package org.bouncycastle.pqc.jcajce.provider.mceliece;
import java.io.IOException;
import java.security.PublicKey;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.pqc.asn1.McEliecePublicKey;
import org.bouncycastle.pqc.crypto.mceliece.McElieceKeyPairGenerator;
import org.bouncycastle.pqc.crypto.mceliece.McElieceParameters;
import org.bouncycastle.pqc.crypto.mceliece.McEliecePublicKeyParameters;
import org.bouncycastle.pqc.jcajce.spec.McEliecePublicKeySpec;
import org.bouncycastle.pqc.math.linearalgebra.GF2Matrix;
/**
* This class implements a McEliece public key and is usually instantiated by
* the {@link McElieceKeyPairGenerator} or {@link McElieceKeyFactorySpi}.
*/
public class BCMcEliecePublicKey
implements CipherParameters, PublicKey
{
/**
*
*/
private static final long serialVersionUID = 1L;
// the OID of the algorithm
private String oid;
/**
* the length of the code
*/
private int n;
/**
* the error correction capability of the code
*/
private int t;
/**
* the generator matrix
*/
private GF2Matrix g;
private McElieceParameters McElieceParams;
/**
* Constructor (used by the {@link McElieceKeyPairGenerator}).
*
* @param oid
* @param n the length of the code
* @param t the error correction capability of the code
* @param g the generator matrix
*/
public BCMcEliecePublicKey(String oid, int n, int t, GF2Matrix g)
{
this.oid = oid;
this.n = n;
this.t = t;
this.g = g;
}
/**
* Constructor (used by the {@link McElieceKeyFactorySpi}).
*
* @param keySpec a {@link McEliecePublicKeySpec}
*/
public BCMcEliecePublicKey(McEliecePublicKeySpec keySpec)
{
this(keySpec.getOIDString(), keySpec.getN(), keySpec.getT(), keySpec.getG());
}
public BCMcEliecePublicKey(McEliecePublicKeyParameters params)
{
this(params.getOIDString(), params.getN(), params.getT(), params.getG());
this.McElieceParams = params.getParameters();
}
/**
* Return the name of the algorithm.
*
* @return "McEliece"
*/
public String getAlgorithm()
{
return "McEliece";
}
/**
* @return the length of the code
*/
public int getN()
{
return n;
}
/**
* @return the dimension of the code
*/
public int getK()
{
return g.getNumRows();
}
/**
* @return the error correction capability of the code
*/
public int getT()
{
return t;
}
/**
* @return the generator matrix
*/
public GF2Matrix getG()
{
return g;
}
/**
* @return a human readable form of the key
*/
public String toString()
{
String result = "McEliecePublicKey:\n";
result += " length of the code : " + n + "\n";
result += " error correction capability: " + t + "\n";
result += " generator matrix : " + g.toString();
return result;
}
/**
* Compare this key with another object.
*
* @param other the other object
* @return the result of the comparison
*/
public boolean equals(Object other)
{
if (!(other instanceof BCMcEliecePublicKey))
{
return false;
}
BCMcEliecePublicKey otherKey = (BCMcEliecePublicKey)other;
return (n == otherKey.n) && (t == otherKey.t) && g.equals(otherKey.g);
}
/**
* @return the hash code of this key
*/
public int hashCode()
{
return n + t + g.hashCode();
}
/**
* @return the OID of the algorithm
*/
public String getOIDString()
{
return oid;
}
/**
* @return the OID to encode in the SubjectPublicKeyInfo structure
*/
protected ASN1ObjectIdentifier getOID()
{
return new ASN1ObjectIdentifier(McElieceKeyFactorySpi.OID);
}
/**
* @return the algorithm parameters to encode in the SubjectPublicKeyInfo
* structure
*/
protected ASN1Primitive getAlgParams()
{
return null; // FIXME: needed at all?
}
/**
* Return the keyData to encode in the SubjectPublicKeyInfo structure.
* <p/>
* The ASN.1 definition of the key structure is
* <p/>
* <pre>
* McEliecePublicKey ::= SEQUENCE {
* n Integer -- length of the code
* t Integer -- error correcting capability
* matrixG OctetString -- generator matrix as octet string
* }
* </pre>
*
* @return the keyData to encode in the SubjectPublicKeyInfo structure
*/
public byte[] getEncoded()
{
McEliecePublicKey key = new McEliecePublicKey(new ASN1ObjectIdentifier(oid), n, t, g);
AlgorithmIdentifier algorithmIdentifier = new AlgorithmIdentifier(this.getOID(), DERNull.INSTANCE);
try
{
SubjectPublicKeyInfo subjectPublicKeyInfo = new SubjectPublicKeyInfo(algorithmIdentifier, key);
return subjectPublicKeyInfo.getEncoded();
}
catch (IOException e)
{
return null;
}
}
public String getFormat()
{
return null;
}
public McElieceParameters getMcElieceParameters()
{
return McElieceParams;
}
}