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/**
* EdDSA-Java by str4d
*
* To the extent possible under law, the person who associated CC0 with
* EdDSA-Java has waived all copyright and related or neighboring rights
* to EdDSA-Java.
*
* You should have received a copy of the CC0 legalcode along with this
* work. If not, see <https://creativecommons.org/publicdomain/zero/1.0/>.
*
*/
package net.i2p.crypto.eddsa.spec;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.spec.AlgorithmParameterSpec;
import net.i2p.crypto.eddsa.math.Curve;
import net.i2p.crypto.eddsa.math.GroupElement;
import net.i2p.crypto.eddsa.math.ScalarOps;
import java.io.Serializable;
/**
* Parameter specification for an EdDSA algorithm.
* @author str4d
*
*/
public class EdDSAParameterSpec implements AlgorithmParameterSpec, Serializable {
private static final long serialVersionUID = 8274987108472012L;
private final Curve curve;
private final String hashAlgo;
private final ScalarOps sc;
private final GroupElement B;
/**
* @param curve the curve
* @param hashAlgo the JCA string for the hash algorithm
* @param sc the parameter L represented as ScalarOps
* @param B the parameter B
* @throws IllegalArgumentException if hash algorithm is unsupported or length is wrong
*/
public EdDSAParameterSpec(Curve curve, String hashAlgo,
ScalarOps sc, GroupElement B) {
try {
MessageDigest hash = MessageDigest.getInstance(hashAlgo);
// EdDSA hash function must produce 2b-bit output
if (curve.getField().getb()/4 != hash.getDigestLength())
throw new IllegalArgumentException("Hash output is not 2b-bit");
} catch (NoSuchAlgorithmException e) {
throw new IllegalArgumentException("Unsupported hash algorithm");
}
this.curve = curve;
this.hashAlgo = hashAlgo;
this.sc = sc;
this.B = B;
}
public Curve getCurve() {
return curve;
}
public String getHashAlgorithm() {
return hashAlgo;
}
public ScalarOps getScalarOps() {
return sc;
}
/**
* @return the base (generator)
*/
public GroupElement getB() {
return B;
}
@Override
public int hashCode() {
return hashAlgo.hashCode() ^
curve.hashCode() ^
B.hashCode();
}
@Override
public boolean equals(Object o) {
if (o == this)
return true;
if (!(o instanceof EdDSAParameterSpec))
return false;
EdDSAParameterSpec s = (EdDSAParameterSpec) o;
return hashAlgo.equals(s.getHashAlgorithm()) &&
curve.equals(s.getCurve()) &&
B.equals(s.getB());
}
}
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