4 Possible SILC protocol and specification document changes. All of these
5 are tentative and doesn't mean that any of them would be done at any
8 o Full rework of the documents as requested by RFC Editor. The plan
9 is to create only two documents:
11 silc-architecture-xx.txt
12 silc-specification-xx.txt
14 o Make @ reserved character in channel names. Accept channel@server
15 names in all commands and notify types.
17 o Add acknowlegments section to specification documents.
19 o Group Diffie-Hellman protocol for establishig key with two or more
22 o Change CTR mode description:
24 Truncated HASH from SKE (4 bytes) - This value is the first 4
25 bytes from the HASH value that was computed as a result of SKE
26 protocol. This acts as session identifier and each rekey MUST
27 produce a new HASH value.
31 Truncated HASH from SKE (4 bytes) - This value is the first 4
32 bytes from the HASH value that was computed in SKE. In each rekey
33 the value MUST be recomputed as follows:
35 HASH = hash(old Truncated HASH from SKE |
36 new Sending/Receiving IV from SKE)
38 The hash function is the one used in SKE. The 'new Sending/Receiving
39 IV from SKE' is the first 8 bytes of the new value computed during
40 rekey. The first 4 bytes are used from the recomputed HASH.
42 o Extend the Channel ID port to be actually a counter, allowing the
43 2^32 channels per cell, instead of 2^16 like now. The port with
44 compliant implementation would always be 706, and it could be used
45 as a counter, starting from 706... For interop, with old code.
47 o In SKE with UDP/IP responder doesn't have to do retransmissions.
48 Initiator will retransmit its packet. Initiator can be considered
49 the one that actually WANTs to establish the keys. So no need for
50 responder to retransmit. Define this clearly in the specs.
52 o Define clearly that the DSS signature format is the the Dss-Sig-Value
53 ASN.1 encoding defined for PKIX.
55 o Define clearly the SSH2 signature format is the one specified for SSH2
58 o Dynamic server and router connections, ala Jabber. SILC has allowed
59 this from the beginning. It should be written out clearly in the
60 specs. Connection would be created with nick strings (which are of
63 o NAT detection protocool during SKE so that party behind NAT can
64 detect if it is behind NAT and receive the public IP address and port
65 that it may need (servers need it to create valid Server ID). (***DONE)
67 o Counter block send/receive IV 64 bits instead of 32 bits, and the
68 value itself is used as 64-bit MSB ordered counter, which must
69 be reset before the packet sequence counter wraps. It's basically
70 a counter which is initially set to a random value. (***DONE)
72 o Nickname to NEW_CLIENT packet. (***DONE)
74 o Add Source and Destination ID in message MAC computation to fully
75 associate the Message Payload with the true sender and the true
76 recipient of the message. This will fix some security issues that
77 currently exists. It is currently possible in some specific set of
78 conditions to mount a replay attack using Message Payload. This change
79 will remove the possibility of these attacks.
81 After including Source and Destination ID in message MAC, ONLY replay
82 attack possible is the following and with ONLY following conditions:
84 1. the attacker is able to record encrypted Message Payloads and has
85 the ability to replay them.
86 2. the message payload is encrypted with static private message key
87 3. the original sender of the message is not anymore in the network,
88 has changed nickname, has detached and resumed, or has reconnected
90 4. the original receiver of the message is still in the network, has
91 not changed nickname, has not detached and resumed, and has not
92 reconnected to any other server, or, some other user has the same
94 5. the attacker is able to get the same client ID as the original
96 6. the original receiver still has the static key set for the same
97 remote client ID (for original sender's client ID).
99 All this is possible to happen though likelyhood is quite small. It
100 does illustrate how inappropriate the use of static keys is. (***DONE)
102 o The SILC public key identifier separator is ', ' not ','. The
103 whitespace is mandatory. (***DONE)
105 o Definition of EAP as new authentication method for connection auth
108 o Count limit to LIST command?
110 o Strict announces if Channel ID is different than on router? To not
111 allow any modes, topic, etc changes from server if the ID was wrong
112 initially? Meaning: riding with netsplits not possible since the
113 channel created during split will not enforce is modes to the
114 router. Or more liberal solution, like now? Read emails on
115 silc-users. (This is very old issue)
117 o The time values in STATS is 32-bits. After 2038 it's over 32-bits.
119 o Consider for future authenticated encryption modes.