Module java.base
Package javax.crypto.spec

Class SecretKeySpec

java.lang.Object
javax.crypto.spec.SecretKeySpec
All Implemented Interfaces:
Serializable, Key, KeySpec, SecretKey, Destroyable
public class SecretKeySpec
extends Object
implements KeySpec, SecretKey
This class specifies a secret key in a provider-independent fashion.

It can be used to construct a SecretKey from a byte array, without having to go through a (provider-based) SecretKeyFactory.

This class is only useful for raw secret keys that can be represented as a byte array and have no key parameters associated with them, e.g., DES or Triple DES keys.

Since:
1.4
See Also:
SecretKey, SecretKeyFactory, Serialized Form

  • Constructor Summary

    Constructors 
    Constructor Description
    SecretKeySpec​(byte[] key, int offset, int len, String algorithm)
    Constructs a secret key from the given byte array, using the first len bytes of key, starting at offset inclusive.
    SecretKeySpec​(byte[] key, String algorithm)
    Constructs a secret key from the given byte array.

  • Method Summary

    Modifier and Type Method Description
    boolean equals​(Object obj)
    Tests for equality between the specified object and this object.
    String getAlgorithm()
    Returns the name of the algorithm associated with this secret key.
    byte[] getEncoded()
    Returns the key material of this secret key.
    String getFormat()
    Returns the name of the encoding format for this secret key.
    int hashCode()
    Calculates a hash code value for the object.

    Methods declared in class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

    Methods declared in interface javax.security.auth.Destroyable

    destroy, isDestroyed

  • Constructor Details

    • SecretKeySpec

      public SecretKeySpec​(byte[] key, String algorithm)
      Constructs a secret key from the given byte array.

      This constructor does not check if the given bytes indeed specify a secret key of the specified algorithm. For example, if the algorithm is DES, this constructor does not check if key is 8 bytes long, and also does not check for weak or semi-weak keys. In order for those checks to be performed, an algorithm-specific key specification class (in this case: DESKeySpec) should be used.

      Parameters:
      key - the key material of the secret key. The contents of the array are copied to protect against subsequent modification.
      algorithm - the name of the secret-key algorithm to be associated with the given key material. See the Java Security Standard Algorithm Names document for information about standard algorithm names.
      Throws:
      IllegalArgumentException - if algorithm is null or key is null or empty.

    • SecretKeySpec

      public SecretKeySpec​(byte[] key, int offset, int len, String algorithm)
      Constructs a secret key from the given byte array, using the first len bytes of key, starting at offset inclusive.

      The bytes that constitute the secret key are those between key[offset] and key[offset+len-1] inclusive.

      This constructor does not check if the given bytes indeed specify a secret key of the specified algorithm. For example, if the algorithm is DES, this constructor does not check if key is 8 bytes long, and also does not check for weak or semi-weak keys. In order for those checks to be performed, an algorithm-specific key specification class (in this case: DESKeySpec) must be used.

      Parameters:
      key - the key material of the secret key. The first len bytes of the array beginning at offset inclusive are copied to protect against subsequent modification.
      offset - the offset in key where the key material starts.
      len - the length of the key material.
      algorithm - the name of the secret-key algorithm to be associated with the given key material. See the Java Security Standard Algorithm Names document for information about standard algorithm names.
      Throws:
      IllegalArgumentException - if algorithm is null or key is null, empty, or too short, i.e. key.length-offset<len.
      ArrayIndexOutOfBoundsException - is thrown if offset or len index bytes outside the key.

  • Method Details

    • getAlgorithm

      public String getAlgorithm()
      Returns the name of the algorithm associated with this secret key.
      Specified by:
      getAlgorithm in interface Key
      Returns:
      the secret key algorithm.

    • getFormat

      public String getFormat()
      Returns the name of the encoding format for this secret key.
      Specified by:
      getFormat in interface Key
      Returns:
      the string "RAW".

    • getEncoded

      public byte[] getEncoded()
      Returns the key material of this secret key.
      Specified by:
      getEncoded in interface Key
      Returns:
      the key material. Returns a new array each time this method is called.

    • hashCode

      public int hashCode()
      Calculates a hash code value for the object. Objects that are equal will also have the same hashcode.
      Overrides:
      hashCode in class Object
      Returns:
      a hash code value for this object.
      See Also:
      Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

    • equals

      public boolean equals​(Object obj)
      Tests for equality between the specified object and this object. Two SecretKeySpec objects are considered equal if they are both SecretKey instances which have the same case-insensitive algorithm name and key encoding.
      Overrides:
      equals in class Object
      Parameters:
      obj - the object to test for equality with this object.
      Returns:
      true if the objects are considered equal, false if obj is null or otherwise.
      See Also:
      Object.hashCode(), HashMap