org.snmp4j.security

Interface PrivacyProtocol

All Superinterfaces:

SecurityProtocol, Serializable

All Known Implementing Classes:

Priv3DES, PrivAES, PrivAES128, PrivAES192, PrivAES192With3DESKeyExtension, PrivAES256, PrivAES256With3DESKeyExtension, PrivAESWith3DESKeyExtension, PrivDES

public interface PrivacyProtocol
extends SecurityProtocol

The PrivacyProtocol interface defines a common interface for all SNMP privacy protocols.

Version:

1.9

Author:

Jochen Katz & Frank Fock

Method Summary

Methods

Modifier and Type	Method and Description
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.
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	getDecryptParamsLength() 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.
OID	getID() Gets the OID uniquely identifying the privacy protocol.
int	getMaxKeyLength() Gets the maximum key size for this privacy protcol.
int	getMinKeyLength() Gets the minimum key size for this privacy protcol.

Method Detail

encrypt

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.

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

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 crypted data. This byte array may contain leading and trailing bytes that will not be decrypted.

offset - the offset into the cryptedData where to start encryption.

length - the length of the substring starting at offset to decrypt.

decryptionKey - the key to be used for decryption.

engineBoots - the engine boots counter to use.

engineTime - the engine time to use.

decryptParams - contains the decryption parameters.

Returns:

the decrypted data, or null if decryption failed.

getID

OID getID()

Gets the OID uniquely identifying the privacy protocol.

Specified by:

getID in interface SecurityProtocol

Returns:

an OID instance.

getEncryptedLength

int getEncryptedLength(int scopedPDULength)

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

int getMinKeyLength()

Gets the minimum key size for this privacy protcol.

Returns:

the minimum key size for this privacy protcol.

getMaxKeyLength

int getMaxKeyLength()

Gets the maximum key size for this privacy protcol.

Returns:

the minimum key size for this privacy protcol.

getDecryptParamsLength

int getDecryptParamsLength()

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.

extendShortKey

byte[] extendShortKey(byte[] shortKey,
                    OctetString password,
                    byte[] engineID,
                    AuthenticationProtocol authProtocol)

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.

Since:

1.9