C# Class SnmpSharpNet.PrivacyAES

AES privacy protocol implementation class.

Inheritance: IPrivacyProtocol

Protected Properties

Property	Type	Description
_keyBytes	int
_salt	System.Int64

Method	Description
Decrypt ( byte cryptedData, int offset, int length, byte key, int engineBoots, int engineTime, byte privacyParameters ) : byte[]	Decrypt ScopedPdu BER encoded byte array.
Encrypt ( byte unencryptedData, int offset, int length, byte key, int engineBoots, int engineTime, byte &privacyParameters, IAuthenticationDigest authDigest ) : byte[]	Encrypt ScopedPdu data BER encoded in a byte array.
ExtendShortKey ( byte shortKey, byte password, byte engineID, IAuthenticationDigest authProtocol ) : byte[]	Some protocols support a method to extend the encryption or decryption key when supplied key is too short.
GetEncryptedLength ( int scopedPduLength ) : int	Calculates and returns length of the buffer that is the result of the encryption method.
PasswordToKey ( byte secret, byte engineId, IAuthenticationDigest authProtocol ) : byte[]	Convert privacy password into encryption key using packet authentication hash.
PrivacyAES ( int keyBytes ) : System	Standard constructor.

Method	Description
NextSalt ( ) : System.Int64	Get next salt Int64 value. Used internally to encrypt data.

Decrypt ScopedPdu BER encoded byte array.

public Decrypt ( byte cryptedData, int offset, int length, byte key, int engineBoots, int engineTime, byte privacyParameters ) : byte[]
cryptedData	byte	Encrypted data byte array
offset	int	Offset within the buffer to start decryption process from
length	int	Length of data to decrypt
key	byte	Decryption key
engineBoots	int	Authoritative engine boots value. Retrieved as part of SNMP v3 discovery procedure
engineTime	int	Authoritative engine time value. Retrieved as part of SNMP v3 discovery procedure
privacyParameters	byte	Privacy parameters parsed from the incoming packet.
return	byte[]

Encrypt ScopedPdu data BER encoded in a byte array.

public Encrypt ( byte unencryptedData, int offset, int length, byte key, int engineBoots, int engineTime, byte &privacyParameters, IAuthenticationDigest authDigest ) : byte[]
unencryptedData	byte	BER encoded byte array that needs to be encrypted
offset	int	Offset within the BER encoded byte array to start encryption operation from.
length	int	Length of data to encrypt
key	byte	Encryption key
engineBoots	int	Authoritative engine boots value. Retrieved as part of SNMP v3 discovery process.
engineTime	int	Authoritative engine time value. Retrieved as part of SNMP v3 discovery process.
privacyParameters	byte	Byte array that will receive privacy parameters information that is the result of the /// encryption procedure.
authDigest	IAuthenticationDigest	Authentication digest reference. Not used by AES protocol and can be null
return	byte[]

Some protocols support a method to extend the encryption or decryption key when supplied key is too short.

public ExtendShortKey ( byte shortKey, byte password, byte engineID, IAuthenticationDigest authProtocol ) : byte[]
shortKey	byte	Key that needs to be extended
password	byte	Privacy password as configured on the SNMP agent.
engineID	byte	Authoritative engine id. Value is retrieved as part of SNMP v3 discovery procedure
authProtocol	IAuthenticationDigest	Authentication protocol class instance cast as
return	byte[]

Calculates and returns length of the buffer that is the result of the encryption method.

public GetEncryptedLength ( int scopedPduLength ) : int
scopedPduLength	int	Length of the buffer that is needs to be encrypted.
return	int

Get next salt Int64 value. Used internally to encrypt data.

protected NextSalt ( ) : System.Int64
return	System.Int64

Convert privacy password into encryption key using packet authentication hash.

Thrown when key size is shorter then MinimumKeyLength

public PasswordToKey ( byte secret, byte engineId, IAuthenticationDigest authProtocol ) : byte[]
secret	byte	Privacy user secret
engineId	byte	Authoritative engine id of the snmp agent
authProtocol	IAuthenticationDigest	Authentication protocol
return	byte[]

Standard constructor.

public PrivacyAES ( int keyBytes ) : System
keyBytes	int	Key size in bytes. Acceptable values are /// 16 = 128-bit key size, 24 = 192-bit key size, or 32 = 256-bit key size.
return	System

AES protocol key bytes. Valid values are 16 (for AES128), 24 (AES192) or 32 (AES256).

protected int _keyBytes
return	int

Salt value

protected Int64,System _salt
return	System.Int64