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.
SecretKey
, SecretKeyFactory
, Serialized Formpublic 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.
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 Appendix A in the Java Cryptography Architecture Reference Guide for information about standard algorithm names.IllegalArgumentException
- if algorithm
is null or key
is null or empty.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.
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 Appendix A in the Java Cryptography Architecture Reference Guide for information about standard algorithm names.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
.public String getAlgorithm()
Returns the name of the algorithm associated with this secret key.
getAlgorithm
in interface Key
public String getFormat()
Returns the name of the encoding format for this secret key.
public byte[] getEncoded()
Returns the key material of this secret key.
getEncoded
in interface Key
public int hashCode()
Calculates a hash code value for the object. Objects that are equal will also have the same hashcode.
hashCode
in class Object
Object.equals(java.lang.Object)
, System.identityHashCode(java.lang.Object)
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.
equals
in class Object
obj
- the object to test for equality with this object.obj
is null or otherwise.Object.hashCode()
, HashMap
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