org.bouncycastle.asn1.tsp.PartialHashtree Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of bcutil-fips Show documentation

The Bouncy Castle Java APIs for ASN.1 extension and utility APIs used to support bcpkix and bctls with the BC FIPS provider. The APIs may also be used with other providers although if being used in a FIPS context it is the responsibility of the user to ensure that any other providers used are FIPS certified and used appropriately.

The newest version!

package org.bouncycastle.asn1.tsp;

import java.util.Enumeration;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.util.Arrays;

/**
 * Implementation of PartialHashtree, as defined in RFC 4998.
 * 
 * The ASN.1 notation for a PartialHashTree is:
 * 
 * PartialHashtree ::= SEQUENCE OF OCTET STRING
 */
public class PartialHashtree
    extends ASN1Object
{
    /**
     * Hash values that constitute the hash tree, as ASN.1 Octet Strings.
     */
    private final ASN1Sequence values;

    /**
     * Return a PartialHashtree from the given object.
     *
     * @param obj the object we want converted.
     * @return a PartialHashtree instance, or null.
     * @throws IllegalArgumentException if the object cannot be converted.
     */
    public static PartialHashtree getInstance(final Object obj)
    {
        if (obj instanceof PartialHashtree)
        {
            return (PartialHashtree)obj;
        }
        else if (obj != null)
        {
            return new PartialHashtree(ASN1Sequence.getInstance(obj));
        }

        return null;
    }

    private PartialHashtree(final ASN1Sequence values)
    {
        for (int i = 0; i != values.size(); i++)
        {
            if (!(values.getObjectAt(i) instanceof ASN1OctetString))
            {
                throw new IllegalArgumentException("unknown object in constructor: " + values
                    .getObjectAt(i).getClass().getName());
            }
        }
        this.values = values;
    }

    public PartialHashtree(byte[] values)
    {
        this(new byte[][] { values });
    }

    public PartialHashtree(byte[][] values)
    {
        ASN1EncodableVector v = new ASN1EncodableVector(values.length);

        for (int i = 0; i != values.length; i++)
        {
            v.add(new DEROctetString(Arrays.clone(values[i])));
        }

        this.values = new DERSequence(v);
    }

    public int getValueCount()
    {
        return values.size();
    }

    public byte[][] getValues()
    {
        byte[][] rv = new byte[values.size()][];

        for (int i = 0; i != rv.length; i++)
        {
            rv[i] = Arrays.clone(ASN1OctetString.getInstance(values.getObjectAt(i)).getOctets());
        }

        return rv;
    }

    public boolean containsHash(byte[] hash)
    {
        Enumeration hashes = values.getObjects();

        while (hashes.hasMoreElements())
        {
            byte[] currentHash = ASN1OctetString.getInstance(hashes.nextElement()).getOctets();

            if (Arrays.constantTimeAreEqual(hash, currentHash))
            {
                return true;
            }
        }

        return false;
    }

    public ASN1Primitive toASN1Primitive()
    {
        return values;
    }
}