net.i2p.client
Interface I2PSession

All Known Implementing Classes:
I2PSessionImpl, I2PSessionImpl2, I2PSessionMuxedImpl, I2PSimpleSession, SubSession

public interface I2PSession

Define the standard means of sending and receiving messages on the I2P network by using the I2CP (the client protocol). This is done over a bidirectional TCP socket. End to end encryption in I2PSession was disabled in release 0.6. Periodically the router will ask the client to authorize a new set of tunnels to be allocated to the client, which the client can accept by sending a LeaseSet signed by the Destination. In addition, the router may on occasion provide the client with an updated clock offset so that the client can stay in sync with the network (even if the host computer's clock is off).


Field Summary
static int PORT_ANY
           
static int PORT_UNSPECIFIED
           
static int PROTO_ANY
           
static int PROTO_DATAGRAM
          Generally a signed datagram, but could also be a raw datagram, depending on the application
static int PROTO_DATAGRAM_RAW
          A raw (unsigned) datagram
static int PROTO_STREAMING
           
static int PROTO_UNSPECIFIED
           
 
Method Summary
 void addMuxedSessionListener(I2PSessionMuxedListener l, int proto, int port)
          Listen on specified protocol and port, and receive notification of proto, fromPort, and toPort for every message.
 void addSessionListener(I2PSessionListener lsnr, int proto, int port)
          Listen on specified protocol and port.
 I2PSession addSubsession(InputStream privateKeyStream, Properties opts)
           
 int[] bandwidthLimits()
          Get the current bandwidth limits.
 void connect()
          Actually connect the session and start receiving/sending messages
 void destroySession()
          Tear down the session and release any resources.
 PrivateKey getDecryptionKey()
          Retrieve the decryption PrivateKey associated with the Destination
 Destination getMyDestination()
          Retrieve the Destination this session serves as the endpoint for.
 SigningPrivateKey getPrivateKey()
          Retrieve the signing SigningPrivateKey associated with the Destination
 List<I2PSession> getSubsessions()
           
 boolean isClosed()
          Have we closed the session?
 Destination lookupDest(Hash h)
          Lookup a Destination by Hash.
 Destination lookupDest(Hash h, long maxWait)
          Lookup a Destination by Hash.
 Destination lookupDest(String name)
          Ask the router to lookup a Destination by host name.
 Destination lookupDest(String name, long maxWait)
          Ask the router to lookup a Destination by host name.
 byte[] receiveMessage(int msgId)
          Receive a message that the router has notified the client about, returning the payload.
 void removeListener(int proto, int port)
          removes the specified listener (only)
 void removeSubsession(I2PSession session)
           
 void reportAbuse(int msgId, int severity)
          Instruct the router that the message received was abusive (including how abusive on a 1-100 scale) in the hopes the router can do something to minimize receiving abusive messages like that in the future.
 boolean sendMessage(Destination dest, byte[] payload)
          Send a new message to the given destination, containing the specified payload, returning true if the router feels confident that the message was delivered.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size)
          Send a new message to the given destination, containing the specified payload, returning true if the router feels confident that the message was delivered.
 boolean sendMessage(Destination dest, byte[] payload, int proto, int fromport, int toport)
          See I2PSessionMuxedImpl for proto/port details.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size, int proto, int fromPort, int toPort, SendMessageOptions options)
          See I2PSessionMuxedImpl for proto/port details.
 long sendMessage(Destination dest, byte[] payload, int offset, int size, int proto, int fromPort, int toPort, SendMessageOptions options, SendMessageStatusListener listener)
          Send a message and request an asynchronous notification of delivery status.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size, SessionKey keyUsed, Set<SessionTag> tagsSent)
          End-to-End Crypto is disabled, tags and keys are ignored.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size, SessionKey keyUsed, Set<SessionTag> tagsSent, int proto, int fromPort, int toPort)
          See I2PSessionMuxedImpl for proto/port details.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size, SessionKey keyUsed, Set<SessionTag> tagsSent, long expire)
          End-to-End Crypto is disabled, tags and keys are ignored.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size, SessionKey keyUsed, Set<SessionTag> tagsSent, long expire, int proto, int fromPort, int toPort)
          See I2PSessionMuxedImpl for proto/port details.
 boolean sendMessage(Destination dest, byte[] payload, int offset, int size, SessionKey keyUsed, Set<SessionTag> tagsSent, long expire, int proto, int fromPort, int toPort, int flags)
          See I2PSessionMuxedImpl for proto/port details.
 boolean sendMessage(Destination dest, byte[] payload, SessionKey keyUsed, Set<SessionTag> tagsSent)
          End-to-End Crypto is disabled, tags and keys are ignored! Like sendMessage above, except the key used and the tags sent are exposed to the application.
 void setSessionListener(I2PSessionListener lsnr)
          Instruct the I2PSession where it should send event notifications WARNING: It is recommended that you use a method that specifies the protocol and ports.
 void updateOptions(Properties options)
          Pass updated options to the router.
 

Field Detail

PORT_ANY

static final int PORT_ANY
See Also:
Constant Field Values

PORT_UNSPECIFIED

static final int PORT_UNSPECIFIED
See Also:
Constant Field Values

PROTO_ANY

static final int PROTO_ANY
See Also:
Constant Field Values

PROTO_UNSPECIFIED

static final int PROTO_UNSPECIFIED
See Also:
Constant Field Values

PROTO_STREAMING

static final int PROTO_STREAMING
See Also:
Constant Field Values

PROTO_DATAGRAM

static final int PROTO_DATAGRAM
Generally a signed datagram, but could also be a raw datagram, depending on the application

See Also:
Constant Field Values

PROTO_DATAGRAM_RAW

static final int PROTO_DATAGRAM_RAW
A raw (unsigned) datagram

Since:
0.9.2
See Also:
Constant Field Values
Method Detail

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload)
                    throws I2PSessionException
Send a new message to the given destination, containing the specified payload, returning true if the router feels confident that the message was delivered. WARNING: It is recommended that you use a method that specifies the protocol and ports.

Parameters:
dest - location to send the message
payload - body of the message to be sent (unencrypted)
Returns:
whether it was accepted by the router for delivery or not
Throws:
I2PSessionException

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size)
                    throws I2PSessionException
Send a new message to the given destination, containing the specified payload, returning true if the router feels confident that the message was delivered. WARNING: It is recommended that you use a method that specifies the protocol and ports.

Parameters:
dest - location to send the message
payload - body of the message to be sent (unencrypted)
Returns:
success
Throws:
I2PSessionException

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int proto,
                    int fromport,
                    int toport)
                    throws I2PSessionException
See I2PSessionMuxedImpl for proto/port details.

Returns:
success
Throws:
I2PSessionException
Since:
0.7.1

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    SessionKey keyUsed,
                    Set<SessionTag> tagsSent)
                    throws I2PSessionException
End-to-End Crypto is disabled, tags and keys are ignored! Like sendMessage above, except the key used and the tags sent are exposed to the application.

If some application layer message delivery confirmation is used, rather than i2p's (slow) built in confirmation via guaranteed delivery mode, the application can update the SessionKeyManager, ala:

   SessionKeyManager.getInstance().tagsDelivered(dest.getPublicKey(), keyUsed, tagsSent);
 
If an application is using guaranteed delivery mode, this is not useful, but for applications using best effort delivery mode, if they can know with certainty that a message was delivered and can update the SessionKeyManager appropriately, a significant performance boost will occur (subsequent message encryption and decryption will be done via AES and a SessionTag, rather than ElGamal+AES, which is 1000x slower).

Parameters:
dest - location to send the message
payload - body of the message to be sent (unencrypted)
keyUsed - UNUSED, IGNORED. Session key delivered to the destination for association with the tags sent. This is essentially an output parameter - keyUsed.getData() is ignored during this call, but after the call completes, it will be filled with the bytes of the session key delivered. Typically the key delivered is the same one as the key encrypted with, but not always. If this is null then the key data will not be exposed.
tagsSent - UNUSED, IGNORED. Set of tags delivered to the peer and associated with the keyUsed. This is also an output parameter - the contents of the set is ignored during the call, but afterwards it contains a set of SessionTag objects that were sent along side the given keyUsed.
Returns:
success
Throws:
I2PSessionException

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size,
                    SessionKey keyUsed,
                    Set<SessionTag> tagsSent)
                    throws I2PSessionException
End-to-End Crypto is disabled, tags and keys are ignored.

Parameters:
keyUsed - UNUSED, IGNORED.
tagsSent - UNUSED, IGNORED.
Returns:
success
Throws:
I2PSessionException

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size,
                    SessionKey keyUsed,
                    Set<SessionTag> tagsSent,
                    long expire)
                    throws I2PSessionException
End-to-End Crypto is disabled, tags and keys are ignored.

Parameters:
keyUsed - UNUSED, IGNORED.
tagsSent - UNUSED, IGNORED.
expire - absolute expiration timestamp, NOT interval from now
Returns:
success
Throws:
I2PSessionException
Since:
0.7.1

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size,
                    SessionKey keyUsed,
                    Set<SessionTag> tagsSent,
                    int proto,
                    int fromPort,
                    int toPort)
                    throws I2PSessionException
See I2PSessionMuxedImpl for proto/port details. End-to-End Crypto is disabled, tags and keys are ignored.

Parameters:
keyUsed - UNUSED, IGNORED.
tagsSent - UNUSED, IGNORED.
proto - 1-254 or 0 for unset; recommended: I2PSession.PROTO_UNSPECIFIED I2PSession.PROTO_STREAMING I2PSession.PROTO_DATAGRAM 255 disallowed
fromPort - 1-65535 or 0 for unset
toPort - 1-65535 or 0 for unset
Returns:
success
Throws:
I2PSessionException
Since:
0.7.1

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size,
                    SessionKey keyUsed,
                    Set<SessionTag> tagsSent,
                    long expire,
                    int proto,
                    int fromPort,
                    int toPort)
                    throws I2PSessionException
See I2PSessionMuxedImpl for proto/port details. End-to-End Crypto is disabled, tags and keys are ignored.

Parameters:
keyUsed - UNUSED, IGNORED.
tagsSent - UNUSED, IGNORED.
expire - absolute expiration timestamp, NOT interval from now
proto - 1-254 or 0 for unset; recommended: I2PSession.PROTO_UNSPECIFIED I2PSession.PROTO_STREAMING I2PSession.PROTO_DATAGRAM 255 disallowed
fromPort - 1-65535 or 0 for unset
toPort - 1-65535 or 0 for unset
Returns:
success
Throws:
I2PSessionException
Since:
0.7.1

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size,
                    SessionKey keyUsed,
                    Set<SessionTag> tagsSent,
                    long expire,
                    int proto,
                    int fromPort,
                    int toPort,
                    int flags)
                    throws I2PSessionException
See I2PSessionMuxedImpl for proto/port details. End-to-End Crypto is disabled, tags and keys are ignored.

Parameters:
keyUsed - UNUSED, IGNORED.
tagsSent - UNUSED, IGNORED.
expire - absolute expiration timestamp, NOT interval from now
proto - 1-254 or 0 for unset; recommended: I2PSession.PROTO_UNSPECIFIED I2PSession.PROTO_STREAMING I2PSession.PROTO_DATAGRAM 255 disallowed
fromPort - 1-65535 or 0 for unset
toPort - 1-65535 or 0 for unset
Returns:
success
Throws:
I2PSessionException
Since:
0.8.4

sendMessage

boolean sendMessage(Destination dest,
                    byte[] payload,
                    int offset,
                    int size,
                    int proto,
                    int fromPort,
                    int toPort,
                    SendMessageOptions options)
                    throws I2PSessionException
See I2PSessionMuxedImpl for proto/port details. See SendMessageOptions for option details.

Parameters:
proto - 1-254 or 0 for unset; recommended: I2PSession.PROTO_UNSPECIFIED I2PSession.PROTO_STREAMING I2PSession.PROTO_DATAGRAM 255 disallowed
fromPort - 1-65535 or 0 for unset
toPort - 1-65535 or 0 for unset
options - to be passed to the router
Returns:
success
Throws:
I2PSessionException
Since:
0.9.2

sendMessage

long sendMessage(Destination dest,
                 byte[] payload,
                 int offset,
                 int size,
                 int proto,
                 int fromPort,
                 int toPort,
                 SendMessageOptions options,
                 SendMessageStatusListener listener)
                 throws I2PSessionException
Send a message and request an asynchronous notification of delivery status. Notifications will be delivered at least up to the expiration specified in the options, or 60 seconds if not specified. See I2PSessionMuxedImpl for proto/port details. See SendMessageOptions for option details.

Parameters:
proto - 1-254 or 0 for unset; recommended: I2PSession.PROTO_UNSPECIFIED I2PSession.PROTO_STREAMING I2PSession.PROTO_DATAGRAM 255 disallowed
fromPort - 1-65535 or 0 for unset
toPort - 1-65535 or 0 for unset
options - to be passed to the router
Returns:
the message ID to be used for later notification to the listener
Throws:
I2PSessionException - on all errors
Since:
0.9.14

receiveMessage

byte[] receiveMessage(int msgId)
                      throws I2PSessionException
Receive a message that the router has notified the client about, returning the payload. This may only be called once for a given msgId (until the counter wraps)

Parameters:
msgId - message to fetch
Returns:
unencrypted body of the message, or null if not found
Throws:
I2PSessionException

reportAbuse

void reportAbuse(int msgId,
                 int severity)
                 throws I2PSessionException
Instruct the router that the message received was abusive (including how abusive on a 1-100 scale) in the hopes the router can do something to minimize receiving abusive messages like that in the future. Unused. Not fully implemented.

Parameters:
msgId - message that was abusive (or -1 for not message related)
severity - how abusive
Throws:
I2PSessionException

setSessionListener

void setSessionListener(I2PSessionListener lsnr)
Instruct the I2PSession where it should send event notifications WARNING: It is recommended that you use a method that specifies the protocol and ports.

Parameters:
lsnr - listener to retrieve events

destroySession

void destroySession()
                    throws I2PSessionException
Tear down the session and release any resources.

Throws:
I2PSessionException

addSubsession

I2PSession addSubsession(InputStream privateKeyStream,
                         Properties opts)
                         throws I2PSessionException
Parameters:
privateKeyStream - null for transient, if non-null must have same encryption keys as primary session and different signing keys
opts - subsession options if any, may be null
Returns:
a new subsession, non-null
Throws:
I2PSessionException
Since:
0.9.21

removeSubsession

void removeSubsession(I2PSession session)
Since:
0.9.21

getSubsessions

List<I2PSession> getSubsessions()
Returns:
a list of subsessions, non-null, does not include the primary session
Since:
0.9.21

connect

void connect()
             throws I2PSessionException
Actually connect the session and start receiving/sending messages

Throws:
I2PSessionException

isClosed

boolean isClosed()
Have we closed the session?

Returns:
true if the session is closed, OR connect() has not been called yet

getMyDestination

Destination getMyDestination()
Retrieve the Destination this session serves as the endpoint for. Returns null if no destination is available.


getDecryptionKey

PrivateKey getDecryptionKey()
Retrieve the decryption PrivateKey associated with the Destination


getPrivateKey

SigningPrivateKey getPrivateKey()
Retrieve the signing SigningPrivateKey associated with the Destination


lookupDest

Destination lookupDest(Hash h)
                       throws I2PSessionException
Lookup a Destination by Hash. Blocking. Waits a max of 10 seconds by default.

Throws:
I2PSessionException

lookupDest

Destination lookupDest(Hash h,
                       long maxWait)
                       throws I2PSessionException
Lookup a Destination by Hash. Blocking.

Parameters:
maxWait - ms
Returns:
null on failure
Throws:
I2PSessionException
Since:
0.8.3

lookupDest

Destination lookupDest(String name)
                       throws I2PSessionException
Ask the router to lookup a Destination by host name. Blocking. Waits a max of 10 seconds by default. This only makes sense for a b32 hostname, OR outside router context. Inside router context, just query the naming service. Outside router context, this does NOT query the context naming service. Do that first if you expect a local addressbook. This will log a warning for non-b32 in router context. Suggested implementation:
  if (name.length() == 60 && name.toLowerCase(Locale.US).endsWith(".b32.i2p")) {
      if (session != null)
          return session.lookup(Hash.create(Base32.decode(name.toLowerCase(Locale.US).substring(0, 52))));
      else
          return ctx.namingService().lookup(name); // simple session for xxx.b32.i2p handled by naming service (optional if you need lookup w/o an existing session)
  } else if (ctx.isRouterContext()) {
      return ctx.namingService().lookup(name); // hostname from router's naming service
  } else {
      Destination d = ctx.namingService().lookup(name); // local naming svc, optional
      if (d != null)
          return d;
      if (session != null)
          return session.lookup(name);
      // simple session (optional if you need lookup w/o an existing session)
      Destination rv = null;
      I2PClient client = new I2PSimpleClient();
      Properties opts = new Properties();
      opts.put(I2PClient.PROP_TCP_HOST, host);
      opts.put(I2PClient.PROP_TCP_PORT, port);
      I2PSession session = null;
      try {
          session = client.createSession(null, opts);
          session.connect();
          rv = session.lookupDest(name);
      } finally {
          if (session != null)
              session.destroySession();
      }
      return rv;
  }
Requires router side to be 0.9.11 or higher. If the router is older, this will return null immediately.

Throws:
I2PSessionException
Since:
0.9.11

lookupDest

Destination lookupDest(String name,
                       long maxWait)
                       throws I2PSessionException
Ask the router to lookup a Destination by host name. Blocking. See above for details.

Parameters:
maxWait - ms
Returns:
null on failure
Throws:
I2PSessionException
Since:
0.9.11

updateOptions

void updateOptions(Properties options)
Pass updated options to the router. Does not remove properties previously present but missing from this options parameter. Fails silently if session is not connected.

Parameters:
options - non-null
Since:
0.8.4

bandwidthLimits

int[] bandwidthLimits()
                      throws I2PSessionException
Get the current bandwidth limits. Blocking.

Throws:
I2PSessionException
Since:
0.8.3

addSessionListener

void addSessionListener(I2PSessionListener lsnr,
                        int proto,
                        int port)
Listen on specified protocol and port. An existing listener with the same proto and port is replaced. Only the listener with the best match is called back for each message.

Parameters:
proto - 1-254 or PROTO_ANY (0) for all; recommended: I2PSession.PROTO_STREAMING I2PSession.PROTO_DATAGRAM 255 disallowed
port - 1-65535 or PORT_ANY (0) for all
Since:
0.7.1

addMuxedSessionListener

void addMuxedSessionListener(I2PSessionMuxedListener l,
                             int proto,
                             int port)
Listen on specified protocol and port, and receive notification of proto, fromPort, and toPort for every message.

Parameters:
proto - 1-254 or PROTO_ANY (0) for all; 255 disallowed
port - 1-65535 or PORT_ANY (0) for all
Since:
0.7.1

removeListener

void removeListener(int proto,
                    int port)
removes the specified listener (only)

Since:
0.7.1