- java.lang.Object
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- javax.crypto.spec.SecretKeySpec
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- 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
SecretKeyfrom 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
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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 firstlenbytes ofkey, starting atoffsetinclusive.SecretKeySpec(byte[] key, String algorithm)Constructs a secret key from the given byte array.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description booleanequals(Object obj)Tests for equality between the specified object and this object.StringgetAlgorithm()Returns the name of the algorithm associated with this secret key.byte[]getEncoded()Returns the key material of this secret key.StringgetFormat()Returns the name of the encoding format for this secret key.inthashCode()Calculates a hash code value for the object.-
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
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Methods declared in interface javax.security.auth.Destroyable
destroy, isDestroyed
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Constructor Detail
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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
keyis 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- ifalgorithmis null orkeyis null or empty.
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SecretKeySpec
public SecretKeySpec(byte[] key, int offset, int len, String algorithm)Constructs a secret key from the given byte array, using the firstlenbytes ofkey, starting atoffsetinclusive.The bytes that constitute the secret key are those between
key[offset]andkey[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
keyis 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 firstlenbytes of the array beginning atoffsetinclusive are copied to protect against subsequent modification.offset- the offset inkeywhere 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- ifalgorithmis null orkeyis null, empty, or too short, i.e.key.length-offset<len.ArrayIndexOutOfBoundsException- is thrown ifoffsetorlenindex bytes outside thekey.
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Method Detail
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getAlgorithm
public String getAlgorithm()
Returns the name of the algorithm associated with this secret key.- Specified by:
getAlgorithmin interfaceKey- Returns:
- the secret key algorithm.
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getFormat
public String getFormat()
Returns the name of the encoding format for this secret key.
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getEncoded
public byte[] getEncoded()
Returns the key material of this secret key.- Specified by:
getEncodedin interfaceKey- Returns:
- the key material. Returns a new array each time this method is called.
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hashCode
public int hashCode()
Calculates a hash code value for the object. Objects that are equal will also have the same hashcode.- Overrides:
hashCodein classObject- Returns:
- the receiver's hash.
- See Also:
Object.equals(java.lang.Object)
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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:
equalsin classObject- Parameters:
obj- the object to test for equality with this object.- Returns:
- true if the objects are considered equal, false if
objis null or otherwise. - See Also:
Object.hashCode()
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