SG_I_RFC2406_2_2 - [Initiator Test] Increasing Sequence Number
SGW
SG_I_RFC2406_2_2.seq [-tooloption ...] -pkt SG_I_RFC2406_2_2.def -tooloption : v6eval tool option
See also ike_common.def and ike_ipsec.def and ike_pkt_ph1_recv.def and ike_pkt_ph2_recv.def
HOST-2(TN)
|3ffe:501:ffff:104::11
|
Net-v --+------------------------+-------- 3ffe:501:ffff:104::/64
|
|
SGW-2(TN):responder
|3ffe:501:ffff:103::11
|
Net-w --+--------+------------------------ 3ffe:501:ffff:103::/64
|
|
ROUTER-2(TN)
| 3ffe:501:ffff:102::11
|
Net-x --+--------+------------------------ 3ffe:501:ffff:102::/64
|
|3ffe:501:ffff:102::1
SGW-1(NUT):initiator
|3ffe:501:ffff:101::1
|
Net-y --+--------+------------------------ 3ffe:501:ffff:101::/64
|
| 3ffe:501:ffff:101::11
ROUTER-1(TN)
|
|
Net-z -----------+---------------+-------- 3ffe:501:ffff:100::/64
|
|3ffe:501:ffff:100::13
HOST-1(TN)
Verification Points
Encapsulating Security Payload Packet Format
Sequence Number
This unsigned 32-bit field contains a monotonically increasing
counter value (sequence number). It is mandatory and is always
present even if the receiver does not elect to enable the anti-replay
service for a specific SA. Processing of the Sequence Number field
is at the discretion of the receiver, i.e., the sender MUST always
transmit this field, but the receiver need not act upon it.
Configuration
Initiator and Responder IKE parameter
At least, following parameter must be included in proposal.
| Machine |
Src |
Dest |
Phase I |
Phase II |
| Ex mode |
Key Value |
Enc Alg |
Hash Alg |
Auth Method |
DH Group |
PH1 Lt |
IDx |
Proto ID |
Trans ID |
Mode |
Auth Alg |
PH2 Lt |
IDci |
IDcr |
Upper |
| SGW-1 |
SGW-1 addr |
SGW-2 addr |
Main |
IKE-TEST |
3DES |
SHA |
pre-shared key |
2 |
8 Hour |
SGW-1 addr |
PROTO_IPSEC_ESP |
ESP_3DES |
Tunnel |
HMAC-SHA |
8 Hour |
HOST-1 addr |
HOST-2 addr |
any |
| SGW-2 |
SGW-2 addr |
SGW-1 addr |
Main |
IKE-TEST |
3DES |
SHA |
pre-shared key |
2 |
8 Hour |
SGW-2 addr |
PROTO_IPSEC_ESP |
ESP_3DES |
Tunnel |
HMAC-SHA |
8 Hour |
HOST-1 addr |
HOST-2 addr |
any |
*Ex Mode = Exchange mode(Aggresive mode can also be chosen as Ex Mode)
*IDx = identity payload(FQDN or user FQDN can also be chosen as IDx)
*IDci = identity payload
*IDcr = identity payload
*Enc Alg = IKE Encryption Algorithm
*Hash Alg = IKE Authentication Algorithm
*Key Value = pre-shared key value
*PH1 Lt = Phase-1 Lifetime
*PH2 Lt = Phase-2 Lifetime
*Proto ID = Protocol Identifier
*Trans ID = Transform Identifier
*Mode = Encapsulation Mode
*Auth Alg = Authentication Algorithm
*Auth Method = Authentication Method
*DH Group = Diffie-Hellman Group
*Upper = Upper Layer Protocol
*SGW-1 addr = SGW-1 address
*SGW-2 addr = SGW-2 address
*HOST-1 addr = HOST-1 address
*HOST-2 addr = HOST-2 address
Pre-Sequence
In order to start the negotiation of IKE,
TN(HOST-1) transmits Echo Request to TN(HOST-2).
This test check is following.
* PHASE I
Either IDENTITY PROTECTION EXCHANGE or AGGRESSIVE EXCHANGE is performed as a pre sequence.
IDENTITY PROTECTION EXCHANGE
# Initiator(NUT) Direction Responder(TN)
(1) HDR; SA ========>
(2) <======== HDR; SA
(3) HDR; KE; NONCE ========>
(4) <======== HDR; KE; NONCE
(5) HDR*; IDii; HASH_I ========>
(6) <======== HDR*; IDir; HASH_R
1. Receive the first message from NUT
In the first message (1), the initiator generates a proposal it
considers adequate to protect traffic for the given situation. The
Security Association, Proposal, and Transform payloads are included
in the Security Association payload (for notation purposes).
2. Send the second message from TN
In the second message (2), the responder indicates the protection
suite it has accepted with the Security Association, Proposal, and
Transform payloads.
3. Receive the third message from NUT
In the third (3) message, the initiator send keying material
used to arrive at a common shared secret and random information
which is used to guarantee liveness and protect against replay attacks.
4. Send the fourth message from TN
In the fourth (4) message, the responder send keying material
used to arrive at a common shared secret and random information
which is used to guarantee liveness and protect against replay attacks.
5. Receive the fifth message from NUT
In the fifth (5) message, the initiator send identification
information and the results of the agreed upon authentication
function(hash function).
6. Send the sixth message from TN
In the sixth (6) message, the responder send identification
information and the results of the agreed upon authentication
function(hash function).
AGGRESSIVE EXCHANGE
# Initiator(NUT) Direction Responder(TN) NOTE
(1) HDR; SA; KE; => Begin ISAKMP-SA or
Proxy negotiation
NONCE; IDii and Key Exchange
(2) <= HDR; SA; KE;
NONCE; IDir; AUTH
Initiator Identity
Verified by Responder
Key Generated
Basic SA agreed upon
(3) HDR*; AUTH =>
Responder Identity
Verified by Initiator
SA established
1. Recieve the first message from NUT
In the first message (1), the initiator generates a proposal it
considers adequate to protect traffic for the given situation. The
Security Association, Proposal, and Transform payloads are included
in the Security Association payload (for notation purposes). There
can be only one Proposal and one Transform offered (i.e. no choices)
in order for the aggressive exchange to work. Keying material used
to arrive at a common shared secret and random information which is
used to guarantee liveness and protect against replay attacks are
also transmitted. Random information provided by both parties SHOULD
be used by the authentication mechanism to provide shared proof of
participation in the exchange. Additionally, the initiator transmits
identification information.
2. Send the second message from TN
In the second message (2), the responder indicates the protection
suite it has accepted with the Security Association, Proposal, and
Transform payloads. Keying material used to arrive at a common
shared secret and random information which is used to guarantee
liveness and protect against replay attacks is also transmitted.
Random information provided by both parties SHOULD be used by the
authentication mechanism to provide shared proof of participation in
the exchange. Additionally, the responder transmits identification
information. All of this information is transmitted under the
protection of the agreed upon authentication function. Local
security policy dictates the action of the responder if no proposed
protection suite is accepted. One possible action is the
transmission of a Notify payload as part of an Informational
Exchange.
3. Recieve the third message from NUT
In the third (3) message, the initiator transmits the results of the
agreed upon authentication function. This information is transmitted
under the protection of the common shared secret. Local security
policy dictates the action if an error occurs during these messages.
One possible action is the transmission of a Notify payload as part
of an Informational Exchange.
* PHASE II
QUICK MODE
# Initiator(NUT) Direction Responder(TN)
(1) HDR*, HASH(1),
SA, Ni,IDci, IDcr; ========>
(2) <======== HDR*, HASH(2), SA, Nr, IDci, IDcr;
(3) HDR*, HASH(3) ========>
1. Receive the first message from NUT
In the first message (1), the initiator generates a proposal it
considers adequate to protect traffic for the given situation. The
Security Association, Proposal, and Transform payloads are included
in the Security Association payload (for notation purposes).
And initiator send HASH(1) and Nonce. HASH(1) is the prf over the
message id (M-ID) from the ISAKMP header concatenated with the entire
message that follows the hash including all payload headers,
but excluding any padding added for encryption. Nonce is random
information which is used to guarantee liveness. IDci and IDcr is
identification information.
2. Send the second message from TN
In the second message (2), the responder indicates the protection
suite it has accepted with the Security Association, Proposal, and
Transform payloads. And responder send HASH(2) and Nonce.
HASH(2) is identical to HASH(1) except the initiator's nonce-- Ni,
minus the payload header-- is added after M-ID but before the
complete message. Nonce is random
information which is used to guarantee liveness. IDci and IDcr is
identification information.
3. Receive the third message from NUT
In the third (3) message, the initiator send HASH(3).
HASH(3)-- for liveliness-- is the prf over the
value zero represented as a single octet, followed by a concatenation
of the message id and the two nonces-- the initiator's followed by
the responder's-- minus the payload header.
The test sequence is following.
* IPsec transmission
# Initiator(NUT) Direction Responder(TN)
(1) IP_HDR; ESP*;
ICMP(Echo request) ========>
(2) IP_HDR; ESP*;
ICMP(Echo request) ========>
Judgement (Check *1)
1. Receive the first message from NUT
In the first message (1), initiator(NUT) forward Echo request from HOST-1(TN)
to responder(TN) with IPsec SA.
2. Receive the second message from NUT
In the second message (2), initiator(NUT) forward Echo request from HOST-1(TN)
to responder(TN) with IPsec SA.
In Phase I , messages must be exchanged correctly.
In Phase II , the first to the third message must be exchanged correctly,
In IPsec SA transmission, the first message's Sequence Number must be "1".
and the second message's Sequence Number must be "2".
And must conform to above Configuration.
Clean up SAD and SPD
RFC2406
2. Encapsulating Security Payload Packet Format
The protocol header (IPv4, IPv6, or Extension) immediately preceding
the ESP header will contain the value 50 in its Protocol (IPv4) or
Next Header (IPv6, Extension) field [STD-2].
0 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ----
| Security Parameters Index (SPI) | ^Auth.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Cov-
| Sequence Number | |erage
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ----
| Payload Data* (variable) | | ^
~ ~ | |
| | |Conf.
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Cov-
| | Padding (0-255 bytes) | |erage*
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
| | Pad Length | Next Header | v v
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ------
| Authentication Data (variable) |
~ ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(omit)
2.2 Sequence Number
This unsigned 32-bit field contains a monotonically increasing
counter value (sequence number). It is mandatory and is always
present even if the receiver does not elect to enable the anti-replay
service for a specific SA. Processing of the Sequence Number field
is at the discretion of the receiver, i.e., the sender MUST always
transmit this field, but the receiver need not act upon it (see the
discussion of Sequence Number Verification in the "Inbound Packet
Processing" section below).
The sender's counter and the receiver's counter are initialized to 0
when an SA is established. (The first packet sent using a given SA
will have a Sequence Number of 1; see Section 3.3.3 for more details
on how the Sequence Number is generated.) If anti-replay is enabled
(the default), the transmitted Sequence Number must never be allowed
to cycle. Thus, the sender's counter and the receiver's counter MUST
be reset (by establishing a new SA and thus a new key) prior to the
transmission of the 2^32nd packet on an SA.
(omit)
3.3.3 Sequence Number Generation
The sender's counter is initialized to 0 when an SA is established.
The sender increments the Sequence Number for this SA and inserts the
new value into the Sequence Number field. Thus the first packet sent
using a given SA will have a Sequence Number of 1.
If anti-replay is enabled (the default), the sender checks to ensure
that the counter has not cycled before inserting the new value in the
Sequence Number field. In other words, the sender MUST NOT send a
packet on an SA if doing so would cause the Sequence Number to cycle.
An attempt to transmit a packet that would result in Sequence Number
overflow is an auditable event. (Note that this approach to Sequence
Number management does not require use of modular arithmetic.)
The sender assumes anti-replay is enabled as a default, unless
otherwise notified by the receiver (see 3.4.3). Thus, if the counter
has cycled, the sender will set up a new SA and key (unless the SA
was configured with manual key management).
If anti-replay is disabled, the sender does not need to monitor or
reset the counter, e.g., in the case of manual key management (see
Section 5). However, the sender still increments the counter and
when it reaches the maximum value, the counter rolls over back to
zero.
perldoc V6evalTool
IKE.html IKE Test Common Utility