org.cryptacular.spec.DigestSpec.java Source code

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Here is the source code for org.cryptacular.spec.DigestSpec.java

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/* See LICENSE for licensing and NOTICE for copyright. */
package org.cryptacular.spec;

import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.GOST3411Digest;
import org.bouncycastle.crypto.digests.MD2Digest;
import org.bouncycastle.crypto.digests.MD4Digest;
import org.bouncycastle.crypto.digests.MD5Digest;
import org.bouncycastle.crypto.digests.RIPEMD128Digest;
import org.bouncycastle.crypto.digests.RIPEMD160Digest;
import org.bouncycastle.crypto.digests.RIPEMD256Digest;
import org.bouncycastle.crypto.digests.RIPEMD320Digest;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.digests.SHA224Digest;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.digests.SHA384Digest;
import org.bouncycastle.crypto.digests.SHA3Digest;
import org.bouncycastle.crypto.digests.SHA512Digest;
import org.bouncycastle.crypto.digests.TigerDigest;
import org.bouncycastle.crypto.digests.WhirlpoolDigest;

/**
 * Describes a message digest function by name and provides a means to create a
 * new instance of the digest via the {@link #newInstance()} method.
 *
 * @author  Middleware Services
 */
public class DigestSpec implements Spec<Digest> {

    /** Digest algorithm name. */
    private final String algorithm;

    /**
     * Requested size of variable-size hash algorithms, e.g. SHA-3. -1 for hashes
     * with fixed size outputs.
     */
    private final int size;

    /**
     * Creates a new instance from the given algorithm name.
     *
     * @param  algName  Digest algorithm name.
     */
    public DigestSpec(final String algName) {
        if (algName == null) {
            throw new IllegalArgumentException("Algorithm name is required.");
        }
        this.algorithm = algName;
        this.size = -1;
    }

    /**
     * Constructor for digests that have variable output size, e.g. SHA3.
     *
     * @param  algName  Digest algorithm name.
     * @param  digestSize  Size of resultant digest in bits.
     */
    public DigestSpec(final String algName, final int digestSize) {
        if (algName == null) {
            throw new IllegalArgumentException("Algorithm name is required.");
        }
        this.algorithm = algName;
        if (digestSize < 0) {
            throw new IllegalArgumentException("Digest size must be positive.");
        }
        this.size = digestSize;
    }

    @Override
    public String getAlgorithm() {
        return algorithm;
    }

    /**
     * @return  Size of digest output in bytes, or -1 if the digest does not
     *          support variable size output.
     */
    public int getSize() {
        return size;
    }

    /**
     * Creates a new digest instance.
     *
     * @return  Digest instance.
     */
    @Override
    public Digest newInstance() {
        final Digest digest;
        if ("GOST3411".equalsIgnoreCase(algorithm)) {
            digest = new GOST3411Digest();
        } else if ("MD2".equalsIgnoreCase(algorithm)) {
            digest = new MD2Digest();
        } else if ("MD4".equalsIgnoreCase(algorithm)) {
            digest = new MD4Digest();
        } else if ("MD5".equalsIgnoreCase(algorithm)) {
            digest = new MD5Digest();
        } else if ("RIPEMD128".equalsIgnoreCase(algorithm) || "RIPEMD-128".equalsIgnoreCase(algorithm)) {
            digest = new RIPEMD128Digest();
        } else if ("RIPEMD160".equalsIgnoreCase(algorithm) || "RIPEMD-160".equalsIgnoreCase(algorithm)) {
            digest = new RIPEMD160Digest();
        } else if ("RIPEMD256".equalsIgnoreCase(algorithm) || "RIPEMD-256".equalsIgnoreCase(algorithm)) {
            digest = new RIPEMD256Digest();
        } else if ("RIPEMD320".equalsIgnoreCase(algorithm) || "RIPEMD-320".equalsIgnoreCase(algorithm)) {
            digest = new RIPEMD320Digest();
        } else if ("SHA1".equalsIgnoreCase(algorithm) || "SHA-1".equalsIgnoreCase(algorithm)) {
            digest = new SHA1Digest();
        } else if ("SHA224".equalsIgnoreCase(algorithm) || "SHA-224".equalsIgnoreCase(algorithm)) {
            digest = new SHA224Digest();
        } else if ("SHA256".equalsIgnoreCase(algorithm) || "SHA-256".equalsIgnoreCase(algorithm)) {
            digest = new SHA256Digest();
        } else if ("SHA384".equalsIgnoreCase(algorithm) || "SHA-384".equalsIgnoreCase(algorithm)) {
            digest = new SHA384Digest();
        } else if ("SHA512".equalsIgnoreCase(algorithm) || "SHA-512".equalsIgnoreCase(algorithm)) {
            digest = new SHA512Digest();
        } else if ("SHA3".equalsIgnoreCase(algorithm) || "SHA-3".equalsIgnoreCase(algorithm)) {
            digest = new SHA3Digest(size);
        } else if ("Tiger".equalsIgnoreCase(algorithm)) {
            digest = new TigerDigest();
        } else if ("Whirlpool".equalsIgnoreCase(algorithm)) {
            digest = new WhirlpoolDigest();
        } else {
            throw new IllegalStateException("Unsupported digest algorithm " + algorithm);
        }
        return digest;
    }

    @Override
    public String toString() {
        return algorithm;
    }
}