- java.lang.Object
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- javax.crypto.spec.DESKeySpec
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Field Summary
Fields Modifier and Type Field Description static intDES_KEY_LENThe constant which defines the length of a DES key in bytes.
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Constructor Summary
Constructors Constructor Description DESKeySpec(byte[] key)Creates a DESKeySpec object using the first 8 bytes inkeyas the key material for the DES key.DESKeySpec(byte[] key, int offset)Creates a DESKeySpec object using the first 8 bytes inkey, beginning atoffsetinclusive, as the key material for the DES key.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description byte[]getKey()Returns the DES key material.static booleanisParityAdjusted(byte[] key, int offset)Checks if the given DES key material, starting atoffsetinclusive, is parity-adjusted.static booleanisWeak(byte[] key, int offset)Checks if the given DES key material is weak or semi-weak.
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Field Detail
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DES_KEY_LEN
public static final int DES_KEY_LEN
The constant which defines the length of a DES key in bytes.- See Also:
- Constant Field Values
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Constructor Detail
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DESKeySpec
public DESKeySpec(byte[] key) throws InvalidKeyExceptionCreates a DESKeySpec object using the first 8 bytes inkeyas 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 isnullInvalidKeyException- if the given key material is shorter than 8 bytes.
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DESKeySpec
public DESKeySpec(byte[] key, int offset) throws InvalidKeyExceptionCreates a DESKeySpec object using the first 8 bytes inkey, beginning atoffsetinclusive, 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 atoffsetinclusive are copied to protect against subsequent modification.offset- the offset inkey, where the DES key material starts.- Throws:
NullPointerException- if the given key material isnullInvalidKeyException- if the given key material, starting atoffsetinclusive, is shorter than 8 bytes.
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Method Detail
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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
public static boolean isParityAdjusted(byte[] key, int offset) throws InvalidKeyExceptionChecks if the given DES key material, starting atoffsetinclusive, 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 atoffsetinclusive, is shorter than 8 bytes.
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isWeak
public static boolean isWeak(byte[] key, int offset) throws InvalidKeyExceptionChecks 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 atoffsetinclusive, is shorter than 8 bytes.
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