2.3.24 Replace ID Payload ................................. 36
2.3.25 Remove ID Payload .................................. 37
2.3.26 Remove Channel User Payload ........................ 38
+ 2.3.27 Set Mode Payload ................................... XXX
2.4 SILC ID Types ............................................. 39
2.5 Packet Encryption And Decryption .......................... 39
2.5.1 Normal Packet Encryption And Decryption ............. 39
Figure 20: New Channel User Payload
Figure 21: Replace ID Payload
Figure 22: Remove Channel User Payload
+Figure 23: Set Mode Payload
.ti 0
this packet. This packet maybe sent to entity that is
indirectly connected to the sender.
- When received and the replaced ID is Client ID the server or
+ When received and the removed ID is Client ID the server or
router must distribute SILC_NOTIFY_TYPE_SIGNOFF to the
local clients on the channels (if any) of the client whose
- ID was changed. However, the notify type must be sent only
+ ID was removed. However, the notify type must be sent only
once per client.
Payload of the packet: See section 2.3.25 Remove ID Payload
that is indirectly connected to the sender.
When received, the server or router must distribute
- SILC_NOTIFY_TYPE_LEAVEW to local clients on the channel.
+ SILC_NOTIFY_TYPE_LEAVE to local clients on the channel.
Payload of the packet: See section 2.3.26 Remove Channel User
Payload
as SILC Key Exchange protocol is executed. This packet does
not have a payload.
+
+ 31 SILC_PACKET_SET_MODE
+
+ This packet is used by servers and routers to inform each
+ other about changed modes. When channel's and client'c channel
+ mode is changed this packet is used to distribute the information
+ to all routers in the network. Server can send this packet but
+ must not receive it. Router can send and receive this packet.
+ Client must not send or receive this packet.
+
+ Payload of the packet: See section 2.3.27 Set Mode Payload
+
+
+ 32 SILC_PACKET_HEARTBEAT
- 31 - 199
+ This packet is used by clients, servers and routers to keep the
+ connection alive. It is recommended that all servers implement
+ keepalive actions and perform it to both direction in a link.
+ This packet does not have a payload.
+
+
+ 33 - 199
Currently undefined commands.
sent from server to client, however, server may send it to another
server as well. This payload may also be sent to a channel. Client must
not send this payload. The receiver of this payload may totally ignore the
-contents of the payload, however, notify message should be noted and
-possibly logged.
+contents of the payload, however, notify message should be audited.
The payload may only be sent with SILC_PACKET_NOTIFY packet. It must
not be sent in any other packet type. Following diagram represents the
The <Client ID> is the client who changed the mode. The <mode mask>
is the new mode mask of the channel. The <Target Client ID> is the
- client whose mode was changed.
+ client which mode was changed.
9 SILC_NOTIFY_TYPE_MOTD
the client. After that, client starts using the key received
in this payload to protect the traffic on the channel.
+The client who is joining to the channel receives its key in the
+SILC_COMMAND_JOIN command reply message thus it is not necessary to
+send this payload to the entity who sent the SILC_COMMAND_JOIN command.
+
Channel keys are cell specific thus every router in cell have
to create a channel key and distribute it if any client in the
cell has joined to a channel. Channel traffic between cell's
can identify which command reply belongs to which originally
sent command. What this field includes is implementation
issue but it is recommended that wrapping counter value is
- used in the field.
+ used in the field. Value zero (0) in this field means that
+ no specific value is set.
.in 3
See [SILC1] for detailed description of different SILC commands,
SILC_PACKET_NEW_SERVER to the router it connected to. The case is same
when router connects to another router.
+However, this payload is not and must not be used to send information
+about new channels. New channels are always distributed by sending the
+dedicated SILC_PACKET_NEW_CHANNEL packet.
+
Hence, this payload is very important and used every time when some
new entity is registered to the SILC network. Client never sends this
payload. Both client and server (and router) may receive this payload.
2.3.25 Remove ID Payload
Remove ID payload is used to remove ID from SILC network. This is used
-for example when client exits SILC network. The server must in this
-case send this payload to notify that this ID is not valid anymore.
-After this has been send the old ID must not be used anymore. Client
-must not send this payload.
+when client, server, router or channel is removed from the SILC network.
+After this payload has been send the old ID must not be used anymore.
+Client must not send or receive this payload.
The packet uses generic ID Payload as New ID Payload. See section
2.3.2.1 for generic ID Payload.
.in 3
+.ti 0
+2.3.27 Set Mode Payload
+
+Set Mode Payload is used by servers and routers to distribute to each
+other the information about changed modes in the SILC network. The
+payload is sent when channel's or client's channel mode is changed.
+Server can send this to router which will broadcast it further to other
+routers. However, normal server must not reiceve this payload. Client
+must not send or receive this payload.
+
+The payload may only be sent with SILC_PACKET_SET_MODE packet.
+It must not be sent in any other packet type. Following diagram
+represents the Set Mode Payload.
+
+
+
+.in 5
+.nf
+.in 5
+.nf
+ 1 2 3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| Mode Type | Payload Length |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| Mode Mask |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| Argument Nums |
++-+-+-+-+-+-+-+-+
+.in 3
+
+.ce
+Figure 23: Set Mode Payload
+
+
+.in 6
+o Mode type (2 bytes) - Indicates the type of the mode that was
+ changed. Every type has arguments associated to the type which
+ are defined below. The following types are defined:
+
+ 0 SILC_MODE_TYPE_CHANNEL
+
+ Max Arguments: 2
+ Arguments: (1) <Channel ID> (2) <Client ID>
+
+ The <Channel ID> is the channel which mode was set and the
+ <Client ID> is the client who set it.
+
+
+ 1 SILC_MODE_TYPE_UCHANNEL
+
+ Max Arguments: 3
+ Arguments: (1) <Channel ID> (2) <Client ID>
+ (3) <Target Client ID>
+
+ The <Channel ID> is the channel where the <Client ID> and
+ the <Target Client ID> is on. The <Client ID> is the client
+ who set the <Target Client ID> mode.
+
+
+ 2 - RESERVED
+
+ Reserved types.
+
+
+ 32768 - Private range
+
+ Rest of the types are reserved for private use.
+
+o Payload Length (2 bytes) - Length of the entire Set Mode Payload
+ including any associated Argument Payloads.
+
+o Mode Mask (4 bytes) - Indicates the set mode mask. This is
+ specified by the mode type. See definitions of SILC_COMMAND_UMODE
+ for client modes, SILC_COMMAND_CMODE for channel modes and
+ SILC_COMMAND_CUMODE for client's channel modes in [SILC1].
+
+o Argument Nums (2 bytes) - Indicates the number of Argument
+ Payloads associated to this payload. Mode types may define
+ arguments to be send along this payload.
+.in 3
+
+
.ti 0
2.4 SILC ID Types
3 Security Considerations
Security is central to the design of this protocol, and these security
-considerations permeate the specification.
+considerations permeate the specification. Common security considerations
+such as keeping private keys truly private and using adequate lengths for
+symmetric and asymmetric keys must be followed in order to maintain the
+security of this protocol.
.ti 0
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