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:

  • 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:

    • 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: