromCharCode(c) +
                          String.fromCharCode(d) +
                          String.fromCharCode(e);
            }
        }
    }
    while (typeof input[ptr] != "undefined");
    output += (n % 4 == 3) ? String.fromCharCode(c) + String.fromCharCode(d) :
              ((n % 4 == 2) ? String.fromCharCode(c) : "");
    return output;
}

</script>

 

 

[Java]

import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;

 

String enc_txt = new BASE64Encoder().encode(txt.getBytes());
String dec_txt = new String(new BASE64Decoder().decodeBuffer(enc_txt)); 

or

imort org.apache.commons.codec.binary.Base64; // commons-codec-1.5.jar
 
String enc_txt = new String(Base64.encodeBase64(txt.getBytes()));
String dec_txt = new String(Base64.decodeBase64(enc_txt));