diff options
Diffstat (limited to 'src/org/catacombae/rarx/RARHeader.java')
| -rw-r--r-- | src/org/catacombae/rarx/RARHeader.java | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/src/org/catacombae/rarx/RARHeader.java b/src/org/catacombae/rarx/RARHeader.java new file mode 100644 index 0000000..c631f5f --- /dev/null +++ b/src/org/catacombae/rarx/RARHeader.java @@ -0,0 +1,121 @@ +/*-
+ * Copyright (C) 2006 Erik Larsson
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+package org.catacombae.rarx;
+
+import java.io.PrintStream;
+import java.util.zip.CRC32;
+
+public abstract class RARHeader {
+ /*
+ * Common fields for all RAR headers
+ * size: 7 bytes
+ *
+ * BP Size Description
+ * 0 2 HeadCRC
+ * 2 1 HeadType
+ * 3 2 Flags
+ * 5 2 HeadSize
+ */
+ // Possible values for the fields headType in various classes
+ //public static final int ALL_HEAD = 0;
+ public static final int MARK_HEAD = 0x72; // 0x69 for UniquE! ones..? However, this field isn't really needed.
+ public static final int MAIN_HEAD = 0x73;
+ public static final int FILE_HEAD = 0x74;
+ public static final int COMM_HEAD = 0x75;
+ public static final int AV_HEAD = 0x76;
+ public static final int SUB_HEAD = 0x77;
+ public static final int PROTECT_HEAD = 0x78;
+ public static final int COMMENT_HEAD = 0x7a;
+ public static final int EOF_HEAD = 0x7b;
+
+ /* The versioning seems very simple. version 2.0 is represented
+ by the value 20 (0x14), 2.6 by the value 26 (0x1a) etc. */
+ public static final int UNPACK_VERSION_2_0 = 0x14;
+ public static final int UNPACK_VERSION_2_6 = 0x1a; // efterlyst-bfc.rar
+ public static final int UNPACK_VERSION_2_9 = 0x1d;
+
+ public static final int METHOD_UNCOMPRESSED = 0x30; // Observerad i 2.0, 2.9
+ public static final int METHOD_COMPRESSION_1 = 0x35; // Observerad i 2.0, 2.9
+ public static final int METHOD_COMPRESSION_2 = 0x33; // Observerad i 2.0 (flera g�nger, men ovanligt), 2.9
+
+ /* Hypotes: de tv� minst signifikanta bitarna i Flags indikerar om en fil
+ forts�tter p� nytt medium. Om bit 0 �r satt �r den aktuella filen en
+ forts�ttning p� en tidigare fil. Om bit 1 �r satt forts�tter den
+ aktuella filen p� ytterligare nya media.
+ Hypotes bekr�ftad. */
+
+
+ private final byte[] headCRC = new byte[2];
+ private final byte[] headType = new byte[1];
+ private final byte[] flags = new byte[2];
+ private final byte[] headSize = new byte[2];
+ private final CRC32 crc = new CRC32();
+
+ public RARHeader(byte[] data, int offset) {
+ System.arraycopy(data, offset+0, headCRC, 0, 2);
+ System.arraycopy(data, offset+2, headType, 0, 1);
+ System.arraycopy(data, offset+3, flags, 0, 2);
+ System.arraycopy(data, offset+5, headSize, 0, 2);
+ }
+
+ public int getSize() { return _getSize(); }
+ private int _getSize() { return 7; }
+
+ protected void validateData() {
+ if(calculateHeadCRC() != getHeadCRC())
+ throw new InvalidDataException("Incorrect header CRC!");
+ }
+
+ public short getHeadCRC() { return Util.readShortLE(headCRC); }
+ public byte getHeadType() { return Util.readByteLE(headType); }
+ public short getFlags() { return Util.readShortLE(flags); }
+ public short getHeadSize() { return Util.readShortLE(headSize); }
+
+ public boolean getFlag(int bitNumber) {
+ return Util.getBit(getFlags(), bitNumber);//((getFlags() >> byteNumber) & 0x1) == 0x1;
+ }
+
+
+ public byte[] getHeaderData() {
+ byte[] data = new byte[_getSize()];
+ System.arraycopy(headCRC, 0, data, 0, headCRC.length);
+ System.arraycopy(headType, 0, data, 2, headType.length);
+ System.arraycopy(flags, 0, data, 3, flags.length);
+ System.arraycopy(headSize, 0, data, 5, headSize.length);
+ return data;
+ }
+
+ public short calculateHeadCRC() {
+ crc.reset();
+ crc.update(getHeaderData(), 2, getSize()-2);
+ return (short)(crc.getValue());
+ }
+ protected void printFields(PrintStream ps, String prefix) {
+ ps.println(prefix + " HeadCRC: " + Util.toHexStringBE(getHeadCRC()));
+ if(calculateHeadCRC() != getHeadCRC())
+ ps.println(prefix + " CHECKSUMS NOT MATCHING! (0x" +
+ Util.toHexStringBE(getHeadCRC()) + " != 0x" +
+ Util.toHexStringBE(calculateHeadCRC()) + "))");
+ ps.println(prefix + " HeadType: " + Util.toHexStringBE(getHeadType()));
+ ps.println(prefix + " Flags: " + Util.toHexStringBE(getFlags()));
+ ps.println(prefix + " HeadSize: " + getHeadSize() + " bytes");
+ }
+}
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