Base64ByteManipulation.lsl

list Base64ToBytes(string base64){
    list result = [];
    integer i;
    integer l = llStringLength(base64);
    for(;i<l;i+=4){
        integer bytes = (llBase64ToInteger(llGetSubString(base64, i,i+4))>>8)&0xFFFFFF;
        result += [bytes>>16, (bytes>>8)&0xFF, bytes&0xFF];
    }
    //TODO: Potential Speedup
    //Instead of doing string comparison, consider checking length of input
    //EG: Use l%3, if 0 = No pad, 1 = Two pad, 2 = One pad.
    integer padLen = 1;
    if(llGetSubString(base64, -2,-1) == "==") padLen = 3;
    else if(llGetSubString(base64, -1,-1) == "=") padLen = 2;
    return llList2List(result, 0, (3*(l/4))-padLen);
}
string BytesToBase64(list bytes){
    string result = "";
    integer i;
    integer l = llGetListLength(bytes);
    for(;i<l;i+=3){
        result += llGetSubString(llIntegerToBase64(((llList2Integer(bytes, i)&0xFF)<<24) | ((llList2Integer(bytes, i+1)&0xFF)<<16) | ((llList2Integer(bytes, i+2)&0xFF)<<8)), 0, 3);
    }
    //There is probably a better way to do padding.
    return llGetSubString(result, 0, llFloor(((l<<2)|2)/3)-1) + llList2String(["","=","=="],l%3);
}

list Int32ToBytes(list array, integer bigEndian){
    list result = [];
    integer i;
    integer l = llGetListLength(array);
    for(;i<l;i++){
        integer byte = llList2Integer(array, i);
        if(bigEndian)
            result += [(byte>>24)&0xFF,(byte>>16)&0xFF,(byte>>8)&0xFF,byte&0xFF];
        else
            result += [byte&0xFF, (byte>>8)&0xFF, (byte>>16)&0xFF, (byte>>24)&0xFF];
    }
    return result;
}

list BytesToInt32(list array, integer bigEndian){
    list result = [];
    integer i;
    integer l = llGetListLength(array);
    for(;i<l;i+=4){
        integer byte = llList2Integer(array, i);
        if(bigEndian)
            result += [((llList2Integer(array, i)&0xFF)<<24) | ((llList2Integer(array, i + 1)&0xFF)<<16) | ((llList2Integer(array, i + 2)&0xFF)<<8) | (llList2Integer(array, i + 3)&0xFF)];
        else
            result += [(llList2Integer(array, i)&0xFF) | ((llList2Integer(array, i + 1)&0xFF)<<8) | ((llList2Integer(array, i + 2)&0xFF)<<16) | ((llList2Integer(array, i + 3)&0xFF)<<24)];
    }
    return result;
}