content: package com.zzzmode.android.server;
  
  import java.io.UnsupportedEncodingException;
  
   final class Base64 {
    private Base64() {
    }
  
    public static byte[] decode(String in) {
      // Ignore trailing '=' padding and whitespace from the input.
      int limit = in.length();
      for (; limit > 0; limit--) {
        char c = in.charAt(limit - 1);
        if (c != '=' && c != '\n' && c != '\r' && c != ' ' && c != '\t') {
          break;
        }
      }
  
      // If the input includes whitespace, this output array will be longer than necessary.
      byte[] out = new byte[(int) (limit * 6L / 8L)];
      int outCount = 0;
      int inCount = 0;
  
      int word = 0;
      for (int pos = 0; pos < limit; pos++) {
        char c = in.charAt(pos);
  
        int bits;
        if (c >= 'A' && c <= 'Z') {
          // char ASCII value
          //  A    65    0
          //  Z    90    25 (ASCII - 65)
          bits = c - 65;
        } else if (c >= 'a' && c <= 'z') {
          // char ASCII value
          //  a    97    26
          //  z    122   51 (ASCII - 71)
          bits = c - 71;
        } else if (c >= '0' && c <= '9') {
          // char ASCII value
          //  0    48    52
          //  9    57    61 (ASCII + 4)
          bits = c + 4;
        } else if (c == '+' || c == '-') {
          bits = 62;
        } else if (c == '/' || c == '_') {
          bits = 63;
        } else if (c == '\n' || c == '\r' || c == ' ' || c == '\t') {
          continue;
        } else {
          return null;
        }
  
        // Append this char's 6 bits to the word.
        word = (word << 6) | (byte) bits;
  
        // For every 4 chars of input, we accumulate 24 bits of output. Emit 3 bytes.
        inCount++;
        if (inCount % 4 == 0) {
          out[outCount++] = (byte) (word >> 16);
          out[outCount++] = (byte) (word >> 8);
          out[outCount++] = (byte) word;
        }
      }
  
      int lastWordChars = inCount % 4;
      if (lastWordChars == 1) {
        // We read 1 char followed by "===". But 6 bits is a truncated byte! Fail.
        return null;
      } else if (lastWordChars == 2) {
        // We read 2 chars followed by "==". Emit 1 byte with 8 of those 12 bits.
        word = word << 12;
        out[outCount++] = (byte) (word >> 16);
      } else if (lastWordChars == 3) {
        // We read 3 chars, followed by "=". Emit 2 bytes for 16 of those 18 bits.
        word = word << 6;
        out[outCount++] = (byte) (word >> 16);
        out[outCount++] = (byte) (word >> 8);
      }
  
      // If we sized our out array perfectly, we're done.
      if (outCount == out.length) return out;
  
      // Copy the decoded bytes to a new, right-sized array.
      byte[] prefix = new byte[outCount];
      System.arraycopy(out, 0, prefix, 0, outCount);
      return prefix;
    }
  
    private static final byte[] MAP = new byte[] {
        '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', '+', '/'
    };
  
    private static final byte[] URL_MAP = new byte[] {
        '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', '-', '_'
    };
  
    public static String encode(byte[] in) {
      return encode(in, MAP);
    }
  
    public static String encodeUrl(byte[] in) {
      return encode(in, URL_MAP);
    }
  
    private static String encode(byte[] in, byte[] map) {
      int length = (in.length + 2) * 4 / 3;
      byte[] out = new byte[length];
      int index = 0, end = in.length - in.length % 3;
      for (int i = 0; i < end; i += 3) {
        out[index++] = map[(in[i] & 0xff) >> 2];
        out[index++] = map[((in[i] & 0x03) << 4) | ((in[i + 1] & 0xff) >> 4)];
        out[index++] = map[((in[i + 1] & 0x0f) << 2) | ((in[i + 2] & 0xff) >> 6)];
        out[index++] = map[(in[i + 2] & 0x3f)];
      }
      switch (in.length % 3) {
        case 1:
          out[index++] = map[(in[end] & 0xff) >> 2];
          out[index++] = map[(in[end] & 0x03) << 4];
          out[index++] = '=';
          out[index++] = '=';
          break;
        case 2:
          out[index++] = map[(in[end] & 0xff) >> 2];
          out[index++] = map[((in[end] & 0x03) << 4) | ((in[end + 1] & 0xff) >> 4)];
          out[index++] = map[((in[end + 1] & 0x0f) << 2)];
          out[index++] = '=';
          break;
      }
      try {
        return new String(out, 0, index, "US-ASCII");
      } catch (UnsupportedEncodingException e) {
        throw new AssertionError(e);
      }
    }
  }