java.lang.Object
javax.crypto.spec.DESKeySpec
- All Implemented Interfaces:
KeySpec
This class specifies a DES key.
- Since:
- 1.4
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Field Summary
Modifier and TypeFieldDescriptionstatic final int
The constant which defines the length of a DES key in bytes. -
Constructor Summary
ConstructorDescriptionDESKeySpec
(byte[] key) Creates a DESKeySpec object using the first 8 bytes inkey
as the key material for the DES key.DESKeySpec
(byte[] key, int offset) Creates a DESKeySpec object using the first 8 bytes inkey
, beginning atoffset
inclusive, as the key material for the DES key. -
Method Summary
Modifier and TypeMethodDescriptionbyte[]
getKey()
Returns the DES key material.static boolean
isParityAdjusted
(byte[] key, int offset) Checks if the given DES key material, starting atoffset
inclusive, is parity-adjusted.static boolean
isWeak
(byte[] key, int offset) Checks if the given DES key material is weak or semi-weak.
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Field Details
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DES_KEY_LEN
public static final int DES_KEY_LENThe constant which defines the length of a DES key in bytes.- See Also:
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Constructor Details
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DESKeySpec
Creates a DESKeySpec object using the first 8 bytes inkey
as the key material for the DES key.The bytes that constitute the DES key are those between
key[0]
andkey[7]
inclusive.- Parameters:
key
- the buffer with the DES key material. The first 8 bytes of the buffer are copied to protect against subsequent modification.- Throws:
NullPointerException
- if the given key material isnull
InvalidKeyException
- if the given key material is shorter than 8 bytes.
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DESKeySpec
Creates a DESKeySpec object using the first 8 bytes inkey
, beginning atoffset
inclusive, as the key material for the DES key.The bytes that constitute the DES key are those between
key[offset]
andkey[offset+7]
inclusive.- Parameters:
key
- the buffer with the DES key material. The first 8 bytes of the buffer beginning atoffset
inclusive are copied to protect against subsequent modification.offset
- the offset inkey
, where the DES key material starts.- Throws:
NullPointerException
- if the given key material isnull
InvalidKeyException
- if the given key material, starting atoffset
inclusive, is shorter than 8 bytes.
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Method Details
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getKey
public byte[] getKey()Returns the DES key material.- Returns:
- the DES key material. Returns a new array each time this method is called.
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isParityAdjusted
Checks if the given DES key material, starting atoffset
inclusive, is parity-adjusted.- Parameters:
key
- the buffer with the DES key material.offset
- the offset inkey
, where the DES key material starts.- Returns:
- true if the given DES key material is parity-adjusted, false otherwise.
- Throws:
InvalidKeyException
- if the given key material isnull
, or starting atoffset
inclusive, is shorter than 8 bytes.
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isWeak
Checks if the given DES key material is weak or semi-weak.- Parameters:
key
- the buffer with the DES key material.offset
- the offset inkey
, where the DES key material starts.- Returns:
- true if the given DES key material is weak or semi-weak, false otherwise.
- Throws:
InvalidKeyException
- if the given key material isnull
, or starting atoffset
inclusive, is shorter than 8 bytes.
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