Client usually sends the commands and server replies by sending a reply
packet to the command. Server MAY also send commands usually to serve
-the original client's request. However, server MUST NOT send commands
-to client and there are some commands that server must not send.
+the original client's request. Usually server cannot send commands to
+clients, however there MAY be commands that allow the server to send
+commands to client. By default servers MAY send commands only to other
+servers and routers.
Note that the command reply is usually sent only after client has sent
the command request but server is allowed to send command reply packet
-to client even if client has not requested the command. Client MAY,
+to client even if client has not requested the command. Client MAY
choose to ignore the command reply.
It is expected that some of the commands may be miss-used by clients
3.9.1 Authentication Payload
Authentication payload is used separately from the SKE and the Connection
-Authentication protocol. It is used during the session to authenticate
+Authentication protocol. It can be used during the session to authenticate
with the remote. For example, the client can authenticate itself to the
server to become server operator. In this case, Authentication Payload is
used.
the signature process, described subsequently.
o Authentication Data Length (2 bytes) - Indicates the
- length of the Authentication Data field.
+ length of the Authentication Data field. If zero (0)
+ value is found in this field the payload MUST be
+ discarded.
o Authentication Data (variable length) - Authentication
method dependent authentication data.
cryptography function selected in the SKE protocol. The public key
is SILC style public key unless certificates are used. The ID is the
entity's ID (Client or Server ID) which is authenticating itself. The
-ID is raw ID data. The random bytes are non-zero random bytes of
-length between 128 and 4096 bytes, and will be included into the
-Public Data field as is.
+ID encoding is described in [SILC2]. The random bytes are non-zero
+random bytes of length between 128 and 4096 bytes, and will be included
+into the Public Data field as is.
The receiver will compute the signature using the random data received
in the payload, the ID associated to the connection and the public key
(or certificate) received in the SKE protocol. After computing the
-receiver MUST verify the signature. In this case also, the entire
-payload is encrypted.
+receiver MUST verify the signature. In case of public key authentication
+this payload is also encrypted.
.ti 0
it should have cached the Client ID from the SILC Packet Header.
If server receives a private message packet which includes invalid
-destionation Client ID the server MUST send SILC_COMMAND_IDENTIFY
-command reply packet destined to the client with error status.
+destionation Client ID the server MUST send SILC_NOTIFY_TYPE_ERROR
+notify to the client with error status indicating that such ID does
+not exist to the client.
See [SILC2] for description of private message encryption and decryption
process.
authentication.
When server receives the SILC_PACKET_RESUME_CLIENT packet it MUST
-verify that the Client ID is valid client and that it has the
-SILC_UMODE_DETACHED mode set. It then MUST verify the Authentication
-Payload with the detached client's public key. If it does not have
-the public key it MUST retrieve it by sending SILC_COMMAND_GETKEY
-command to the server that has the public key from the original
-client connection. The server MUST NOT use the public key received
-in the SKE protocol for this connection. If the signature is valid
-the server MUST unset the SILC_UMODE_DETACHED flag, and send the
-SILC_PACKET_RESUME_CLIENT packet to its primary router. The routers
-MUST broadcast the packet and unset the SILC_UMODE_DETACHED flag
-when the packet is received. If the server is router server it also
-MUST send the SILC_PACKET_RESUME_CLIENT packet to the original server
-whom owned the detached client.
+do the following: Server checks that the Client ID is valid client
+and that it has the SILC_UMODE_DETACHED mode set. Then it verifies
+the Authentication Payload with the detached client's public key.
+If it does not have the public key it retrieves it by sending
+SILC_COMMAND_GETKEY command to the server that has the public key from
+the original client connection. The server MUST NOT use the public
+key received in the SKE protocol for this connection. If the
+signature is valid the server unsets the SILC_UMODE_DETACHED flag,
+and sends the SILC_PACKET_RESUME_CLIENT packet to its primary router.
+The routers MUST broadcast the packet and unset the SILC_UMODE_DETACHED
+flag when the packet is received. If the server is router server it
+also MUST send the SILC_PACKET_RESUME_CLIENT packet to the original
+server whom owned the detached client.
The servers and routers that receives the SILC_PACKET_RESUME_CLIENT
packet MUST know whether the packet already has been received for
same server that it originally came from. They must update their
caches according this. The server that now owns the client session
MUST check whether the Client ID of the resumed client is based
-on the server's Server ID. If it is not it MUST create new Client
+on the server's Server ID. If it is not it creates a new Client
ID and send SILC_NOTIFY_TYPE_NICK_CHANGE to the network. It MUST
also send the channel keys of all channels that the client is
joined to the client since it does not have them. Whether the
to the network and may start sending packets and messages.
It is also possible that the server does not know about the channels
-that the client has joined. In this case it MUST join client internally
+that the client has joined. In this case it join the client internally
to the channels, generate new channel keys and distribute the keys
to the channels as described in section 4.4.
projects / silc.git / blobdiff