/extern/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/dh/BCDHPublicKey.java

  1package org.spongycastle.jcajce.provider.asymmetric.dh;
  2
  3import java.io.IOException;
  4import java.io.ObjectInputStream;
  5import java.io.ObjectOutputStream;
  6import java.math.BigInteger;
  7
  8import javax.crypto.interfaces.DHPublicKey;
  9import javax.crypto.spec.DHParameterSpec;
 10import javax.crypto.spec.DHPublicKeySpec;
 11
 12import org.spongycastle.asn1.ASN1Integer;
 13import org.spongycastle.asn1.ASN1ObjectIdentifier;
 14import org.spongycastle.asn1.ASN1Sequence;
 15import org.spongycastle.asn1.pkcs.DHParameter;
 16import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers;
 17import org.spongycastle.asn1.x509.AlgorithmIdentifier;
 18import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
 19import org.spongycastle.asn1.x9.DHDomainParameters;
 20import org.spongycastle.asn1.x9.X9ObjectIdentifiers;
 21import org.spongycastle.crypto.params.DHPublicKeyParameters;
 22import org.spongycastle.jcajce.provider.asymmetric.util.KeyUtil;
 23
 24public class BCDHPublicKey
 25    implements DHPublicKey
 26{
 27    static final long serialVersionUID = -216691575254424324L;
 28    
 29    private BigInteger              y;
 30
 31    private transient DHParameterSpec         dhSpec;
 32    private transient SubjectPublicKeyInfo    info;
 33    
 34    BCDHPublicKey(
 35        DHPublicKeySpec spec)
 36    {
 37        this.y = spec.getY();
 38        this.dhSpec = new DHParameterSpec(spec.getP(), spec.getG());
 39    }
 40
 41    BCDHPublicKey(
 42        DHPublicKey key)
 43    {
 44        this.y = key.getY();
 45        this.dhSpec = key.getParams();
 46    }
 47
 48    BCDHPublicKey(
 49        DHPublicKeyParameters params)
 50    {
 51        this.y = params.getY();
 52        this.dhSpec = new DHParameterSpec(params.getParameters().getP(), params.getParameters().getG(), params.getParameters().getL());
 53    }
 54
 55    BCDHPublicKey(
 56        BigInteger y,
 57        DHParameterSpec dhSpec)
 58    {
 59        this.y = y;
 60        this.dhSpec = dhSpec;
 61    }
 62
 63    public BCDHPublicKey(
 64        SubjectPublicKeyInfo info)
 65    {
 66        this.info = info;
 67
 68        ASN1Integer              derY;
 69        try
 70        {
 71            derY = (ASN1Integer)info.parsePublicKey();
 72        }
 73        catch (IOException e)
 74        {
 75            throw new IllegalArgumentException("invalid info structure in DH public key");
 76        }
 77
 78        this.y = derY.getValue();
 79
 80        ASN1Sequence seq = ASN1Sequence.getInstance(info.getAlgorithm().getParameters());
 81        ASN1ObjectIdentifier id = info.getAlgorithm().getAlgorithm();
 82
 83        // we need the PKCS check to handle older keys marked with the X9 oid.
 84        if (id.equals(PKCSObjectIdentifiers.dhKeyAgreement) || isPKCSParam(seq))
 85        {
 86            DHParameter             params = DHParameter.getInstance(seq);
 87
 88            if (params.getL() != null)
 89            {
 90                this.dhSpec = new DHParameterSpec(params.getP(), params.getG(), params.getL().intValue());
 91            }
 92            else
 93            {
 94                this.dhSpec = new DHParameterSpec(params.getP(), params.getG());
 95            }
 96        }
 97        else if (id.equals(X9ObjectIdentifiers.dhpublicnumber))
 98        {
 99            DHDomainParameters params = DHDomainParameters.getInstance(seq);
100
101            this.dhSpec = new DHParameterSpec(params.getP().getValue(), params.getG().getValue());
102        }
103        else
104        {
105            throw new IllegalArgumentException("unknown algorithm type: " + id);
106        }
107    }
108
109    public String getAlgorithm()
110    {
111        return "DH";
112    }
113
114    public String getFormat()
115    {
116        return "X.509";
117    }
118
119    public byte[] getEncoded()
120    {
121        if (info != null)
122        {
123            return KeyUtil.getEncodedSubjectPublicKeyInfo(info);
124        }
125
126        return KeyUtil.getEncodedSubjectPublicKeyInfo(new AlgorithmIdentifier(PKCSObjectIdentifiers.dhKeyAgreement, new DHParameter(dhSpec.getP(), dhSpec.getG(), dhSpec.getL()).toASN1Primitive()), new ASN1Integer(y));
127    }
128
129    public DHParameterSpec getParams()
130    {
131        return dhSpec;
132    }
133
134    public BigInteger getY()
135    {
136        return y;
137    }
138
139    private boolean isPKCSParam(ASN1Sequence seq)
140    {
141        if (seq.size() == 2)
142        {
143            return true;
144        }
145        
146        if (seq.size() > 3)
147        {
148            return false;
149        }
150
151        ASN1Integer l = ASN1Integer.getInstance(seq.getObjectAt(2));
152        ASN1Integer p = ASN1Integer.getInstance(seq.getObjectAt(0));
153
154        if (l.getValue().compareTo(BigInteger.valueOf(p.getValue().bitLength())) > 0)
155        {
156            return false;
157        }
158
159        return true;
160    }
161
162    public int hashCode()
163    {
164        return this.getY().hashCode() ^ this.getParams().getG().hashCode()
165                ^ this.getParams().getP().hashCode() ^ this.getParams().getL();
166    }
167
168    public boolean equals(
169        Object o)
170    {
171        if (!(o instanceof DHPublicKey))
172        {
173            return false;
174        }
175
176        DHPublicKey other = (DHPublicKey)o;
177
178        return this.getY().equals(other.getY())
179            && this.getParams().getG().equals(other.getParams().getG())
180            && this.getParams().getP().equals(other.getParams().getP())
181            && this.getParams().getL() == other.getParams().getL();
182    }
183
184    private void readObject(
185        ObjectInputStream   in)
186        throws IOException, ClassNotFoundException
187    {
188        in.defaultReadObject();
189
190        this.dhSpec = new DHParameterSpec((BigInteger)in.readObject(), (BigInteger)in.readObject(), in.readInt());
191        this.info = null;
192    }
193
194    private void writeObject(
195        ObjectOutputStream  out)
196        throws IOException
197    {
198        out.defaultWriteObject();
199
200        out.writeObject(dhSpec.getP());
201        out.writeObject(dhSpec.getG());
202        out.writeInt(dhSpec.getL());
203    }
204}