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
Constructor | Description |
---|---|
SecretKeySpec(byte[] key,
int offset,
int len,
String algorithm) | Constructs a secret key from the given byte array, using the first |
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 Detail
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
- ifalgorithm
is null orkey
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 firstlen
bytes of the array beginning atoffset
inclusive are copied to protect against subsequent modification. -
offset
- the offset inkey
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
- ifalgorithm
is null orkey
is null, empty, or too short, i.e.key.length-offset<len
. -
ArrayIndexOutOfBoundsException
- is thrown ifoffset
orlen
index bytes outside thekey
.
Method Detail
getAlgorithm
public String getAlgorithm()
Returns the name of the algorithm associated with this secret key.
- Specified by:
-
getAlgorithm
in interfaceKey
- Returns:
- the secret key algorithm.
getFormat
public String getFormat()
Returns the name of the encoding format for this secret key.
getEncoded
public byte[] getEncoded()
Returns the key material of this secret key.
- Specified by:
-
getEncoded
in interfaceKey
- 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 classObject
- 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 classObject
- 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