bintzwing/core/codecBytes.js
2010-05-26 15:34:42 -07:00

37 lines
843 B
JavaScript

/** @fileOverview Bit array codec implementations.
*
* @author Emily Stark
* @author Mike Hamburg
* @author Dan Boneh
*/
/** @namespace Arrays of bytes */
sjcl.codec.bytes = {
/** Convert from a bitArray to an array of bytes. */
fromBits: function (arr) {
var out = [], bl = sjcl.bitArray.bitLength(arr), i, tmp;
for (i=0; i<bl/8; i++) {
if ((i&3) === 0) {
tmp = arr[i/4];
}
out.push(tmp >>> 24);
tmp <<= 8;
}
return out;
},
/** Convert from an array of bytes to a bitArray. */
toBits: function (bytes) {
var out = [], i, tmp=0;
for (i=0; i<bytes.length; i++) {
tmp = tmp << 8 | bytes[i];
if ((i&3) === 3) {
out.push(tmp);
tmp = 0;
}
}
if (i&3) {
out.push(sjcl.bitArray.partial(8*(i&3), tmp));
}
return out;
}
};