mailiverse/web/WebContent/js/crypt/tomwu/base64.js

93 lines
1.8 KiB
JavaScript

var b64map="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var b64pad="=";
function hex2b64(h) {
var i;
var c;
var ret = "";
for(i = 0; i+3 <= h.length; i+=3) {
c = parseInt(h.substring(i,i+3),16);
ret += b64map.charAt(c >> 6) + b64map.charAt(c & 63);
}
if(i+1 == h.length) {
c = parseInt(h.substring(i,i+1),16);
ret += b64map.charAt(c << 2);
}
else if(i+2 == h.length) {
c = parseInt(h.substring(i,i+2),16);
ret += b64map.charAt(c >> 2) + b64map.charAt((c & 3) << 4);
}
while((ret.length & 3) > 0) ret += b64pad;
return ret;
}
// convert a base64 string to hex
function b64tohex(s) {
var ret = ""
var i;
var k = 0; // b64 state, 0-3
var slop;
for(i = 0; i < s.length; ++i) {
if(s.charAt(i) == b64pad) break;
v = b64map.indexOf(s.charAt(i));
if(v < 0) continue;
if(k == 0) {
ret += int2char(v >> 2);
slop = v & 3;
k = 1;
}
else if(k == 1) {
ret += int2char((slop << 2) | (v >> 4));
slop = v & 0xf;
k = 2;
}
else if(k == 2) {
ret += int2char(slop);
ret += int2char(v >> 2);
slop = v & 3;
k = 3;
}
else {
ret += int2char((slop << 2) | (v >> 4));
ret += int2char(v & 0xf);
k = 0;
}
}
if(k == 1)
ret += int2char(slop << 2);
return ret;
}
function hextoBA(h)
{
var a = new Array();
for(i = 0; 2*i < h.length; ++i) {
a[i] = parseInt(h.substring(2*i,2*i+2),16);
}
return a;
}
// convert a base64 string to a byte/number array
function b64toBA(s) {
//piggyback on b64tohex for now, optimize later
return hextoBA(b64tohex(s));
}
function BAtohex(a)
{
var ret = "";
var i, v, c1, c2;
for (i=0; i<a.length; ++i)
{
v = a[i];
c1 = int2char((v & 0xf0) >> 4);
c2 = int2char((v & 0x0f) );
ret += c1;
ret += c2;
}
return ret;
}