IKEv2, ESP PFS. Which packets includes the configuration?
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i am investigating currently the IKEv2 protocol with ESP payload encryption. For ESP i want to use PFS with DH Group 5 (which works).
However, i am not able to figure out in which packet this settings is sent to the partner.
In the first two packets (IKE_SA_INIT) i am able to find the DH group for the IKE SA. I assume that the setting is sent in the 3rd/4th message (IKE AUTH) _since all the CHILD_SA relevant stuff is in it (ENC/AUTH algorithm). But i can't find it (i decrypted the packet using wireshark isakmp decryption).
Where is this setting hidden?
Thanks
networking encryption wireshark
asked Nov 11 '15 at 16:49
user1816723
133
add a comment |
up vote
0
down vote
favorite
i am investigating currently the IKEv2 protocol with ESP payload encryption. For ESP i want to use PFS with DH Group 5 (which works).
However, i am not able to figure out in which packet this settings is sent to the partner.
In the first two packets (IKE_SA_INIT) i am able to find the DH group for the IKE SA. I assume that the setting is sent in the 3rd/4th message (IKE AUTH) _since all the CHILD_SA relevant stuff is in it (ENC/AUTH algorithm). But i can't find it (i decrypted the packet using wireshark isakmp decryption).
Where is this setting hidden?
Thanks
networking encryption wireshark
asked Nov 11 '15 at 16:49
user1816723
133
If you're using PFS, then how did Wireshark decrypt it?
– grawity
Nov 12 '15 at 14:27
doesn't answer my question. however, as far as i know for the first 4 packets (2x IKE_SA_INIT, 2x IKE_AUTH) PFS is not relevant since PFS is only used for the next CHILD_SA rekeying. To decrypt IKE_AUTH packets i used the computed SK_Ei, SK_Er
– user1816723
Nov 13 '15 at 17:49
1
The comment wasn't meant to answer the question, it was meant to ask one...
– grawity
Nov 13 '15 at 17:52
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
i am investigating currently the IKEv2 protocol with ESP payload encryption. For ESP i want to use PFS with DH Group 5 (which works).
However, i am not able to figure out in which packet this settings is sent to the partner.
In the first two packets (IKE_SA_INIT) i am able to find the DH group for the IKE SA. I assume that the setting is sent in the 3rd/4th message (IKE AUTH) _since all the CHILD_SA relevant stuff is in it (ENC/AUTH algorithm). But i can't find it (i decrypted the packet using wireshark isakmp decryption).
Where is this setting hidden?
Thanks
networking encryption wireshark
asked Nov 11 '15 at 16:49
user1816723
133
i am investigating currently the IKEv2 protocol with ESP payload encryption. For ESP i want to use PFS with DH Group 5 (which works).
However, i am not able to figure out in which packet this settings is sent to the partner.
In the first two packets (IKE_SA_INIT) i am able to find the DH group for the IKE SA. I assume that the setting is sent in the 3rd/4th message (IKE AUTH) _since all the CHILD_SA relevant stuff is in it (ENC/AUTH algorithm). But i can't find it (i decrypted the packet using wireshark isakmp decryption).
Where is this setting hidden?
Thanks
networking encryption wireshark
networking encryption wireshark
asked Nov 11 '15 at 16:49
user1816723
133
asked Nov 11 '15 at 16:49
user1816723
133
asked Nov 11 '15 at 16:49
user1816723
133
asked Nov 11 '15 at 16:49
user1816723
133
asked Nov 11 '15 at 16:49
user1816723
133
133
If you're using PFS, then how did Wireshark decrypt it?
– grawity
Nov 12 '15 at 14:27
doesn't answer my question. however, as far as i know for the first 4 packets (2x IKE_SA_INIT, 2x IKE_AUTH) PFS is not relevant since PFS is only used for the next CHILD_SA rekeying. To decrypt IKE_AUTH packets i used the computed SK_Ei, SK_Er
– user1816723
Nov 13 '15 at 17:49
1
The comment wasn't meant to answer the question, it was meant to ask one...
– grawity
Nov 13 '15 at 17:52
add a comment |
If you're using PFS, then how did Wireshark decrypt it?
– grawity
Nov 12 '15 at 14:27
doesn't answer my question. however, as far as i know for the first 4 packets (2x IKE_SA_INIT, 2x IKE_AUTH) PFS is not relevant since PFS is only used for the next CHILD_SA rekeying. To decrypt IKE_AUTH packets i used the computed SK_Ei, SK_Er
– user1816723
Nov 13 '15 at 17:49
1
The comment wasn't meant to answer the question, it was meant to ask one...
– grawity
Nov 13 '15 at 17:52
If you're using PFS, then how did Wireshark decrypt it?
– grawity
Nov 12 '15 at 14:27
If you're using PFS, then how did Wireshark decrypt it?
– grawity
Nov 12 '15 at 14:27
doesn't answer my question. however, as far as i know for the first 4 packets (2x IKE_SA_INIT, 2x IKE_AUTH) PFS is not relevant since PFS is only used for the next CHILD_SA rekeying. To decrypt IKE_AUTH packets i used the computed SK_Ei, SK_Er
– user1816723
Nov 13 '15 at 17:49
doesn't answer my question. however, as far as i know for the first 4 packets (2x IKE_SA_INIT, 2x IKE_AUTH) PFS is not relevant since PFS is only used for the next CHILD_SA rekeying. To decrypt IKE_AUTH packets i used the computed SK_Ei, SK_Er
– user1816723
Nov 13 '15 at 17:49
1
1
The comment wasn't meant to answer the question, it was meant to ask one...
– grawity
Nov 13 '15 at 17:52
The comment wasn't meant to answer the question, it was meant to ask one...
– grawity
Nov 13 '15 at 17:52
add a comment |
1 Answer
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The first Child SA is negotiated within the IKE_AUTH Payload. It's called SA[i|r]2 https://tools.ietf.org/html/rfc7296#section-1.2 . It's an extra SA Payload within the IKE_AUTH Payload.
The RFC states:
Note that IKE_AUTH messages do not contain KEi/KEr or Ni/Nr payloads.
Thus, the SA payloads in the IKE_AUTH exchange cannot contain
Transform Type 4 (Diffie-Hellman group) with any value other than
NONE. Implementations SHOULD omit the whole transform substructure
instead of sending value NONE.
To precisely answer your question: There is no PFS for the first CHILD_SA that is part of the IKE_AUTH exchanges. Any setting regarding PFS for CHILD_SAs only apply to CHILD_SA exchanges to create new CHILD_SAs after the initial exchanges.
answered Nov 29 at 13:31
Bezalel_DE
1
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The first Child SA is negotiated within the IKE_AUTH Payload. It's called SA[i|r]2 https://tools.ietf.org/html/rfc7296#section-1.2 . It's an extra SA Payload within the IKE_AUTH Payload.
The RFC states:
Note that IKE_AUTH messages do not contain KEi/KEr or Ni/Nr payloads.
Thus, the SA payloads in the IKE_AUTH exchange cannot contain
Transform Type 4 (Diffie-Hellman group) with any value other than
NONE. Implementations SHOULD omit the whole transform substructure
instead of sending value NONE.
To precisely answer your question: There is no PFS for the first CHILD_SA that is part of the IKE_AUTH exchanges. Any setting regarding PFS for CHILD_SAs only apply to CHILD_SA exchanges to create new CHILD_SAs after the initial exchanges.
answered Nov 29 at 13:31
Bezalel_DE
1
add a comment |
up vote
0
down vote
The first Child SA is negotiated within the IKE_AUTH Payload. It's called SA[i|r]2 https://tools.ietf.org/html/rfc7296#section-1.2 . It's an extra SA Payload within the IKE_AUTH Payload.
The RFC states:
Note that IKE_AUTH messages do not contain KEi/KEr or Ni/Nr payloads.
Thus, the SA payloads in the IKE_AUTH exchange cannot contain
Transform Type 4 (Diffie-Hellman group) with any value other than
NONE. Implementations SHOULD omit the whole transform substructure
instead of sending value NONE.
To precisely answer your question: There is no PFS for the first CHILD_SA that is part of the IKE_AUTH exchanges. Any setting regarding PFS for CHILD_SAs only apply to CHILD_SA exchanges to create new CHILD_SAs after the initial exchanges.
answered Nov 29 at 13:31
Bezalel_DE
1
add a comment |
up vote
0
down vote
up vote
0
down vote
The first Child SA is negotiated within the IKE_AUTH Payload. It's called SA[i|r]2 https://tools.ietf.org/html/rfc7296#section-1.2 . It's an extra SA Payload within the IKE_AUTH Payload.
The RFC states:
Note that IKE_AUTH messages do not contain KEi/KEr or Ni/Nr payloads.
Thus, the SA payloads in the IKE_AUTH exchange cannot contain
Transform Type 4 (Diffie-Hellman group) with any value other than
NONE. Implementations SHOULD omit the whole transform substructure
instead of sending value NONE.
To precisely answer your question: There is no PFS for the first CHILD_SA that is part of the IKE_AUTH exchanges. Any setting regarding PFS for CHILD_SAs only apply to CHILD_SA exchanges to create new CHILD_SAs after the initial exchanges.
answered Nov 29 at 13:31
Bezalel_DE
1
The first Child SA is negotiated within the IKE_AUTH Payload. It's called SA[i|r]2 https://tools.ietf.org/html/rfc7296#section-1.2 . It's an extra SA Payload within the IKE_AUTH Payload.
The RFC states:
Note that IKE_AUTH messages do not contain KEi/KEr or Ni/Nr payloads.
Thus, the SA payloads in the IKE_AUTH exchange cannot contain
Transform Type 4 (Diffie-Hellman group) with any value other than
NONE. Implementations SHOULD omit the whole transform substructure
instead of sending value NONE.
To precisely answer your question: There is no PFS for the first CHILD_SA that is part of the IKE_AUTH exchanges. Any setting regarding PFS for CHILD_SAs only apply to CHILD_SA exchanges to create new CHILD_SAs after the initial exchanges.
answered Nov 29 at 13:31
Bezalel_DE
1
answered Nov 29 at 13:31
Bezalel_DE
1
answered Nov 29 at 13:31
Bezalel_DE
1
answered Nov 29 at 13:31
Bezalel_DE
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If you're using PFS, then how did Wireshark decrypt it?
– grawity
Nov 12 '15 at 14:27
doesn't answer my question. however, as far as i know for the first 4 packets (2x IKE_SA_INIT, 2x IKE_AUTH) PFS is not relevant since PFS is only used for the next CHILD_SA rekeying. To decrypt IKE_AUTH packets i used the computed SK_Ei, SK_Er
– user1816723
Nov 13 '15 at 17:49
1
The comment wasn't meant to answer the question, it was meant to ask one...
– grawity
Nov 13 '15 at 17:52