From 5ddcbdec4ae4a8670697c5c8b6e6baa17e7cf02b Mon Sep 17 00:00:00 2001 From: adam Date: Tue, 13 Jul 2004 02:13:23 +0000 Subject: [PATCH] imported Base64 darcs-hash:20040713021323-5007d-311bd662d3919d0566031502d450e537a6269afe.gz --- src/org/ibex/util/Base64.java | 185 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 src/org/ibex/util/Base64.java diff --git a/src/org/ibex/util/Base64.java b/src/org/ibex/util/Base64.java new file mode 100644 index 0000000..d3bb10d --- /dev/null +++ b/src/org/ibex/util/Base64.java @@ -0,0 +1,185 @@ +package org.ibex.util; + +public class Base64 { + + private static final 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; + + int modulus = data.length % 3; + if (modulus == 0) { + bytes = new byte[4 * data.length / 3]; + } else { + bytes = new byte[4 * ((data.length / 3) + 1)]; + } + + int dataLength = (data.length - modulus); + int a1, a2, a3; + for (int i = 0, j = 0; i < dataLength; i += 3, j += 4) { + a1 = data[i] & 0xff; + a2 = data[i + 1] & 0xff; + a3 = data[i + 2] & 0xff; + + bytes[j] = encodingTable[(a1 >>> 2) & 0x3f]; + bytes[j + 1] = encodingTable[((a1 << 4) | (a2 >>> 4)) & 0x3f]; + bytes[j + 2] = encodingTable[((a2 << 2) | (a3 >>> 6)) & 0x3f]; + bytes[j + 3] = encodingTable[a3 & 0x3f]; + } + + int b1, b2, b3; + int d1, d2; + + switch (modulus) { + 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; + } + + private static final 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; + } +} -- 1.7.10.4