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package com.sun.crypto.provider;

import java.io.*;
import java.util.Objects;
import java.math.BigInteger;
import java.security.KeyRep;
import java.security.InvalidKeyException;
import java.security.ProviderException;
import java.security.PublicKey;
import javax.crypto.spec.DHParameterSpec;
import sun.security.util.*;


A public key in X.509 format for the Diffie-Hellman key agreement algorithm.
Author:Jan Luehe
See Also:
/** * A public key in X.509 format for the Diffie-Hellman key agreement algorithm. * * @author Jan Luehe * * * @see DHPrivateKey * @see java.security.KeyAgreement */
final class DHPublicKey implements PublicKey, javax.crypto.interfaces.DHPublicKey, Serializable { static final long serialVersionUID = 7647557958927458271L; // the public key private BigInteger y; // the key bytes, without the algorithm information private byte[] key; // the encoded key private byte[] encodedKey; // the prime modulus private BigInteger p; // the base generator private BigInteger g; // the private-value length (optional) private int l; private int DH_data[] = { 1, 2, 840, 113549, 1, 3, 1 };
Make a DH public key out of a public value y, a prime modulus p, and a base generator g.
Params:
  • y – the public value
  • p – the prime modulus
  • g – the base generator
Throws:
/** * Make a DH public key out of a public value <code>y</code>, a prime * modulus <code>p</code>, and a base generator <code>g</code>. * * @param y the public value * @param p the prime modulus * @param g the base generator * * @exception InvalidKeyException if the key cannot be encoded */
DHPublicKey(BigInteger y, BigInteger p, BigInteger g) throws InvalidKeyException { this(y, p, g, 0); }
Make a DH public key out of a public value y, a prime modulus p, a base generator g, and a private-value length l.
Params:
  • y – the public value
  • p – the prime modulus
  • g – the base generator
  • l – the private-value length
Throws:
/** * Make a DH public key out of a public value <code>y</code>, a prime * modulus <code>p</code>, a base generator <code>g</code>, and a * private-value length <code>l</code>. * * @param y the public value * @param p the prime modulus * @param g the base generator * @param l the private-value length * * @exception ProviderException if the key cannot be encoded */
DHPublicKey(BigInteger y, BigInteger p, BigInteger g, int l) { this.y = y; this.p = p; this.g = g; this.l = l; try { this.key = new DerValue(DerValue.tag_Integer, this.y.toByteArray()).toByteArray(); this.encodedKey = getEncoded(); } catch (IOException e) { throw new ProviderException("Cannot produce ASN.1 encoding", e); } }
Make a DH public key from its DER encoding (X.509).
Params:
  • encodedKey – the encoded key
Throws:
/** * Make a DH public key from its DER encoding (X.509). * * @param encodedKey the encoded key * * @exception InvalidKeyException if the encoded key does not represent * a Diffie-Hellman public key */
DHPublicKey(byte[] encodedKey) throws InvalidKeyException { InputStream inStream = new ByteArrayInputStream(encodedKey); try { DerValue derKeyVal = new DerValue(inStream); if (derKeyVal.tag != DerValue.tag_Sequence) { throw new InvalidKeyException ("Invalid key format"); } /* * Parse the algorithm identifier */ DerValue algid = derKeyVal.data.getDerValue(); if (algid.tag != DerValue.tag_Sequence) { throw new InvalidKeyException("AlgId is not a SEQUENCE"); } DerInputStream derInStream = algid.toDerInputStream(); ObjectIdentifier oid = derInStream.getOID(); if (oid == null) { throw new InvalidKeyException("Null OID"); } if (derInStream.available() == 0) { throw new InvalidKeyException("Parameters missing"); } /* * Parse the parameters */ DerValue params = derInStream.getDerValue(); if (params.tag == DerValue.tag_Null) { throw new InvalidKeyException("Null parameters"); } if (params.tag != DerValue.tag_Sequence) { throw new InvalidKeyException("Parameters not a SEQUENCE"); } params.data.reset(); this.p = params.data.getBigInteger(); this.g = params.data.getBigInteger(); // Private-value length is OPTIONAL if (params.data.available() != 0) { this.l = params.data.getInteger(); } if (params.data.available() != 0) { throw new InvalidKeyException("Extra parameter data"); } /* * Parse the key */ this.key = derKeyVal.data.getBitString(); parseKeyBits(); if (derKeyVal.data.available() != 0) { throw new InvalidKeyException("Excess key data"); } this.encodedKey = encodedKey.clone(); } catch (IOException | NumberFormatException e) { throw new InvalidKeyException("Error parsing key encoding", e); } }
Returns the encoding format of this key: "X.509"
/** * Returns the encoding format of this key: "X.509" */
public String getFormat() { return "X.509"; }
Returns the name of the algorithm associated with this key: "DH"
/** * Returns the name of the algorithm associated with this key: "DH" */
public String getAlgorithm() { return "DH"; }
Get the encoding of the key.
/** * Get the encoding of the key. */
public synchronized byte[] getEncoded() { if (this.encodedKey == null) { try { DerOutputStream algid = new DerOutputStream(); // store oid in algid algid.putOID(new ObjectIdentifier(DH_data)); // encode parameters DerOutputStream params = new DerOutputStream(); params.putInteger(this.p); params.putInteger(this.g); if (this.l != 0) { params.putInteger(this.l); } // wrap parameters into SEQUENCE DerValue paramSequence = new DerValue(DerValue.tag_Sequence, params.toByteArray()); // store parameter SEQUENCE in algid algid.putDerValue(paramSequence); // wrap algid into SEQUENCE, and store it in key encoding DerOutputStream tmpDerKey = new DerOutputStream(); tmpDerKey.write(DerValue.tag_Sequence, algid); // store key data tmpDerKey.putBitString(this.key); // wrap algid and key into SEQUENCE DerOutputStream derKey = new DerOutputStream(); derKey.write(DerValue.tag_Sequence, tmpDerKey); this.encodedKey = derKey.toByteArray(); } catch (IOException e) { return null; } } return this.encodedKey.clone(); }
Returns the public value, y.
Returns:the public value, y
/** * Returns the public value, <code>y</code>. * * @return the public value, <code>y</code> */
public BigInteger getY() { return this.y; }
Returns the key parameters.
Returns:the key parameters
/** * Returns the key parameters. * * @return the key parameters */
public DHParameterSpec getParams() { if (this.l != 0) { return new DHParameterSpec(this.p, this.g, this.l); } else { return new DHParameterSpec(this.p, this.g); } } public String toString() { String LINE_SEP = System.getProperty("line.separator"); StringBuffer strbuf = new StringBuffer("SunJCE Diffie-Hellman Public Key:" + LINE_SEP + "y:" + LINE_SEP + Debug.toHexString(this.y) + LINE_SEP + "p:" + LINE_SEP + Debug.toHexString(this.p) + LINE_SEP + "g:" + LINE_SEP + Debug.toHexString(this.g)); if (this.l != 0) strbuf.append(LINE_SEP + "l:" + LINE_SEP + " " + this.l); return strbuf.toString(); } private void parseKeyBits() throws InvalidKeyException { try { DerInputStream in = new DerInputStream(this.key); this.y = in.getBigInteger(); } catch (IOException e) { throw new InvalidKeyException( "Error parsing key encoding: " + e.toString()); } }
Calculates a hash code value for the object. Objects that are equal will also have the same hashcode.
/** * Calculates a hash code value for the object. * Objects that are equal will also have the same hashcode. */
public int hashCode() { return Objects.hash(y, p, g); } public boolean equals(Object obj) { if (this == obj) return true; if (!(obj instanceof javax.crypto.interfaces.DHPublicKey)) { return false; } javax.crypto.interfaces.DHPublicKey other = (javax.crypto.interfaces.DHPublicKey) obj; DHParameterSpec otherParams = other.getParams(); return ((this.y.compareTo(other.getY()) == 0) && (this.p.compareTo(otherParams.getP()) == 0) && (this.g.compareTo(otherParams.getG()) == 0)); }
Replace the DH public key to be serialized.
Throws:
Returns:the standard KeyRep object to be serialized
/** * Replace the DH public key to be serialized. * * @return the standard KeyRep object to be serialized * * @throws java.io.ObjectStreamException if a new object representing * this DH public key could not be created */
private Object writeReplace() throws java.io.ObjectStreamException { return new KeyRep(KeyRep.Type.PUBLIC, getAlgorithm(), getFormat(), getEncoded()); } }