/// <summary>Copy constructor. Initialize the class with the values of the parameter class values.</summary>
/// <param name="second">Parameter class.</param>
public SecureAgentParameters(SecureAgentParameters second)
: this()
{
contextEngineId.Set(second.ContextEngineId);
contextName.Set(second.ContextName);
engineBoots.Value = second.EngineBoots.Value;
engineId.Set(second.EngineId);
engineTime.Value = second.EngineTime.Value;
engineTimeStamp = second.EngineTimeStamp();
maxMessageSize.Value = second.MaxMessageSize.Value;
privacyProtocol = second.Privacy;
privacySecret.Set(second.PrivacySecret);
authenticationProtocol = second.Authentication;
authenticationSecret.Set(second.AuthenticationSecret);
reportable = second.Reportable;
securityName.Set(second.SecurityName);
if (second.AuthenticationKey != null)
{
authenticationKey = (byte[])second.AuthenticationKey.Clone();
}
if (second.PrivacyKey != null)
{
privacyKey = (byte[])second.PrivacyKey.Clone();
}
}
/// <summary>
/// Prepare class for noAuthNoPriv operations. Set authentication and privacy protocols to none.
/// </summary>
/// <param name="securityName">User security name</param>
public void noAuthNoPriv(string securityName)
{
_securityName.Set(securityName);
_authenticationProtocol = AuthenticationDigests.None;
_authenticationSecret.Clear();
_privacyProtocol = PrivacyProtocols.None;
_privacySecret.Clear();
}
/// <summary>BER encode security model field.</summary>
/// <remarks>
/// USM security model is a SEQUENCE encoded inside a OCTETSTRING. To encode it, first encode the sequence
/// of class values then "wrap" it inside a OCTETSTRING field
/// </remarks>
/// <param name="buffer">Buffer to store encoded USM security model header</param>
public override void encode(MutableByte buffer)
{
MutableByte tmp = new MutableByte();
// First encode all the values that will form the sequence
_engineId.encode(tmp);
// Encode engine boots
_engineBoots.encode(tmp);
// encode engine time
_engineTime.encode(tmp);
_securityName.encode(tmp);
if (_authentication != AuthenticationDigests.None)
{
if (_authenticationParameters.Length <= 0)
{
// If authentication is used, set authentication parameters field to 12 bytes set to 0x00
_authenticationParameters.Set(new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 });
}
}
else
{
_authenticationParameters.Reset();
}
_authenticationParameters.encode(tmp);
if (_privacy != PrivacyProtocols.None)
{
if (_privacyParameters.Length <= 0)
{
IPrivacyProtocol privProto = PrivacyProtocol.GetInstance(_privacy);
if (privProto != null)
{
byte[] parameter = new byte[privProto.PrivacyParametersLength];
for (int i = 0; i < privProto.PrivacyParametersLength; i++)
{
parameter[i] = 0x00; // This is not necessary since all array members are, by default, initialized to 0
}
_privacyParameters.Set(parameter);
}
else
{
throw new SnmpException(SnmpException.UnsupportedPrivacyProtocol, "Unrecognized privacy protocol specified.");
}
}
}
else
{
_privacyParameters.Reset();
}
_privacyParameters.encode(tmp);
MutableByte tmp1 = new MutableByte();
BuildHeader(tmp1, SnmpConstants.SMI_SEQUENCE, tmp.Length);
tmp1.Append(tmp);
BuildHeader(buffer, OCTETSTRING, tmp1.Length);
buffer.Append(tmp1);
}
/// <summary>
/// Copy constructor.
/// </summary>
/// <param name="value">Class to copy values from</param>
public UserSecurityModel(UserSecurityModel value)
: this()
{
_engineId.Set(value.EngineId);
_engineBoots.Value = value.EngineBoots;
_engineTime.Value = value.EngineTime;
_securityName.Set(value.SecurityName);
_authenticationParameters = new OctetString();
_privacySecret = new MutableByte();
_privacy = PrivacyProtocols.None;
_privacyParameters = new OctetString();
}
/// <summary>
/// Update class values with SNMP version 3 discovery values from the supplied <see cref="SnmpV3Packet"/>
/// class. Values updated are EngineId, EngineTime and EngineBoots.
/// </summary>
/// <param name="packet"><see cref="SnmpV3Packet"/> class cast as <see cref="SnmpPacket"/></param>
/// <exception cref="SnmpInvalidVersionException">Thrown when SNMP packet class other then version 3
/// is passed as parameter</exception>
public void UpdateDiscoveryValues(SnmpPacket packet)
{
if (packet is SnmpV3Packet)
{
SnmpV3Packet pkt = (SnmpV3Packet)packet;
_engineId.Set(pkt.USM.EngineId);
_engineTime.Value = pkt.USM.EngineTime;
_engineBoots.Value = pkt.USM.EngineBoots;
UpdateTimeStamp();
_contextEngineId.Set(pkt.ScopedPdu.ContextEngineId);
_contextName.Set(pkt.ScopedPdu.ContextName);
}
else
{
throw new SnmpInvalidVersionException("Invalid SNMP version.");
}
}
/// <summary>
/// Copy all relevant values from the SnmpV3Packet class. Do not use this class for
/// updating the SNMP version 3 discovery process results because secret name, authentication
/// and privacy values are updated as well which discovery process doesn't use.
/// </summary>
/// <param name="packet"><see cref="SnmpV3Packet"/> cast as <see cref="SnmpPacket"/></param>
/// <exception cref="SnmpInvalidVersionException">Thrown when SNMP packet class other then version 3
/// is passed as parameter</exception>
public void UpdateValues(SnmpPacket packet)
{
if (packet is SnmpV3Packet)
{
SnmpV3Packet pkt = (SnmpV3Packet)packet;
_authenticationProtocol = pkt.USM.Authentication;
_privacyProtocol = pkt.USM.Privacy;
_authenticationSecret.Set(pkt.USM.AuthenticationSecret);
_privacySecret.Set(pkt.USM.PrivacySecret);
_securityName.Set(pkt.USM.SecurityName);
if (pkt.MaxMessageSize < _maxMessageSize.Value)
{
_maxMessageSize.Value = pkt.MaxMessageSize;
}
UpdateDiscoveryValues(pkt);
}
else
{
throw new SnmpInvalidVersionException("Invalid SNMP version.");
}
}
/// <summary>Encode SNMP version 3 packet</summary>
/// <param name="authKey">Authentication key (not password)</param>
/// <param name="privKey">Privacy key (not password)</param>
/// <remarks>
/// Before encoding the packet into a byte array you need to ensure all required information is
/// set. Examples of required information is request type, Vbs (Oid + values pairs), USM settings including
/// SecretName, authentication method and secret (if needed), privacy method and secret (if needed), etc.
/// </remarks>
/// <returns>Byte array BER encoded SNMP packet.</returns>
public byte[] Encode(byte[] authKey, byte[] privKey)
{
MutableByte buffer = new MutableByte();
// encode the global message data sequence header information
MutableByte globalMessageData = new MutableByte();
// if message id is 0 then generate a new, random message id
if (messageId.Value == 0)
{
Random rand = new Random();
messageId.Value = rand.Next(1, int.MaxValue);
}
// encode message id
messageId.Encode(globalMessageData);
// encode max message size
maxMessageSize.Encode(globalMessageData);
// message flags
messageFlags.Encode(globalMessageData);
// security model code
securityModel.Value = userSecurityModel.Type;
securityModel.Encode(globalMessageData);
// add global message data to the main buffer
// encode sequence header and add data
AsnType.BuildHeader(buffer, SnmpConstants.SmiSequence, globalMessageData.Length);
buffer.Append(globalMessageData);
MutableByte packetHeader = new MutableByte(buffer);
// before going down this road, check if this is a discovery packet
OctetString savedUserName = new OctetString();
bool privacy = messageFlags.Privacy;
bool authentication = messageFlags.Authentication;
bool reportable = messageFlags.Reportable;
if (userSecurityModel.EngineId.Length <= 0)
{
// save USM settings prior to encoding a Discovery packet
savedUserName.Set(userSecurityModel.SecurityName);
userSecurityModel.SecurityName.Reset(); // delete security name for discovery packets
messageFlags.Authentication = false;
messageFlags.Privacy = false;
messageFlags.Reportable = true;
}
userSecurityModel.Encode(buffer);
if (userSecurityModel.EngineId.Length <= 0)
{
// restore saved USM values
userSecurityModel.SecurityName.Set(savedUserName);
messageFlags.Authentication = authentication;
messageFlags.Privacy = privacy;
messageFlags.Reportable = reportable;
}
// Check if privacy encryption is required
MutableByte encodedPdu = new MutableByte();
if (messageFlags.Privacy && userSecurityModel.EngineId.Length > 0)
{
IPrivacyProtocol privacyProtocol = PrivacyProtocol.GetInstance(userSecurityModel.Privacy);
if (privacyProtocol == null)
{
throw new SnmpException(SnmpException.EErrorCode.UnsupportedPrivacyProtocol, "Specified privacy protocol is not supported.");
}
// Get BER encoded ScopedPdu
MutableByte unencryptedPdu = new MutableByte();
scopedPdu.Encode(unencryptedPdu);
// we have to expand the key
IAuthenticationDigest auth = Authentication.GetInstance(userSecurityModel.Authentication);
if (auth == null)
{
throw new SnmpException(SnmpException.EErrorCode.UnsupportedNoAuthPriv, "Invalid authentication protocol. noAuthPriv mode not supported.");
}
byte[] encryptedBuffer = privacyProtocol.Encrypt(unencryptedPdu, 0, unencryptedPdu.Length, privKey, userSecurityModel.EngineBoots, userSecurityModel.EngineTime, out byte[] privacyParameters, auth);
userSecurityModel.PrivacyParameters.Set(privacyParameters);
OctetString encryptedOctetString = new OctetString(encryptedBuffer);
encryptedOctetString.Encode(encodedPdu);
// now redo packet encoding
buffer.Reset();
buffer.Set(packetHeader);
userSecurityModel.Encode(buffer);
int preEncodedLength = encodedPdu.Length;
buffer.Append(encodedPdu);
if (maxMessageSize.Value != 0)
{
// verify compliance with maximum message size
if ((encodedPdu.Length - preEncodedLength) > maxMessageSize)
{
throw new SnmpException(SnmpException.EErrorCode.MaximumMessageSizeExceeded, "ScopedPdu exceeds maximum message size.");
}
}
}
else
{
scopedPdu.Encode(encodedPdu);
buffer.Append(encodedPdu);
}
Encode(buffer);
if (messageFlags.Authentication && userSecurityModel.EngineId.Length > 0)
{
userSecurityModel.Authenticate(authKey, ref buffer);
// Now re-encode the packet with the authentication information
userSecurityModel.Encode(packetHeader);
packetHeader.Append(encodedPdu);
Encode(packetHeader);
buffer = packetHeader;
}
return(buffer);
}
/// <summary>
/// Standard constructor.
/// </summary>
/// <param name="snmpCommunity">SNMP community name for the packet</param>
public SnmpV2Packet(string snmpCommunity)
: this()
{
_snmpCommunity.Set(snmpCommunity);
}
/// <summary>
/// Copy constructor. Initialize the class with the values of the parameter class values.
/// </summary>
/// <param name="second">Parameter class.</param>
public AgentParameters(AgentParameters second)
{
_version.Value = (int)second.Version;
_community.Set(second.Community);
}
/// <summary>
/// Encode SNMP version 3 packet
/// </summary>
/// <remarks>
/// Before encoding the packet into a byte array you need to ensure all required information is
/// set. Examples of required information is request type, Vbs (Oid + values pairs), USM settings including
/// SecretName, authentication method and secret (if needed), privacy method and secret (if needed), etc.
/// </remarks>
/// <returns>Byte array BER encoded SNMP packet.</returns>
public override byte[] encode()
{
MutableByte buffer = new MutableByte();
// encode the global message data sequence header information
MutableByte globalMessageData = new MutableByte();
// if message id is 0 then generate a new, random message id
if (_messageId.Value == 0)
{
Random rand = new Random();
_messageId.Value = rand.Next(1, Int32.MaxValue);
}
// encode message id
_messageId.encode(globalMessageData);
// encode max message size
_maxMessageSize.encode(globalMessageData);
// message flags
_msgFlags.encode(globalMessageData);
// security model code
_securityModel.Value = _userSecurityModel.Type;
_securityModel.encode(globalMessageData);
// add global message data to the main buffer
// encode sequence header and add data
AsnType.BuildHeader(buffer, SnmpConstants.SMI_SEQUENCE, globalMessageData.Length);
buffer.Append(globalMessageData);
MutableByte packetHeader = new MutableByte(buffer);
// before going down this road, check if this is a discovery packet
OctetString savedUserName = new OctetString();
bool privacy = _msgFlags.Privacy;
bool authentication = _msgFlags.Authentication;
bool reportable = _msgFlags.Reportable;
if (_userSecurityModel.EngineId.Length <= 0)
{
// save USM settings prior to encoding a Discovery packet
savedUserName.Set(_userSecurityModel.SecurityName);
_userSecurityModel.SecurityName.Reset(); // delete security name for discovery packets
_msgFlags.Authentication = false;
_msgFlags.Privacy = false;
_msgFlags.Reportable = true;
}
_userSecurityModel.encode(buffer);
if (_userSecurityModel.EngineId.Length <= 0)
{
// restore saved USM values
_userSecurityModel.SecurityName.Set(savedUserName);
_msgFlags.Authentication = authentication;
_msgFlags.Privacy = privacy;
_msgFlags.Reportable = reportable;
}
// Check if privacy encryption is required
MutableByte encodedPdu = new MutableByte();
if (_msgFlags.Privacy && _userSecurityModel.EngineId.Length > 0)
{
IPrivacyProtocol privacyProtocol = PrivacyProtocol.GetInstance(_userSecurityModel.Privacy);
if (privacyProtocol == null)
{
throw new SnmpException(SnmpException.UnsupportedPrivacyProtocol, "Specified privacy protocol is not supported.");
}
// Get BER encoded ScopedPdu
MutableByte unencryptedPdu = new MutableByte();
_scopedPdu.encode(unencryptedPdu);
byte[] privacyParameters = null;
// we have to expand the key
IAuthenticationDigest auth = Authentication.GetInstance(_userSecurityModel.Authentication);
if (auth == null)
{
throw new SnmpException(SnmpException.UnsupportedNoAuthPriv, "Invalid authentication protocol. noAuthPriv mode not supported.");
}
byte[] pkey = privacyProtocol.PasswordToKey(_userSecurityModel.PrivacySecret, _userSecurityModel.EngineId, auth);
byte[] encryptedBuffer = privacyProtocol.Encrypt(unencryptedPdu, 0, unencryptedPdu.Length, pkey, _userSecurityModel.EngineBoots, _userSecurityModel.EngineTime, out privacyParameters, auth);
_userSecurityModel.PrivacyParameters.Set(privacyParameters);
OctetString encryptedOctetString = new OctetString(encryptedBuffer);
encryptedOctetString.encode(encodedPdu);
// now redo packet encoding
buffer.Reset();
buffer.Set(packetHeader);
_userSecurityModel.encode(buffer);
int preEncodedLength = encodedPdu.Length;
buffer.Append(encodedPdu);
if (_maxMessageSize.Value != 0)
{
// verify compliance with maximum message size
if ((encodedPdu.Length - preEncodedLength) > _maxMessageSize)
{
throw new SnmpException(SnmpException.MaximumMessageSizeExceeded, "ScopedPdu exceeds maximum message size.");
}
}
}
else
{
_scopedPdu.encode(encodedPdu);
buffer.Append(encodedPdu);
}
int preVersionLength = buffer.Length;
base.encode(buffer);
int versionHeaderLength = buffer.Length - preVersionLength;
if (_msgFlags.Authentication && _userSecurityModel.EngineId.Length > 0)
{
_userSecurityModel.Authenticate(ref buffer);
// Now re-encode the packet with the authentication information
_userSecurityModel.encode(packetHeader);
packetHeader.Append(encodedPdu);
base.encode(packetHeader);
buffer = packetHeader;
}
return(buffer);
}
/// <summary>Copy constructor. Initialize the class with the values of the parameter class values.</summary>
/// <param name="second">Parameter class.</param>
public AgentParameters(AgentParameters second)
{
version.Value = (int)second.Version;
community.Set(second.Community);
disableReplySourceCheck = second.DisableReplySourceCheck;
}
