--- /dev/null
+package org.bouncycastle.util.encoders;
+
+public class Base64
+{
+ private static byte[] encodingTable =
+ {
+ (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
+ (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
+ (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
+ (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
+ (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
+ (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
+ (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
+ (byte)'v',
+ (byte)'w', (byte)'x', (byte)'y', (byte)'z',
+ (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5', (byte)'6',
+ (byte)'7', (byte)'8', (byte)'9',
+ (byte)'+', (byte)'/'
+ };
+
+ /**
+ * encode the input data producong a base 64 encoded byte array.
+ *
+ * @return a byte array containing the base 64 encoded data.
+ */
+ public static byte[] encode(
+ byte[] data)
+ {
+ byte[] bytes;
+
+ if ((data.length % 3) == 0)
+ {
+ bytes = new byte[4 * data.length / 3];
+ }
+ else
+ {
+ bytes = new byte[4 * ((data.length / 3) + 1)];
+ }
+
+ for (int i = 0, j = 0;
+ i < ((data.length / 3) * 3); i += 3, j += 4)
+ {
+ int b1, b2, b3, b4;
+ int d1, d2, d3;
+
+ d1 = data[i] & 0xff;
+ d2 = data[i + 1] & 0xff;
+ d3 = data[i + 2] & 0xff;
+
+ b1 = (d1 >>> 2) & 0x3f;
+ b2 = ((d1 << 4) | (d2 >>> 4)) & 0x3f;
+ b3 = ((d2 << 2) | (d3 >>> 6)) & 0x3f;
+ b4 = d3 & 0x3f;
+
+ bytes[j] = encodingTable[b1];
+ bytes[j + 1] = encodingTable[b2];
+ bytes[j + 2] = encodingTable[b3];
+ bytes[j + 3] = encodingTable[b4];
+ }
+
+ /*
+ * process the tail end.
+ */
+ int b1, b2, b3;
+ int d1, d2;
+
+ switch (data.length % 3)
+ {
+ case 0: /* nothing left to do */
+ break;
+ case 1:
+ d1 = data[data.length - 1] & 0xff;
+ b1 = (d1 >>> 2) & 0x3f;
+ b2 = (d1 << 4) & 0x3f;
+
+ bytes[bytes.length - 4] = encodingTable[b1];
+ bytes[bytes.length - 3] = encodingTable[b2];
+ bytes[bytes.length - 2] = (byte)'=';
+ bytes[bytes.length - 1] = (byte)'=';
+ break;
+ case 2:
+ d1 = data[data.length - 2] & 0xff;
+ d2 = data[data.length - 1] & 0xff;
+
+ b1 = (d1 >>> 2) & 0x3f;
+ b2 = ((d1 << 4) | (d2 >>> 4)) & 0x3f;
+ b3 = (d2 << 2) & 0x3f;
+
+ bytes[bytes.length - 4] = encodingTable[b1];
+ bytes[bytes.length - 3] = encodingTable[b2];
+ bytes[bytes.length - 2] = encodingTable[b3];
+ bytes[bytes.length - 1] = (byte)'=';
+ break;
+ }
+
+ return bytes;
+ }
+
+ /*
+ * set up the decoding table.
+ */
+ private static byte[] decodingTable;
+
+ static
+ {
+ decodingTable = new byte[128];
+
+ for (int i = 'A'; i <= 'Z'; i++)
+ {
+ decodingTable[i] = (byte)(i - 'A');
+ }
+
+ for (int i = 'a'; i <= 'z'; i++)
+ {
+ decodingTable[i] = (byte)(i - 'a' + 26);
+ }
+
+ for (int i = '0'; i <= '9'; i++)
+ {
+ decodingTable[i] = (byte)(i - '0' + 52);
+ }
+
+ decodingTable['+'] = 62;
+ decodingTable['/'] = 63;
+ }
+
+ /**
+ * decode the base 64 encoded input data.
+ *
+ * @return a byte array representing the decoded data.
+ */
+ public static byte[] decode(
+ byte[] data)
+ {
+ byte[] bytes;
+ byte b1, b2, b3, b4;
+
+ if (data[data.length - 2] == '=')
+ {
+ bytes = new byte[(((data.length / 4) - 1) * 3) + 1];
+ }
+ else if (data[data.length - 1] == '=')
+ {
+ bytes = new byte[(((data.length / 4) - 1) * 3) + 2];
+ }
+ else
+ {
+ bytes = new byte[((data.length / 4) * 3)];
+ }
+
+ for (int i = 0, j = 0; i < data.length - 4; i += 4, j += 3)
+ {
+ b1 = decodingTable[data[i]];
+ b2 = decodingTable[data[i + 1]];
+ b3 = decodingTable[data[i + 2]];
+ b4 = decodingTable[data[i + 3]];
+
+ bytes[j] = (byte)((b1 << 2) | (b2 >> 4));
+ bytes[j + 1] = (byte)((b2 << 4) | (b3 >> 2));
+ bytes[j + 2] = (byte)((b3 << 6) | b4);
+ }
+
+ if (data[data.length - 2] == '=')
+ {
+ b1 = decodingTable[data[data.length - 4]];
+ b2 = decodingTable[data[data.length - 3]];
+
+ bytes[bytes.length - 1] = (byte)((b1 << 2) | (b2 >> 4));
+ }
+ else if (data[data.length - 1] == '=')
+ {
+ b1 = decodingTable[data[data.length - 4]];
+ b2 = decodingTable[data[data.length - 3]];
+ b3 = decodingTable[data[data.length - 2]];
+
+ bytes[bytes.length - 2] = (byte)((b1 << 2) | (b2 >> 4));
+ bytes[bytes.length - 1] = (byte)((b2 << 4) | (b3 >> 2));
+ }
+ else
+ {
+ b1 = decodingTable[data[data.length - 4]];
+ b2 = decodingTable[data[data.length - 3]];
+ b3 = decodingTable[data[data.length - 2]];
+ b4 = decodingTable[data[data.length - 1]];
+
+ bytes[bytes.length - 3] = (byte)((b1 << 2) | (b2 >> 4));
+ bytes[bytes.length - 2] = (byte)((b2 << 4) | (b3 >> 2));
+ bytes[bytes.length - 1] = (byte)((b3 << 6) | b4);
+ }
+
+ return bytes;
+ }
+
+ /**
+ * decode the base 64 encoded String data.
+ *
+ * @return a byte array representing the decoded data.
+ */
+ public static byte[] decode(
+ String data)
+ {
+ byte[] bytes;
+ byte b1, b2, b3, b4;
+
+ if (data.charAt(data.length() - 2) == '=')
+ {
+ bytes = new byte[(((data.length() / 4) - 1) * 3) + 1];
+ }
+ else if (data.charAt(data.length() - 1) == '=')
+ {
+ bytes = new byte[(((data.length() / 4) - 1) * 3) + 2];
+ }
+ else
+ {
+ bytes = new byte[((data.length() / 4) * 3)];
+ }
+
+ for (int i = 0, j = 0; i < data.length() - 4; i += 4, j += 3)
+ {
+ b1 = decodingTable[data.charAt(i)];
+ b2 = decodingTable[data.charAt(i + 1)];
+ b3 = decodingTable[data.charAt(i + 2)];
+ b4 = decodingTable[data.charAt(i + 3)];
+
+ bytes[j] = (byte)((b1 << 2) | (b2 >> 4));
+ bytes[j + 1] = (byte)((b2 << 4) | (b3 >> 2));
+ bytes[j + 2] = (byte)((b3 << 6) | b4);
+ }
+
+ if (data.charAt(data.length() - 2) == '=')
+ {
+ b1 = decodingTable[data.charAt(data.length() - 4)];
+ b2 = decodingTable[data.charAt(data.length() - 3)];
+
+ bytes[bytes.length - 1] = (byte)((b1 << 2) | (b2 >> 4));
+ }
+ else if (data.charAt(data.length() - 1) == '=')
+ {
+ b1 = decodingTable[data.charAt(data.length() - 4)];
+ b2 = decodingTable[data.charAt(data.length() - 3)];
+ b3 = decodingTable[data.charAt(data.length() - 2)];
+
+ bytes[bytes.length - 2] = (byte)((b1 << 2) | (b2 >> 4));
+ bytes[bytes.length - 1] = (byte)((b2 << 4) | (b3 >> 2));
+ }
+ else
+ {
+ b1 = decodingTable[data.charAt(data.length() - 4)];
+ b2 = decodingTable[data.charAt(data.length() - 3)];
+ b3 = decodingTable[data.charAt(data.length() - 2)];
+ b4 = decodingTable[data.charAt(data.length() - 1)];
+
+ bytes[bytes.length - 3] = (byte)((b1 << 2) | (b2 >> 4));
+ bytes[bytes.length - 2] = (byte)((b2 << 4) | (b3 >> 2));
+ bytes[bytes.length - 1] = (byte)((b3 << 6) | b4);
+ }
+
+ return bytes;
+ }
+}
projects / org.ibex.core.git / blobdiff