java.lang.Object
- javacard.security.MessageDigest

Direct Known Subclasses:

InitializedMessageDigest, MessageDigest.OneShot
```
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.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`MessageDigest.OneShot`	The `OneShot` class is a specialization of the `MessageDigest` class intended to support efficient one-shot hash operations that may avoid persistent memory writes entirely.

Field Summary

Fields
Modifier and Type	Field	Description
`static byte`	`ALG_MD5`	Message Digest algorithm MD5.
`static byte`	`ALG_NULL`	This constant indicates that there is no discrete message digest algorithm.
`static byte`	`ALG_RIPEMD160`	Message Digest algorithm RIPE MD-160.
`static byte`	`ALG_SHA`	Message Digest algorithm SHA-1.
`static byte`	`ALG_SHA_224`	Message Digest algorithm SHA-224.
`static byte`	`ALG_SHA_256`	Message Digest algorithm SHA-256.
`static byte`	`ALG_SHA_384`	Message Digest algorithm SHA-384.
`static byte`	`ALG_SHA_512`	Message Digest algorithm SHA-512.
`static byte`	`ALG_SHA3_224`	Message Digest algorithm SHA3-224.
`static byte`	`ALG_SHA3_256`	Message Digest algorithm SHA3-256.
`static byte`	`ALG_SHA3_384`	Message Digest algorithm SHA3-384.
`static byte`	`ALG_SHA3_512`	Message Digest algorithm SHA3-512.
`static byte`	`ALG_SM3`	Message Digest algorithm SM3.
`static byte`	`LENGTH_MD5`	Length of digest in bytes for MD5
`static byte`	`LENGTH_RIPEMD160`	Length of digest in bytes for RIPE MD-160
`static byte`	`LENGTH_SHA`	Length of digest in bytes for SHA-1
`static byte`	`LENGTH_SHA_224`	Length of digest in bytes for SHA-224
`static byte`	`LENGTH_SHA_256`	Length of digest in bytes for SHA-256
`static byte`	`LENGTH_SHA_384`	Length of digest in bytes for SHA-384
`static byte`	`LENGTH_SHA_512`	Length of digest in bytes for SHA-512
`static byte`	`LENGTH_SHA3_224`	Length of digest in bytes for SHA3-224
`static byte`	`LENGTH_SHA3_256`	Length of digest in bytes for SHA3-256
`static byte`	`LENGTH_SHA3_384`	Length of digest in bytes for SHA3-384
`static byte`	`LENGTH_SHA3_512`	Length of digest in bytes for SHA3-512
`static byte`	`LENGTH_SM3`	Length of digest in bytes for SM3

Constructor Summary

Constructors
Modifier Constructor Description

protected MessageDigest()
Protected Constructor

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract short`	`doFinal(byte[] inBuff, short inOffset, short inLength, byte[] outBuff, short outOffset)`	Generates a hash of all/last input data.
`abstract short`	`doIntermediateMessageDigest(byte[] outBuff, short outOffset)`	Generates a hash of all/last input data.
`abstract byte`	`getAlgorithm()`	Gets the Message digest algorithm.
`static InitializedMessageDigest`	`getInitializedMessageDigestInstance(byte algorithm, boolean externalAccess)`	Creates a `InitializedMessageDigest` object instance of the selected algorithm.
`static MessageDigest`	`getInstance(byte algorithm, boolean externalAccess)`	Creates a `MessageDigest` object instance of the selected algorithm.
`abstract byte`	`getLength()`	Returns the byte length of the hash.
`static boolean`	`isIntermediateMessageDigestSupported(byte algorithm)`	This method is used to determine if instances of MessageDigest or InitializedMessageDigest classes support intermediate hash calculation for a given algorithm.
`abstract void`	`reset()`	Resets the `MessageDigest` object to the initial state for further use.
`abstract void`	`update(byte[] inBuff, short inOffset, short inLength)`	Accumulates a hash of the input data.

Methods inherited from class java.lang.Object
equals

- Field Detail
  - ALG_NULL
```
public static final byte ALG_NULL
```
    This constant indicates that there is no discrete message digest algorithm. It is intended for use in the Signature.getInstance(byte, byte, byte, boolean) method.
    If this constant in used in the getInstance(byte, boolean) it results in a CryptoException.
    
    See Also:
    
    Constant Field Values
  - ALG_SHA
```
public static final byte ALG_SHA
```
    Message Digest algorithm SHA-1. The block size used by this algorithm is 64 bytes. The intermediate state of a SHA-1 hash is a sequence of 20 bytes representing the concatenation of the five 32-bit words of the intermediate hash value H(i) (section 6.1.2 of FIPS180-4) converted to a hex string (section 3.1 of FIPS180-4).
    
    See Also:
    
    Constant Field Values
  - ALG_MD5
```
public static final byte ALG_MD5
```
    Message Digest algorithm MD5. The block size used by this algorithm is 64 bytes. The intermediate state size used by this algorithm is 16 bytes.
    
    See Also:
    
    Constant Field Values
  - ALG_RIPEMD160
```
public static final byte ALG_RIPEMD160
```
    Message Digest algorithm RIPE MD-160. The block size used by this algorithm is 64 bytes. The intermediate state size used by this algorithm is 20 bytes.
    
    See Also:
    
    Constant Field Values
  - ALG_SHA_256
```
public static final byte ALG_SHA_256
```
    Message Digest algorithm SHA-256. The block size used by this algorithm is 64 bytes. The intermediate state of a SHA-256 hash is a sequence of 32 bytes representing the concatenation of the 8 words of 32-bit of the intermediate hash value H(i) (section 6.2.2 of FIPS180-4) converted to a hex string (section 3.1 of FIPS180-4).
    
    See Also:
    
    Constant Field Values
  - ALG_SHA_384
```
public static final byte ALG_SHA_384
```
    Message Digest algorithm SHA-384. The block size used by this algorithm is 128 bytes. The intermediate state of a SHA-384 hash is a sequence of 64 bytes representing the concatenation of the 8 words of 64-bit of the intermediate hash value H(i) (section 6.4.2 of FIPS180-4) converted to a hex string (section 3.1 of FIPS180-4).
    
    See Also:
    
    Constant Field Values
  - ALG_SHA_512
```
public static final byte ALG_SHA_512
```
    Message Digest algorithm SHA-512. The block size used by this algorithm is 128 bytes. The intermediate state of a SHA-512 hash is a sequence of 64 bytes representing the concatenation of the 8 words of 64-bit of the intermediate hash value H(i) (section 6.4.2 of FIPS180-4) converted to a hex string (section 3.1 of FIPS180-4).
    
    See Also:
    
    Constant Field Values
  - ALG_SHA_224
```
public static final byte ALG_SHA_224
```
    Message Digest algorithm SHA-224. The block size used by this algorithm is 64 bytes. The intermediate state of a SHA-224 hash is a sequence of 32 bytes representing the concatenation of the 8 words of 32-bit of the intermediate hash value H(i) (section 6.2.2 of FIPS180-4) converted to a hex string (section 3.1 of FIPS180-4).
    
    See Also:
    
    Constant Field Values
  - ALG_SHA3_224
```
public static final byte ALG_SHA3_224
```
    Message Digest algorithm SHA3-224. The block size used by this algorithm is 144 bytes. The intermediate state size used by this algorithm is 200 bytes.
    
    See Also:
    
    Constant Field Values
  - ALG_SHA3_256
```
public static final byte ALG_SHA3_256
```
    Message Digest algorithm SHA3-256. The block size used by this algorithm is 136 bytes. The intermediate state size used by this algorithm is 200 bytes.
    
    See Also:
    
    Constant Field Values
  - ALG_SHA3_384
```
public static final byte ALG_SHA3_384
```
    Message Digest algorithm SHA3-384. The block size used by this algorithm is 104 bytes. The intermediate state size used by this algorithm is 200 bytes.
    
    See Also:
    
    Constant Field Values
  - ALG_SHA3_512
```
public static final byte ALG_SHA3_512
```
    Message Digest algorithm SHA3-512. The block size used by this algorithm is 72 bytes. The intermediate state size used by this algorithm is 200 bytes.
    
    See Also:
    
    Constant Field Values
  - ALG_SM3
```
public static final byte ALG_SM3
```
    Message Digest algorithm SM3. The block size used by this algorithm is 64 bytes (512-bit). The intermediate state size used by this algorithm is 32 bytes.
    
    Since:
    
    3.1
    
    See Also:
    
    Constant Field Values
  - LENGTH_MD5
```
public static final byte LENGTH_MD5
```
    Length of digest in bytes for MD5
    
    See Also:
    
    Constant Field Values
  - LENGTH_RIPEMD160
```
public static final byte LENGTH_RIPEMD160
```
    Length of digest in bytes for RIPE MD-160
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA
```
public static final byte LENGTH_SHA
```
    Length of digest in bytes for SHA-1
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA_224
```
public static final byte LENGTH_SHA_224
```
    Length of digest in bytes for SHA-224
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA_256
```
public static final byte LENGTH_SHA_256
```
    Length of digest in bytes for SHA-256
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA_384
```
public static final byte LENGTH_SHA_384
```
    Length of digest in bytes for SHA-384
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA_512
```
public static final byte LENGTH_SHA_512
```
    Length of digest in bytes for SHA-512
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA3_224
```
public static final byte LENGTH_SHA3_224
```
    Length of digest in bytes for SHA3-224
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA3_256
```
public static final byte LENGTH_SHA3_256
```
    Length of digest in bytes for SHA3-256
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA3_384
```
public static final byte LENGTH_SHA3_384
```
    Length of digest in bytes for SHA3-384
    
    See Also:
    
    Constant Field Values
  - LENGTH_SHA3_512
```
public static final byte LENGTH_SHA3_512
```
    Length of digest in bytes for SHA3-512
    
    See Also:
    
    Constant Field Values
  - LENGTH_SM3
```
public static final byte LENGTH_SM3
```
    Length of digest in bytes for SM3
    
    Since:
    
    3.1
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - MessageDigest
```
protected MessageDigest()
```
    Protected Constructor
- Method Detail
  - getInstance
```
public static final MessageDigest getInstance(byte algorithm,
                                              boolean externalAccess)
                                       throws CryptoException
```
    Creates a MessageDigest object instance of the selected algorithm.
    Note:
    
    To create an InitializedMessageDigest instance, use getInitializedMessageDigestInstance(byte,boolean)
    Parameters:
    
    algorithm - the desired message digest algorithm. Valid codes listed in ALG_* constants above, for example, ALG_SHA.
    
    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. interface) 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 algorithm
    
    Throws:
    
    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, ALG_SHA.
    
    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. interface) 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 algorithm
    
    Throws:
    
    CryptoException - with the following reason codes:
    
    CryptoException.NO_SUCH_ALGORITHM if the requested algorithm or shared access mode is not supported.
    
    Since:
    
    2.2.2
  - isIntermediateMessageDigestSupported
```
public static final boolean isIntermediateMessageDigestSupported(byte algorithm)
```
    This method is used to determine if instances of MessageDigest or InitializedMessageDigest classes support intermediate hash calculation for a given algorithm.
    Notes:
    
    if this method returns true and if a MessageDigest instance or an InitializedMessageDigest instance is created respectively by getInstance(byte, boolean) or getInitializedMessageDigestInstance(byte, boolean) by passing the same algorithm as isIntermediateMessageDigestSupported(byte) as parameter, it implies that the related instance supports intermediate hash calculation.
    
    if this method returns true for a given algorithm it implies that at least one method (it can be both) getInstance(byte, boolean) or getInitializedMessageDigestInstance(byte, boolean) must successfully create respectively a MessageDigest or an InitializedMessageDigest instance by passing the same algorithm as isIntermediateMessageDigestSupported(byte) as parameter.
    
    if this method returns false, it does does not prevent a MessageDigest instance or an InitializedMessageDigest instance from being created by getInstance(byte, boolean) or getInitializedMessageDigestInstance(byte, boolean) by passing the same algorithm as isIntermediateMessageDigestSupported(byte) as parameter but intermediate hash calculation is not supported.
    Parameters:
    
    algorithm - the desired message digest algorithm. Valid codes listed in ALG_* constants above, for example, ALG_SHA.
    
    Returns:
    
    true if intermediate hash is supported, false otherwise
    
    Since:
    
    3.2
    
    See Also:
    
    doIntermediateMessageDigest
  - getAlgorithm
```
public abstract byte getAlgorithm()
```
    Gets the Message digest algorithm.
    
    Returns:
    
    the algorithm code defined above
  - getLength
```
public abstract byte getLength()
```
    Returns the byte length of the hash.
    
    Returns:
    
    hash length
  - doIntermediateMessageDigest
```
public abstract short doIntermediateMessageDigest(byte[] outBuff,
                                                  short outOffset)
                                           throws CryptoException
```
    Generates a hash of all/last input data. Completes and returns the hash computation after performing final operations such as padding. The data format is big-endian. Then, the MessageDigest object has the exact same internal state after the call is made as before the call. Thus, it is possible to continue the hash calculation with the exact same input data as before the call to this method.
    This method can be used for intermediate hash calculation and avoid to start a hash calculation with the same exact first input data.
    In addition to returning a short result, this method sets the result in an internal state which can be rechecked using assertion methods of the SensitiveResult class, if supported by the platform.
    Parameters:
    
    outBuff - the output buffer
    
    outOffset - the offset into the output buffer where the resulting hash value begins
    
    Returns:
    
    number of bytes of hash output in outBuff
    
    Throws:
    
    CryptoException - with the following reason codes:
    
    CryptoException.ILLEGAL_USE if the related MessageDigest or InitializedMessageDigest instance does not support intermediate hash.
    
    Since:
    
    3.2
    
    See Also:
    
    isIntermediateMessageDigestSupported
  - doFinal
```
public abstract short doFinal(byte[] inBuff,
                              short inOffset,
                              short inLength,
                              byte[] outBuff,
                              short outOffset)
                       throws CryptoException
```
    Generates a hash of all/last input data. Completes and returns the hash computation after performing final operations such as padding. The MessageDigest object is reset to the initial state after this call is made. The data format is big-endian.
    The input and output buffer data may overlap.
    In addition to returning a short result, this method sets the result in an internal state which can be rechecked using assertion methods of the SensitiveResult class, if supported by the platform.
    Parameters:
    
    inBuff - the input buffer of data to be hashed
    
    inOffset - the offset into the input buffer at which to begin hash generation
    
    inLength - the byte length to hash
    
    outBuff - the output buffer, may be the same as the input buffer
    
    outOffset - the offset into the output buffer where the resulting hash value begins
    
    Returns:
    
    number of bytes of hash output in outBuff
    
    Throws:
    
    CryptoException - with the following reason codes:
    
    CryptoException.ILLEGAL_USE if the accumulated message length is greater than the maximum length supported by the algorithm.
  - update
```
public abstract void update(byte[] inBuff,
                            short inOffset,
                            short inLength)
                     throws CryptoException
```
    Accumulates a hash of the input data. This method requires temporary storage of intermediate results. In addition, if the input data length is not block aligned (multiple of block size) then additional internal storage may be allocated at this time to store a partial input data block. This may result in additional resource consumption and/or slow performance. This method should only be used if all the input data required for the hash is not available in one byte array. If all of the input data required for the hash is located in a single byte array, use of the doFinal() method is recommended. The doFinal() method must be called to complete processing of input data accumulated by one or more calls to the update() method. The data format is big-endian.
    Note:
    
    If inLength is 0 this method does nothing.
    Parameters:
    
    inBuff - the input buffer of data to be hashed
    
    inOffset - the offset into the input buffer at which to begin hash generation
    
    inLength - the byte length to hash
    
    Throws:
    
    CryptoException - with the following reason codes:
    
    CryptoException.ILLEGAL_USE if the accumulated message length is greater than the maximum length supported by the algorithm.
    
    See Also:
    
    doFinal
  - reset
```
public abstract void reset()
```
    Resets the MessageDigest object to the initial state for further use.

Class MessageDigest

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ALG_NULL

ALG_SHA

ALG_MD5

ALG_RIPEMD160

ALG_SHA_256

ALG_SHA_384

ALG_SHA_512

ALG_SHA_224

ALG_SHA3_224

ALG_SHA3_256

ALG_SHA3_384

ALG_SHA3_512

ALG_SM3

LENGTH_MD5

LENGTH_RIPEMD160

LENGTH_SHA

LENGTH_SHA_224

LENGTH_SHA_256

LENGTH_SHA_384

LENGTH_SHA_512

LENGTH_SHA3_224

LENGTH_SHA3_256

LENGTH_SHA3_384

LENGTH_SHA3_512

LENGTH_SM3

Constructor Detail

MessageDigest

Method Detail

getInstance

getInitializedMessageDigestInstance

isIntermediateMessageDigestSupported

getAlgorithm

getLength

doIntermediateMessageDigest

doFinal

update

reset