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
server to client, although it may be sent from server to another
server as well. Client never sends this packet. Server may
send this packet to channel as well when the packet is
- distributed to all clients on the channel. Receiver of this
- packet may ignore the packet if it chooses so. However, it
- should not be ignored.
+ distributed to all clients on the channel.
Payload of the packet: See section 2.3.7 Notify Payload.
packet maybe sent to entity that is indirectly connected to
the sender.
+ When received, the server or router must distribute
+ SILC_NOTIFY_TYPE_JOIN to local clients on the channel.
+
Payload of the packet: See section 2.3.21 New Channel User
Payload
packet SILC_PACKET_NEW_CHANNEL_USER except that it may
include several payloads. Client must not send this packet.
+ When received, the server or router must distribute
+ SILC_NOTIFY_TYPE_JOIN to local clients on the channel.
+
Payload of the packet: See section 2.3.23 New Channel User
List Payload
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
+ router must distribute SILC_NOTIFY_TYPE_NICK_CHANGE to the
+ local clients on the channels (if any) of the client whose
+ ID was changed. However, the notify type must be sent only
+ once per client.
+
Payload of the packet: See section 2.3.24 Replace ID Payload
this packet. This packet maybe sent to entity that is
indirectly connected to the sender.
+ 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 removed. However, the notify type must be sent only
+ once per client.
+
Payload of the packet: See section 2.3.25 Remove ID Payload
client has left a channel. This packet maybe sent to entity
that is indirectly connected to the sender.
+ When received, the server or router must distribute
+ 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
+
+ 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.
+
- 31 - 199
+ 33 - 199
Currently undefined commands.
Notify payload is used to send notify messages. The payload is usually
sent from server to client, however, server may send it to another
-server as well. 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.
+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 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
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-| Notify Type | Message Length |
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-| Argument Nums | |
-+-+-+-+-+-+-+-+-+ +
-| |
-~ Notify Message ~
-| |
+| Notify Type | Payload Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| Argument Nums |
++-+-+-+-+-+-+-+-+
.in 3
.ce
o Notify Type (2 bytes) - Indicates the type of the notify
message.
-o Message Length (2 bytes) - Length of the Notify Message area
- not ncluding the length of any other fields in the payload.
+o Payload Length (2 bytes) - Length of the entire Notify Payload
+ including any associated Argument Payloads.
o Argument Nums (2 bytes) - Indicates the number of Argument
Payloads associated to this payload. Notify types may define
arguments to be send along the notify message.
-
-o Notify Message (variable length) - Human readable notify
- message. The format of this message is implementation specific.
- The message can be for example "%s has joined channel %s".
.in 3
-Following notify types has been defined:
+Following list of currently defined notify types. The format for notify
+arguments is same as in SILC commands described in [SILC1]. Also, all
+ID's sent in arguments are sent inside ID Payload.
.in 6
0 SILC_NOTIFY_TYPE_NONE
- If no specific notify type apply for the notify
- message this type may be used.
+ If no specific notify type apply for the notify message this type
+ may be used.
+
+ Max Arguments: 1
+ Arguments: (1) <message>
+
+ The <message> is implementation specific free text string. Receiver
+ may ignore this message.
- No arguments associated to this type.
1 SILC_NOTIFY_TYPE_INVITE
- Sent when receiver has been invited to a channel.
+ Sent when receiver has been invited to a channel. This type must be
+ sent directly to the invited client.
+
+ Max Arguments: 2
+ Arguments: (1) <Client ID> (2) <Channel ID>
+
+ The <Client ID> is the client who invites the receiver of this type
+ to channel indicated by <Channel ID>.
- This type includes two arguments: nickname and channel name.
2 SILC_NOTIFY_TYPE_JOIN
- Sent when client has joined to a channel.
+ Sent when client has joined to a channel. The server must distribute
+ this type only to the local clients on the channel and then send
+ SILC_PACKET_NEW_CHANNEL_USER packet to its primary route. The router
+ or server receiving the packet distributes this type to the local
+ clients on the channel. See description of SILC_PACKET_NEW_CHANNEL_USER
+ packet for more information.
+
+ Max Arguments: 1
+ Arguments: (1) <Client ID>
+
+ The <Client ID> is the client that joined to the channel.
- This type includes six arguments: Client ID, nickname, username,
- hostname, Channel ID and channel name. The Client ID and Channel ID
- are sent inside ID Payload.
3 SILC_NOTIFY_TYPE_LEAVE
- Sent when client has left a channel.
+ Sent when client has left a channel. The server must distribute
+ this type only to the local clients on the channel and then send
+ SILC_PACKET_REMOVE_CHANNEL_USER packet to its primary route. The
+ router or server receiving the packet distributes this type to the
+ local clients on the channel. See description of
+ SILC_PACKET_REMOVE_CHANNEL_USER packet for more information.
+
+ Max Arguments: 1
+ Arguments: (1) <Client ID>
+
+ The <Client ID> is the client who left the channel.
- This type includes four arguments: nickname, server name,
- Channel ID and channel name. The Channel ID is sent inside ID
- Payload.
4 SILC_NOTIFY_TYPE_SIGNOFF
- Sent when client signoffs from SILC network.
+ Sent when client signoffs from SILC network. This type is sent only
+ if the client was joined to any channel. This type is sent by server
+ or router when SILC_PACKET_REMOVE_ID packet has been received. See
+ detailed information from description of SILC_PACKET_REMOVE_ID packet.
+
+ Max Arguments: 1
+ Arguments: (1) <Client ID>
+
+ The <Client ID> is the client who left SILC network.
- This type includes three arguments: nickname, server name and
- Channel ID. The Channel ID is sent inside ID Payload.
5 SILC_NOTIFY_TYPE_TOPIC_SET
- Sent when topic is set/changed on a channel.
+ Sent when topic is set/changed on a channel. This type must be sent
+ only to the clients who is joined on the channel whose topic was
+ set or changed.
+
+ Max Arguments: 2
+ Arguments: (1) <Client ID> (2) <topic>
+
+ The <Client ID> is the client who set or changed the <topic>.
- This type includes four arguments: Channel ID, topic, nickname and
- hostname. The Channel ID is sent inside ID Payload.
6 SILC_NOTIFY_TYPE_NICK_CHANGE
- Sent when client changes nick on a channel.
+ Sent when client changes nick on a channel. This type is sent only if
+ the client has joined to any channel. This type is sent by server or
+ router when SILC_PACKET_REPLACE_ID packet has been received. See
+ detailed information from description of SILC_PACKET_REPLACE_ID packet.
+
+ Max Arguments: 2
+ Arguments: (1) <Old Client ID> (2) <New Client ID>
+
+ The <Old Client ID> is the old ID of the client who changed the
+ nickname. The <New Client ID> is the new ID generated by the change
+ of the nickname.
+
+
+7 SILC_NOTIFY_TYPE_CMODE_CHANGE
+
+ Sent when channel mode has changed. This type must be sent only to
+ the clients who is joined on the channel whose mode was changed.
+
+ Max Arguments: 2
+ Arguments: (1) <Client ID> (2) <mode mask>
+
+ The <Client ID> is the client who changed the mode. The <mode mask>
+ is the new mode mask of the channel.
+
+
+8 SILC_NOTIFY_TYPE_CUMODE_CHANGE
+
+ Sent when user mode on channel has changed. This type must be sent
+ only to the clients who is joined on the channel where the target
+ client is on.
+
+ Max Arguments: 3
+ Arguments: (1) <Client ID> (2) <mode mask>
+ (3) <Target Client ID>
+
+ 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 which mode was changed.
+
+
+9 SILC_NOTIFY_TYPE_MOTD
+
+ Sent when Message of the Day (motd) is sent to client.
+
+ Max Arguments: 1
+ Arguments: (1) <motd>
- This type includes two arguments: nickname and Channel ID.
- The Channel ID is sent inside ID Payload.
+ The <motd> is the Message of the Day.
.in 3
Notify types starting from 16384 are reserved for private notify
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