Function b64pad

Plugins/UnLuaExtensions/LuaSocket/Source/src/mime.cpp:287–311

-------------------------------------------------------------------------*\ * Encodes the Base64 last 1 or 2 bytes and adds padding '=' * Result, if any, is appended to buffer. * Returns 0. \*-------------------------------------------------------------------------*/

* Returns 0.
\*-------------------------------------------------------------------------*/
static size_t b64pad(const UC *input, size_t size,
        luaL_Buffer *buffer)
{
    unsigned long value = 0;
    UC code[4] = {'=', '=', '=', '='};
    switch (size) {
        case 1:
            value = input[0] << 4;
            code[1] = b64base[value & 0x3f]; value >>= 6;
            code[0] = b64base[value];
            luaL_addlstring(buffer, (char *) code, 4);
            break;
        case 2:
            value = input[0]; value <<= 8;
            value |= input[1]; value <<= 2;
            code[2] = b64base[value & 0x3f]; value >>= 6;
            code[1] = b64base[value & 0x3f]; value >>= 6;
            code[0] = b64base[value];
            luaL_addlstring(buffer, (char *) code, 4);
            break;
        default:
            break;
    }
    return 0;
}

/*-------------------------------------------------------------------------*\
* Acumulates bytes in input buffer until 4 bytes are available.