Package com.amazon.corretto.crypto.provider

Class MD5Spi

java.lang.Object

java.security.MessageDigestSpi

com.amazon.corretto.crypto.provider.MD5Spi

All Implemented Interfaces:

java.lang.Cloneable

public final class MD5Spi
extends java.security.MessageDigestSpi
implements java.lang.Cloneable

Template for hash function bindings. Unfortunately using openssl's common EVP interface for hash functions introduces significant performance overhead (to the point that the default JCE provider is faster for <= 32 byte hashes). As such we build direct bindings to the older interfaces for each of our supported hash functions - since these are nearly identical, though, we use templates on both the Java and C++ sides to accomplish this. To further improve performance, we avoid using the C++ heap to allocate the state datastructure for our hash function - instead, we allocate a java byte array and put the hash state in it directly. This is safe as long as 1) byte[]s are aligned properly (seems to be the case due to Java object headers) and 2) no native-side pointers exist pointing inside the hash function state structure. Since the latter is currently true and changing it would break the openssl ABI we should be safe. By doing this hack, then, we avoid malloc/free overheads as well as Java finalizer overhead, and can avoid a native call for initializing the hash function (by instead cloning a copy of the initial state of the hash function).

Constructor Summary

Constructors

Constructor	Description
MD5Spi()

Method Summary

Modifier and Type	Method	Description
java.lang.Object	clone()
protected byte[]	engineDigest()
protected int	engineDigest(byte[] buf, int offset, int len)
protected int	engineGetDigestLength()
protected void	engineReset()
protected void	engineUpdate(byte input)
protected void	engineUpdate(byte[] input, int offset, int length)
protected void	engineUpdate(java.nio.ByteBuffer buf)

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MD5Spi

public MD5Spi()

Method Detail

engineUpdate

protected void engineUpdate(byte input)

Specified by:

engineUpdate in class java.security.MessageDigestSpi

engineUpdate

protected void engineUpdate(byte[] input,
                            int offset,
                            int length)

Specified by:

engineUpdate in class java.security.MessageDigestSpi

engineUpdate

protected void engineUpdate(java.nio.ByteBuffer buf)

Overrides:

engineUpdate in class java.security.MessageDigestSpi

engineGetDigestLength

protected int engineGetDigestLength()

Overrides:

engineGetDigestLength in class java.security.MessageDigestSpi

clone

public java.lang.Object clone()

Overrides:

clone in class java.security.MessageDigestSpi

engineDigest

protected byte[] engineDigest()

Specified by:

engineDigest in class java.security.MessageDigestSpi

engineDigest

protected int engineDigest(byte[] buf,
                           int offset,
                           int len)
                    throws java.security.DigestException

Overrides:

engineDigest in class java.security.MessageDigestSpi

Throws:

java.security.DigestException

engineReset

protected void engineReset()

Specified by:

engineReset in class java.security.MessageDigestSpi