messagedigest_messagedigest序列化_messagedigest 算法

Direct Known Subclasses:

public abstract class MessageDigest
extends Object

The MessageDigest class is the base class for hashing algorithms. Implementations of MessageDigest algorithms must extend this class and implement all the abstract methods.

A tear or card reset event resets a MessageDigest object to the initial state (state upon construction).

Even if a transaction is in progress, update of intermediate result state in the implementation instance shall not participate in the transaction.

Field Summary

Constructor Summary

Method Summary

(byte[]inBuff,shortinOffset,shortinLength,byte[]outBuff,shortoutOffset)

Generates a hash of all/last input data.

Methods inherited from class java.lang.Object

Field Detail

ALG_SHA

public static final byte ALG_SHA

Message Digest algorithm SHA. The block size used by this algorithm is 64 bytes.

See Also:

ALG_MD5

public static final byte ALG_MD5

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ALG_RIPEMD160

public static final byte ALG_RIPEMD160

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ALG_SHA_256

public static final byte ALG_SHA_256

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ALG_SHA_384

public static final byte ALG_SHA_384

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ALG_SHA_512

public static final byte ALG_SHA_512

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LENGTH_MD5

public static final byte LENGTH_MD5

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LENGTH_RIPEMD160

public static final byte LENGTH_RIPEMD160

See Also:

LENGTH_SHA

public static final byte LENGTH_SHA

See Also:

LENGTH_SHA_256

public static final byte LENGTH_SHA_256

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LENGTH_SHA_384

public static final byte LENGTH_SHA_384

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LENGTH_SHA_512

public static final byte LENGTH_SHA_512

See Also:

Constructor Detail

MessageDigest

protected MessageDigest()

Method Detail

getInstance

public static final MessageDigest getInstance(byte algorithm,
                                              boolean externalAccess)
                                       throws CryptoException

Parameters:algorithm - the desired message digest algorithm. Valid codes listed in ALG_* constants above, for example, .externalAccess - true indicates that the instance will be shared among multiple applet instances and that the MessageDigest instance will also be accessed (via a Shareable. intece) when the owner of the MessageDigest instance is not the currently selected applet. If true the implementation must not allocate CLEAR_ON_DESELECT transient space for internal data.Returns:the MessageDigest object instance of the requested algorithmThrows:CryptoException - with the following reason codes:

CryptoException.NO_SUCH_ALGORITHM if the requested algorithm or shared access mode is not supported.

getInitializedMessageDigestInstance

public static final InitializedMessageDigest getInitializedMessageDigestInstance(byte algorithm,
                                                                                 boolean externalAccess)
                                                                          throws CryptoException

Creates a InitializedMessageDigest object instance of the selected algorithm.

Parameters:algorithm - the desired message digest algorithm. Valid codes listed in ALG_* constants above, for example, .externalAccess - true indicates that the instance will be shared among multiple applet instances and that the InitializedMessageDigest instance will also be accessed (via a Shareable. intece) when the owner of the InitializedMessageDigest instance is not the currently selected applet. If true the implementation must not allocate CLEAR_ON_DESELECT transient space for internal data.Returns:the InitializedMessageDigest object instance of the requested algorithmThrows:CryptoException - with the following reason codes:

CryptoException.NO_SUCH_ALGORITHM if the requested algorithm or shared access mode is not supported.Since:

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