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Questions[eap](server)

Martin Hope
Domokun
Asked: 2020-08-06 10:42:59 +0800 CST
  • 3

I have a project that involves custom client authentication for the StrongSwan IKEv2 server implementation on Linux.

I am running: StrongSwan 5.4.0 with eap-radius plugin

Currently, we use FreeRadius to speak EAP-MSCHAPv2 with various client platforms (Windows, Mac, Linux). Due to some limitations, we need to implement our own RADIUS "speaking" + EAP-MSCHAPv2 server to replace FreeRadius. I wont go into details as to why this is needed (but I will say that it is required), but, I am running into an issue that I can't seem to figure out.

Following the RFC specs for the RADIUS protocol, as well as the EAP and MSCHAPv2 protocols, I have created a POC server that authenticates clients. The implementation works for all Mac OSX clients, Android clients (using strongswan app), and linux clients.

The issues start with Windows clients (tested Windows 10 + 7). For some reason, the Windows client errors out with code 691, which is a generic error that implies either a wrong username/password, or wrong authentication protocol.

I have confirmed in numerous ways that my EAP-MSCHAPv2 implementation follows the RFC specs:

MSCHAPv2 RFC: https://www.rfc-editor.org/rfc/rfc2759

At the bottom of that RFC, there are example data sets. When I use the username and password in those examples, my code generates the correct output:

INPUTS:
AuthenticatorChallenge = 5B5D7C7D7B3F2F3E3C2C602132262628
PeerChallenge = 21402324255E262A28295F2B3A337C7E
username = "User"
password = "clientPass"

OUTPUT:
8-octet Challenge: = D02E4386BCE91226
24 octet NT-Response:: 82309ECD8D708B5EA08FAA3981CD83544233114A3D85D6DF
42-octet AuthenticatorResponse: S=407A5589115FD0D6209F510FE9C04566932CDA56

This validates that my implementation is following the RFC spec for the data that should be calculated during the MSCHAPv2 portions of the EAP conversation. This is also confirmed by the fact that Mac, Android and Linux clients authenticate successfully.

This leads me to beleive that the Windows error is related to the packet format, and not the underlying values being generated by my code. To that end, I enabled full debug logging in StrongSwan and pointed the authentication back to FreeRadius, so that I could log a successful authentication conversation with FreeRadius, then compare the packets with my own POC.

The following is a successful Windows EAP conversation with FreeRadius:

  1. EAP Identity + Challenge Response
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1> sending RADIUS Access-Request to server '127.0.0.1'
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1> => 168 bytes @ 0x7f55f00014b0
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>    0: 01 F6 00 A8 73 40 3E 5D A8 2A 50 21 53 8E FE 52  ....s@>].*P!S..R
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>   16: 0F 14 D1 8E 01 12 72 34 32 6D 33 6E 63 76 2D 65  ......r42m3ncv-e
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>   32: 38 77 66 70 67 33 3D 06 00 00 00 05 06 06 00 00  8wfpg3=.........
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>   48: 00 02 05 06 00 00 00 01 57 10 69 6B 65 76 32 2D  ........W.ikev2-
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>   64: 6D 73 63 68 61 70 76 32 04 06 C4 34 2E 23 1E 0E  mschapv2...4.#..
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>   80: 31 39 36 2E 35 32 2E 34 36 2E 33 35 1F 10 36 36  196.52.46.35..66
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>   96: 2E 32 30 37 2E 32 30 38 2E 32 32 36 4F 17 02 00  .207.208.226O...
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>  112: 00 15 01 72 34 32 6D 33 6E 63 76 2D 65 38 77 66  ...r42m3ncv-e8wf
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>  128: 70 67 33 20 13 63 61 2D 30 30 31 5F 73 74 72 6F  pg3 .ca-001_stro
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>  144: 6E 67 73 77 61 6E 50 12 E1 CD BD 37 42 F0 6C BE  ngswanP....7B.l.
Jul 30 01:02:38 87[CFG] <ikev2-mschapv2|1>  160: 64 AB BD F6 19 B6 9A A6                          d.......
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1> received RADIUS Access-Challenge from server '127.0.0.1'
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1> => 112 bytes @ 0x7f55f0000de0
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>    0: 0B F6 00 70 ED 7D 83 2C AF 6E 81 05 ED E7 73 43  ...p.}.,.n....sC
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>   16: 60 19 76 B7 1A 0C 00 00 01 37 1C 06 0A FF FF 03  `.v......7......
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>   32: 4F 2C 01 01 00 2A 1A 01 01 00 25 10 FC 80 3D 84  O,...*....%...=.
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>   48: 7A A0 ED DC FF E3 CB 7C C3 07 62 FC 72 34 32 6D  z......|..b.r42m
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>   64: 33 6E 63 76 2D 65 38 77 66 70 67 33 50 12 63 4F  3ncv-e8wfpg3P.cO
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>   80: 24 0B F0 D1 B3 09 7B 74 40 5C DF FC FB CC 18 12  $.....{t@\......
Jul 30 01:02:39 87[CFG] <ikev2-mschapv2|1>   96: 01 A0 90 AE 01 A1 8A DA 3E A1 21 17 0E 05 88 2C  ........>.!....,
Jul 30 01:02:39 87[IKE] <ikev2-mschapv2|1> EAP_MSCHAPV2 payload => 42 bytes @ 0x7f55f0000ee0
Jul 30 01:02:39 87[IKE] <ikev2-mschapv2|1>    0: 01 01 00 2A 1A 01 01 00 25 10 FC 80 3D 84 7A A0  ...*....%...=.z.
Jul 30 01:02:39 87[IKE] <ikev2-mschapv2|1>   16: ED DC FF E3 CB 7C C3 07 62 FC 72 34 32 6D 33 6E  .....|..b.r42m3n
Jul 30 01:02:39 87[IKE] <ikev2-mschapv2|1>   32: 63 76 2D 65 38 77 66 70 67 33                    cv-e8wfpg3
Jul 30 01:02:39 87[IKE] <ikev2-mschapv2|1> initiating EAP_MSCHAPV2 method (id 0x01)
  1. EAP Request Packet + Success Packet (Access-Challenge) Response:
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1> sending RADIUS Access-Request to server '127.0.0.1'
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1> => 240 bytes @ 0x7f5618001570
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>    0: 01 F7 00 F0 8A 5D 27 E3 01 D1 65 4C 07 7B CC 4A  .....]'...eL.{.J
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   16: 41 12 87 95 01 12 72 34 32 6D 33 6E 63 76 2D 65  A.....r42m3ncv-e
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   32: 38 77 66 70 67 33 3D 06 00 00 00 05 06 06 00 00  8wfpg3=.........
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   48: 00 02 05 06 00 00 00 01 57 10 69 6B 65 76 32 2D  ........W.ikev2-
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   64: 6D 73 63 68 61 70 76 32 04 06 C4 34 2E 23 1E 0E  mschapv2...4.#..
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   80: 31 39 36 2E 35 32 2E 34 36 2E 33 35 1F 10 36 36  196.52.46.35..66
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   96: 2E 32 30 37 2E 32 30 38 2E 32 32 36 4F 4D 02 01  .207.208.226OM..
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  112: 00 4B 1A 02 01 00 46 31 7F D3 69 D7 24 FB 6A 9E  .K....F1..i.$.j.
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  128: 22 39 C7 3F B0 43 94 3C 00 00 00 00 00 00 00 00  "9.?.C.<........
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  144: 76 E7 D7 C3 6B 69 85 B0 1F 7E EF 8D 11 C6 78 28  v...ki...~....x(
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  160: D3 F4 78 04 40 BD BD 39 00 72 34 32 6D 33 6E 63  [email protected]
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  176: 76 2D 65 38 77 66 70 67 33 20 13 63 61 2D 30 30  v-e8wfpg3 .ca-00
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  192: 31 5F 73 74 72 6F 6E 67 73 77 61 6E 18 12 01 A0  1_strongswan....
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  208: 90 AE 01 A1 8A DA 3E A1 21 17 0E 05 88 2C 50 12  ......>.!....,P.
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  224: 73 4F EF F8 F6 08 B9 31 DA FC 35 25 0F CF 00 30  sO.....1..5%...0
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1> received RADIUS Access-Challenge from server '127.0.0.1'
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1> => 121 bytes @ 0x7f5618001160
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>    0: 0B F7 00 79 F6 E1 7C CC C5 C7 FA 31 F7 9A 68 45  ...y..|....1..hE
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   16: 71 6A D6 A9 1A 0C 00 00 01 37 1C 06 0A FF FF 03  qj.......7......
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   32: 4F 35 01 02 00 33 1A 03 01 00 2E 53 3D 32 30 46  O5...3.....S=20F
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   48: 46 45 45 38 39 43 31 31 41 39 37 36 44 45 43 34  FEE89C11A976DEC4
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   64: 38 46 42 46 44 34 44 44 31 33 32 46 43 31 36 33  8FBFD4DD132FC163
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   80: 36 39 33 35 31 50 12 D1 D9 D9 CB 8D C1 9A F8 EE  69351P..........
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>   96: 40 12 C5 13 F5 CD 40 18 12 01 A0 90 AE 00 A2 8A  @.....@.........
Jul 30 01:02:39 48[CFG] <ikev2-mschapv2|1>  112: DA 3E A1 21 17 0E 05 88 2C                       .>.!....,
Jul 30 01:02:39 48[IKE] <ikev2-mschapv2|1> EAP_MSCHAPV2 payload => 51 bytes @ 0x7f56180012c0
Jul 30 01:02:39 48[IKE] <ikev2-mschapv2|1>    0: 01 02 00 33 1A 03 01 00 2E 53 3D 32 30 46 46 45  ...3.....S=20FFE
Jul 30 01:02:39 48[IKE] <ikev2-mschapv2|1>   16: 45 38 39 43 31 31 41 39 37 36 44 45 43 34 38 46  E89C11A976DEC48F
Jul 30 01:02:39 48[IKE] <ikev2-mschapv2|1>   32: 42 46 44 34 44 44 31 33 32 46 43 31 36 33 36 39  BFD4DD132FC16369
Jul 30 01:02:39 48[IKE] <ikev2-mschapv2|1>   48: 33 35 31                                         351
Jul 30 01:02:39 48[ENC] <ikev2-mschapv2|1> added payload of type EAP to message
  1. EAP Success -> Success (Access-Accept) Response:
Jul 30 01:02:39 124[ENC] <ikev2-mschapv2|1> parsed IKE_AUTH request 4 [ EAP/RES/MSCHAPV2 ]
Jul 30 01:02:39 124[IKE] <ikev2-mschapv2|1> EAP_MSCHAPV2 payload => 6 bytes @ 0x7f55d80012f0
Jul 30 01:02:39 124[IKE] <ikev2-mschapv2|1>    0: 02 02 00 06 1A 03                                ......
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1> sending RADIUS Access-Request to server '127.0.0.1'
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1> => 171 bytes @ 0x7f55d8000980
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>    0: 01 A8 00 AB CA 0B A5 7E 53 26 BB 1F 7B F5 BC 66  .......~S&..{..f
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   16: BD 7B 9D 87 01 12 72 34 32 6D 33 6E 63 76 2D 65  .{....r42m3ncv-e
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   32: 38 77 66 70 67 33 3D 06 00 00 00 05 06 06 00 00  8wfpg3=.........
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   48: 00 02 05 06 00 00 00 01 57 10 69 6B 65 76 32 2D  ........W.ikev2-
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   64: 6D 73 63 68 61 70 76 32 04 06 C4 34 2E 23 1E 0E  mschapv2...4.#..
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   80: 31 39 36 2E 35 32 2E 34 36 2E 33 35 1F 10 36 36  196.52.46.35..66
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   96: 2E 32 30 37 2E 32 30 38 2E 32 32 36 4F 08 02 02  .207.208.226O...
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  112: 00 06 1A 03 20 13 63 61 2D 30 30 31 5F 73 74 72  .... .ca-001_str
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  128: 6F 6E 67 73 77 61 6E 18 12 01 A0 90 AE 00 A2 8A  ongswan.........
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  144: DA 3E A1 21 17 0E 05 88 2C 50 12 AA 6E 35 90 03  .>.!....,P..n5..
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  160: 74 77 80 4A 2E BD FD A7 B2 C5 5B                 tw.J......[
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1> received RADIUS Access-Accept from server '127.0.0.1'
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1> => 182 bytes @ 0x7f55d8001750
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>    0: 02 A8 00 B6 61 C5 9A 92 51 CB DD 0B DF 37 3A 0F  ....a...Q....7:.
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   16: 83 40 AB F2 1A 0C 00 00 01 37 1C 06 0A FF FF 03  [email protected]......
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   32: 1A 0C 00 00 01 37 07 06 00 00 00 01 1A 0C 00 00  .....7..........
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   48: 01 37 08 06 00 00 00 06 1A 2A 00 00 01 37 10 24  .7.......*...7.$
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   64: E6 DC E1 89 5C 76 E8 8A BA 58 F7 7B B6 5E 62 4C  ....\v...X.{.^bL
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   80: 7F EB BB C2 45 5A 6B F7 0E 01 F3 9E 0F AD 0E AE  ....EZk.........
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>   96: A3 92 1A 2A 00 00 01 37 11 24 ED F6 C9 A5 D7 3A  ...*...7.$.....:
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  112: 0D C4 4D 93 4F 99 6E 81 28 AC B1 CE 30 DA A0 AF  ..M.O.n.(...0...
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  128: 4F 28 71 60 12 E5 35 39 04 27 A6 68 4F 06 03 02  O(q`..59.'.hO...
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  144: 00 04 50 12 C3 89 53 1A 29 FD 07 DD 11 FB 65 82  ..P...S.).....e.
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  160: 73 93 0C B2 01 12 72 34 32 6D 33 6E 63 76 2D 65  s.....r42m3ncv-e
Jul 30 01:02:39 124[CFG] <ikev2-mschapv2|1>  176: 38 77 66 70 67 33                                8wfpg3

Now the EAP conversation with my POC:

  1. EAP Identity + Challenge Response
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1> sending RADIUS Access-Request to server '127.0.0.1'
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1> => 168 bytes @ 0x7fc2800019c0
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>    0: 01 56 00 A8 C3 0E 12 EC A6 1A 72 E2 3C CA 4A 78  .V........r.<.Jx
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   16: 54 E4 35 51 01 12 72 34 32 6D 33 6E 63 76 2D 65  T.5Q..r42m3ncv-e
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   32: 38 77 66 70 67 33 3D 06 00 00 00 05 06 06 00 00  8wfpg3=.........
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   48: 00 02 05 06 00 00 00 01 57 10 69 6B 65 76 32 2D  ........W.ikev2-
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   64: 6D 73 63 68 61 70 76 32 04 06 C4 34 2E 23 1E 0E  mschapv2...4.#..
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   80: 31 39 36 2E 35 32 2E 34 36 2E 33 35 1F 10 36 36  196.52.46.35..66
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   96: 2E 32 30 37 2E 32 30 38 2E 32 32 36 4F 17 02 00  .207.208.226O...
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>  112: 00 15 01 72 34 32 6D 33 6E 63 76 2D 65 38 77 66  ...r42m3ncv-e8wf
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>  128: 70 67 33 20 13 63 61 2D 30 30 31 5F 73 74 72 6F  pg3 .ca-001_stro
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>  144: 6E 67 73 77 61 6E 50 12 0F F1 22 79 D1 AD DE 25  ngswanP..."y...%
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>  160: 5B 01 3D A7 19 81 8A AC                          [.=.....
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1> received RADIUS Access-Challenge from server '127.0.0.1'
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1> => 100 bytes @ 0x7fc280000d20
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>    0: 0B 56 00 64 BF 61 D9 0F 42 95 2C 76 A4 41 C3 0F  .V.d.a..B.,v.A..
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   16: 59 9B A4 FA 4F 2C 01 01 00 2A 1A 01 01 00 25 10  Y...O,...*....%.
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   32: 15 C1 FB 92 B0 5A D7 64 1D 60 C5 46 69 00 DA E5  .....Z.d.`.Fi...
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   48: 72 34 32 6D 33 6E 63 76 2D 65 38 77 66 70 67 33  r42m3ncv-e8wfpg3
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   64: 18 12 15 C1 FB 92 B0 5A D7 64 1D 60 C5 46 69 00  .......Z.d.`.Fi.
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   80: DA E5 50 12 41 E8 6C 15 EF 59 DC CC A0 C7 7A A7  ..P.A.l..Y....z.
Jul 30 00:33:24 89[CFG] <ikev2-mschapv2|1>   96: 3A 70 2D 82                                      :p-.
Jul 30 00:33:24 89[IKE] <ikev2-mschapv2|1> EAP_MSCHAPV2 payload => 42 bytes @ 0x7fc280001650
Jul 30 00:33:24 89[IKE] <ikev2-mschapv2|1>    0: 01 01 00 2A 1A 01 01 00 25 10 15 C1 FB 92 B0 5A  ...*....%......Z
Jul 30 00:33:24 89[IKE] <ikev2-mschapv2|1>   16: D7 64 1D 60 C5 46 69 00 DA E5 72 34 32 6D 33 6E  .d.`.Fi...r42m3n
Jul 30 00:33:24 89[IKE] <ikev2-mschapv2|1>   32: 63 76 2D 65 38 77 66 70 67 33                    cv-e8wfpg3
Jul 30 00:33:24 89[IKE] <ikev2-mschapv2|1> initiating EAP_MSCHAPV2 method (id 0x01)
  1. EAP Request Packet + Success Packet (Access-Challenge) Response:
Jul 30 00:33:24 100[ENC] <ikev2-mschapv2|1> parsed IKE_AUTH request 3 [ EAP/RES/MSCHAPV2 ]
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1> EAP_MSCHAPV2 payload => 75 bytes @ 0x7fc2940069c0
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>    0: 02 01 00 4B 1A 02 01 00 46 31 B2 2F A8 1C 2F 1A  ...K....F1./../.
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   16: EF 66 C0 F1 A6 B7 27 BD 51 5F 00 00 00 00 00 00  .f....'.Q_......
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   32: 00 00 64 97 7D 85 D1 6B DD 8C 82 82 A0 CB EB D7  ..d.}..k........
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   48: D8 D0 21 1C 27 96 63 7B 3D 13 00 72 34 32 6D 33  ..!.'.c{=..r42m3
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   64: 6E 63 76 2D 65 38 77 66 70 67 33                 ncv-e8wfpg3
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1> sending RADIUS Access-Request to server '127.0.0.1'
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1> => 240 bytes @ 0x7fc294003d60
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>    0: 01 7C 00 F0 DB AB 7C BF 31 2A CA A3 A1 33 93 7B  .|....|.1*...3.{
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   16: DB A4 B3 C5 01 12 72 34 32 6D 33 6E 63 76 2D 65  ......r42m3ncv-e
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   32: 38 77 66 70 67 33 3D 06 00 00 00 05 06 06 00 00  8wfpg3=.........
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   48: 00 02 05 06 00 00 00 01 57 10 69 6B 65 76 32 2D  ........W.ikev2-
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   64: 6D 73 63 68 61 70 76 32 04 06 C4 34 2E 23 1E 0E  mschapv2...4.#..
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   80: 31 39 36 2E 35 32 2E 34 36 2E 33 35 1F 10 36 36  196.52.46.35..66
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   96: 2E 32 30 37 2E 32 30 38 2E 32 32 36 4F 4D 02 01  .207.208.226OM..
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  112: 00 4B 1A 02 01 00 46 31 B2 2F A8 1C 2F 1A EF 66  .K....F1./../..f
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  128: C0 F1 A6 B7 27 BD 51 5F 00 00 00 00 00 00 00 00  ....'.Q_........
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  144: 64 97 7D 85 D1 6B DD 8C 82 82 A0 CB EB D7 D8 D0  d.}..k..........
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  160: 21 1C 27 96 63 7B 3D 13 00 72 34 32 6D 33 6E 63  !.'.c{=..r42m3nc
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  176: 76 2D 65 38 77 66 70 67 33 20 13 63 61 2D 30 30  v-e8wfpg3 .ca-00
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  192: 31 5F 73 74 72 6F 6E 67 73 77 61 6E 18 12 15 C1  1_strongswan....
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  208: FB 92 B0 5A D7 64 1D 60 C5 46 69 00 DA E5 50 12  ...Z.d.`.Fi...P.
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  224: DC 26 57 40 79 91 11 FC 3F 6A C0 AD 0A 66 A0 4D  .&W@y...?j...f.M
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1> received RADIUS Access-Challenge from server '127.0.0.1'
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1> => 121 bytes @ 0x7fc294006930
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>    0: 0B 7C 00 79 35 C3 A8 F7 CC BE 84 13 5D 37 B0 66  .|.y5.......]7.f
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   16: A7 78 94 4A 1A 0C 00 00 01 37 1C 06 0A FF FF 02  .x.J.....7......
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   32: 4F 35 01 01 00 33 1A 03 01 00 2E 53 3D 33 39 39  O5...3.....S=399
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   48: 45 33 42 36 43 43 43 31 46 42 44 32 37 36 41 42  E3B6CCC1FBD276AB
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   64: 34 45 39 32 33 33 31 33 32 42 34 33 46 37 39 41  4E9233132B43F79A
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   80: 31 31 39 45 37 18 12 15 C1 FB 92 B0 5A D7 64 1D  119E7.......Z.d.
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>   96: 60 C5 46 69 00 DA E5 50 12 1F C6 29 3B 96 8E C4  `.Fi...P...);...
Jul 30 00:33:24 100[CFG] <ikev2-mschapv2|1>  112: EE A4 39 67 FB 3B AE 12 8E                       ..9g.;...
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1> EAP_MSCHAPV2 payload => 51 bytes @ 0x7fc2940045e0
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>    0: 01 01 00 33 1A 03 01 00 2E 53 3D 33 39 39 45 33  ...3.....S=399E3
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   16: 42 36 43 43 43 31 46 42 44 32 37 36 41 42 34 45  B6CCC1FBD276AB4E
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   32: 39 32 33 33 31 33 32 42 34 33 46 37 39 41 31 31  9233132B43F79A11
Jul 30 00:33:24 100[IKE] <ikev2-mschapv2|1>   48: 39 45 37                                         9E7
Jul 30 00:33:24 100[ENC] <ikev2-mschapv2|1> added payload of type EAP to message

At this point, no further communication is seen from the client. Client side, the error 691 is shown. This implies that the client was not able to validate the Access-Challenge sent by my POC. Which is either due to bad packet format, or, bad success packet value.

I have taken the peer and authenticator challenges from the successful log, and ran it through my code to see if I can get the same success packet output, and it does indeed generate the same value.

Looking at the format of the packet byte by byte, I cannot see any differece in either format or value, yet, Windows rejects this response and terminates the EAP conversation.

If anyone has any in depth knowledge of Windows + EAP + MSCHAPv2 implementations, I would greatly appreciate the help, as at this point I have compared the data byte by byte and cannot see any differences.

Here are more references to the RFCs implemented:

Additional Notes:

I was originally suspecting that the issue could be in the RADIUS packets, and not in the EAP messages, since the EAP payload look identical in both the FreeRadius (working) conversation, and my POC. The reason I abandoned that theory is that both client and server logs show that the error happens during the EAP authentication stage.

Could there be something in the RADIUS protocol/packets that can affect the validity or acceptance of EAP messages by the client?

Also, the error is thrown during the "Success Packet" Access-Challenge stage of the EAP conversation, but, could earlier steps fail silently and cause this error at a later stage? I haven't found anything in any of the above RFCs that would suggest that, but I'm not ruling anything out at this point as I've been at it for nearly 2 weeks.

Lastly, I have tried to get more debug information out of Windows to see the exact data that Windows is using to determine the validity of the message, but, all I was able to get from the "Remote Access Diagnostic Report" is this:

[3004] 07-30 11:38:21:863: EapBegin(fServer=0)
[3004] 07-30 11:38:21:863: EapBegin: EapTypeToBeUsed=26, EapAuthType=2
[3004] 07-30 11:38:21:863: EapBegin: ThisIsARenegotiation=0, SaveCredsToCredMan=0, UseWinlogonCredentials=0.
[3004] 07-30 11:38:21:864: EapBegin: Connection handle: 1835008
[3004] 07-30 11:38:21:864: EapBegin: EAP user blob is not passed so using the credentials.
[3004] 07-30 11:38:21:864: fRetry = 0.
[3004] 07-30 11:38:21:865: Eap user data size: 1021.
[3004] 07-30 11:38:21:865: EapBegin done
[3004] 07-30 11:38:21:865: EapMakeMessage,RBuf=4b78910
[3004] 07-30 11:38:21:865: MakeAuthenticateeMessage...
[3004] 07-30 11:38:21:865: EAPSTATE_Initial
[3004] 07-30 11:38:21:865: EapMethodBegin(Flags=0x10, Remaining retry count=3)
[3004] 07-30 11:38:21:866: EAPSTATE_Working
[3004] 07-30 11:38:21:866: HandleEapResponse -- Entering.
[3004] 07-30 11:38:21:866: EapHost returned Action = EapHostPeerResponseSend. Processing send packet...
[3004] 07-30 11:38:21:866: RasProcessEapHostSendPacket -- Entering.
[3004] 07-30 11:38:21:866: Got identity: r42m3ncv-e8wfpg3.
[3004] 07-30 11:38:21:866: RasProcessEapHostSendPacket: Sending packet.
[3004] 07-30 11:38:21:866: RasProcessEapHostSendPacket -- Leaving: 0x0.
[3004] 07-30 11:38:21:866: HandleEapResponse -- Leaving: 0x0.
[3004] 07-30 11:38:21:869: EapMakeMessage,RBuf=4b78910
[3004] 07-30 11:38:21:869: MakeAuthenticateeMessage...
[3004] 07-30 11:38:21:869: EAPSTATE_Working
[3004] 07-30 11:38:21:870: HandleEapResponse -- Entering.
[3004] 07-30 11:38:21:870: EapHost returned Action = EapHostPeerResponseSend. Processing send packet...
[3004] 07-30 11:38:21:870: RasProcessEapHostSendPacket -- Entering.
[3004] 07-30 11:38:21:870: RasProcessEapHostSendPacket: Sending packet.
[3004] 07-30 11:38:21:870: RasProcessEapHostSendPacket -- Leaving: 0x0.
[3004] 07-30 11:38:21:870: HandleEapResponse -- Leaving: 0x0.
[3004] 07-30 11:38:21:873: EapMakeMessage,RBuf=4b78910
[3004] 07-30 11:38:21:873: MakeAuthenticateeMessage...
[3004] 07-30 11:38:21:873: EAPSTATE_Working
[3004] 07-30 11:38:21:873: HandleEapResponse -- Entering.
[3004] 07-30 11:38:21:873: EapHost returned Action = EapHostPeerResponseResult. Retreiving result...
[3004] 07-30 11:38:21:873: RasGetEapHostAuthResult -- Entering.
[3004] 07-30 11:38:21:873: RasSetQuarantineStatus -- Entering.
[3004] 07-30 11:38:21:873: ISOLATION_STATE_UNKNOWN
[3004] 07-30 11:38:21:873: RasSetQuarantineStatus -- Leaving: 0x0.
[3004] 07-30 11:38:21:873: EAP Authentication failed with error: Internal = 0x2b3, External = 0x80420112.
[3004] 07-30 11:38:21:873: RasGetEapHostAuthResult -- Leaving: 0x0.
[3004] 07-30 11:38:21:873: HandleEapResponse -- Leaving: 0x0.
[960] 07-30 11:38:21:881: EapEnd
[960] 07-30 11:38:21:881: EapMethodEnd called for EAP Index 26

If anyone knows how to get any useful debugging data for EAP-MSCHAPV2 on Windows, that could also be very helpful. Ideally I would want to see the individual inputs to the various calculations performed by the Windows implementation as I see no logical reason why it's not working as the spec is being followed.

windows radius ikev2 eap
Martin Hope
user397220
Asked: 2017-01-27 06:06:34 +0800 CST
  • 2

I'm using FreeRadius with a Ubitquiti WiFi AP with 802.1x auth using EAP-TLS (mutual client/server cert based auth). This is working well for static VLANs (i.e. specified on the AP).

I'd like to offload the VLAN assignment to Radius so that different users can be assigned to different VLANs.

I am not sure how to do this using EAP-TLS. All docs I've found online use the users file but are using other EAP methods.

So for, I've put this at the top of my /etc/freeradius/users file:

DEFAULT        Tunnel-Medium-Type = 6
               Tunnel-Private-Group-ID = [12],
               Tunnel-Type = VLAN

However no VLAN is assigned by Radius.

I'm not sure where to go from here. Perhaps I need something inside the tls section of /etc/freeradius/eap.conf to tell it to use the users file?

Help is appreciated, thanks!

802.1 ssl radius freeradius eap
Martin Hope
Vinícius Ferrão
Asked: 2016-05-14 20:23:16 +0800 CST
  • 5

I'm deploying an IKEv2 VPN authenticating against a RADIUS service within a pfSense 2.3-RELEASE box. But I'm afraid of the complications of this approach when the RADIUS server is down.

Since the RADIUS is behind the pfSense box, in an event of a failure, I'll lose the ability to connect to the IKEv2 VPN and left without any option to enter the LAN.

I could do a simple workaround with some fallback mode with a local user account within the pfSense box, but the problem is this "fallback mode". This even exist?

What are the options in this case?

vpn radius pfsense ikev2 eap
Martin Hope
HopelessN00b
Asked: 2012-07-17 09:48:30 +0800 CST
  • 5

So, I guess the short version of the question is:

I'm unable to get clients to connect to an enterprise-WPA wireless network after setting up a "new" NPS server and a new CA. After I manually request a new cert on my client from the NPS/CA server and trying to connect to the wireless network, they sit at "Attempting to authenticate"/"Waiting for network to be ready" for about a minute before giving up and saying they can't connect.

The logs on my NPS/CA server give an IAS4142 "Reason Code" of 23... which is absent from the technet documentation on what the various error codes mean. >:/ What's going on, and does anyone know how to fix it? Or where to begin troubleshooting this? (Google's been pretty unhelpful... found a few people with the same problem, but no solutions.)

The longer version, which hopefully contains information that can help someone help me is:

A couple weeks back, we had an event that involved forcefully seizing FSMO roles from our two "main" DCs at the home office (2k3 R2). As a result, they're offline, and aren't coming back. Of course, after doing this, and resolving the immediate crisis, we were getting reports that wireless access wasn't working anymore. Which made sense, when we went back and looked at the disconnected former DCs, and found that one was our only IAS server, and the other was the only CA in our environment. Of course, we use WPA-enterprise wireless encryption with certificates issued to client machine accounts, and domain credentials required to authenticate (the lazy way, allowing clients to use their logon credentials to auth automagically with no user interaction). So the problem was that there was no RADIUS server available to service the requests, and the issuing CA was gone anyway.

The solution, which seemed like a good one at the time, was to stand up a new server, and because of equipment limitations, put the CA and NPS roles on it. I would have liked to also make it a DC, but was unable to as a result of other limitations. Everything I know, and read, indicated this would be fine. I also had the comical assumption that I'd be able to set it up right this way and not have all the irritations of the previous setup. And, not wanting to manually re-enter a couple hundred clients and a couple dozen policies, I followed this technet article on how to migrate NPS servers (and the fix for the incorrect IAS to NPS EAP parameter. Mostly. Instead of 0,16,515 in that section, I had 0,15,521... so I corrected the '0' as directed and moved on.)

I changed a few CA crypto settings (SHA-1 to SHA-512, on account of SHA-1 being insecure these days, named the root cert in a less retarded manner, etc.), registered NPS in AD, and thought I was good to go. Then I ran into the issue that XP can't use SHA-2 certs for AAA (&%#^!!!), which is problematic when our clients are still on XP. Applied that hotfix (which mentions that the update will be included in XP SP4... :/ ), and still no joy. Found the error code with a little more work than I'd like to admit (especially when I later noticed the error in the Security Event Logs, so I wasted my time deciphering the ****ing IAS logs), and went to Google for help, and came up almost completely empty. Other people have reported the same issue, but no one seems to know what's wrong, or how to fix it. EventLog text:

Log Name:      Security
Source:        Microsoft-Windows-Security-Auditing
Date:          7/16/2012 11:25:37 AM
Event ID:      6273
Task Category: Network Policy Server
Level:         Information
Keywords:      Audit Failure
User:          N/A
Computer:      [The NPS/CA server]
Description:
Network Policy Server denied access to a user.

Contact the Network Policy Server administrator for more information.

User:
    Security ID:            [domain\username]
    Account Name:           [domain\username]
    Account Domain:         [domain]
    Fully Qualified Account Name:   [domain\username]

Client Machine:
    Security ID:            NULL SID
    Account Name:           -
    Fully Qualified Account Name:   -
    OS-Version:         -
    Called Station Identifier:      003a.9a18.7671
    Calling Station Identifier:     0013.e888.ecef

NAS:
    NAS IPv4 Address:       [AP's IP]
    NAS IPv6 Address:       -
    NAS Identifier:         [AP's name]
    NAS Port-Type:          Wireless - IEEE 802.11
    NAS Port:           1939

RADIUS Client:
    Client Friendly Name:       [AP's name]
    Client IP Address:          [AP's IP]

Authentication Details:
    Connection Request Policy Name: [Wifi access policy name]
    Network Policy Name:        [Wifi access policy name]
    Authentication Provider:        Windows
    Authentication Server:      [The NPS/CA server.domain.tld]
    Authentication Type:        PEAP
    EAP Type:           -
    Account Session Identifier:     -
    Logging Results:            Accounting information was written to the local log file.
    Reason Code:            23
    Reason:             An error occurred during the Network Policy Server use of the Extensible Authentication Protocol (EAP). Check EAP log files for EAP errors.

And, actually, as I was going through the logs to grab that error, I noticed this one just before it (same timestamp, but just before the other in the EventLog)... not sure what it means... my root cert is bad?!?!?

Log Name:      Security
Source:        Microsoft-Windows-Security-Auditing
Date:          7/16/2012 11:25:37 AM
Event ID:      5061
Task Category: System Integrity
Level:         Information
Keywords:      Audit Failure
User:          N/A
Computer:      [The NPS/CA server]
Description:
Cryptographic operation.

Subject:
    Security ID:        SYSTEM
    Account Name:       [The NPS/CA server]
    Account Domain:     [domain]
    Logon ID:       0x3e7

Cryptographic Parameters:
    Provider Name:  Microsoft Software Key Storage Provider
    Algorithm Name: RSA
    Key Name:   [Root cert created when the CA was installed]
    Key Type:   Machine key.

Cryptographic Operation:
    Operation:  Decrypt.
    Return Code:    0x80090010

Before I do something drastic, [cry] like reinstalling our CA and NPS server, then configuring it all by hand... or buying a bunch of ammo and driving toward Remdond [/cry] does anyone have any ideas on less painful measures that might help resolve my problem?

windows-xp troubleshooting radius windows-server-2008-r2 eap
Martin Hope
mgorven
Asked: 2012-06-09 15:28:07 +0800 CST
  • 3

I have WPA2 802.11x EAP authentication setup using FreeRADIUS 2.1.8 on Ubuntu 10.04.4 talking to OpenLDAP, and can successfully authenticate using PEAP/MSCHAPv2, TTLS/MSCHAPv2 and TTLS/PAP (both via the AP and using eapol_test). I am now trying to restrict access to specific SSIDs based on the LDAP groups which the user belongs to.

I have configured group membership checking in /etc/freeradius/modules/ldap like so:

groupname_attribute = cn
groupmembership_filter = "(|(&(objectClass=posixGroup)(memberUid=%{User-Name}))(&(objectClass=posixGroup)(uniquemember=%{User-Name})))"

and I have configured extraction of the SSID from Called-Station-Id into Called-Station-SSID based on the Mac Auth wiki page. In /etc/freeradius/eap.conf I have enabled copying attributes from the outer tunnel into the inner tunnel, and usage of the inner tunnel response in the outer tunnel (for both PEAP and TTLS). I had the same behaviour before changing these options however.

copy_request_to_tunnel = yes
use_tunneled_reply = yes

I'm running eapol_test like this to test the setup:

eapol_test -c peap-mschapv2.conf -a 172.16.0.16 -s testing123 -N 30:s:01-23-45-67-89-01:Example-EAP

with the following peap-mschapv2.conf file:

network={
    ssid="Example-EAP"
    key_mgmt=WPA-EAP
    eap=PEAP
    identity="mgorven"
    anonymous_identity="anonymous"
    password="foobar"
    phase2="autheap=MSCHAPV2"
}

With the following in /etc/freeradius/users: 

DEFAULT Ldap-Group == "employees"

and running freeradius-Xx, I can see that the LDAP group retrieval works, and that the SSID is extracted.

Debug:   [ldap] performing search in dc=example,dc=com, with filter (&(cn=employees)(|(&(objectClass=posixGroup)(memberUid=mgorven))(&(objectClass=posixGroup)(uniquemember=mgorven))))
Debug: rlm_ldap::ldap_groupcmp: User found in group employees
...
Info:        expand: %{7} -> Example-EAP

Next I try to only allow access to users in the employees group (regardless of SSID), so I put the following in /etc/freeradius/users:

DEFAULT Ldap-Group == "employees"

DEFAULT Auth-Type := Reject

But this immediately rejects the Access-Request in the outer tunnel because the anonymous user is not in the employees group. So I modify it to only match inner tunnel requests like so:

DEFAULT Ldap-Group == "employees"

DEFAULT FreeRADIUS-Proxied-To == "127.0.0.1"
        Auth-Type := Reject, Reply-Message = "User does not belong to any groups which may access this SSID."

Now users which are in the employees group are authenticated, but so are users which are not in the employees group. I see the reject entry being matched, and the Reply-Message is set, but the client receives an Access-Accept.

Debug: rlm_ldap::ldap_groupcmp: Group employees not found or user is not a member.
Info: [files] users: Matched entry DEFAULT at line 209
Info: ++[files] returns ok
...
Auth: Login OK: [mgorven] (from client test port 0 cli 02-00-00-00-00-01 via TLS tunnel)
Info:   WARNING: Empty section.  Using default return values.
...
Info: [peap] Got tunneled reply code 2
        Auth-Type := Reject
        Reply-Message = "User does not belong to any groups which may access this SSID."
...
Info: [peap] Got tunneled reply RADIUS code 2
        Auth-Type := Reject
        Reply-Message = "User does not belong to any groups which may access this SSID."
...
Info: [peap] Tunneled authentication was successful.
Info: [peap] SUCCESS
Info: [peap] Saving tunneled attributes for later
...
Sending Access-Accept of id 11 to 172.16.2.44 port 60746
        Reply-Message = "User does not belong to any groups which may access this SSID."
        User-Name = "mgorven"

and eapol_test reports:

RADIUS message: code=2 (Access-Accept) identifier=11 length=233
   Attribute 18 (Reply-Message) length=64
      Value: 'User does not belong to any groups which may access this SSID.'
   Attribute 1 (User-Name) length=9
      Value: 'mgorven'
...
SUCCESS

Why isn't the request being rejected, and is this the right way to implement this?

ldap wpa2 radius freeradius eap