gdx/utils/Base64Coder.java

//Copyright 2003-2010 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
// www.source-code.biz, www.inventec.ch/chdh
//
// This module is multi-licensed and may be used under the terms
// of any of the following licenses:
//
//  EPL, Eclipse Public License, V1.0 or later, http://www.eclipse.org/legal
//  LGPL, GNU Lesser General Public License, V2.1 or later, http://www.gnu.org/licenses/lgpl.html
//  GPL, GNU General Public License, V2 or later, http://www.gnu.org/licenses/gpl.html
//  AL, Apache License, V2.0 or later, http://www.apache.org/licenses
//  BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php
//
// Please contact the author if you need another license.
// This module is provided "as is", without warranties of any kind.
/**
 * A Base64 encoder/decoder.
 *
 * <p>
 * This class is used to encode and decode data in Base64 format as described in RFC 1521.
 *
 * <p>
 * Project home page: <a href="http://www.source-code.biz/base64coder/java/">www.source-code.biz/base64coder/java</a><br>
 * Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland<br>
 * Multi-licensed: EPL / LGPL / GPL / AL / BSD.
 *
 * @author Christian d'Heureuse
 * @author vaxquis
 */

package com.badlogic.gdx.utils;

public class Base64Coder {
	public static class CharMap {
		protected final char[] encodingMap = new char[64];
		protected final byte[] decodingMap = new byte[128];

		public CharMap (char char63, char char64) {
			int i = 0;
			for (char c = 'A'; c <= 'Z'; c++) {
				encodingMap[i++] = c;
			}
			for (char c = 'a'; c <= 'z'; c++) {
				encodingMap[i++] = c;
			}
			for (char c = '0'; c <= '9'; c++) {
				encodingMap[i++] = c;
			}
			encodingMap[i++] = char63;
			encodingMap[i++] = char64;
			for (i = 0; i < decodingMap.length; i++) {
				decodingMap[i] = -1;
			}
			for (i = 0; i < 64; i++) {
				decodingMap[encodingMap[i]] = (byte)i;
			}
		}

		public byte[] getDecodingMap () {
			return decodingMap;
		}

		public char[] getEncodingMap () {
			return encodingMap;
		}
	}

	// The line separator string of the operating system.
	private static final String systemLineSeparator = "\n";

	public static final CharMap regularMap = new CharMap('+', '/'), urlsafeMap = new CharMap('-', '_');

	/** Encodes a string into Base64 format. No blanks or line breaks are inserted.
	 * @param s A String to be encoded.
	 * @return A String containing the Base64 encoded data. */
	public static String encodeString (String s) {
		return encodeString(s, false);
	}

	public static String encodeString (String s, boolean useUrlsafeEncoding) {
		return new String(encode(s.getBytes(), useUrlsafeEncoding ? urlsafeMap.encodingMap : regularMap.encodingMap));
	}

	/** Encodes a byte array into Base 64 format and breaks the output into lines of 76 characters. This method is compatible with
	 * <code>sun.misc.BASE64Encoder.encodeBuffer(byte[])</code>.
	 * @param in An array containing the data bytes to be encoded.
	 * @return A String containing the Base64 encoded data, broken into lines. */
	public static String encodeLines (byte[] in) {
		return encodeLines(in, 0, in.length, 76, systemLineSeparator, regularMap.encodingMap);
	}

	public static String encodeLines (byte[] in, int iOff, int iLen, int lineLen, String lineSeparator, CharMap charMap) {
		return encodeLines(in, iOff, iLen, lineLen, lineSeparator, charMap.encodingMap);
	}

	/** Encodes a byte array into Base 64 format and breaks the output into lines.
	 * @param in An array containing the data bytes to be encoded.
	 * @param iOff Offset of the first byte in <code>in</code> to be processed.
	 * @param iLen Number of bytes to be processed in <code>in</code>, starting at <code>iOff</code>.
	 * @param lineLen Line length for the output data. Should be a multiple of 4.
	 * @param lineSeparator The line separator to be used to separate the output lines.
	 * @param charMap char map to use
	 * @return A String containing the Base64 encoded data, broken into lines. */
	public static String encodeLines (byte[] in, int iOff, int iLen, int lineLen, String lineSeparator, char[] charMap) {
		int blockLen = (lineLen * 3) / 4;
		if (blockLen <= 0) {
			throw new IllegalArgumentException();
		}
		int lines = (iLen + blockLen - 1) / blockLen;
		int bufLen = ((iLen + 2) / 3) * 4 + lines * lineSeparator.length();
		StringBuilder buf = new StringBuilder(bufLen);
		int ip = 0;
		while (ip < iLen) {
			int l = Math.min(iLen - ip, blockLen);
			buf.append(encode(in, iOff + ip, l, charMap));
			buf.append(lineSeparator);
			ip += l;
		}
		return buf.toString();
	}

	/** Encodes a byte array into Base64 format. No blanks or line breaks are inserted in the output.
	 * @param in An array containing the data bytes to be encoded.
	 * @return A character array containing the Base64 encoded data. */
	public static char[] encode (byte[] in) {
		return encode(in, regularMap.encodingMap);
	}

	public static char[] encode (byte[] in, CharMap charMap) {
		return encode(in, 0, in.length, charMap);
	}

    public static char[] encode (byte[] in, char[] charMap) {
		return encode(in, 0, in.length, charMap);
	}

	/** Encodes a byte array into Base64 format. No blanks or line breaks are inserted in the output.
	 * @param in An array containing the data bytes to be encoded.
	 * @param iLen Number of bytes to process in <code>in</code>.
	 * @return A character array containing the Base64 encoded data. */
	public static char[] encode (byte[] in, int iLen) {
		return encode(in, 0, iLen, regularMap.encodingMap);
	}

	public static char[] encode (byte[] in, int iOff, int iLen, CharMap charMap) {
		return encode(in, iOff, iLen, charMap.encodingMap);
	}

	/** Encodes a byte array into Base64 format. No blanks or line breaks are inserted in the output.
	 * @param in An array containing the data bytes to be encoded.
	 * @param iOff Offset of the first byte in <code>in</code> to be processed.
	 * @param iLen Number of bytes to process in <code>in</code>, starting at <code>iOff</code>.
	 * @param charMap char map to use
	 * @return A character array containing the Base64 encoded data. */
	public static char[] encode (byte[] in, int iOff, int iLen, char[] charMap) {
		int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
		int oLen = ((iLen + 2) / 3) * 4; // output length including padding
		char[] out = new char[oLen];
		int ip = iOff;
		int iEnd = iOff + iLen;
		int op = 0;
		while (ip < iEnd) {
			int i0 = in[ip++] & 0xff;
			int i1 = ip < iEnd ? in[ip++] & 0xff : 0;
			int i2 = ip < iEnd ? in[ip++] & 0xff : 0;
			int o0 = i0 >>> 2;
			int o1 = ((i0 & 3) << 4) | (i1 >>> 4);
			int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
			int o3 = i2 & 0x3F;
			out[op++] = charMap[o0];
			out[op++] = charMap[o1];
			out[op] = op < oDataLen ? charMap[o2] : '=';
			op++;
			out[op] = op < oDataLen ? charMap[o3] : '=';
			op++;
		}
		return out;
	}

	/** Decodes a string from Base64 format. No blanks or line breaks are allowed within the Base64 encoded input data.
	 * @param s A Base64 String to be decoded.
	 * @return A String containing the decoded data.
	 * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */
	public static String decodeString (String s) {
		return decodeString(s, false);
	}

	public static String decodeString (String s, boolean useUrlSafeEncoding) {
		return new String(decode(s.toCharArray(), useUrlSafeEncoding ? urlsafeMap.decodingMap : regularMap.decodingMap));
	}

    public static byte[] decodeLines (String s) {
        return decodeLines(s, regularMap.decodingMap);
    }

    public static byte[] decodeLines (String s, CharMap inverseCharMap) {
        return decodeLines(s, inverseCharMap.decodingMap);
    }

	/** Decodes a byte array from Base64 format and ignores line separators, tabs and blanks. CR, LF, Tab and Space characters are
	 * ignored in the input data. This method is compatible with <code>sun.misc.BASE64Decoder.decodeBuffer(String)</code>.
	 * @param s A Base64 String to be decoded.
     * @param inverseCharMap
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */
	public static byte[] decodeLines (String s, byte[] inverseCharMap) {
		char[] buf = new char[s.length()];
		int p = 0;
		for (int ip = 0; ip < s.length(); ip++) {
			char c = s.charAt(ip);
			if (c != ' ' && c != '\r' && c != '\n' && c != '\t') {
				buf[p++] = c;
			}
		}
		return decode(buf, 0, p, inverseCharMap);
	}

	/** Decodes a byte array from Base64 format. No blanks or line breaks are allowed within the Base64 encoded input data.
	 * @param s A Base64 String to be decoded.
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */
	public static byte[] decode (String s) {
		return decode(s.toCharArray());
	}

	/** Decodes a byte array from Base64 format. No blanks or line breaks are allowed within the Base64 encoded input data.
	 * @param s A Base64 String to be decoded.
	 * @param inverseCharMap
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */
	public static byte[] decode (String s, CharMap inverseCharMap) {
		return decode(s.toCharArray(), inverseCharMap);
	}

    public static byte[] decode (char[] in, byte[] inverseCharMap) {
		return decode(in, 0, in.length, inverseCharMap);
	}

	public static byte[] decode (char[] in, CharMap inverseCharMap) {
		return decode(in, 0, in.length, inverseCharMap);
	}

	/** Decodes a byte array from Base64 format. No blanks or line breaks are allowed within the Base64 encoded input data.
	 * @param in A character array containing the Base64 encoded data.
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */
	public static byte[] decode (char[] in) {
		return decode(in, 0, in.length, regularMap.decodingMap);
	}

	public static byte[] decode (char[] in, int iOff, int iLen, CharMap inverseCharMap) {
		return decode(in, iOff, iLen, inverseCharMap.decodingMap);
	}

	/** Decodes a byte array from Base64 format. No blanks or line breaks are allowed within the Base64 encoded input data.
	 * @param in A character array containing the Base64 encoded data.
	 * @param iOff Offset of the first character in <code>in</code> to be processed.
	 * @param iLen Number of characters to process in <code>in</code>, starting at <code>iOff</code>.
	 * @param inverseCharMap charMap to use
	 * @return An array containing the decoded data bytes.
	 * @throws IllegalArgumentException If the input is not valid Base64 encoded data. */
	public static byte[] decode (char[] in, int iOff, int iLen, byte[] inverseCharMap) {
		if (iLen % 4 != 0) {
			throw new IllegalArgumentException("Length of Base64 encoded input string is not a multiple of 4.");
		}
		while (iLen > 0 && in[iOff + iLen - 1] == '=') {
			iLen--;
		}
		int oLen = (iLen * 3) / 4;
		byte[] out = new byte[oLen];
		int ip = iOff;
		int iEnd = iOff + iLen;
		int op = 0;
		while (ip < iEnd) {
			int i0 = in[ip++];
			int i1 = in[ip++];
			int i2 = ip < iEnd ? in[ip++] : 'A';
			int i3 = ip < iEnd ? in[ip++] : 'A';
			if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127) {
				throw new IllegalArgumentException("Illegal character in Base64 encoded data.");
			}
			int b0 = inverseCharMap[i0];
			int b1 = inverseCharMap[i1];
			int b2 = inverseCharMap[i2];
			int b3 = inverseCharMap[i3];
			if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0) {
				throw new IllegalArgumentException("Illegal character in Base64 encoded data.");
			}
			int o0 = (b0 << 2) | (b1 >>> 4);
			int o1 = ((b1 & 0xf) << 4) | (b2 >>> 2);
			int o2 = ((b2 & 3) << 6) | b3;
			out[op++] = (byte)o0;
			if (op < oLen) {
				out[op++] = (byte)o1;
			}
			if (op < oLen) {
				out[op++] = (byte)o2;
			}
		}
		return out;
	}

	// Dummy constructor.
	private Base64Coder () {
	}
}