Attestation Server

The Attestation Server manages the remote attestation of endpoints running Platform Security Services (PTS) based on a local Trusted Platform Module (TPM). The requested Boot Event Log and the corresponding final state of the Platform Configuration Registers (PCRs) are stored by the Attestation IMV in the SQLite config.db database which is shared with the powerful strongTNC policy management tool.

Attestation IMV

The Attestation IMV implements the over-engineered, feature-laden TCG Attestation PTS Protocol: Binding to TNC IF-M v1.0, an extension to the PA-TNC (TCG TNC IF-M) measurement protocol.

Attestation Client >

Plugin Configuration

For Remote Attestation, the OS IMV and the Attestation IMV have to be enabled in the /etc/tnc_config configuration file

#IMV-Configuration

IMV "OS"           /usr/lib/ipsec/imcvs/imv-os.so
IMV "Attestation"  /usr/lib/ipsec/imcvs/imv-attestation.so

These two Integrity Measurement Verifiers have to be built beforehand with the ./configure options

--enable-imv-os --enable-imv-attestation

When the charon daemon starts up, the IMVs are loaded. IMV 1 OS and IMV 2 Attestation both subscribe to the standard PA-TNC message subtype Operating System and the Attestation IMV`additionally subscribes to the PTS`message subtype defined in the `TCG namespace

00[DMN] Starting IKE charon daemon (strongSwan 5.9.7, Linux 5.13.0-44-generic, x86_64)
00[TNC] TNC recommendation policy is 'default'
00[TNC] loading IMVs from '/etc/tnc_config'
00[TNC] added IETF attributes
00[TNC] added ITA-HSR attributes
00[TNC] added PWG attributes
00[TNC] added TCG attributes
00[PTS] added TCG functional component namespace
00[PTS] added ITA-HSR functional component namespace
00[PTS] added ITA-HSR functional component 'Trusted GRUB Boot Loader'
00[PTS] added ITA-HSR functional component 'Trusted Boot'
00[PTS] added ITA-HSR functional component 'Linux IMA'
00[LIB] libimcv initialized
00[IMV] IMV 1 "OS" initialized
00[TNC] IMV 1 supports 1 message type: 'IETF/Operating System' 0x000000/0x00000001
00[TNC] IMV 1 "OS" loaded from '/usr/lib/ipsec/imcvs/imv-os.so'
00[IMV] IMV 2 "Attestation" initialized
00[PTS] loading PTS ca certificates from '/etc/pts/cacerts'
00[PTS]   mandatory PTS measurement algorithm HASH_SHA1[openssl] available
00[PTS]   mandatory PTS measurement algorithm HASH_SHA2_256[openssl] available
00[PTS]   optional  PTS measurement algorithm HASH_SHA2_384[openssl] available
00[PTS]   optional  PTS measurement algorithm HASH_SHA2_512[openssl] available
00[PTS]   optional  PTS DH group MODP_2048[openssl] available
00[PTS]   optional  PTS DH group MODP_1536[openssl] available
00[PTS]   optional  PTS DH group MODP_1024[openssl] available
00[PTS]   mandatory PTS DH group ECP_256[openssl] available
00[PTS]   optional  PTS DH group ECP_384[openssl] available
00[TNC] IMV 2 supports 2 message types: 'TCG/PTS' 0x005597/0x00000001 'IETF/Operating System' 0x000000/0x00000001
00[TNC] IMV 2 "ATTESTATION" loaded from '/usr/lib/ipsec/imcvs/imv-attestation.so'

Attestation Client >

VPN Configuration

The VPN configuration choses for this example is the same as for the general TNC server but just uses different client and server identities. For reasons of brevity we will omit the PT-EAP and IKEv2 EAP transport layers.

Attestation Client >

PB-TNC Connection

The TNC server receives the first PB-TNC Client Data batch and assigns the PB-TNC (TCG TNC IF-TNCCS 2.0) Connection ID 1 to the connection and also creates a new state for both the OS IMV and the Attestation IMV. The OS IMV gets the Access requestor’s identities mijas.strongsec.com and 10.10.1.52 from the TNC server via the TNC IF-IMV API.

13[TNC] assigned TNCCS Connection ID 1
13[IMV] IMV 1 "OS" created a state for IF-TNCCS 2.0 Connection ID 1: +long +excl -soh
13[IMV]   over IF-T for Tunneled EAP 2.0 with maximum PA-TNC message size of 65490 bytes
13[IMV]   user AR identity 'mijas.strongsec.com' of type username authenticated by certificate
13[IMV]   machine AR identity '10.10.1.52' of type IPv4 address authenticated by unknown method
13[IMV] IMV 2 "Attestation" created a state for IF-TNCCS 2.0 Connection ID 1: +long +excl -soh
13[IMV]   over IF-T for Tunneled EAP 2.0 with maximum PA-TNC message size of 65490 bytes
13[IMV] IMV 1 "OS" changed state of Connection ID 1 to 'Handshake'
13[IMV] IMV 2 "Attestation" changed state of Connection ID 1 to 'Handshake'

Attestation Client >

OS Information

The TNC server receives a PB-TNC Client Data batch containing a standard PB-Language-Preference message which sets the preferred language to English [en] and a PA-TNC message

13[TNC] received TNCCS batch (269 bytes)
13[TNC] TNC server is handling inbound connection
13[TNC] processing PB-TNC CDATA batch for Connection ID 1
13[TNC] PB-TNC state transition from 'Init' to 'Server Working'
13[TNC] processing IETF/PB-Language-Preference message (31 bytes)
13[TNC] processing IETF/PB-PA message (230 bytes)
13[TNC] setting language preference to 'en'

The PA-TNC message of standard subtype Operating System containing seven PA-TNC attributes is processed by the OS IMV. The most important attribute is the Device ID defined in the ITA-HSR namespace. Based on the keyid of the endpoint’s Attestation Key it uniquely identfies the endpoint to be measured

13[TNC] handling PB-PA message type 'IETF/Operating System' 0x000000/0x00000001
13[IMV] IMV 1 "OS" received message for Connection ID 1 from IMC 1
13[TNC] processing PA-TNC message with ID 0xa8ddde49
13[TNC] processing PA-TNC attribute type 'IETF/Product Information' 0x000000/0x00000002
13[TNC] processing PA-TNC attribute type 'IETF/String Version' 0x000000/0x00000004
13[TNC] processing PA-TNC attribute type 'IETF/Numeric Version' 0x000000/0x00000003
13[TNC] processing PA-TNC attribute type 'IETF/Operational Status' 0x000000/0x00000005
13[TNC] processing PA-TNC attribute type 'IETF/Forwarding Enabled' 0x000000/0x0000000b
13[TNC] processing PA-TNC attribute type 'IETF/Factory Default Password Enabled' 0x000000/0x0000000c
13[TNC] processing PA-TNC attribute type 'ITA-HSR/Device ID' 0x00902a/0x00000008
13[IMV] operating system name is 'Ubuntu' from vendor Canonical
13[IMV] operating system version is '20.04 x86_64'
13[IMV] operating system numeric version is 20.4
13[IMV] operational status: operational, result: successful
13[IMV] last boot: May 31 08:26:18 UTC 2022
13[IMV] IPv4 forwarding is enabled
13[IMV] factory default password is disabled
13[IMV] device ID is 732c769e8d1b2efef8b64d5ae83f84d129733fdd

The Attestation IMV has subscribed to messages of subtype Operating System as well

13[IMV] IMV 2 "Attestation" received message for Connection ID 1 from IMC 1
13[TNC] processing PA-TNC message with ID 0xa8ddde49
13[TNC] processing PA-TNC attribute type 'IETF/Product Information' 0x000000/0x00000002
13[TNC] processing PA-TNC attribute type 'IETF/String Version' 0x000000/0x00000004
13[TNC] processing PA-TNC attribute type 'IETF/Numeric Version' 0x000000/0x00000003
13[TNC] processing PA-TNC attribute type 'IETF/Operational Status' 0x000000/0x00000005
13[TNC] processing PA-TNC attribute type 'IETF/Forwarding Enabled' 0x000000/0x0000000b
13[TNC] processing PA-TNC attribute type 'IETF/Factory Default Password Enabled' 0x000000/0x0000000c
13[TNC] processing PA-TNC attribute type 'ITA-HSR/Device ID' 0x00902a/0x00000008
13[IMV] operating system name is 'Ubuntu' from vendor Canonical
13[IMV] operating system version is '20.04 x86_64'
13[IMV] device ID is 732c769e8d1b2efef8b64d5ae83f84d129733fdd

Attestation Client >

IMV Policy Workitems

The imv_policy_manager program is executed which connects to the TNC database and assigns the session number 354 to the current connection 1. Only one measurement workitem is configured in the database:

TPMRA - TPM Remote Attestation

which is handled by the Attestation IMV

13[IMV] assigned session ID 354 to Connection ID 1
13[IMV] policy: imv_policy_manager start successful
13[IMV] TPMRA workitem 650

OS Assessment Result

No policy enforcements are defined for the OS IMV, so standard Assessment Result and Remediation Instructions are generated and inserted into a first PA-TNC message of standard subtype Operating Systems

13[IMV] IMV 1 has no workitems - no evaluation requested
13[TNC] creating PA-TNC message with ID 0xc82bacd2
13[TNC] creating PA-TNC attribute type 'IETF/Assessment Result' 0x000000/0x00000009
13[TNC] creating PA-TNC attribute type 'IETF/Remediation Instructions' 0x000000/0x0000000a
13[TNC] creating PB-PA message type 'IETF/Operating System' 0x000000/0x00000001
13[TNC] IMV 1 provides recommendation 'allow' and evaluation 'don't know'

Attestation Client >

PTS Configuration

The Attestation IMV generates the following three PA-TNC attributes defined in the TCG namespace

- Segmentation Contract Request
- Request PTS Protocol Capabilities
- PTS Measurement Algorithm Request

and inserts them into a second PA-TNC message of subtype PTS defined in the TCG namespace

13[IMV] IMV 2 requests a segmentation contract for PA message type 'TCG/PTS' 0x005597/0x00000001
13[IMV]   no message size limit, maximum segment size of 65466 bytes
13[TNC] creating PA-TNC message with ID 0x0c1897a0
13[TNC] creating PA-TNC attribute type 'TCG/Segmentation Contract Request' 0x005597/0x00000021
13[TNC] creating PA-TNC attribute type 'TCG/Request PTS Protocol Capabilities' 0x005597/0x01000000
13[TNC] creating PA-TNC attribute type 'TCG/PTS Measurement Algorithm Request' 0x005597/0x06000000
13[TNC] creating PB-PA message type 'TCG/PTS' 0x005597/0x00000001

The two PA-TNC messages together with a PB-TNC PDP-Referral* message defined in the TCG namespace are sent in a PB-TNC Server Data batch to the TNC client

13[TNC] TNC server is handling outbound connection
13[TNC] PB-TNC state transition from 'Server Working' to 'Client Working'
13[TNC] creating PB-TNC SDATA batch
13[TNC] adding TCG/PB-PDP-Referral message
13[TNC] adding IETF/PB-PA message
13[TNC] adding IETF/PB-PA message
13[TNC] sending PB-TNC SDATA batch (274 bytes) for Connection ID 1

The TNC server receives a PB-TNC Client Data batch containing a PA-TNC message

05[TNC] received TNCCS batch (92 bytes)
05[TNC] TNC server is handling inbound connection
05[TNC] processing PB-TNC CDATA batch for Connection ID 1
05[TNC] PB-TNC state transition from 'Client Working' to 'Server Working'
05[TNC] processing IETF/PB-PA message (84 bytes)

The PA-TNC message of subtype PTS defined in the TCG namespace contains the following three attributes defined in the TCG namespace

- Segmentation Contract Response
- PTS Protocol Capabilities
- PTS Measurement Algorithm

as a response to the previous requests.

05[TNC] handling PB-PA message type 'TCG/PTS' 0x005597/0x00000001
05[IMV] IMV 2 "Attestation" received message for Connection ID 1 from IMC 2 to IMV 2
05[TNC] processing PA-TNC message with ID 0x056d62cb
05[TNC] processing PA-TNC attribute type 'TCG/Segmentation Contract Response' 0x005597/0x00000022
05[TNC] processing PA-TNC attribute type 'TCG/PTS Protocol Capabilities' 0x005597/0x02000000
05[TNC] processing PA-TNC attribute type 'TCG/PTS Measurement Algorithm' 0x005597/0x07000000
05[IMV] IMV 2 received a segmentation contract response from IMC 2 for PA message type 'TCG/PTS' 0x005597/0x00000001
05[IMV]   no message size limit, maximum segment size of 32698 bytes
05[PTS] supported PTS protocol capabilities: .VDT.
05[PTS] selected PTS measurement algorithm is HASH_SHA2_256
05[IMV] IMV 2 handles TPMRA workitem 650

The Attestation IMV creates a DH Nonce Parameters Request in the TCG namespace and inserts it into a PA-TNC message of subtype PTS defined in the TCG namespace

05[TNC] creating PA-TNC message with ID 0x87e01f73
05[TNC] creating PA-TNC attribute type 'TCG/DH Nonce Parameters Request' 0x005597/0x03000000
05[TNC] creating PB-PA message type 'TCG/PTS' 0x005597/0x00000001

The PA-TNC message is sent in a PB-TNC Server Data batch to the TNC client

05[TNC] TNC server is handling outbound connection
05[TNC] PB-TNC state transition from 'Server Working' to 'Client Working'
05[TNC] creating PB-TNC SDATA batch
05[TNC] adding IETF/PB-PA message
05[TNC] sending PB-TNC SDATA batch (56 bytes) for Connection ID 1

The TNC server receives a PB-TNC Client Data batch containing a PA-TNC message

01[TNC] received TNCCS batch (144 bytes)
01[TNC] TNC server is handling inbound connection
01[TNC] processing PB-TNC CDATA batch for Connection ID 1
01[TNC] PB-TNC state transition from 'Client Working' to 'Server Working'
01[TNC] processing IETF/PB-PA message (136 bytes)

The PA-TNC message of subtype PTS defined in the TCG namespace contains the DH Nonce Parameters Response defined in the TCG namespace which sets the Diffie-Hellman group to ECP_256. the hash algorithm to SHA_256 and the nonce length to 20 bytes

01[TNC] handling PB-PA message type 'TCG/PTS' 0x005597/0x00000001
01[IMV] IMV 2 "Attestation" received message for Connection ID 1 from IMC 2 to IMV 2
01[TNC] processing PA-TNC message with ID 0x9b6ae702
01[TNC] processing PA-TNC attribute type 'TCG/DH Nonce Parameters Response' 0x005597/0x04000000
01[PTS] selected DH hash algorithm is HASH_SHA2_256
01[PTS] selected PTS DH group is ECP_256
01[PTS] nonce length is 20

The Attestation IMV creates the following three attributes defined in the TCG namespace

- DH Nonce Finish
- Get TPM Version Information
- Get Attestation Identity Key

and inserts them in a PA-TNC message of subtype PTS defined in the TCG namespace

01[TNC] creating PA-TNC message with ID 0xfbdd9494
01[TNC] creating PA-TNC attribute type 'TCG/DH Nonce Finish' 0x005597/0x05000000
01[TNC] creating PA-TNC attribute type 'TCG/Get TPM Version Information' 0x005597/0x08000000
01[TNC] creating PA-TNC attribute type 'TCG/Get Attestation Identity Key' 0x005597/0x0d000000
01[TNC] creating PB-PA message type 'TCG/PTS' 0x005597/0x00000001

The PA-TNC message is sent in a PB-TNC Server Data batch to the TNC client

01[TNC] TNC server is handling outbound connection
01[TNC] PB-TNC state transition from 'Server Working' to 'Client Working'
01[TNC] creating PB-TNC SDATA batch
01[TNC] adding IETF/PB-PA message
01[TNC] sending PB-TNC SDATA batch (172 bytes) for Connection ID 1

The TNC server receives a PB-TNC Client Data batch containing a PA-TNC message

06[TNC] received TNCCS batch (172 bytes)
06[TNC] TNC server is handling inbound connection
06[TNC] processing PB-TNC CDATA batch for Connection ID 1
06[TNC] PB-TNC state transition from 'Client Working' to 'Server Working'
06[TNC] processing IETF/PB-PA message (164 bytes)

The PA-TNC message of subtype PTS defined in the TCG namespace contains two attributes defined in the TCG namespace:

TPM Version Information:
Indicates the version of the implemented TPM standard (rev. 1.38), the chip or firmware vendor (STM) as well as the startup locality (3) that is important to correctly initialize PCR0 of the IMV’s own PCR bank emulation
Attestation Identity Key:
This is the public part of the enpoint’s Attestation Key (AK) which is used by the Attestion IMV to verify the TPM Quote Signature. The keyid is usually equivalent to the endpoint’s hardware ID. Using strongTNC, the Trusted flag must be set in the Device Info view. As an alternative the attribute can transport the endpoint’s AK certificate.

06[TNC] handling PB-PA message type 'TCG/PTS' 0x005597/0x00000001
06[IMV] IMV 2 "Attestation" received message for Connection ID 1 from IMC 2 to IMV 2
06[TNC] processing PA-TNC message with ID 0x436bed34
06[TNC] processing PA-TNC attribute type 'TCG/TPM Version Information' 0x005597/0x09000000
06[TNC] processing PA-TNC attribute type 'TCG/Attestation Identity Key' 0x005597/0x0e000000
06[PTS] Version Information: TPM 2.0 rev. 1.38 2018 STM  - startup locality: 3
06[IMV] verifying AIK with keyid 73:2c:76:9e:8d:1b:2e:fe:f8:b6:4d:5a:e8:3f:84:d1:29:73:3f:dd
06[IMV] AIK public key is trusted
06[IMV] evidence request by

Attestation Client >

Boot Event Measurements

The following three attributes are inserted into a PA-TNC message of subtype PTS defined in the TCG namespace:

Get Symlinks defined in the ITA-HSR namespace:
Request a list of symbolic links created by the operating system due to UsrMerge (eg. /bin → /usr/bin).
Request Functional Component Evidence defined in the TCG namespace:
Request BIOS pre-boot evidence.
Generate Attestation Evidence defined in the TCG namespace:
Request a TPM Quote Signature over the final state of the PCR registers involved in the evidence measurement.

06[TNC] creating PA-TNC message with ID 0xcf126135
06[TNC] creating PA-TNC attribute type 'ITA-HSR/Get Symlinks' 0x00902a/0x00000009
06[TNC] creating PA-TNC attribute type 'TCG/Request Functional Component Evidence' 0x005597/0x00100000
06[TNC] creating PA-TNC attribute type 'TCG/Generate Attestation Evidence' 0x005597/0x00200000
06[TNC] creating PB-PA message type 'TCG/PTS' 0x005597/0x00000001

The PA-TNC message is sent in a PB-TNC Server Data batch to the TNC client

06[TNC] TNC server is handling outbound connection
06[TNC] PB-TNC state transition from 'Server Working' to 'Client Working'
06[TNC] creating PB-TNC SDATA batch
06[TNC] adding IETF/PB-PA message
06[TNC] sending PB-TNC SDATA batch (93 bytes) for Connection ID 1

The TNC server receives a PB-TNC Client Data batch containing a PA-TNC message

06[TNC] received TNCCS batch (11789 bytes)
06[TNC] TNC server is handling inbound connection
06[TNC] processing PB-TNC CDATA batch for Connection ID 1
06[TNC] PB-TNC state transition from 'Client Working' to 'Server Working'
06[TNC] processing IETF/PB-PA message (11781 bytes)

The PA-TNC message of subtype PTS contains the following attributes:

Symlinks defined in the ITA-HSR namespace:
If the endpoint’s Linux distribution supports UsrMerge then it sends a list of directory symbolic links.
Simple Component Evidence (136 instances):
Each attribute instance contains a single Boot Event measurement (SHA256 hash value plus event log entry).
Simple Evidence Final:
Contains a TPM Quote Signature over the PCR Composite digest and some additional system information.

06[TNC] handling PB-PA message type 'TCG/PTS' 0x005597/0x00000001
06[IMV] IMV 2 "Attestation" received message for Connection ID 1 from IMC 2 to IMV 2
06[TNC] processing PA-TNC message with ID 0x23ebec16
06[TNC] processing PA-TNC attribute type 'ITA-HSR/Symlinks' 0x00902a/0x0000000a
06[TNC] processing PA-TNC attribute type 'TCG/Simple Component Evidence' 0x005597/0x00300000
06[TNC] processing PA-TNC attribute type 'TCG/Simple Component Evidence' 0x005597/0x00300000
        ...
06[TNC] processing PA-TNC attribute type 'TCG/Simple Component Evidence' 0x005597/0x00300000
06[TNC] processing PA-TNC attribute type 'TCG/Simple Component Evidence' 0x005597/0x00300000
06[TNC] processing PA-TNC attribute type 'TCG/Simple Evidence Final' 0x005597/0x00400000
06[PTS] adding directory symlinks:
06[PTS]   /lib32 -> /usr/lib32
06[PTS]   /lib -> /usr/lib
06[PTS]   /libx32 -> /usr/libx32
06[PTS]   /sbin -> /usr/sbin
06[PTS]   /bin -> /usr/bin
06[PTS]   /lib64 -> /usr/lib64
06[PTS] TPM 2.0 - locality indicator set to 3
06[PTS] registering BIOS evidence measurements
06[PTS] constructed PCR Composite: => 352 bytes @ 0x7f9758029790
06[PTS]    0: 06 15 6C E6 46 85 9E E3 81 09 57 54 9A 18 4B 7A  ..l.F.....WT..Kz
06[PTS]   16: 2E A6 C6 C0 4F 3D DB 8A 2C D3 A3 67 F4 93 16 71  ....O=..,..g...q
06[PTS]   32: 6C B0 42 07 6E C2 B8 67 A9 2B CB 8E 12 F9 14 D6  l.B.n..g.+......
06[PTS]   48: 4A 06 E2 9B A1 08 0C E4 E0 27 55 C0 21 23 6C 81  J........'U.!#l.
06[PTS]   64: 30 3B 09 87 95 4C D0 9C A1 78 B8 6B DD 60 55 40  0;...L...x.k.`U@
06[PTS]   80: F4 00 40 E8 E6 42 BD 11 73 AC 45 BC 9B 36 A3 49  ..@..B..s.E..6.I
06[PTS]   96: 3D 45 8C FE 55 CC 03 EA 1F 44 3F 15 62 BE EC 8D  =E..U....D?.b...
06[PTS]  112: F5 1C 75 E1 4A 9F CF 9A 72 34 A1 3F 19 8E 79 69  ..u.J...r4.?..yi
06[PTS]  128: A3 1D BF 9D 3B CE 32 03 F2 54 59 8D 69 35 1D 8E  ....;.2..TY.i5..
06[PTS]  144: 4B 7E 1B 54 CD 43 3D 1C 71 07 92 52 24 6A EC EF  K~.T.C=.q..R$j..
06[PTS]  160: BB 49 6D 97 1F AB AC 31 BC 4D 1C A2 F2 EA F7 C0  .Im....1.M......
06[PTS]  176: 82 F3 E9 3C 25 6F 07 93 E0 CF 67 14 FD 36 40 4D  ...<%o....g..6@M
06[PTS]  192: 3D 45 8C FE 55 CC 03 EA 1F 44 3F 15 62 BE EC 8D  =E..U....D?.b...
06[PTS]  208: F5 1C 75 E1 4A 9F CF 9A 72 34 A1 3F 19 8E 79 69  ..u.J...r4.?..yi
06[PTS]  224: 44 6F 7A 67 D5 78 B2 F9 47 C4 E1 12 F7 69 96 E7  Dozg.x..G....i..
06[PTS]  240: E3 67 D2 74 AF AF BE 77 89 94 C4 1A 4B 67 BC FE  .g.t...w....Kg..
06[PTS]  256: 36 77 2C B7 7B 34 C1 BC DC 41 6E 3C C0 50 E7 26  6w,.{4...An<.P.&
06[PTS]  272: 7B 64 C2 91 28 12 9B 6A 3A 13 8A 74 C6 58 73 AD  {d..(..j:..t.Xs.
06[PTS]  288: E2 09 7C E2 17 04 A8 46 B3 55 3F 24 DF 4E 57 26  ..|....F.U?$.NW&
06[PTS]  304: F1 B9 86 DC 31 C3 11 B8 30 28 8D 86 00 21 EE 57  ....1...0(...!.W
06[PTS]  320: E3 99 1B 7D DD 47 BE 7E 92 72 6A 83 2D 68 74 C5  ...}.G.~.rj.-ht.
06[PTS]  336: 34 9B 52 B7 89 FA 0D B8 B5 58 C6 9F EA 29 57 4E  4.R......X...)WN
06[PTS] constructed PCR Composite digest: => 32 bytes @ 0x7f97580281f0
06[PTS]    0: 29 6C 1D BC 8B F0 3D A1 AD 87 AC 08 45 34 78 64  )l....=.....E4xd
06[PTS]   16: 78 EE 63 92 1B D0 E5 E2 C8 54 AB 4E A7 7D 53 E6  x.c......T.N.}S.
06[PTS] constructed TPM Quote Info: => 145 bytes @ 0x7f9758028f50
06[PTS]    0: FF 54 43 47 80 18 00 22 00 0B BD E2 F1 F3 E7 B6  .TCG..."........
06[PTS]   16: 0C A6 6D 93 1C EC AC 7D 25 B4 69 F0 E3 9E 96 9D  ..m....}%.i.....
06[PTS]   32: 3D B8 A8 79 89 FB E2 C1 9B C5 00 20 7E 42 B5 09  =..y....... ~B..
06[PTS]   48: 42 91 35 72 87 1A 47 61 8F FF F5 C0 FE CD 4D A7  B.5r..Ga......M.
06[PTS]   64: AE 2C 98 F0 A9 81 F9 B7 F7 C4 27 19 00 00 00 00  .,........'.....
06[PTS]   80: 5F A7 4E 12 00 00 01 13 00 00 00 00 01 00 01 01  _.N.............
06[PTS]   96: 02 00 00 00 00 00 00 00 01 00 0B 03 FF 43 00 00  .............C..
06[PTS]  112: 20 29 6C 1D BC 8B F0 3D A1 AD 87 AC 08 45 34 78   )l....=.....E4x
06[PTS]  128: 64 78 EE 63 92 1B D0 E5 E2 C8 54 AB 4E A7 7D 53  dx.c......T.N.}S
06[PTS]  144: E6                                               .
06[IMV] TPM Quote Info signature verification successful

The first time the BIOS Event Measurements are received, they are stored in the strongTNC database.

06[PTS] registered 136 BIOS evidence measurements
06[IMV] IMV 2 handled TPMRA workitem 650: allow - registered 136 BIOS evidence measurements

The second time and in every session after, the received BIOS Event Measurements are compared to the reference values stored in the strongTNC database

10[PTS] 136 BIOS evidence measurements are ok
10[IMV] IMV 2 handled TPMRA workitem 651: allow - 136 BIOS evidence measurements are ok

Attestation Client >

TNC Assessment Result

Since all 136 BIOS evidence measurements and the TPM Quote Signature were correct, the Attestation IMV generates a standard Assessment Result attribute with the evaluation compliant and the recommendation allow and inserts it in a PA-TNC message of subtype PTS defined in the TGC namespace

06[TNC] creating PA-TNC message with ID 0x6d4576ee
06[TNC] creating PA-TNC attribute type 'IETF/Assessment Result' 0x000000/0x00000009
06[TNC] creating PB-PA message type 'TCG/PTS' 0x005597/0x00000001
06[TNC] IMV 2 provides recommendation 'allow' and evaluation 'compliant'

The overall policy recommendation issued by the TNC server is allow and communicated to the TNC client in the form of a PB-TNC Assessment-Result and a PB-TNC Access-Recommendation payload, both of which are sent together with the PA-TNC message from the Attestation IMV in a PB-TNC Result batch to the TNC client

06[TNC] TNC server is handling outbound connection
06[IMV] policy: recommendation for access requestor 10.10.1.52 is allow
06[IMV] policy: imv_policy_manager stop successful
06[IMV] IMV 1 "OS" changed state of Connection ID 1 to 'Allowed'
06[IMV] IMV 2 "Attestation" changed state of Connection ID 1 to 'Allowed'
06[TNC] PB-TNC state transition from 'Server Working' to 'Decided'
06[TNC] creating PB-TNC RESULT batch
06[TNC] adding IETF/PB-PA message
06[TNC] adding IETF/PB-Assessment-Result message
06[TNC] adding IETF/PB-Access-Recommendation message
06[TNC] sending PB-TNC RESULT batch (88 bytes) for Connection ID 1

The TNC client replies with a PB-TNC Close batch which causes the causes the OS IMV, and Attestation IMV states as well as the PB-TNC connection to be deleted. Due to the positive final recommendation, the IKEv2 connection is allowed to complete

15[TNC] received TNCCS batch (8 bytes)
15[TNC] TNC server is handling inbound connection
15[TNC] processing PB-TNC CLOSE batch for Connection ID 1
15[TNC] PB-TNC state transition from 'Decided' to 'End'
15[TNC] final recommendation is 'allow' and evaluation is 'compliant'
15[TNC] policy enforced on peer 'mijas.strongsec.com' is 'allow'
15[TNC] policy enforcement point added group membership 'allow'
15[IKE] EAP_TTLS phase2 authentication of 'mijas.strongsec.com' with EAP_PT_EAP successful
15[IMV] IMV 1 "OS" deleted the state of Connection ID 1
15[IMV] IMV 2 "Attestation" deleted the state of Connection ID 1
15[TNC] removed TNCCS Connection ID 1

Attestation Client >

IKEv2 Authentication Success

The EAP TTLS authentication based on a TLS client certificate plus the TNC measurements was successful. Thus an EAP-SUCCESS message is sent to the EAP client

15[IKE] EAP method EAP_TTLS succeeded, MSK established
15[ENC] generating IKE_AUTH response 25 [ EAP/SUCC ]
15[NET] sending packet: from 10.10.0.150[4500] to 10.10.1.52[4500] (80 bytes)

The IKEv2 client sends an AUTH payload depending on the MSK (Master Secret Key) derived from the EAP-TTLS session

07[NET] received packet: from 10.10.1.52[4500] to 10.10.0.150[4500] (112 bytes)
07[ENC] parsed IKE_AUTH request 26 [ AUTH ]
07[IKE] authentication of 'mijas.strongsec.com' with EAP successful
07[IKE] authentication of 'vpn.strongswan.org' (myself) with EAP
07[IKE] IKE_SA eap[1] established between 10.10.0.150[vpn.strongswan.org]...10.10.1.52[mijas.strongsec.com]

The IKEv2 server in turn authenticates itself again via an AUTH payload depending on the EAP-TTLS MSK as well

07[IKE] maximum IKE_SA lifetime 11522s
07[IKE] peer requested virtual IP %any
07[CFG] assigning new lease to 'mijas.strongsec.com'
07[IKE] assigning virtual IP 10.10.1.65 to peer 'mijas.strongsec.com'
07[CFG] selected proposal: ESP:AES_CBC_256/HMAC_SHA2_256_128/NO_EXT_SEQ
07[IKE] CHILD_SA eap{1} established with SPIs ce4c682b_i cbc81685_o and TS 10.10.0.150/32 == 10.10.1.65/32
07[ENC] generating IKE_AUTH response 26 [ AUTH CPRP(ADDR DNS) SA TSi TSr N(AUTH_LF>
07[NET] sending packet: from 10.10.0.150[4500] to 10.10.1.52[4500] (272 bytes)

The IKEv2 connection has been successfully established.

Attestation Client >