Generate Mac For Key And Value Java

  • Mar 03, 2020  The service uses the device public key (uploaded before the JWT is sent) to verify the device's identity. Cloud IoT Core supports the RSA and Elliptic Curve algorithms. For details on key formats, see Public key format. Generating an RSA key. You can generate a 2048-bit RSA key pair with the following commands.
  • Jul 04, 2019 To generate UUID in Java we can use the java.util.UUID class. This class was introduced in JDK 1.5. The UUID.randomUUID method return a UUID object. To obtain the value of the random string generated we need to call the UUID.toString method.
  • Java Cryptography - Creating a MAC - MAC (Message Authentication Code) algorithm is a symmetric key cryptographic technique to provide message authentication. For establishing MAC process, the send. Generate key using generateKey method of the KeyGenerator class as shown below.
  • To generate a new public/private key pair in a Java keystore. Use the -genkeypair option to generate a key and save it to a Java keystore (newkeystore.jks in this example). The example shown here prompts you to enter values for items that make up the distinguished name (DN) in the certificate.
  • Key generators are constructed using one of the getInstance class methods of this class. KeyGenerator objects are reusable, i.e., after a key has been generated, the same KeyGenerator object can be re-used to generate further keys. There are two ways to generate a key: in an algorithm-independent manner, and in an algorithm-specific manner.

The Java KeyGenerator class (javax.crypto.KeyGenerator) is used to generate symmetric encryption keys. A symmetric encryption key is a key that is used for both encryption and decryption of data, by a symmetric encryption algorithm. In this Java KeyGenerator tutorial I will show you how to generate symmetric encryption keys.

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Creating a KeyGenerator Instance

Generate public key mac openssl. Before you can use the Java KeyGenerator class you must create a KeyGenerator instance. You create a KeyGenerator instance by calling the static method getInstance() passing as parameter the name of the encryption algorithm to create a key for. Here is an example of creating a Java KeyGenerator instance:

This example creates a KeyGenerator instance which can generate keys for the AES encryption algorithm.

Initializing the KeyGenerator

After creating the KeyGenerator instance you must initialize it. Initializing a KeyGenerator instance is done by calling its init() method. Here is an example of initializing a KeyGenerator instance:

The KeyGeneratorinit() method takes two parameters: The bit size of the keys to generate, and a SecureRandom that is used during key generation.

Generating a Key

Once the Java KeyGenerator instance is initialized you can use it to generate keys. Generating a key is done by calling the KeyGeneratorgenerateKey() method. Here is an example of generating a symmetric key:

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  • Class

Generate Mac For Key And Value Java Software

Class Mac

    • javax.crypto.Mac
  • All Implemented Interfaces:
    Cloneable

    This class provides the functionality of a 'Message Authentication Code' (MAC) algorithm.

    A MAC provides a way to check the integrity of information transmitted over or stored in an unreliable medium, based on a secret key. Typically, message authentication codes are used between two parties that share a secret key in order to validate information transmitted between these parties.

    A MAC mechanism that is based on cryptographic hash functions is referred to as HMAC. HMAC can be used with any cryptographic hash function, e.g., SHA256 or SHA384, in combination with a secret shared key. HMAC is specified in RFC 2104.

    Every implementation of the Java platform is required to support the following standard Mac algorithms:

    • HmacMD5
    • HmacSHA1
    • HmacSHA256
    These algorithms are described in the Mac section of the Java Cryptography Architecture Standard Algorithm Name Documentation. Consult the release documentation for your implementation to see if any other algorithms are supported.
    Since:
    1.4

Java Key Value List

    • Constructor Summary

      Constructors
      ModifierConstructor and Description
      protected Mac(MacSpi macSpi, Provider provider, String algorithm)
    • Method Summary

      Methods
      Modifier and TypeMethod and Description
      Objectclone()
      Returns a clone if the provider implementation is cloneable.
      byte[]doFinal()
      byte[]doFinal(byte[] input)
      Processes the given array of bytes and finishes the MAC operation.
      voiddoFinal(byte[] output, int outOffset)
      StringgetAlgorithm()
      Returns the algorithm name of this Mac object.
      static MacgetInstance(String algorithm)
      Returns a Mac object that implements the specified MAC algorithm.
      static MacgetInstance(String algorithm, Provider provider)
      Returns a Mac object that implements the specified MAC algorithm.
      static MacgetInstance(String algorithm, String provider)
      Returns a Mac object that implements the specified MAC algorithm.
      intgetMacLength()
      ProvidergetProvider()
      Returns the provider of this Mac object.
      voidinit(Key key)
      voidinit(Key key, AlgorithmParameterSpec params)
      Initializes this Mac object with the given key and algorithm parameters.
      voidreset()
      voidupdate(byte input)
      Processes the given byte.
      voidupdate(byte[] input)
      voidupdate(byte[] input, int offset, int len)
      Processes the first len bytes in input, starting at offset inclusive.
      voidupdate(ByteBuffer input)
      Processes input.remaining() bytes in the ByteBuffer input, starting at input.position().
      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • Mac

        Parameters:
        macSpi - the delegate
        provider - the provider
        algorithm - the algorithm
    • Method Detail

      • getAlgorithm

        Returns the algorithm name of this Mac object.

        This is the same name that was specified in one of the getInstance calls that created this Mac object.

        Returns:
        the algorithm name of this Mac object.
      • getInstance

        Returns a Mac object that implements the specified MAC algorithm.

        This method traverses the list of registered security Providers, starting with the most preferred Provider. A new Mac object encapsulating the MacSpi implementation from the first Provider that supports the specified algorithm is returned.

        Note that the list of registered providers may be retrieved via the Security.getProviders() method.

        Parameters:
        algorithm - the standard name of the requested MAC algorithm. See the Mac section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
        Returns:
        the new Mac object.
        Throws:
        NoSuchAlgorithmException - if no Provider supports a MacSpi implementation for the specified algorithm.
        See Also:
        Provider
      • getInstance

        Returns a Mac object that implements the specified MAC algorithm.

        A new Mac object encapsulating the MacSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.

        Note that the list of registered providers may be retrieved via the Security.getProviders() method.

        Parameters:
        algorithm - the standard name of the requested MAC algorithm. See the Mac section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
        provider - the name of the provider.
        Returns:
        the new Mac object.
        Throws:
        NoSuchAlgorithmException - if a MacSpi implementation for the specified algorithm is not available from the specified provider.
        NoSuchProviderException - if the specified provider is not registered in the security provider list.
        IllegalArgumentException - if the provider is null or empty.
        See Also:
        Provider
      • getInstance

        Returns a Mac object that implements the specified MAC algorithm.

        A new Mac object encapsulating the MacSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.

        Parameters:
        algorithm - the standard name of the requested MAC algorithm. See the Mac section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
        provider - the provider.
        Returns:
        the new Mac object.
        Throws:
        NoSuchAlgorithmException - if a MacSpi implementation for the specified algorithm is not available from the specified Provider object.
        IllegalArgumentException - if the provider is null.
        See Also:
        Provider
      • getProvider

        Returns:
        the provider of this Mac object.
      • getMacLength

        Returns the length of the MAC in bytes.
        Returns:
        the MAC length in bytes.
      • init

        Parameters:
        key - the key.
        Throws:
        InvalidKeyException - if the given key is inappropriate for initializing this MAC.
      • init

        Initializes this Mac object with the given key and algorithm parameters.
        Parameters:
        key - the key.
        params - the algorithm parameters.
        Throws:
        InvalidKeyException - if the given key is inappropriate for initializing this MAC.
        InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this MAC.
      • update

        Parameters:
        input - the input byte to be processed.
        Throws:
        IllegalStateException - if this Mac has not been initialized.
      • update

        Processes the given array of bytes.
        Parameters:
        input - the array of bytes to be processed.
        Throws:
        IllegalStateException - if this Mac has not been initialized.
      • update

        Processes the first len bytes in input, starting at offset inclusive.
        Parameters:
        input - the input buffer.
        offset - the offset in input where the input starts.
        len - the number of bytes to process.
        Throws:
        IllegalStateException - if this Mac has not been initialized.
      • update

        Processes input.remaining() bytes in the ByteBuffer input, starting at input.position(). Upon return, the buffer's position will be equal to its limit; its limit will not have changed.
        Parameters:
        input - the ByteBuffer
        Throws:
        IllegalStateException - if this Mac has not been initialized.
        Since:
        1.5
      • doFinal

        Finishes the MAC operation.

        A call to this method resets this Mac object to the state it was in when previously initialized via a call to init(Key) or init(Key, AlgorithmParameterSpec). That is, the object is reset and available to generate another MAC from the same key, if desired, via new calls to update and doFinal. (In order to reuse this Mac object with a different key, it must be reinitialized via a call to init(Key) or init(Key, AlgorithmParameterSpec).

        Returns:
        the MAC result.
        Throws:
        IllegalStateException - if this Mac has not been initialized.
      • doFinal

        Finishes the MAC operation.

        A call to this method resets this Mac object to the state it was in when previously initialized via a call to init(Key) or init(Key, AlgorithmParameterSpec). That is, the object is reset and available to generate another MAC from the same key, if desired, via new calls to update and doFinal. (In order to reuse this Mac object with a different key, it must be reinitialized via a call to init(Key) or init(Key, AlgorithmParameterSpec).

        The MAC result is stored in output, starting at outOffset inclusive.

        Parameters:
        output - the buffer where the MAC result is stored
        outOffset - the offset in output where the MAC is stored
        Throws:
        ShortBufferException - if the given output buffer is too small to hold the result
        IllegalStateException - if this Mac has not been initialized.
      • doFinal

        Processes the given array of bytes and finishes the MAC operation.

        A call to this method resets this Mac object to the state it was in when previously initialized via a call to init(Key) or init(Key, AlgorithmParameterSpec). That is, the object is reset and available to generate another MAC from the same key, if desired, via new calls to update and doFinal. (In order to reuse this Mac object with a different key, it must be reinitialized via a call to init(Key) or init(Key, AlgorithmParameterSpec). Crusader kings 2 key generator.

        Parameters:
        input - data in bytes
        Returns:
        the MAC result.
        Throws:
        IllegalStateException - if this Mac has not been initialized.
      • reset

        Resets this Mac object.

        A call to this method resets this Mac object to the state it was in when previously initialized via a call to init(Key) or init(Key, AlgorithmParameterSpec). That is, the object is reset and available to generate another MAC from the same key, if desired, via new calls to update and doFinal. (In order to reuse this Mac object with a different key, it must be reinitialized via a call to init(Key) or init(Key, AlgorithmParameterSpec).

      • clone

        Returns a clone if the provider implementation is cloneable.
        Overrides:
        clone in class Object
        Returns:
        a clone if the provider implementation is cloneable.
        Throws:
        CloneNotSupportedException - if this is called on a delegate that does not support Cloneable.
        See Also:
        Cloneable
  • Class
  • Summary:
  • Nested
  • Field
  • Constr
  • Detail:
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