using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace WMFConverter.Util { /// /// Base 64 encode /// public class Base64 { #region Local Variables private static char[] ENCODE_DATA = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; #endregion #region Public Methods /// /// Encode byte array. /// /// /// public static string Encode(byte[] data) { char[] buffer = null; if (data.Length % 3 == 0) buffer = new char[data.Length / 3 * 4]; else buffer = new char[(data.Length / 3 + 1) * 4]; int buf = 0; for (int i = 0; i < data.Length; i++) { switch (i % 3) { case 0 : buffer[i / 3 * 4] = ENCODE_DATA[(data[i] & 0xFC) >> 2]; buf = (data[i] & 0x03) << 4; if (i + 1 == data.Length) { buffer[i / 3 * 4 + 1] = ENCODE_DATA[buf]; buffer[i / 3 * 4 + 2] = '='; buffer[i / 3 * 4 + 3] = '='; } break; case 1 : buf += (data[i] & 0xF0) >> 4; buffer[i / 3 * 4 + 1] = ENCODE_DATA[buf]; buf = (data[i] & 0x0F) << 2; if (i + 1 == data.Length) { buffer[i / 3 * 4 + 2] = ENCODE_DATA[buf]; buffer[i / 3 * 4 + 3] = '='; } break; case 2 : buf += (data[i] & 0xC0) >> 6; buffer[i / 3 * 4 + 2] = ENCODE_DATA[buf]; buffer[i / 3 * 4 + 3] = ENCODE_DATA[data[i] & 0x3F]; break; } } return new string(buffer); } #endregion } }