Module org.snmp4j

Class AuthGeneric

    • Constructor Summary

      Constructors 
      Constructor Description
      AuthGeneric​(java.lang.String protoName, int digestLength)
      Creates an authentication protocol with the specified name (ID) and digest length and using the DEFAULT_AUTHENTICATION_CODE_LENGTH default code length.
      AuthGeneric​(java.lang.String protoName, int digestLength, int authenticationCodeLength)
      Creates an authentication protocol with the specified name (ID) and digest length and using the DEFAULT_AUTHENTICATION_CODE_LENGTH default code length.
      AuthGeneric​(java.lang.String protoName, int digestLength, int authenticationCodeLength, int hmacBlockSize)
      Creates an authentication protocol with the specified name (ID) and digest length and using the DEFAULT_AUTHENTICATION_CODE_LENGTH default code length.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean authenticate​(byte[] authenticationKey, byte[] message, int messageOffset, int messageLength, ByteArrayWindow digest)
      Authenticates an outgoing message.
      byte[] changeDelta​(byte[] oldKey, byte[] newKey, byte[] random)
      Computes the delta digest needed to remotely change an user's authenitcation key.
      int getAuthenticationCodeLength()
      The length of the authentication code (the hashing output length) in octets.
      int getDigestLength()
      Gets the length of the message digest used by this authentication protocol.
      protected java.security.MessageDigest getDigestObject()
      Get a fresh MessageDigest object of the Algorithm specified in the constructor.
      int getMaxKeyLength()
      Get the maximum length of the key in bytes for this security protocol.
      byte[] hash​(byte[] data)
      Generates a hash value for the given data.
      byte[] hash​(byte[] data, int offset, int length)
      Generates a hash value for the given data.
      boolean isAuthentic​(byte[] authenticationKey, byte[] message, int messageOffset, int messageLength, ByteArrayWindow digest)
      Authenticates an incoming message.
      boolean isSupported()
      Checks whether this security protocol is actually supported by this Java runtime environment.
      byte[] passwordToKey​(OctetString passwordString, byte[] engineID)
      Generates the localized key for the given password and engine id.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • HMAC_BLOCK_SIZE

        public static int HMAC_BLOCK_SIZE
      • hmacBlockSize

        protected int hmacBlockSize
    • Constructor Detail

      • AuthGeneric

        public AuthGeneric​(java.lang.String protoName,
                           int digestLength)
        Creates an authentication protocol with the specified name (ID) and digest length and using the DEFAULT_AUTHENTICATION_CODE_LENGTH default code length.
        Parameters:
        protoName - the name (ID) of the authentication protocol. Only names that are supported by the used security provider can be used.
        digestLength - the digest length.
      • AuthGeneric

        public AuthGeneric​(java.lang.String protoName,
                           int digestLength,
                           int authenticationCodeLength)
        Creates an authentication protocol with the specified name (ID) and digest length and using the DEFAULT_AUTHENTICATION_CODE_LENGTH default code length.
        Parameters:
        protoName - the name (ID) of the authentication protocol. Only names that are supported by the used security provider can be used.
        digestLength - the digest length.
        authenticationCodeLength - the length of the hash output (i.e., the authentication code length).
        Since:
        2.4.0
      • AuthGeneric

        public AuthGeneric​(java.lang.String protoName,
                           int digestLength,
                           int authenticationCodeLength,
                           int hmacBlockSize)
        Creates an authentication protocol with the specified name (ID) and digest length and using the DEFAULT_AUTHENTICATION_CODE_LENGTH default code length.
        Parameters:
        protoName - the name (ID) of the authentication protocol. Only names that are supported by the used security provider can be used.
        digestLength - the digest length.
        authenticationCodeLength - the length of the hash output (i.e., the authentication code length).
        hmacBlockSize - the HMAC block size of the authentication protocol.
        Since:
        2.5.4
    • Method Detail

      • getDigestLength

        public int getDigestLength()
        Gets the length of the message digest used by this authentication protocol.
        Specified by:
        getDigestLength in interface AuthenticationProtocol
        Returns:
        the number of octets in the digest.
      • getMaxKeyLength

        public int getMaxKeyLength()
        Description copied from interface: SecurityProtocol
        Get the maximum length of the key in bytes for this security protocol.
        Specified by:
        getMaxKeyLength in interface SecurityProtocol
        Returns:
        the (maximum) length of the security protocols key.
      • getAuthenticationCodeLength

        public int getAuthenticationCodeLength()
        The length of the authentication code (the hashing output length) in octets.
        Specified by:
        getAuthenticationCodeLength in interface AuthenticationProtocol
        Returns:
        the length of the authentication code.
        Since:
        2.4.0
      • getDigestObject

        protected java.security.MessageDigest getDigestObject()
        Get a fresh MessageDigest object of the Algorithm specified in the constructor.
        Returns:
        a new, fresh Message Digest object.
      • 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
        Returns:
        true if this security protocol is supported, false otherwise.
      • authenticate

        public boolean authenticate​(byte[] authenticationKey,
                                    byte[] message,
                                    int messageOffset,
                                    int messageLength,
                                    ByteArrayWindow digest)
        Description copied from interface: AuthenticationProtocol
        Authenticates an outgoing message. This method fills the authentication parameters field of the given message. The parameter digestOffset offset is pointing inside the message buffer and must be zeroed before the authentication value is computed.
        Specified by:
        authenticate in interface AuthenticationProtocol
        Parameters:
        authenticationKey - the authentication key to be used for authenticating the message.
        message - the entire message for which the digest should be determined.
        messageOffset - the offset in message where the message actually starts.
        messageLength - the actual message length (may be smaller than message.length).
        digest - the offset in message where to store the digest.
        Returns:
        true if the message digest has been successfully computed and set, false otherwise.
      • isAuthentic

        public boolean isAuthentic​(byte[] authenticationKey,
                                   byte[] message,
                                   int messageOffset,
                                   int messageLength,
                                   ByteArrayWindow digest)
        Description copied from interface: AuthenticationProtocol
        Authenticates an incoming message. This method checks if the value in the authentication parameters field of the message is valid. The following procedure is used to verify the authenitcation value
        • copy the authentication value to a temp buffer
        • zero the auth field
        • recalculate the authenthication value
        • compare the two authentcation values
        • write back the received authentication value
        Specified by:
        isAuthentic in interface AuthenticationProtocol
        Parameters:
        authenticationKey - the authentication key to be used for authenticating the message.
        message - the entire message for which the digest should be determined.
        messageOffset - the offset in message where the message actually starts.
        messageLength - the actual message length (may be smaller than message.length).
        digest - the digest of the message.
        Returns:
        true if the message is authentic, false otherwise.
      • changeDelta

        public byte[] changeDelta​(byte[] oldKey,
                                  byte[] newKey,
                                  byte[] random)
        Description copied from interface: AuthenticationProtocol
        Computes the delta digest needed to remotely change an user's authenitcation key. The length of the old key (e.g. 16 for MD5, 20 for SHA) must match the length of the new key.
        Specified by:
        changeDelta in interface AuthenticationProtocol
        Parameters:
        oldKey - the old authentication/privacy key.
        newKey - the new authentication/privacy key.
        random - the random 'seed' to be used to produce the digest.
        Returns:
        the byte array representing the delta for key change operations. To obtain the key change value, append this delta to the random array.
      • passwordToKey

        public byte[] passwordToKey​(OctetString passwordString,
                                    byte[] engineID)
        Description copied from interface: AuthenticationProtocol
        Generates the localized key for the given password and engine id.
        Specified by:
        passwordToKey in interface AuthenticationProtocol
        Parameters:
        passwordString - the authentication pass phrase.
        engineID - the engine ID of the authoritative engine.
        Returns:
        the localized authentication key.
      • hash

        public byte[] hash​(byte[] data)
        Description copied from interface: AuthenticationProtocol
        Generates a hash value for the given data.
        Specified by:
        hash in interface AuthenticationProtocol
        Parameters:
        data - the data
        Returns:
        the generated hash.
      • hash

        public byte[] hash​(byte[] data,
                           int offset,
                           int length)
        Description copied from interface: AuthenticationProtocol
        Generates a hash value for the given data.
        Specified by:
        hash in interface AuthenticationProtocol
        Parameters:
        data - the data
        offset - offset into data
        length - length of data to hash
        Returns:
        the generated hash.