hmackey
javacard.security
Interface HMACKey
All Superinterfaces: Key , SecretKey
HMACKey contains a key for HMAC operations. This key can be of any length, but it is strongly recommended that the key is not shorter than the byte length of the hash output used in the HMAC implementation. Keys with length greater than the hash block length are first hashed with the hash algorithm used for the HMAC implementation.Implementations must support an HMAC key length equal to the length of the supported hash algorithm block size (e.g 64 bits for SHA-1) When the key data is set, the key is initialized and ready for use.
Since:
2.2.2
See Also:KeyBuilder ,Signature ,javacardx.crypto.Cipher ,javacardx.crypto.KeyEncryption
Method Summary | |
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byte | getKey (byte[] keyData,short kOff) Returns the Key data in plain text. |
void | setKey (byte[] keyData,short kOff,short kLen) Sets the Key data. |
Methods inherited from interface javacard.security.Key |
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clearKey , getSize , getType , isInitialized |
Method Detail |
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setKey
void setKey(byte[] keyData, short kOff, short kLen) throws CryptoException , NullPointerException , ArrayIndexOutOfBoundsException
Sets the Key data.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
kLen - the byte length of the key initialization data
Throws: CryptoException- with the following reason code:
- CryptoException.ILLEGAL_VALUE if input data decryption is required and fails.
ArrayIndexOutOfBoundsException- if kOff is negative or the keyData array is too short
NullPointerException- if the keyData parameter is null
getKey
byte getKey(byte[] keyData, short kOff)
Returns the Key data in plain text. The key can be any length, but should be longer than the byte length of the hash algorithm output used. 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: 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:Key