| /* |
| * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.jndi.ldap; |
| |
| import java.io.UnsupportedEncodingException; |
| |
| /** |
| * A BER decoder. Contains methods to parse a BER buffer. |
| * |
| * @author Jagane Sundar |
| * @author Vincent Ryan |
| */ |
| public final class BerDecoder extends Ber { |
| |
| private int origOffset; // The start point in buf to decode |
| |
| /** |
| * Creates a BER decoder that reads bytes from the specified buffer. |
| */ |
| public BerDecoder(byte buf[], int offset, int bufsize) { |
| |
| this.buf = buf; // shared buffer, be careful to use this class |
| this.bufsize = bufsize; |
| this.origOffset = offset; |
| |
| reset(); |
| } |
| |
| /** |
| * Resets this decode to start parsing from the initial offset |
| * (ie., same state as after calling the constructor). |
| */ |
| public void reset() { |
| offset = origOffset; |
| } |
| |
| /** |
| * Returns the current parse position. |
| * It points to the byte that will be parsed next. |
| * Useful for parsing sequences. |
| */ |
| public int getParsePosition() { |
| return offset; |
| } |
| |
| /** |
| * Parses a possibly variable length field. |
| */ |
| public int parseLength() throws DecodeException { |
| |
| int lengthbyte = parseByte(); |
| |
| if ((lengthbyte & 0x80) == 0x80) { |
| |
| lengthbyte &= 0x7f; |
| |
| if (lengthbyte == 0) { |
| throw new DecodeException( |
| "Indefinite length not supported"); |
| } |
| |
| if (lengthbyte > 4) { |
| throw new DecodeException("encoding too long"); |
| } |
| |
| if (bufsize - offset < lengthbyte) { |
| throw new DecodeException("Insufficient data"); |
| } |
| |
| int retval = 0; |
| |
| for( int i = 0; i < lengthbyte; i++) { |
| retval = (retval << 8) + (buf[offset++] & 0xff); |
| } |
| if (retval < 0) { |
| throw new DecodeException("Invalid length bytes"); |
| } |
| return retval; |
| } else { |
| return lengthbyte; |
| } |
| } |
| |
| /** |
| * Parses the next sequence in this BER buffer. |
| * @param rlen An array for returning size of the sequence in bytes. If null, |
| * the size is not returned. |
| * @return The sequence's tag. |
| */ |
| public int parseSeq(int rlen[]) throws DecodeException { |
| |
| int seq = parseByte(); |
| int len = parseLength(); |
| if (rlen != null) { |
| rlen[0] = len; |
| } |
| return seq; |
| } |
| |
| /** |
| * Used to skip bytes. Usually used when trying to recover from parse error. |
| * Don't need to be public right now? |
| * @param i The number of bytes to skip |
| */ |
| void seek(int i) throws DecodeException { |
| if (offset + i > bufsize || offset + i < 0) { |
| throw new DecodeException("array index out of bounds"); |
| } |
| offset += i; |
| } |
| |
| /** |
| * Parses the next byte in this BER buffer. |
| * @return The byte parsed. |
| */ |
| public int parseByte() throws DecodeException { |
| if (bufsize - offset < 1) { |
| throw new DecodeException("Insufficient data"); |
| } |
| return buf[offset++] & 0xff; |
| } |
| |
| |
| /** |
| * Returns the next byte in this BER buffer without consuming it. |
| * @return The next byte. |
| */ |
| public int peekByte() throws DecodeException { |
| if (bufsize - offset < 1) { |
| throw new DecodeException("Insufficient data"); |
| } |
| return buf[offset] & 0xff; |
| } |
| |
| /** |
| * Parses an ASN_BOOLEAN tagged integer from this BER buffer. |
| * @return true if the tagged integer is 0; false otherwise. |
| */ |
| public boolean parseBoolean() throws DecodeException { |
| return ((parseIntWithTag(ASN_BOOLEAN) == 0x00) ? false : true); |
| } |
| |
| /** |
| * Parses an ASN_ENUMERATED tagged integer from this BER buffer. |
| * @return The tag of enumeration. |
| */ |
| public int parseEnumeration() throws DecodeException { |
| return parseIntWithTag(ASN_ENUMERATED); |
| } |
| |
| /** |
| * Parses an ASN_INTEGER tagged integer from this BER buffer. |
| * @return The value of the integer. |
| */ |
| public int parseInt() throws DecodeException { |
| return parseIntWithTag(ASN_INTEGER); |
| } |
| |
| /** |
| * Parses an integer that's preceded by a tag. |
| *<blockquote><pre> |
| * BER integer ::= tag length byte {byte}* |
| *</pre></blockquote> |
| */ |
| private int parseIntWithTag(int tag) throws DecodeException { |
| |
| |
| if (parseByte() != tag) { |
| throw new DecodeException("Encountered ASN.1 tag " + |
| Integer.toString(buf[offset - 1] & 0xff) + |
| " (expected tag " + Integer.toString(tag) + ")"); |
| } |
| |
| int len = parseLength(); |
| |
| if (len > 4) { |
| throw new DecodeException("INTEGER too long"); |
| } else if (len > bufsize - offset) { |
| throw new DecodeException("Insufficient data"); |
| } |
| |
| byte fb = buf[offset++]; |
| int value = 0; |
| |
| value = fb & 0x7F; |
| for( int i = 1 /* first byte already read */ ; i < len; i++) { |
| value <<= 8; |
| value |= (buf[offset++] & 0xff); |
| } |
| |
| if ((fb & 0x80) == 0x80) { |
| value = -value; |
| } |
| |
| return value; |
| } |
| |
| /** |
| * Parses a string. |
| */ |
| public String parseString(boolean decodeUTF8) throws DecodeException { |
| return parseStringWithTag(ASN_SIMPLE_STRING, decodeUTF8, null); |
| } |
| |
| /** |
| * Parses a string of a given tag from this BER buffer. |
| *<blockquote><pre> |
| *BER simple string ::= tag length {byte}* |
| *</pre></blockquote> |
| * @param rlen An array for holding the relative parsed offset; if null |
| * offset not set. |
| * @param decodeUTF8 If true, use UTF-8 when decoding the string; otherwise |
| * use ISO-Latin-1 (8859_1). Use true for LDAPv3; false for LDAPv2. |
| * @param tag The tag that precedes the string. |
| * @return The non-null parsed string. |
| */ |
| public String parseStringWithTag(int tag, boolean decodeUTF8, int rlen[]) |
| throws DecodeException { |
| |
| int st; |
| int origOffset = offset; |
| |
| if ((st = parseByte()) != tag) { |
| throw new DecodeException("Encountered ASN.1 tag " + |
| Integer.toString((byte)st) + " (expected tag " + tag + ")"); |
| } |
| |
| int len = parseLength(); |
| |
| if (len > bufsize - offset) { |
| throw new DecodeException("Insufficient data"); |
| } |
| |
| String retstr; |
| if (len == 0) { |
| retstr = ""; |
| } else { |
| byte[] buf2 = new byte[len]; |
| |
| System.arraycopy(buf, offset, buf2, 0, len); |
| if (decodeUTF8) { |
| try { |
| retstr = new String(buf2, "UTF8"); |
| } catch (UnsupportedEncodingException e) { |
| throw new DecodeException("UTF8 not available on platform"); |
| } |
| } else { |
| try { |
| retstr = new String(buf2, "8859_1"); |
| } catch (UnsupportedEncodingException e) { |
| throw new DecodeException("8859_1 not available on platform"); |
| } |
| } |
| offset += len; |
| } |
| |
| if (rlen != null) { |
| rlen[0] = offset - origOffset; |
| } |
| |
| return retstr; |
| } |
| |
| /** |
| * Parses an octet string of a given type(tag) from this BER buffer. |
| * <blockquote><pre> |
| * BER Binary Data of type "tag" ::= tag length {byte}* |
| *</pre></blockquote> |
| * |
| * @param tag The tag to look for. |
| * @param rlen An array for returning the relative parsed position. If null, |
| * the relative parsed position is not returned. |
| * @return A non-null array containing the octet string. |
| * @throws DecodeException If the next byte in the BER buffer is not |
| * {@code tag}, or if length specified in the BER buffer exceeds the |
| * number of bytes left in the buffer. |
| */ |
| public byte[] parseOctetString(int tag, int rlen[]) throws DecodeException { |
| |
| int origOffset = offset; |
| int st; |
| if ((st = parseByte()) != tag) { |
| |
| throw new DecodeException("Encountered ASN.1 tag " + |
| Integer.toString(st) + |
| " (expected tag " + Integer.toString(tag) + ")"); |
| } |
| |
| int len = parseLength(); |
| |
| if (len > bufsize - offset) { |
| throw new DecodeException("Insufficient data"); |
| } |
| |
| byte retarr[] = new byte[len]; |
| if (len > 0) { |
| System.arraycopy(buf, offset, retarr, 0, len); |
| offset += len; |
| } |
| |
| if (rlen != null) { |
| rlen[0] = offset - origOffset; |
| } |
| |
| return retarr; |
| } |
| |
| /** |
| * Returns the number of unparsed bytes in this BER buffer. |
| */ |
| public int bytesLeft() { |
| return bufsize - offset; |
| } |
| } |