Package org.snmp4j.security

Class PrivDES

java.lang.Object
org.snmp4j.security.PrivacyGeneric
org.snmp4j.security.PrivDES
All Implemented Interfaces:
Serializable, PrivacyProtocol, SecurityProtocol
public class PrivDES extends PrivacyGeneric
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:

  • Field Details

    • ID

      public static final OID ID
      Unique ID of this privacy protocol.

    • salt

      protected org.snmp4j.security.Salt salt

  • Constructor Details

    • PrivDES

      public PrivDES()

  • Method Details

    • 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 the unencryptedData where to start encryption.
      length - the length of the substring starting at offset 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.

    • 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 into cryptedData 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.

    • getID

      public OID getID()
      Gets the OID uniquely identifying the privacy protocol.
      Returns:
      an OID instance.

    • 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 interface SecurityProtocol
      Overrides:
      isSupported in class PrivacyGeneric
      Returns:
      true if this security protocol is supported, false otherwise.

    • 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.

    • 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.

    • 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.

    • 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.

    • 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 using AuthenticationProtocol.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.