**javacard.security** 
 ====Interface DESKey  ====

**All Superinterfaces:** [[javacard:java-card-api:Key|Key]] , [[javacard:java-card-api:SecretKey|SecretKey]]  
 



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  *[[javacard:java-card-api:secretkey|SecretKey]] \\ 




DESKey contains an 8/16/24-byte key for single/2 key triple DES/3 key triple DES
 operations.
 When the key data is set, the key is initialized and ready for use.





**See Also:**[[javacard:java-card-api:KeyBuilder|KeyBuilder]] , 
[[javacard:java-card-api:Signature|Signature]] , 
[[javacard:java-card-api:Cipher|javacardx.crypto.Cipher]] , 
[[javacard:java-card-api:KeyEncryption|javacardx.crypto.KeyEncryption]]  
 


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^ Method Summary ^^ 
| ** byte** | **[[javacard:java-card-api:DESKey#getKey(byte[], short)|getKey]] **(byte[] keyData,short kOff)          Returns the Key data in plain text. |
| ** void** | **[[javacard:java-card-api:DESKey#setKey(byte[], short)|setKey]] **(byte[] keyData,short kOff)          Sets the Key data. |

 

^ Methods inherited from interface javacard.security.Key ^ 
| [[javacard:java-card-api:Key#clearKey()|clearKey]] , [[javacard:java-card-api:Key#getSize()|getSize]] , [[javacard:java-card-api:Key#getType()|getType]] , [[javacard:java-card-api:Key#isInitialized()|isInitialized]]  |

 






^ Method Detail ^ 



 === setKey === 
void **setKey**(byte[] keyData,
short kOff)
throws [[javacard:java-card-api:CryptoException|CryptoException]] ,
[[javacard:java-card-api:NullPointerException|NullPointerException]] ,
[[javacard:java-card-api:ArrayIndexOutOfBoundsException|ArrayIndexOutOfBoundsException]] 

Sets the Key data. The plain text length of input key data is 8 bytes for DES,
 16 bytes for 2-key triple DES and 24 bytes for 3-key triple DES.
 The data format is big-endian and right-aligned (the least significant bit is the least significant
 bit of last byte). Input key data is copied into the internal representation.
 Note:
 \\ 
 
  *//If the key object implements the //javacardx.crypto.KeyEncryption// interface and the //Cipher// object specified via //setKeyCipher()// is not //null//, //keyData// is decrypted using the //Cipher// object.// 
 \\  

 
 


 
 


**Parameters:**keyData - byte array containing key initialization data 
 
kOff - offset within keyData to start
 
 
**Throws:**
[[javacard:java-card-api:CryptoException|CryptoException]]  - with the following reason code:
 \\ 
 
  *CryptoException.ILLEGAL_VALUE if input data decryption is required and fails.
 \\  
 
 
[[javacard:java-card-api:ArrayIndexOutOfBoundsException|ArrayIndexOutOfBoundsException]]  - if kOff is negative
 or the keyData array is too short
 
 
[[javacard:java-card-api:NullPointerException|NullPointerException]]  - if the keyData parameter is null 
 

 
 



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 === getKey === 
byte **getKey**(byte[] keyData,
short kOff)

Returns the Key data in plain text. The length of output key data is 8 bytes for DES,
 16 bytes for 2-key triple DES and 24 bytes for 3-key triple DES.
 The data format is big-endian and right-aligned (the least significant bit is the least significant
 bit of last byte).

 
 


 
 


**Parameters:**keyData - byte array to return key data 
 
kOff - offset within keyData to start
 
 
**Returns:**the byte length of the key data returned
 
 
**Throws:**
[[javacard:java-card-api:CryptoException|CryptoException]]  - with the following reason code:
 \\ 
 
  *CryptoException.UNINITIALIZED_KEY if the key data has not been successfully initialized since the time the initialized state of the key was set to false. 
 \\   
 
**See Also:**[[javacard:java-card-api:Key|Key]]