1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.api.asn1.ber.tlv;
21
22
23 import org.apache.directory.api.i18n.I18n;
24
25
26 /**
27 * Parse and decode a Long value.
28 *
29 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
30 */
31 public final class LongDecoder
32 {
33 /** A mask used to get only the necessary bytes */
34 private static final long[] MASK = new long[]
35 { 0x00000000000000FFL, 0x000000000000FFFFL, 0x0000000000FFFFFFL, 0x00000000FFFFFFFFL, 0x000000FFFFFFFFFFL,
36 0x0000FFFFFFFFFFFFL, 0x00FFFFFFFFFFFFFFL, 0xFFFFFFFFFFFFFFFFL };
37
38
39 /**
40 * Parse a byte buffer and send back an long, controlling that this number
41 * is in a specified interval.
42 *
43 * @param value The byte buffer to parse
44 * @param min Lowest value allowed, included
45 * @param max Highest value allowed, included
46 * @return An integer
47 * @throws LongDecoderException Thrown if the byte stream does not contains an integer
48 */
49 public static long parse( BerValue value, long min, long max ) throws LongDecoderException
50 {
51 long result = parseLong( value );
52
53 if ( ( result >= min ) && ( result <= max ) )
54 {
55 return result;
56 }
57 else
58 {
59 throw new LongDecoderException( I18n.err( I18n.ERR_00038_VALUE_NOT_IN_RANGE, min, max ) );
60 }
61 }
62
63
64 /**
65 * Parse a byte buffer and send back an integer
66 *
67 * @param value The byte buffer to parse
68 * @return An integer
69 * @throws LongDecoderException Thrown if the byte stream does not contains an integer
70 */
71 public static long parse( BerValue value ) throws LongDecoderException
72 {
73 return parseLong( value );
74 }
75
76
77 /**
78 * Helper method used to parse the long. We don't check any minimal or maximal
79 * bound.
80 */
81 public static long parseLong( BerValue value ) throws LongDecoderException
82 {
83 long result = 0;
84
85 byte[] bytes = value.getData();
86
87 if ( ( bytes == null ) || ( bytes.length == 0 ) )
88 {
89 throw new LongDecoderException( I18n.err( I18n.ERR_00039_0_BYTES_LONG_LONG ) );
90 }
91
92 if ( bytes.length > 8 )
93 {
94 throw new LongDecoderException( I18n.err( I18n.ERR_00039_0_BYTES_LONG_LONG ) );
95 }
96
97 for ( int i = 0; ( i < bytes.length ) && ( i < 9 ); i++ )
98 {
99 result = ( result << 8 ) | ( bytes[i] & 0x00FF );
100 }
101
102 if ( ( bytes[0] & 0x80 ) == 0x80 )
103 {
104 result = -( ( ( ~result ) + 1 ) & MASK[bytes.length - 1] );
105 }
106
107 return result;
108 }
109 }