1package org.bouncycastle.jcajce.provider.asymmetric.dsa;
2
3import java.security.InvalidKeyException;
4import java.security.PrivateKey;
5import java.security.PublicKey;
6import java.security.interfaces.DSAParams;
7import java.security.interfaces.DSAPrivateKey;
8import java.security.interfaces.DSAPublicKey;
9import java.security.spec.DSAParameterSpec;
10
11import org.bouncycastle.asn1.ASN1ObjectIdentifier;
12import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers;
13import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
14import org.bouncycastle.asn1.x9.X9ObjectIdentifiers;
15import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
16import org.bouncycastle.crypto.params.DSAParameters;
17import org.bouncycastle.crypto.params.DSAPrivateKeyParameters;
18import org.bouncycastle.crypto.params.DSAPublicKeyParameters;
19
20/**
21 * utility class for converting jce/jca DSA objects
22 * objects into their org.bouncycastle.crypto counterparts.
23 */
24public class DSAUtil
25{
26    public static final ASN1ObjectIdentifier[] dsaOids =
27    {
28        X9ObjectIdentifiers.id_dsa,
29        // Android-added: Add missing OID for DSA-with-SHA1
30        X9ObjectIdentifiers.id_dsa_with_sha1,
31        OIWObjectIdentifiers.dsaWithSHA1
32    };
33
34    public static boolean isDsaOid(
35        ASN1ObjectIdentifier algOid)
36    {
37        for (int i = 0; i != dsaOids.length; i++)
38        {
39            if (algOid.equals(dsaOids[i]))
40            {
41                return true;
42            }
43        }
44
45        return false;
46    }
47
48    static DSAParameters toDSAParameters(DSAParams spec)
49    {
50        if (spec != null)
51        {
52             return new DSAParameters(spec.getP(), spec.getQ(), spec.getG());
53        }
54
55        return null;
56    }
57
58    static public AsymmetricKeyParameter generatePublicKeyParameter(
59        PublicKey    key)
60        throws InvalidKeyException
61    {
62        if (key instanceof BCDSAPublicKey)
63        {
64            return ((BCDSAPublicKey)key).engineGetKeyParameters();
65        }
66
67        if (key instanceof DSAPublicKey)
68        {
69            return new BCDSAPublicKey((DSAPublicKey)key).engineGetKeyParameters();
70        }
71
72        try
73        {
74            byte[]  bytes = key.getEncoded();
75
76            BCDSAPublicKey bckey = new BCDSAPublicKey(SubjectPublicKeyInfo.getInstance(bytes));
77
78            return bckey.engineGetKeyParameters();
79        }
80        catch (Exception e)
81        {
82            throw new InvalidKeyException("can't identify DSA public key: " + key.getClass().getName());
83        }
84    }
85
86    static public AsymmetricKeyParameter generatePrivateKeyParameter(
87        PrivateKey    key)
88        throws InvalidKeyException
89    {
90        if (key instanceof DSAPrivateKey)
91        {
92            DSAPrivateKey    k = (DSAPrivateKey)key;
93
94            return new DSAPrivateKeyParameters(k.getX(),
95                new DSAParameters(k.getParams().getP(), k.getParams().getQ(), k.getParams().getG()));
96        }
97
98        throw new InvalidKeyException("can't identify DSA private key.");
99    }
100}
101