1package org.bouncycastle.asn1;
2
3import java.io.IOException;
4
5/**
6 * Parser for indefinite-length tagged objects.
7 */
8public class BERTaggedObjectParser
9    implements ASN1TaggedObjectParser
10{
11    private boolean _constructed;
12    private int _tagNumber;
13    private ASN1StreamParser _parser;
14
15    BERTaggedObjectParser(
16        boolean             constructed,
17        int                 tagNumber,
18        ASN1StreamParser    parser)
19    {
20        _constructed = constructed;
21        _tagNumber = tagNumber;
22        _parser = parser;
23    }
24
25    /**
26     * Return true if this tagged object is marked as constructed.
27     *
28     * @return true if constructed, false otherwise.
29     */
30    public boolean isConstructed()
31    {
32        return _constructed;
33    }
34
35    /**
36     * Return the tag number associated with this object.
37     *
38     * @return the tag number.
39     */
40    public int getTagNo()
41    {
42        return _tagNumber;
43    }
44
45    /**
46     * Return an object parser for the contents of this tagged object.
47     *
48     * @param tag the actual tag number of the object (needed if implicit).
49     * @param isExplicit true if the contained object was explicitly tagged, false if implicit.
50     * @return an ASN.1 encodable object parser.
51     * @throws IOException if there is an issue building the object parser from the stream.
52     */
53    public ASN1Encodable getObjectParser(
54        int     tag,
55        boolean isExplicit)
56        throws IOException
57    {
58        if (isExplicit)
59        {
60            if (!_constructed)
61            {
62                throw new IOException("Explicit tags must be constructed (see X.690 8.14.2)");
63            }
64            return _parser.readObject();
65        }
66
67        return _parser.readImplicit(_constructed, tag);
68    }
69
70    /**
71     * Return an in-memory, encodable, representation of the tagged object.
72     *
73     * @return an ASN1TaggedObject.
74     * @throws IOException if there is an issue loading the data.
75     */
76    public ASN1Primitive getLoadedObject()
77        throws IOException
78    {
79        return _parser.readTaggedObject(_constructed, _tagNumber);
80    }
81
82    /**
83     * Return an ASN1TaggedObject representing this parser and its contents.
84     *
85     * @return an ASN1TaggedObject
86     */
87    public ASN1Primitive toASN1Primitive()
88    {
89        try
90        {
91            return this.getLoadedObject();
92        }
93        catch (IOException e)
94        {
95            throw new ASN1ParsingException(e.getMessage());
96        }
97    }
98}