diff options
Diffstat (limited to 'prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/elgamal/BCElGamalPublicKey.java')
-rw-r--r-- | prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/elgamal/BCElGamalPublicKey.java | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/elgamal/BCElGamalPublicKey.java b/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/elgamal/BCElGamalPublicKey.java new file mode 100644 index 00000000..86ee5226 --- /dev/null +++ b/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/elgamal/BCElGamalPublicKey.java @@ -0,0 +1,172 @@ +package org.spongycastle.jcajce.provider.asymmetric.elgamal; + +import java.io.IOException; +import java.io.ObjectInputStream; +import java.io.ObjectOutputStream; +import java.math.BigInteger; + +import javax.crypto.interfaces.DHPublicKey; +import javax.crypto.spec.DHParameterSpec; +import javax.crypto.spec.DHPublicKeySpec; + +import org.spongycastle.asn1.ASN1Encoding; +import org.spongycastle.asn1.ASN1Integer; +import org.spongycastle.asn1.oiw.ElGamalParameter; +import org.spongycastle.asn1.oiw.OIWObjectIdentifiers; +import org.spongycastle.asn1.x509.AlgorithmIdentifier; +import org.spongycastle.asn1.x509.SubjectPublicKeyInfo; +import org.spongycastle.crypto.params.ElGamalPublicKeyParameters; +import org.spongycastle.jce.interfaces.ElGamalPublicKey; +import org.spongycastle.jce.spec.ElGamalParameterSpec; +import org.spongycastle.jce.spec.ElGamalPublicKeySpec; + +public class BCElGamalPublicKey + implements ElGamalPublicKey, DHPublicKey +{ + static final long serialVersionUID = 8712728417091216948L; + + private BigInteger y; + private transient ElGamalParameterSpec elSpec; + + BCElGamalPublicKey( + ElGamalPublicKeySpec spec) + { + this.y = spec.getY(); + this.elSpec = new ElGamalParameterSpec(spec.getParams().getP(), spec.getParams().getG()); + } + + BCElGamalPublicKey( + DHPublicKeySpec spec) + { + this.y = spec.getY(); + this.elSpec = new ElGamalParameterSpec(spec.getP(), spec.getG()); + } + + BCElGamalPublicKey( + ElGamalPublicKey key) + { + this.y = key.getY(); + this.elSpec = key.getParameters(); + } + + BCElGamalPublicKey( + DHPublicKey key) + { + this.y = key.getY(); + this.elSpec = new ElGamalParameterSpec(key.getParams().getP(), key.getParams().getG()); + } + + BCElGamalPublicKey( + ElGamalPublicKeyParameters params) + { + this.y = params.getY(); + this.elSpec = new ElGamalParameterSpec(params.getParameters().getP(), params.getParameters().getG()); + } + + BCElGamalPublicKey( + BigInteger y, + ElGamalParameterSpec elSpec) + { + this.y = y; + this.elSpec = elSpec; + } + + BCElGamalPublicKey( + SubjectPublicKeyInfo info) + { + ElGamalParameter params = ElGamalParameter.getInstance(info.getAlgorithm().getParameters()); + ASN1Integer derY = null; + + try + { + derY = (ASN1Integer)info.parsePublicKey(); + } + catch (IOException e) + { + throw new IllegalArgumentException("invalid info structure in DSA public key"); + } + + this.y = derY.getValue(); + this.elSpec = new ElGamalParameterSpec(params.getP(), params.getG()); + } + + public String getAlgorithm() + { + return "ElGamal"; + } + + public String getFormat() + { + return "X.509"; + } + + public byte[] getEncoded() + { + try + { + SubjectPublicKeyInfo info = new SubjectPublicKeyInfo(new AlgorithmIdentifier(OIWObjectIdentifiers.elGamalAlgorithm, new ElGamalParameter(elSpec.getP(), elSpec.getG())), new ASN1Integer(y)); + + return info.getEncoded(ASN1Encoding.DER); + } + catch (IOException e) + { + return null; + } + } + + public ElGamalParameterSpec getParameters() + { + return elSpec; + } + + public DHParameterSpec getParams() + { + return new DHParameterSpec(elSpec.getP(), elSpec.getG()); + } + + public BigInteger getY() + { + return y; + } + + public int hashCode() + { + return this.getY().hashCode() ^ this.getParams().getG().hashCode() + ^ this.getParams().getP().hashCode() ^ this.getParams().getL(); + } + + public boolean equals( + Object o) + { + if (!(o instanceof DHPublicKey)) + { + return false; + } + + DHPublicKey other = (DHPublicKey)o; + + return this.getY().equals(other.getY()) + && this.getParams().getG().equals(other.getParams().getG()) + && this.getParams().getP().equals(other.getParams().getP()) + && this.getParams().getL() == other.getParams().getL(); + } + + private void readObject( + ObjectInputStream in) + throws IOException, ClassNotFoundException + { + in.defaultReadObject(); + + this.elSpec = new ElGamalParameterSpec((BigInteger)in.readObject(), (BigInteger)in.readObject()); + } + + private void writeObject( + ObjectOutputStream out) + throws IOException + { + out.defaultWriteObject(); + + out.writeObject(elSpec.getP()); + out.writeObject(elSpec.getG()); + } +} |