java.lang.Object
org.snmp4j.security.PrivacyGeneric
org.snmp4j.security.PrivDES
- All Implemented Interfaces:
Serializable
,PrivacyProtocol
,SecurityProtocol
Privacy protocol class for DES.
This class uses DES in CBC mode to encrypt the data. The protocol is defined in the IETF standard "User-based Security Model (USM) for SNMPv3".
- Version:
- 2.5.0
- Author:
- Jochen Katz
- See Also:
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Field Summary
Modifier and TypeFieldDescriptionstatic final OID
Unique ID of this privacy protocol.protected Salt
Fields inherited from class org.snmp4j.security.PrivacyGeneric
cipherPool, initVectorLength, keyBytes, protocolClass, protocolId
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionbyte[]
decrypt
(byte[] cryptedData, int offset, int length, byte[] decryptionKey, long engineBoots, long engineTime, DecryptParams decryptParams) Decrypts a message using a given decryption key, engine boots count, and engine ID.byte[]
encrypt
(byte[] unencryptedData, int offset, int length, byte[] encryptionKey, long engineBoots, long engineTime, DecryptParams decryptParams) Encrypts a message using a given encryption key, engine boots count, and engine ID.byte[]
extendShortKey
(byte[] shortKey, OctetString password, byte[] engineID, AuthenticationProtocol authProtocol) Extend a localized key that is too short.int
Gets the length of the decryption parameters used by this security protocol.int
getEncryptedLength
(int scopedPDULength) Gets the length of a scoped PDU when encrypted with this security protocol.getID()
Gets the OID uniquely identifying the privacy protocol.int
Gets the maximum key size for this privacy protocol.int
Gets the minimum key size for this privacy protocol.boolean
Checks whether this security protocol is actually supported by this Java runtime environment.Methods inherited from class org.snmp4j.security.PrivacyGeneric
doDecrypt, doFinal, doFinalWithPadding, doInit
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Field Details
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ID
Unique ID of this privacy protocol. -
salt
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Constructor Details
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PrivDES
public PrivDES()
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Method Details
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encrypt
public byte[] encrypt(byte[] unencryptedData, int offset, int length, byte[] encryptionKey, long engineBoots, long engineTime, DecryptParams decryptParams) Description copied from interface:PrivacyProtocol
Encrypts a message using a given encryption key, engine boots count, and engine ID.- Parameters:
unencryptedData
- the unencrypted data. This byte array may contain leading and trailing bytes that will not be encrypted.offset
- the offset into theunencryptedData
where to start encryption.length
- the length of the substring starting atoffset
to encrypt.encryptionKey
- the key to be used for encryption.engineBoots
- the engine boots counter to use.engineTime
- the engine time to use.decryptParams
- returns the decryption parameters needed to decrypt the data that has been encrypted by this method.- Returns:
- the encrypted copy of
unencryptedData
.
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decrypt
public byte[] decrypt(byte[] cryptedData, int offset, int length, byte[] decryptionKey, long engineBoots, long engineTime, DecryptParams decryptParams) Decrypts a message using a given decryption key, engine boots count, and engine ID.- Parameters:
cryptedData
- the data to decrypt.offset
- the offset intocryptedData
to start decryption.length
- the length of the data to decrypt.decryptionKey
- the decryption key.engineBoots
- the engine boots counter.engineTime
- the engine time value.decryptParams
- contains the decryption parameters.- Returns:
- the decrypted data, or
null
if decryption failed.
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getID
Gets the OID uniquely identifying the privacy protocol.- Returns:
- an
OID
instance.
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isSupported
public boolean isSupported()Description copied from interface:SecurityProtocol
Checks whether this security protocol is actually supported by this Java runtime environment.- Specified by:
isSupported
in interfaceSecurityProtocol
- Overrides:
isSupported
in classPrivacyGeneric
- Returns:
true
if this security protocol is supported,false
otherwise.
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getEncryptedLength
public int getEncryptedLength(int scopedPDULength) Description copied from interface:PrivacyProtocol
Gets the length of a scoped PDU when encrypted with this security protocol.- Parameters:
scopedPDULength
- the length of the (unencrypted) scoped PDU.- Returns:
- the length of the encrypted scoped PDU.
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getMinKeyLength
public int getMinKeyLength()Description copied from interface:PrivacyProtocol
Gets the minimum key size for this privacy protocol.- Returns:
- the minimum key size for this privacy protocol.
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getDecryptParamsLength
public int getDecryptParamsLength()Description copied from interface:PrivacyProtocol
Gets the length of the decryption parameters used by this security protocol.- Returns:
- a positive integer denoting the length of decryption parameters returned by this security protocol.
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getMaxKeyLength
public int getMaxKeyLength()Description copied from interface:PrivacyProtocol
Gets the maximum key size for this privacy protocol.- Returns:
- the minimum key size for this privacy protocol.
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extendShortKey
public byte[] extendShortKey(byte[] shortKey, OctetString password, byte[] engineID, AuthenticationProtocol authProtocol) Description copied from interface:PrivacyProtocol
Extend a localized key that is too short. Some privacy protocols require a key that is longer than the key generated by the password-to-key algorithm of the authentication protocol. This function extends a short key to the required length.- Parameters:
shortKey
- the short key that was generated usingAuthenticationProtocol.passwordToKey(org.snmp4j.smi.OctetString, byte[])
function.password
- the password to use for key extension.engineID
- the SNMP engine ID of the authoritative engine.authProtocol
- the authentication protocol that should be used.- Returns:
- the extended key or
shortKey
if no extension is needed.
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