http://www.bouncycastle.org/java.html: The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 to JDK 1.8. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.operator;


Interface for ContentVerifiers that also support raw signatures that can be
verified using the digest of the calculated data.

/**
 * Interface for ContentVerifiers that also support raw signatures that can be
 * verified using the digest of the calculated data.
 */
public interface RawContentVerifier
{
    
Verify that the expected signature value was derived from the passed in digest.

Params:
  • digest – digest calculated from the content.
  • expected – expected value of the signature
Returns:true if the expected signature is derived from the digest, false otherwise.
/**
     * Verify that the expected signature value was derived from the passed in digest.
     *
     * @param digest digest calculated from the content.
     * @param expected expected value of the signature
     * @return true if the expected signature is derived from the digest, false otherwise.
     */
    boolean verify(byte[] digest, byte[] expected);
}