http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.8.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.crypto;


interface that a message digest conforms to.

/**
 * interface that a message digest conforms to.
 */
public interface Digest
{
    
return the algorithm name

Returns:the algorithm name
/**
     * return the algorithm name
     *
     * @return the algorithm name
     */
    public String getAlgorithmName();

    
return the size, in bytes, of the digest produced by this message digest.

Returns:the size, in bytes, of the digest produced by this message digest.
/**
     * return the size, in bytes, of the digest produced by this message digest.
     *
     * @return the size, in bytes, of the digest produced by this message digest.
     */
    public int getDigestSize();

    
update the message digest with a single byte.

Params:
  • in – the input byte to be entered.
/**
     * update the message digest with a single byte.
     *
     * @param in the input byte to be entered.
     */
    public void update(byte in);

    
update the message digest with a block of bytes.

Params:
  • in – the byte array containing the data.
  • inOff – the offset into the byte array where the data starts.
  • len – the length of the data.
/**
     * update the message digest with a block of bytes.
     *
     * @param in the byte array containing the data.
     * @param inOff the offset into the byte array where the data starts.
     * @param len the length of the data.
     */
    public void update(byte[] in, int inOff, int len);

    
close the digest, producing the final digest value. The doFinal
call leaves the digest reset.

Params:
  • out – the array the digest is to be copied into.
  • outOff – the offset into the out array the digest is to start at.
/**
     * close the digest, producing the final digest value. The doFinal
     * call leaves the digest reset.
     *
     * @param out the array the digest is to be copied into.
     * @param outOff the offset into the out array the digest is to start at.
     */
    public int doFinal(byte[] out, int outOff);

    
reset the digest back to it's initial state.

/**
     * reset the digest back to it's initial state.
     */
    public void reset();
}