1 package org.bouncycastle.asn1.x509;
2 
3 import org.bouncycastle.asn1.ASN1Encodable;
4 import org.bouncycastle.asn1.ASN1EncodableVector;
5 import org.bouncycastle.asn1.ASN1Object;
6 import org.bouncycastle.asn1.ASN1ObjectIdentifier;
7 import org.bouncycastle.asn1.ASN1Primitive;
8 import org.bouncycastle.asn1.ASN1Sequence;
9 import org.bouncycastle.asn1.ASN1TaggedObject;
10 import org.bouncycastle.asn1.DERSequence;
11 
12 public class AlgorithmIdentifier
13     extends ASN1Object
14 {
15     private ASN1ObjectIdentifier algorithm;
16     private ASN1Encodable       parameters;
17 
getInstance( ASN1TaggedObject obj, boolean explicit)18     public static AlgorithmIdentifier getInstance(
19         ASN1TaggedObject obj,
20         boolean          explicit)
21     {
22         return getInstance(ASN1Sequence.getInstance(obj, explicit));
23     }
24 
getInstance( Object obj)25     public static AlgorithmIdentifier getInstance(
26         Object  obj)
27     {
28         if (obj instanceof AlgorithmIdentifier)
29         {
30             return (AlgorithmIdentifier)obj;
31         }
32         else if (obj != null)
33         {
34             return new AlgorithmIdentifier(ASN1Sequence.getInstance(obj));
35         }
36 
37         return null;
38     }
39 
AlgorithmIdentifier( ASN1ObjectIdentifier algorithm)40     public AlgorithmIdentifier(
41         ASN1ObjectIdentifier algorithm)
42     {
43         this.algorithm = algorithm;
44     }
45 
AlgorithmIdentifier( ASN1ObjectIdentifier algorithm, ASN1Encodable parameters)46     public AlgorithmIdentifier(
47         ASN1ObjectIdentifier algorithm,
48         ASN1Encodable           parameters)
49     {
50         this.algorithm = algorithm;
51         this.parameters = parameters;
52     }
53 
AlgorithmIdentifier( ASN1Sequence seq)54     private AlgorithmIdentifier(
55         ASN1Sequence   seq)
56     {
57         if (seq.size() < 1 || seq.size() > 2)
58         {
59             throw new IllegalArgumentException("Bad sequence size: "
60                     + seq.size());
61         }
62 
63         algorithm = ASN1ObjectIdentifier.getInstance(seq.getObjectAt(0));
64 
65         if (seq.size() == 2)
66         {
67             parameters = seq.getObjectAt(1);
68         }
69         else
70         {
71             parameters = null;
72         }
73     }
74 
getAlgorithm()75     public ASN1ObjectIdentifier getAlgorithm()
76     {
77         return algorithm;
78     }
79 
getParameters()80     public ASN1Encodable getParameters()
81     {
82         return parameters;
83     }
84 
85     /**
86      * Produce an object suitable for an ASN1OutputStream.
87      * <pre>
88      *      AlgorithmIdentifier ::= SEQUENCE {
89      *                            algorithm OBJECT IDENTIFIER,
90      *                            parameters ANY DEFINED BY algorithm OPTIONAL }
91      * </pre>
92      */
toASN1Primitive()93     public ASN1Primitive toASN1Primitive()
94     {
95         ASN1EncodableVector  v = new ASN1EncodableVector();
96 
97         v.add(algorithm);
98 
99         if (parameters != null)
100         {
101             v.add(parameters);
102         }
103 
104         return new DERSequence(v);
105     }
106 }
107