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Viewing changes to src/org/bouncycastle/crypto/generators/ECKeyPairGenerator.java

  • Committer: Brian Thomason
  • Date: 2011-12-20 17:20:32 UTC
  • Revision ID: brian.thomason@canonical.com-20111220172032-rdtm13jgdxtksacr
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src/org/bouncycastle/crypto/generators/ECKeyPairGenerator.java
 
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package org.bouncycastle.crypto.generators;
 
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import java.math.BigInteger;
 
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import java.security.SecureRandom;
 
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import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
 
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import org.bouncycastle.crypto.AsymmetricCipherKeyPairGenerator;
 
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import org.bouncycastle.crypto.KeyGenerationParameters;
 
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import org.bouncycastle.crypto.params.ECDomainParameters;
 
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import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
 
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import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
 
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import org.bouncycastle.crypto.params.ECPublicKeyParameters;
 
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import org.bouncycastle.math.ec.ECConstants;
 
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import org.bouncycastle.math.ec.ECPoint;
 
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public class ECKeyPairGenerator
 
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    implements AsymmetricCipherKeyPairGenerator, ECConstants
 
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{
 
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    ECDomainParameters  params;
 
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    SecureRandom        random;
 
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    public void init(
 
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        KeyGenerationParameters param)
 
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    {
 
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        ECKeyGenerationParameters  ecP = (ECKeyGenerationParameters)param;
 
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        this.random = ecP.getRandom();
 
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        this.params = ecP.getDomainParameters();
 
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    }
 
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    /**
 
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     * Given the domain parameters this routine generates an EC key
 
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     * pair in accordance with X9.62 section 5.2.1 pages 26, 27.
 
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     */
 
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    public AsymmetricCipherKeyPair generateKeyPair()
 
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    {
 
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        BigInteger n = params.getN();
 
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        int        nBitLength = n.bitLength();
 
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        BigInteger d;
 
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        do
 
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        {
 
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            d = new BigInteger(nBitLength, random);
 
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        }
 
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        while (d.equals(ZERO)  || (d.compareTo(n) >= 0));
 
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        ECPoint Q = params.getG().multiply(d);
 
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        return new AsymmetricCipherKeyPair(
 
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            new ECPublicKeyParameters(Q, params),
 
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            new ECPrivateKeyParameters(d, params));
 
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    }
 
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}