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Spongy Castle is a package-rename (org.bouncycastle.* to org.spongycastle.*) of Bouncy Castle
intended for the Android platform. Android unfortunately ships with a stripped-down version of
Bouncy Castle, which prevents easy upgrades - Spongy Castle overcomes this and provides a full,
up-to-date version of the Bouncy Castle cryptographic libs.
package org.spongycastle.pqc.jcajce.provider.mceliece;
import java.io.IOException;
import java.security.PrivateKey;
import org.spongycastle.asn1.ASN1ObjectIdentifier;
import org.spongycastle.asn1.ASN1Primitive;
import org.spongycastle.asn1.DERNull;
import org.spongycastle.asn1.pkcs.PrivateKeyInfo;
import org.spongycastle.asn1.x509.AlgorithmIdentifier;
import org.spongycastle.crypto.CipherParameters;
import org.spongycastle.pqc.asn1.McElieceCCA2PrivateKey;
import org.spongycastle.pqc.crypto.mceliece.McElieceCCA2KeyPairGenerator;
import org.spongycastle.pqc.crypto.mceliece.McElieceCCA2Parameters;
import org.spongycastle.pqc.crypto.mceliece.McElieceCCA2PrivateKeyParameters;
import org.spongycastle.pqc.jcajce.spec.McElieceCCA2PrivateKeySpec;
import org.spongycastle.pqc.math.linearalgebra.GF2Matrix;
import org.spongycastle.pqc.math.linearalgebra.GF2mField;
import org.spongycastle.pqc.math.linearalgebra.Permutation;
import org.spongycastle.pqc.math.linearalgebra.PolynomialGF2mSmallM;
/**
* This class implements a McEliece CCA2 private key and is usually instantiated
* by the {@link McElieceCCA2KeyPairGenerator} or {@link McElieceCCA2KeyFactorySpi}.
*
* @see McElieceCCA2KeyPairGenerator
*/
public class BCMcElieceCCA2PrivateKey
implements CipherParameters, PrivateKey
{
/**
*
*/
private static final long serialVersionUID = 1L;
// the OID of the algorithm
private String oid;
// the length of the code
private int n;
// the dimension of the code, k>=n-mt
private int k;
// the finte field GF(2^m)
private GF2mField field;
// the irreducible Goppa polynomial
private PolynomialGF2mSmallM goppaPoly;
// the permutation
private Permutation p;
// the canonical check matrix
private GF2Matrix h;
// the matrix used to compute square roots in (GF(2^m))^t
private PolynomialGF2mSmallM[] qInv;
private McElieceCCA2Parameters mcElieceCCA2Params;
/**
* Constructor (used by the {@link McElieceCCA2KeyPairGenerator}).
*
* @param n the length of the code
* @param k the dimension of the code
* @param field the field polynomial
* @param gp the irreducible Goppa polynomial
* @param p the permutation
* @param h the canonical check matrix
* @param qInv the matrix used to compute square roots in
* (GF(2^m))^t
*/
public BCMcElieceCCA2PrivateKey(String oid, int n, int k, GF2mField field,
PolynomialGF2mSmallM gp, Permutation p, GF2Matrix h,
PolynomialGF2mSmallM[] qInv)
{
this.oid = oid;
this.n = n;
this.k = k;
this.field = field;
this.goppaPoly = gp;
this.p = p;
this.h = h;
this.qInv = qInv;
}
/**
* Constructor (used by the {@link McElieceCCA2KeyFactorySpi}).
*
* @param keySpec a {@link McElieceCCA2PrivateKeySpec}
*/
public BCMcElieceCCA2PrivateKey(McElieceCCA2PrivateKeySpec keySpec)
{
this(keySpec.getOIDString(), keySpec.getN(), keySpec.getK(), keySpec.getField(), keySpec
.getGoppaPoly(), keySpec.getP(), keySpec.getH(), keySpec
.getQInv());
}
public BCMcElieceCCA2PrivateKey(McElieceCCA2PrivateKeyParameters params)
{
this(params.getOIDString(), params.getN(), params.getK(), params.getField(), params.getGoppaPoly(),
params.getP(), params.getH(), params.getQInv());
this.mcElieceCCA2Params = 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 k;
}
/**
* @return the degree of the Goppa polynomial (error correcting capability)
*/
public int getT()
{
return goppaPoly.getDegree();
}
/**
* @return the finite field
*/
public GF2mField getField()
{
return field;
}
/**
* @return the irreducible Goppa polynomial
*/
public PolynomialGF2mSmallM getGoppaPoly()
{
return goppaPoly;
}
/**
* @return the permutation vector
*/
public Permutation getP()
{
return p;
}
/**
* @return the canonical check matrix
*/
public GF2Matrix getH()
{
return h;
}
/**
* @return the matrix used to compute square roots in (GF(2^m))^t
*/
public PolynomialGF2mSmallM[] getQInv()
{
return qInv;
}
/**
* @return a human readable form of the key
*/
public String toString()
{
String result = "";
result += " extension degree of the field : " + n + "\n";
result += " dimension of the code : " + k + "\n";
result += " irreducible Goppa polynomial : " + goppaPoly + "\n";
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 == null || !(other instanceof BCMcElieceCCA2PrivateKey))
{
return false;
}
BCMcElieceCCA2PrivateKey otherKey = (BCMcElieceCCA2PrivateKey)other;
return (n == otherKey.n) && (k == otherKey.k)
&& field.equals(otherKey.field)
&& goppaPoly.equals(otherKey.goppaPoly) && p.equals(otherKey.p)
&& h.equals(otherKey.h);
}
/**
* @return the hash code of this key
*/
public int hashCode()
{
return k + n + field.hashCode() + goppaPoly.hashCode() + p.hashCode()
+ h.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(McElieceCCA2KeyFactorySpi.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.
*
* The ASN.1 definition of the key structure is
*
*
* McEliecePrivateKey ::= SEQUENCE {
* m INTEGER -- extension degree of the field
* k INTEGER -- dimension of the code
* field OCTET STRING -- field polynomial
* goppaPoly OCTET STRING -- irreducible Goppa polynomial
* p OCTET STRING -- permutation vector
* matrixH OCTET STRING -- canonical check matrix
* sqRootMatrix SEQUENCE OF OCTET STRING -- square root matrix
* }
*
*
* @return the keyData to encode in the SubjectPublicKeyInfo structure
*/
public byte[] getEncoded()
{
McElieceCCA2PrivateKey privateKey = new McElieceCCA2PrivateKey(new ASN1ObjectIdentifier(oid), n, k, field, goppaPoly, p, h, qInv);
PrivateKeyInfo pki;
try
{
AlgorithmIdentifier algorithmIdentifier = new AlgorithmIdentifier(this.getOID(), DERNull.INSTANCE);
pki = new PrivateKeyInfo(algorithmIdentifier, privateKey);
}
catch (IOException e)
{
e.printStackTrace();
return null;
}
try
{
byte[] encoded = pki.getEncoded();
return encoded;
}
catch (IOException e)
{
e.printStackTrace();
return null;
}
}
public String getFormat()
{
// TODO Auto-generated method stub
return null;
}
public McElieceCCA2Parameters getMcElieceCCA2Parameters()
{
return mcElieceCCA2Params;
}
}
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