IvAlgorithmParameters.java revision e6bf3e8dfa2804891a82075cb469b736321b4827 
1package org.bouncycastle.jcajce.provider.symmetric.util;
2
3import java.io.IOException;
4import java.security.spec.AlgorithmParameterSpec;
5import java.security.spec.InvalidParameterSpecException;
6
7import javax.crypto.spec.IvParameterSpec;
8
9import org.bouncycastle.asn1.ASN1OctetString;
10import org.bouncycastle.asn1.ASN1Primitive;
11import org.bouncycastle.asn1.DEROctetString;
12import org.bouncycastle.util.Arrays;
13
14public class IvAlgorithmParameters
15    extends BaseAlgorithmParameters
16{
17    private byte[] iv;
18
19    protected byte[] engineGetEncoded()
20        throws IOException
21    {
22        return engineGetEncoded("ASN.1");
23    }
24
25    protected byte[] engineGetEncoded(
26        String format)
27        throws IOException
28    {
29        if (isASN1FormatString(format))
30        {
31            return new DEROctetString(engineGetEncoded("RAW")).getEncoded();
32        }
33
34        if (format.equals("RAW"))
35        {
36            return Arrays.clone(iv);
37        }
38
39        return null;
40    }
41
42    protected AlgorithmParameterSpec localEngineGetParameterSpec(
43        Class paramSpec)
44        throws InvalidParameterSpecException
45    {
46        if (paramSpec == IvParameterSpec.class)
47        {
48            return new IvParameterSpec(iv);
49        }
50
51        throw new InvalidParameterSpecException("unknown parameter spec passed to IV parameters object.");
52    }
53
54    protected void engineInit(
55        AlgorithmParameterSpec paramSpec)
56        throws InvalidParameterSpecException
57    {
58        if (!(paramSpec instanceof IvParameterSpec))
59        {
60            throw new InvalidParameterSpecException("IvParameterSpec required to initialise a IV parameters algorithm parameters object");
61        }
62
63        this.iv = ((IvParameterSpec)paramSpec).getIV();
64    }
65
66    protected void engineInit(
67        byte[] params)
68        throws IOException
69    {
70        //
71        // check that we don't have a DER encoded octet string
72        //
73        if ((params.length % 8) != 0
74            && params[0] == 0x04 && params[1] == params.length - 2)
75        {
76            ASN1OctetString oct = (ASN1OctetString)ASN1Primitive.fromByteArray(params);
77
78            params = oct.getOctets();
79        }
80
81        this.iv = Arrays.clone(params);
82    }
83
84    protected void engineInit(
85        byte[] params,
86        String format)
87        throws IOException
88    {
89        if (isASN1FormatString(format))
90        {
91            try
92            {
93                ASN1OctetString oct = (ASN1OctetString)ASN1Primitive.fromByteArray(params);
94
95                engineInit(oct.getOctets());
96            }
97            catch (Exception e)
98            {
99                throw new IOException("Exception decoding: " + e);
100            }
101
102            return;
103        }
104
105        if (format.equals("RAW"))
106        {
107            engineInit(params);
108            return;
109        }
110
111        throw new IOException("Unknown parameters format in IV parameters object");
112    }
113
114    protected String engineToString()
115    {
116        return "IV Parameters";
117    }
118}
119