org.bouncycastle.asn1.pkcs.RSASSAPSSparams.java Source code

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Here is the source code for org.bouncycastle.asn1.pkcs.RSASSAPSSparams.java

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package org.bouncycastle.asn1.pkcs;

import java.math.BigInteger;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;
import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;

public class RSASSAPSSparams extends ASN1Object {
    private AlgorithmIdentifier hashAlgorithm;
    private AlgorithmIdentifier maskGenAlgorithm;
    private ASN1Integer saltLength;
    private ASN1Integer trailerField;

    public final static AlgorithmIdentifier DEFAULT_HASH_ALGORITHM = new AlgorithmIdentifier(
            OIWObjectIdentifiers.idSHA1, DERNull.INSTANCE);
    public final static AlgorithmIdentifier DEFAULT_MASK_GEN_FUNCTION = new AlgorithmIdentifier(
            PKCSObjectIdentifiers.id_mgf1, DEFAULT_HASH_ALGORITHM);
    public final static ASN1Integer DEFAULT_SALT_LENGTH = new ASN1Integer(20);
    public final static ASN1Integer DEFAULT_TRAILER_FIELD = new ASN1Integer(1);

    public static RSASSAPSSparams getInstance(Object obj) {
        if (obj instanceof RSASSAPSSparams) {
            return (RSASSAPSSparams) obj;
        } else if (obj != null) {
            return new RSASSAPSSparams(ASN1Sequence.getInstance(obj));
        }

        return null;
    }

    /**
     * The default version
     */
    public RSASSAPSSparams() {
        hashAlgorithm = DEFAULT_HASH_ALGORITHM;
        maskGenAlgorithm = DEFAULT_MASK_GEN_FUNCTION;
        saltLength = DEFAULT_SALT_LENGTH;
        trailerField = DEFAULT_TRAILER_FIELD;
    }

    public RSASSAPSSparams(AlgorithmIdentifier hashAlgorithm, AlgorithmIdentifier maskGenAlgorithm,
            ASN1Integer saltLength, ASN1Integer trailerField) {
        this.hashAlgorithm = hashAlgorithm;
        this.maskGenAlgorithm = maskGenAlgorithm;
        this.saltLength = saltLength;
        this.trailerField = trailerField;
    }

    private RSASSAPSSparams(ASN1Sequence seq) {
        hashAlgorithm = DEFAULT_HASH_ALGORITHM;
        maskGenAlgorithm = DEFAULT_MASK_GEN_FUNCTION;
        saltLength = DEFAULT_SALT_LENGTH;
        trailerField = DEFAULT_TRAILER_FIELD;

        for (int i = 0; i != seq.size(); i++) {
            ASN1TaggedObject o = (ASN1TaggedObject) seq.getObjectAt(i);

            switch (o.getTagNo()) {
            case 0:
                hashAlgorithm = AlgorithmIdentifier.getInstance(o, true);
                break;
            case 1:
                maskGenAlgorithm = AlgorithmIdentifier.getInstance(o, true);
                break;
            case 2:
                saltLength = ASN1Integer.getInstance(o, true);
                break;
            case 3:
                trailerField = ASN1Integer.getInstance(o, true);
                break;
            default:
                throw new IllegalArgumentException("unknown tag");
            }
        }
    }

    public AlgorithmIdentifier getHashAlgorithm() {
        return hashAlgorithm;
    }

    public AlgorithmIdentifier getMaskGenAlgorithm() {
        return maskGenAlgorithm;
    }

    public BigInteger getSaltLength() {
        return saltLength.getValue();
    }

    public BigInteger getTrailerField() {
        return trailerField.getValue();
    }

    /**
     * <pre>
     * RSASSA-PSS-params ::= SEQUENCE {
     *   hashAlgorithm      [0] OAEP-PSSDigestAlgorithms  DEFAULT sha1,
     *    maskGenAlgorithm   [1] PKCS1MGFAlgorithms  DEFAULT mgf1SHA1,
     *    saltLength         [2] INTEGER  DEFAULT 20,
     *    trailerField       [3] TrailerField  DEFAULT trailerFieldBC
     *  }
     *
     * OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {
     *    { OID id-sha1 PARAMETERS NULL   }|
     *    { OID id-sha256 PARAMETERS NULL }|
     *    { OID id-sha384 PARAMETERS NULL }|
     *    { OID id-sha512 PARAMETERS NULL },
     *    ...  -- Allows for future expansion --
     * }
     *
     * PKCS1MGFAlgorithms    ALGORITHM-IDENTIFIER ::= {
     *   { OID id-mgf1 PARAMETERS OAEP-PSSDigestAlgorithms },
     *    ...  -- Allows for future expansion --
     * }
     * 
     * TrailerField ::= INTEGER { trailerFieldBC(1) }
     * </pre>
     * @return the asn1 primitive representing the parameters.
     */
    public ASN1Primitive toASN1Primitive() {
        ASN1EncodableVector v = new ASN1EncodableVector(4);

        if (!hashAlgorithm.equals(DEFAULT_HASH_ALGORITHM)) {
            v.add(new DERTaggedObject(true, 0, hashAlgorithm));
        }

        if (!maskGenAlgorithm.equals(DEFAULT_MASK_GEN_FUNCTION)) {
            v.add(new DERTaggedObject(true, 1, maskGenAlgorithm));
        }

        if (!saltLength.equals(DEFAULT_SALT_LENGTH)) {
            v.add(new DERTaggedObject(true, 2, saltLength));
        }

        if (!trailerField.equals(DEFAULT_TRAILER_FIELD)) {
            v.add(new DERTaggedObject(true, 3, trailerField));
        }

        return new DERSequence(v);
    }
}