strongSwan

h1. Trusted Platform Module 2.0

{{>toc}}

h2. Connect to a TPM 2.0 Device

h3. Install the tpm2-tss Software Stack and the tpm2-tools Command Set

In order to connect to a TPM 2.0 hardware or firmware device a software stack implementing the "TCG TSS 2.0 System Level API":https://trustedcomputinggroup.org/resource/tcg-tss-2-0-system-level-api-sapi-specification/ is needed. An excellent open source "tpm2-tss":https://github.com/tpm2-software/tpm2-tss library is available from the "tpm2-software":https://github.com/tpm2-software project which also offers a set of "tpm2-tools":https://github.com/tpm2-software/tpm2-tools which itself uses the "TCG TSS 2.0 Enhanced System Level API":https://trustedcomputinggroup.org/resource/tcg-tss-2-0-enhanced-system-api-esapi-specification/.

When using the latest *strongswan-5.9.1* version with a *Linux 5.4* kernel or newer, we recommend these latest versions:

* *tpm2-tss* version 3.0.3: https://github.com/tpm2-software/tpm2-tss/releases/tag/3.0.3

* *tpm2-tools* version 5.0: https://github.com/tpm2-software/tpm2-tools/releases/tag/5.0

Support for earlier strongSwan versions and Linux kernels can be found [[TpmPluginOld|here]].

In order to test if we can connect to the TPM 2.0 device we list all persistent keys stored in the Non-Volatile (NV) RAM:

<pre>

tpm2_getcap handles-persistent

- 0x81000001

- 0x81000002

- 0x81010001

</pre>

A manual showing all *tpm2-tools* functions with their arguments can be found "here":https://github.com/tpm2-software/tpm2-tools/tree/5.0/man.

h3. Enable the strongSwan tpm Plugin

The strongSwan libtpmtss *tpm* plugin and the TSS2 interface are enabled and built with the following options

  ./configure --enable-tss-tss2 --enable-tpm  ...

h2. TPM 2.0 Algorithm IDs

h3. Hash Algorithms

|0x0004 |SHA-1     |

|0x000B |SHA-2_256 |

|0x000C |SHA-2_384 |

|0x000D |SHA-2_512 |

Currently available TPM 2.0 devices like the Infineon *Optiga SLB 9670 VQ2.0* hardware TPM or Intel's *PTT* firmware TPM integrated into the Management Engine starting with the 4th generation (Haswell) of the *Core* processor family, support the *SHA-1* and *SHA-2_256* algorithms.

h3. Public Key Types

|0x0001 |RSA |

|0x0023 |ECC |

Currently RSA keys have a modulus size of 2048 bits and ECC keys are based on the 256 bit NIST curve.

h3. Signature Schemes

|0x0014 |RSASSA |

|0x0016 |RSAPSS |

|0x0018 |ECDSA  |

h2. TPM 2.0 Attributes

h3. Object Attributes

|0x00002 |fixedTPM             |

|0x00004 |stClear              |

|0x00010 |fixedParent          |

|0x00020 |sensitiveDataOrigin  |

|0x00040 |userWithAuth         |

|0x00080 |adminWithPolicy      |

|0x00400 |noDA                 |

|0x00800 |encryptedDuplication |

|0x10000 |restricted           |

|0x20000 |decrypt              |

|0x40000 |sign                 |

h3. NV Index Attributes

|0x00000001 |NV_PPWRITE        |

|0x00000002 |NV_OWNERWRITE     |

|0x00000004 |NV_AUTHWRITE      |

|0x00000008 |NV_POLICYWRITE    |

|0x000000F0 |NT                |

|0x00000400 |NV_POLICY_DELETE  |

|0x00000800 |NV_WRITELOCKED    |

|0x00001000 |NV_WRITEALL       |

|0x00002000 |NV_WRITEDEFINE    |

|0x00004000 |NV_WRITE_STCLEAR  |

|0x00008000 |NV_GLOBALLOCK     |

|0x00010000 |NV_PPEREAD        |

|0x00020000 |NV_OWNERREAD      |

|0x00040000 |NV_AUTHREAD       |

|0x00080000 |NV_POLICYREAD     |

|0x02000000 |NV_NO_DA          |

|0x04000000 |NV_ORDERLY        |

|0x08000000 |NV_CLEAR_STCLEAR  |

|0x10000000 |NV_READLOCKED     |

|0x20000000 |NV_WRITTEN        |

|0x40000000 |NV_PLATFORMCREATE |

|0x80000000 |NV_READ_STCLEAR   |

h2. Derive a Persistent RSA Endorsement Key

The following tpm2-tools command derives a 2048 bit RSA Endorsement Key (EK) in a deterministic way from the secret _Endorsement Primary Seed_ *unique* to each TPM device and makes the key persistent in the non-volatile memory of the TPM under the object handle 0x81010001

 tpm2_getpubek -H 0x81010001 -g rsa -f ek_rsa.pub

The EK public key stored in the ek_rsa.pub file is encoded in a TPM 2.0 proprietary format but the key can be exported from the TPM in the regular PKCS#1 format using the *pki* tool

 pki --pub --keyid 0x81010001 --outform pem > ek_rsa_pub.pem

The fingerprint of the RSA EK public key can be displayed with the command

 pki --print --type pub --in ek_rsa_pub.pem

  pubkey:    RSA 2048 bits

  keyid:     d1:f1:49:84:36:44:e6:8c:d2:a6:69:ee:fd:b5:7d:56:2f:39:ff:58

  subjkey:   c1:1b:8e:f1:c7:f8:8a:1e:9a:dd:7e:82:2f:7a:a3:f5:c0:e2:4d:7d

h2. Generate a Persistent RSA Attestation Key

A 2048 bit RSA Attestation Key (AK) bound to the EK with handle 0x81010001 can be created and made persistent under the handle 0x81010002 with the following tpm2-tools command

 tpm2_getpubak -E 0x81010001 -g rsa -D sha256 -s rsassa -k 0x81010002 -P 123456 -f ak_rsa2.pub -n ak_rsa2.name

This AK key is protected by the PIN (-P parameter) *123456*. The AK public key can now be exported in PKCS#1 format from the TPM using the *pki* tool

 pki --pub --keyid 0x81010002 --outform pem > ak_rsa_pub.pem

The fingerprint of the RSA AK public key can be displayed with the command

 pki --print --type pub --in ak_rsa_pub.pem

  pubkey:    RSA 2048 bits

  keyid:     71:21:f5:d4:7e:59:4a:88:16:ca:57:85:98:3d:36:a7:b1:d5:75:fa

  subjkey:   f4:9e:85:7d:de:4e:67:f5:fb:87:03:98:67:3f:20:7c:f3:3f:2b:66

h2. Derive a Persistent ECC Endorsement Key

The following tpm2-tools command derives a 256 bit ECC Endorsement Key (EK) in a deterministic way from the secret _Endorsement Primary Seed_ *unique* to each TPM device and makes the key persistent in the non-volatile memory of the TPM under the object handle 0x81010003:

 tpm2_getpubek -H 0x81010003 -g ecc -f ek_ecc.pub

Without exporting the public key first the fingerprint of the ECC EK private key can be directly displayed with the command

 pki --print --type priv --keyid 0x81010003

  pubkey:    ECDSA 256 bits

  keyid:     7f:39:ca:e6:83:9b:a9:06:97:40:27:6a:e1:bf:8f:f5:9f:d3:a5:31

  subjkey:   8b:43:4d:5e:5e:7b:ff:c2:54:4d:ef:88:cb:0c:7c:47:75:28:4d:09

h2. Generate a Persistent ECC Attestation Key

A 256 bit ECC Attestation Key (AK) bound to the EK with handle 0x81010003 can be created and made persistent under the handle 0x81010004 with the following tpm2-tools command

 tpm2_getpubak -E 0x81010003 -g ecc -D sha256 -s ecdsa -k 0x81010004 -f ak_ecc4.pub -n ak_ecc4.name

The AK public key can be exported in PKCS#1 format from the TPM using the *pki* tool

 pki --pub --keyid 0x81010004 > ak_ecc_pub.der

The fingerprint of the ECC AK public key can be displayed with the command

 pki --print --type pub --in ak_ecc_pub.der

  pubkey:    ECDSA 256 bits

  keyid:     71:49:7c:42:41:e7:c6:81:bc:31:73:f0:0f:7e:4a:e1:2d:53:00:38

  subjkey:   c7:0e:63:f8:7f:6f:f6:55:00:e5:05:7f:5a:3e:6b:6c:e7:d2:d5:13

h2. Generate Another ECC Attestation Key

Multiple AK keys bound to a common EK key can be generated

 tpm2_getpubak -E 0x81010003 -g ecc -D sha256 -s ecdsa -k 0x81010005 -f ak_ecc5.pub -n ak_ecc5.name

The fingerprint of the second ECC AK private key can be displayed with the command

 pki --print --type priv --in 0x81010005

  pubkey:    ECDSA 256 bits

  keyid:     c4:b4:9c:95:27:9e:ce:81:2f:98:42:c8:1b:f0:54:ff:d4:d1:24:34

  subjkey:   cf:44:f4:f7:9d:97:09:ad:b1:09:3a:8e:6f:23:eb:9f:2c:35:94:c9

h2. Remove a Persistent Key Object

Since the non-volatile memory of the TPM is limited any persistent key object can be removed to free storage space.

The following tpm2-tools command removes the ECC AK key with persistent handle 0x81010005

 tpm2_evictcontrol -A o -H 0x81010005 -S 0x81010005

h2. List Persistent Objects

The following tpm2-tools command lists all persistent objects stored by the TPM in non-volatile memory

 tpm2_listpersistent

<pre>

6 persistent objects defined.

0. Persistent handle: 0x81000001

{

        Type: 0x23

        Hash algorithm(nameAlg): 0xb

        Attributes: 0x30072

}

1. Persistent handle: 0x81000002

{

        Type: 0x23

        Hash algorithm(nameAlg): 0xb

        Attributes: 0x60072

}

2. Persistent handle: 0x81010001

{

        Type: 0x1

        Hash algorithm(nameAlg): 0xb

        Attributes: 0x300b2

}

3. Persistent handle: 0x81010002

{

        Type: 0x1

        Hash algorithm(nameAlg): 0xb

        Attributes: 0x50072

}

4. Persistent handle: 0x81010003

{

        Type: 0x23

        Hash algorithm(nameAlg): 0xb

        Attributes: 0x300b2

}

5. Persistent handle: 0x81010004

{

        Type: 0x23

        Hash algorithm(nameAlg): 0xb

        Attributes: 0x50072

}

</pre>

h2. Create a Demo Root CA

The following *pki* command creates a 256 bit ECDSA private key for the Demo CA

<pre>

pki --gen --type ecdsa --size 256 --outform pem > demoCaKey.pem

</pre>

Next we create a self-signed Root CA certificate

<pre>

pki --self --ca --type ecdsa --in demoCaKey.pem --dn="C=US, O=TNC Demo, CN=TNC Demo CA" --lifetime 3652 --outform pem > demoCaCert.pem

</pre>

h2. Issue an RSA AIK Certificate

Based on the RSA AK public key exported from the TPM, the following *pki* command generates an Attestation Identity Key (AIK) certificate signed by the Demo CA

<pre>

pki --issue --cacert demoCaCert.pem --cakey demoCaKey.pem --type pub --in ak_rsa_pub.der --dn "C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com" --san raspi5.example.com --lifetime 3651 > raspi5_ak_rsa_Cert.der

</pre>

h2. Issue an ECC AIK Certificate

Based on the ECC AK public key exported from the TPM, the following *pki* command generates an Attestation Identity Key (AIK) certificate signed by the Demo CA

<pre>

pki --issue --cacert demoCaCert.pem --cakey demoCaKey.pem --type pub --in ak_ecc_pub.der --dn "C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com" --san raspi5.example.com --lifetime 3651 > raspi5_ak_ecc_Cert.der

</pre>

Many certification authorities issue certificates based on PKCS#10 certificate requests. This approach is also possible. First a certificate request is generated on the host the TPM resides on

<pre>

 pki --req --keyid 0x81010004 --dn "C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com" --san raspi5.example.com > ak_ecc_req.der

</pre>

When you are prompted for a smartcard PIN just press <enter> since this TPM private key is not protected by a PIN. In a second step the CA issues the AIK certificate based on the PKCS#10 certificate request

<pre>

pki --issue --cacert demoCaCert.pem --cakey demoCaKey.pem --type pkcs10 --in ak_ecc_req.der --lifetime 3651 > raspi5_ak_ecc_Cert.der

</pre>

h2. Store the ECC AIK Certificate in the NV RAM of the TPM

A TPM 2.0 has a certain amount of Non Volatile Random Access Memory (NV RAM) that can be used to store arbitrary data, e.g. the X.509 certificates matching the persistent keys. IF both the certificates and keys are persisted in the TPM then the system disk of the host can be reformatted at any time without loosing the machine or user credentials.As with smartcards the needed amount of memory must be reserved first so we check the size of the X.509 ECC certificate

<pre>

ls -l raspi5_ak_ecc_Cert.der

-rw-r--r-- 1 root root 449 Feb 17  2017 raspi5_ak_ecc_Cert.der

</pre>

We then define a memory location with a size of 449 bytes that can be accessed via the handle 0x01800004 which is also called the NV index

<pre>

tpm2_nvdefine -x 0x01800004 -a 0x40000001 -s 449 -t 0x2000A

</pre>

Then we write the certificate file to the NV RAM destination

<pre>

tpm2_nvwrite -x 0x01800004 -a 0x40000001 raspi5_ak_ecc_Cert.der

</pre>

h2. List of NV Indexes

A list of all defined NV indexes can be obtained with

 tpm2_nvlist

<pre>

2 NV indexes defined.

  0. NV Index: 0x1500015

  {

	Hash algorithm(nameAlg):4

 	The Index attributes(attributes):0x44040004

 	The size of the data area(dataSize):4

   }

  1. NV Index: 0x1800004

  {

	Hash algorithm(nameAlg):11

 	The Index attributes(attributes):0x2002000a

 	The size of the data area(dataSize):449

   }

</pre>

h2. Remove NV Index

The memory assigned to a given NV index can be released with the command

<pre>

tpm2_nvrelease -x 0x01800001 -a 0x40000001

</pre>

h2. Configure TPM Private Key Access via VICI Interface

Configuration of TPM private key access as tokens in the secrets section of *swanctl.conf*

 secrets {

    token_ak_rsa {

       handle = 81010002

       pin = 123456

    }

    token_ak_ecc {

       handle = 81010004

    }

}

Since the use of the RSA AK private key is password-protected, the PIN *123456* is added.

h2. Define IPsec Connection with RSA AK Client Key

This connection configuration in *swanctl.conf* uses the RSA AK certificate for client authentication

<pre>

connections {

   rsa {

      local_addrs  = 10.10.0.105

      remote_addrs = 10.10.0.104

      local {

         auth = pubkey 

         certs = raspi5_ak_rsa_Cert.der

      }

      remote {

         auth = pubkey 

         id = raspi4.example.com

      }

      children {

         rsa {

            mode = transport

            esp_proposals = aes128-sha256-curve25519

         }

      }

      version = 2

      proposals = aes128-sha256-curve25519

   }

}

</pre>

h2. Define IPsec Connection with ECC AK Client Key

This connection configuration in *swanctl.conf* references the ECC AK certificate used for client authentication via its handle, i.e. the NV index

<pre>

connections {

   ecc {

      local_addrs  = 10.10.0.105

      remote_addrs = 10.10.0.104

      local {

         auth = pubkey

         cert-tpm {

            handle = 0x01800004

         }

      }

      remote {

         auth = pubkey

         id = raspi4.example.com

      }

      children {

         ecc {

            mode = transport

            esp_proposals = aes128-sha256-curve25519

         }

      }

      version = 2

      proposals = aes128-sha256-curve25519

   }

}

</pre>

h2. Starting the strongSwan Daemon

<pre>

systemctl start strongswan-swanctl

</pre>

<pre>

Feb 19 10:52:01 raspi5 systemd[1]: Starting strongSwan IPsec IKEv1/IKEv2 daemon using swanctl...

Feb 19 10:52:01 raspi5 charon-systemd[21165]: loaded plugins: charon-systemd charon-systemd random nonce x509 constraints openssl pem pkcs1 pkcs8 pkcs12 pubkey mgf1 ntru curve25519 eap-identity eap-ttls eap-tnc tnc-tnccs tnc-imc tnccs-20 socket-default kernel-netlink vici tpm

Feb 19 10:52:01 raspi5 charon-systemd[21165]: spawning 16 worker threads

Feb 19 10:52:01 raspi5 charon-systemd[21165]: loaded certificate 'C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com'

Feb 19 10:52:01 raspi5 charon-systemd[21165]: loaded certificate 'C=US, O=TNC Demo, CN=TNC Demo CA'

</pre>

The RSA AK private key is attached to the *charon-systemd* daemon via the TPM 2.0 resource manager

<pre>

Feb 19 10:52:01 raspi5 charon-systemd[21165]: TPM 2.0 - manufacturer: IFX (SLB9670) rev: 01.16 2015

Feb 19 10:52:01 raspi5 charon-systemd[21165]: TPM 2.0 - algorithms: RSA SHA1 HMAC AES KEYEDHASH XOR SHA256 RSASSA RSAES RSAPSS OAEP ECDSA ECDH SM2 KDF1_SP800_56A KDF1_SP800_108 ECC SYMCIPHER CFB

Feb 19 10:52:01 raspi5 charon-systemd[21165]: TPM 2.0 - ECC curves: NIST_P256 BN_P256

Feb 19 10:52:01 raspi5 charon-systemd[21165]: TPM 2.0 via TSS2 v2 available

Feb 19 10:52:01 raspi5 charon-systemd[21165]: AIK signature algorithm is RSASSA with SHA256 hash

Feb 19 10:52:01 raspi5 charon-systemd[21165]: loaded RSA private key from token

F</pre>

The ECC AK private key is attached to the *charon-systemd* daemon via the TPM 2.0 resource manager

<pre>

Feb 19 10:52:01 raspi5 charon-systemd[21165]: TPM 2.0 - manufacturer: IFX (SLB9670) rev: 01.16 2015

Feb 19 10:52:01 raspi5 charon-systemd[21165]: TPM 2.0 - algorithms: RSA SHA1 HMAC AES KEYEDHASH XOR SHA256 RSASSA RSAES RSAPSS OAEP ECDSA ECDH SM2 KDF1_SP800_56A KDF1_SP800_108 ECC SYMCIPHER CFB

Feb 19 10:52:02 raspi5 charon-systemd[21165]: TPM 2.0 - ECC curves: NIST_P256 BN_P256

Feb 19 10:52:02 raspi5 charon-systemd[21165]: TPM 2.0 via TSS2 v2 available

Feb 19 10:52:02 raspi5 charon-systemd[21165]: AIK signature algorithm is ECDSA with SHA256 hash

Feb 19 10:52:02 raspi5 charon-systemd[21165]: loaded ECDSA private key from token

</pre>

The ECC AIK certificate is loaded by the *charon-systemd* daemon via the TPM 2.0 resource manager

<pre>

Feb 19 10:52:02 raspi5 charon-systemd[21165]: TPM 2.0 - manufacturer: IFX (SLB9670) rev: 01.16 2015

Feb 19 10:52:02 raspi5 charon-systemd[21165]: TPM 2.0 - algorithms: RSA SHA1 HMAC AES KEYEDHASH XOR SHA256 RSASSA RSAES RSAPSS OAEP ECDSA ECDH SM2 KDF1_SP800_56A KDF1_SP800_108 ECC SYMCIPHER CFB

Feb 19 10:52:02 raspi5 charon-systemd[21165]: TPM 2.0 - ECC curves: NIST_P256 BN_P256

Feb 19 10:52:02 raspi5 charon-systemd[21165]: TPM 2.0 via TSS2 v2 available

Feb 19 10:52:02 raspi5 charon-systemd[21165]: loaded certificate from TPM NV index 0x01800004

</pre>

The two connection definitions are received by the *charon-systemd* daemon from the *swanctl* command line tool via the VICI interface

<pre>

Feb 19 10:52:02 raspi5 charon-systemd[21165]:   id not specified, defaulting to cert subject 'C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com'

Feb 19 10:52:02 raspi5 charon-systemd[21165]: added vici connection: rsa

Feb 19 10:52:02 raspi5 charon-systemd[21165]:   id not specified, defaulting to cert subject 'C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com'

Feb 19 10:52:02 raspi5 charon-systemd[21165]: added vici connection: ecc

</pre>

The *swanctl* command line tool reports its actions

<pre>

Feb 19 10:52:02 raspi5 swanctl[21183]: loaded certificate from '/etc/swanctl/x509/raspi5_ak_rsa_Cert.der'

Feb 19 10:52:02 raspi5 swanctl[21183]: loaded certificate from '/etc/swanctl/x509ca/demoCaCert.pem'

Feb 19 10:52:02 raspi5 swanctl[21183]: loaded key token_ak_rsa from token [keyid: f49e857dde4e67f5fb870398673f207cf33f2b66]

Feb 19 10:52:02 raspi5 swanctl[21183]: loaded key token_ak_ecc from token [keyid: c70e63f87f6ff65500e5057f5a3e6b6ce7d2d513]

Feb 19 10:52:02 raspi5 swanctl[21183]: loaded connection 'rsa'

Feb 19 10:52:02 raspi5 swanctl[21183]: loaded connection 'ecc'

Feb 19 10:52:02 raspi5 swanctl[21183]: successfully loaded 2 connections, 0 unloaded

</pre>

<pre>

Feb 19 10:52:02 raspi5 systemd[1]: Started strongSwan IPsec IKEv1/IKEv2 daemon using swanctl.

</pre>

The following *swanctl* command shows the two loaded connections

<pre>

swanctl --list-conns

</pre>

<pre>

rsa: IKEv2, reauthentication every 10800s, no rekeying

  local:  10.10.0.105

  remote: 10.10.0.104

  local public key authentication:

    id: C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com

    certs: C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com

  remote public key authentication:

    id: raspi4.example.com

  rsa: TRANSPORT, rekeying every 3600s or 300000000 bytes or 500000 packets

    local:  dynamic

    remote: dynamic

</pre>

<pre>

ecc: IKEv2, reauthentication every 10800s, no rekeying

  local:  10.10.0.105

  remote: 10.10.0.104

  local public key authentication:

    id: C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com

    certs: C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com

  remote public key authentication:

    id: raspi4.example.com

  ecc: TRANSPORT, rekeying every 3600s or 300000000 bytes or 500000 packets

    local:  dynamic

    remote: dynamic

</pre>

The loaded certificates can also be displayed

<pre>

swanctl --list-certs

</pre>

You can clearly see that the connection between the AK certificates and their matching AK private key has been established (..., has private key)

<pre>

List of X.509 End Entity Certificates

  subject:  "C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com"

  issuer:   "C=US, O=TNC Demo, CN=TNC Demo CA"

  validity:  not before Feb 19 09:33:43 2017, ok

             not after  Aug 29 10:33:43 2026, ok (expires in 3477 days)

  serial:    11:57:33:3e:2a:8e:8a:32

  altNames:  raspi5.example.com

  authkeyId: 21:02:7e:2d:de:8b:77:48:75:de:56:2f:b5:d4:62:ec:c3:09:15:f2

  subjkeyId: f4:9e:85:7d:de:4e:67:f5:fb:87:03:98:67:3f:20:7c:f3:3f:2b:66

  pubkey:    RSA 2048 bits, has private key

  keyid:     71:21:f5:d4:7e:59:4a:88:16:ca:57:85:98:3d:36:a7:b1:d5:75:fa

  subjkey:   f4:9e:85:7d:de:4e:67:f5:fb:87:03:98:67:3f:20:7c:f3:3f:2b:66

  subject:  "C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com"

  issuer:   "C=US, O=TNC Demo, CN=TNC Demo CA"

  validity:  not before Feb 17 23:17:19 2017, ok

             not after  Aug 30 00:17:19 2026, ok (expires in 3478 days)

  serial:    52:9d:3e:42:6f:71:63:3d

  altNames:  raspi5.example.com

  authkeyId: 21:02:7e:2d:de:8b:77:48:75:de:56:2f:b5:d4:62:ec:c3:09:15:f2

  subjkeyId: c7:0e:63:f8:7f:6f:f6:55:00:e5:05:7f:5a:3e:6b:6c:e7:d2:d5:13

  pubkey:    ECDSA 256 bits, has private key

  keyid:     71:49:7c:42:41:e7:c6:81:bc:31:73:f0:0f:7e:4a:e1:2d:53:00:38

  subjkey:   c7:0e:63:f8:7f:6f:f6:55:00:e5:05:7f:5a:3e:6b:6c:e7:d2:d5:13

</pre>

<pre>

List of X.509 CA Certificates

  subject:  "C=US, O=TNC Demo, CN=TNC Demo CA"

  issuer:   "C=US, O=TNC Demo, CN=TNC Demo CA"

  validity:  not before Aug 31 10:29:27 2016, ok

             not after  Aug 31 10:29:27 2026, ok (expires in 3479 days)

  serial:    02:c8:85:e1:ef:fa:8f:20

  flags:     CA CRLSign self-signed 

  subjkeyId: 21:02:7e:2d:de:8b:77:48:75:de:56:2f:b5:d4:62:ec:c3:09:15:f2

  pubkey:    ECDSA 256 bits

  keyid:     a1:b5:e0:29:d0:4c:a7:62:bd:ca:a3:b4:af:18:42:2c:4a:01:55:9a

  subjkey:   21:02:7e:2d:de:8b:77:48:75:de:56:2f:b5:d4:62:ec:c3:09:15:f2

</pre>

h2. IKEv2 Authentication with RSA AIK Certificate

With the following *swanctl* command the "rsa" connection is established

<pre>

swanctl --initiate --child rsa

</pre>

<pre>

Feb 19 10:52:21 raspi5 charon-systemd[21165]: vici initiate 'rsa'

Feb 19 10:52:21 raspi5 charon-systemd[21165]: initiating IKE_SA rsa[1] to 10.10.0.104

Feb 19 10:52:21 raspi5 charon-systemd[21165]: generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) N(HASH_ALG) N(REDIR_SUP) V ]

Feb 19 10:52:21 raspi5 charon-systemd[21165]: sending packet: from 10.10.0.105[500] to 10.10.0.104[500] (1257 bytes)

Feb 19 10:52:21 raspi5 charon-systemd[21165]: received packet: from 10.10.0.104[500] to 10.10.0.105[500] (1259 bytes)

Feb 19 10:52:21 raspi5 charon-systemd[21165]: parsed IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) CERTREQ N(HASH_ALG) V ]

Feb 19 10:52:21 raspi5 charon-systemd[21165]: received strongSwan vendor ID

Feb 19 10:52:21 raspi5 charon-systemd[21165]: received cert request for "C=US, O=TNC Demo, CN=TNC Demo CA"

Feb 19 10:52:21 raspi5 charon-systemd[21165]: sending cert request for "C=US, O=TNC Demo, CN=TNC Demo CA"

</pre>

The RSA AK private key stored in the TPM 2.0 is used to generate an *RSA_EMSA_PKCS1_SHA2_256* signature which is sent in the AUTH payload of the IKE_AUTH request. The matching client certificate is sent int the CERT payload.

<pre>

Feb 19 10:52:24 raspi5 charon-systemd[21165]: authentication of 'C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com' (myself) with RSA_EMSA_PKCS1_SHA2_256 successful

Feb 19 10:52:24 raspi5 charon-systemd[21165]: sending end entity cert "C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com"

</pre>

<pre>

Feb 19 10:52:24 raspi5 charon-systemd[21165]: establishing CHILD_SA rsa

Feb 19 10:52:24 raspi5 charon-systemd[21165]: generating IKE_AUTH request 1 [ IDi CERT CERTREQ IDr AUTH N(USE_TRANSP) SA TSi TSr N(MOBIKE_SUP) N(ADD_6_ADDR) N(EAP_ONLY) N(MSG_ID_SYN_SUP) ]

Feb 19 10:52:24 raspi5 charon-systemd[21165]: sending packet: from 10.10.0.105[4500] to 10.10.0.104[4500] (1296 bytes)

Feb 19 10:52:24 raspi5 charon-systemd[21165]: received packet: from 10.10.0.104[4500] to 10.10.0.105[4500] (752 bytes)

Feb 19 10:52:24 raspi5 charon-systemd[21165]: parsed IKE_AUTH response 1 [ IDr CERT AUTH N(USE_TRANSP) SA TSi TSr N(AUTH_LFT) N(MOBIKE_SUP) N(NO_ADD_ADDR) ]

Feb 19 10:52:24 raspi5 charon-systemd[21165]: received end entity cert "C=US, O=TNC Demo, CN=raspi4.example.com"

Feb 19 10:52:24 raspi5 charon-systemd[21165]:   using certificate "C=US, O=TNC Demo, CN=raspi4.example.com"

Feb 19 10:52:24 raspi5 charon-systemd[21165]:   using trusted ca certificate "C=US, O=TNC Demo, CN=TNC Demo CA"

Feb 19 10:52:24 raspi5 charon-systemd[21165]:   reached self-signed root ca with a path length of 0

Feb 19 10:52:24 raspi5 charon-systemd[21165]: authentication of 'raspi4.example.com' with ECDSA_WITH_SHA256_DER successful

Feb 19 10:52:24 raspi5 charon-systemd[21165]: IKE_SA rsa[1] established between 10.10.0.105[C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com]...10.10.0.104[raspi4.example.com]

Feb 19 10:52:24 raspi5 charon-systemd[21165]: scheduling reauthentication in 10507s

Feb 19 10:52:24 raspi5 charon-systemd[21165]: maximum IKE_SA lifetime 11587s

Feb 19 10:52:24 raspi5 charon-systemd[21165]: CHILD_SA rsa{1} established with SPIs c23deb9d_i ce48d08e_o and TS 10.10.0.105/32 === 10.10.0.104/32

Feb 19 10:52:24 raspi5 charon-systemd[21165]: received AUTH_LIFETIME of 10103s, scheduling reauthentication in 9023s

Feb 19 10:52:24 raspi5 charon-systemd[21165]: peer supports MOBIKE

</pre>

The following *swanctl* command shows the established IPsec connection

<pre>

 swanctl --list-sas

</pre>

<pre>

rsa: #1, ESTABLISHED, IKEv2, 7ba3b4d06c051ecb_i* 14e1769a8aeb7f28_r

  local  'C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com' @ 10.10.0.105[4500]

  remote 'raspi4.example.com' @ 10.10.0.104[4500]

  AES_CBC-128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/CURVE_25519

  established 252s ago, reauth in 8771s

  rsa: #1, reqid 1, INSTALLED, TRANSPORT, ESP:AES_CBC-128/HMAC_SHA2_256_128

    installed 252s ago, rekeying in 3258s, expires in 3708s

    in  c23deb9d,    640 bytes,    10 packets,     3s ago

    out ce48d08e,    640 bytes,    10 packets,     3s ago

    local  10.10.0.105/32

    remote 10.10.0.104/32

</pre>

With this *swanctl* command the "rsa" connection is terminated

<pre>

swanctl --terminate --ike rsa

</pre>

<pre>

Feb 19 10:59:16 raspi5 charon-systemd[21165]: vici terminate IKE_SA 'rsa'

Feb 19 10:59:16 raspi5 charon-systemd[21165]: deleting IKE_SA rsa[1] between 10.10.0.105[C=US, O=TNC Demo, OU=AIK RSA, CN=raspi5.example.com]...10.10.0.104[raspi4.example.com]

Feb 19 10:59:16 raspi5 charon-systemd[21165]: sending DELETE for IKE_SA rsa[1]

Feb 19 10:59:16 raspi5 charon-systemd[21165]: generating INFORMATIONAL request 2 [ D ]

Feb 19 10:59:16 raspi5 charon-systemd[21165]: sending packet: from 10.10.0.105[4500] to 10.10.0.104[4500] (80 bytes)

Feb 19 10:59:16 raspi5 charon-systemd[21165]: received packet: from 10.10.0.104[4500] to 10.10.0.105[4500] (80 bytes)

Feb 19 10:59:16 raspi5 charon-systemd[21165]: parsed INFORMATIONAL response 2 [ ]

Feb 19 10:59:16 raspi5 charon-systemd[21165]: IKE_SA deleted

</pre>

h2. IKEv2 Authentication with ECC AIK Certificate

Next we initiate the "ecc" connection

<pre>

swanctl --initiate --child ecc

</pre>

<pre>

Feb 19 11:00:32 raspi5 charon-systemd[21165]: vici initiate 'ecc'

Feb 19 11:00:32 raspi5 charon-systemd[21165]: initiating IKE_SA ecc[2] to 10.10.0.104

Feb 19 11:00:32 raspi5 charon-systemd[21165]: generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) N(HASH_ALG) N(REDIR_SUP) V ]

Feb 19 11:00:32 raspi5 charon-systemd[21165]: sending packet: from 10.10.0.105[500] to 10.10.0.104[500] (1257 bytes)

Feb 19 11:00:32 raspi5 charon-systemd[21165]: received packet: from 10.10.0.104[500] to 10.10.0.105[500] (1259 bytes)

Feb 19 11:00:32 raspi5 charon-systemd[21165]: parsed IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) CERTREQ N(HASH_ALG) V ]

Feb 19 11:00:32 raspi5 charon-systemd[21165]: received strongSwan vendor ID

Feb 19 11:00:32 raspi5 charon-systemd[21165]: received cert request for "C=US, O=TNC Demo, CN=TNC Demo CA"

Feb 19 11:00:32 raspi5 charon-systemd[21165]: sending cert request for "C=US, O=TNC Demo, CN=TNC Demo CA"

</pre>

The ECC AK private key stored in the TPM 2.0 is used to generate an *ECDSA_WITH_SHA256_DER* signature which is sent in the AUTH payload of the IKE_AUTH request. The matching client certificate is sent int the CERT payload.

<pre>

Feb 19 11:00:34 raspi5 charon-systemd[21165]: authentication of 'C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com' (myself) with ECDSA_WITH_SHA256_DER successful

Feb 19 11:00:34 raspi5 charon-systemd[21165]: sending end entity cert "C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com"

</pre>

<pre>

Feb 19 11:00:34 raspi5 charon-systemd[21165]: establishing CHILD_SA ecc

Feb 19 11:00:34 raspi5 charon-systemd[21165]: generating IKE_AUTH request 1 [ IDi CERT CERTREQ IDr AUTH N(USE_TRANSP) SA TSi TSr N(MOBIKE_SUP) N(ADD_6_ADDR) N(EAP_ONLY) N(MSG_ID_SYN_SUP) ]

Feb 19 11:00:34 raspi5 charon-systemd[21165]: sending packet: from 10.10.0.105[4500] to 10.10.0.104[4500] (912 bytes)

Feb 19 11:00:34 raspi5 charon-systemd[21165]: received packet: from 10.10.0.104[4500] to 10.10.0.105[4500] (752 bytes)

Feb 19 11:00:34 raspi5 charon-systemd[21165]: parsed IKE_AUTH response 1 [ IDr CERT AUTH N(USE_TRANSP) SA TSi TSr N(AUTH_LFT) N(MOBIKE_SUP) N(NO_ADD_ADDR) ]

Feb 19 11:00:34 raspi5 charon-systemd[21165]: received end entity cert "C=US, O=TNC Demo, CN=raspi4.example.com"

Feb 19 11:00:34 raspi5 charon-systemd[21165]:   using certificate "C=US, O=TNC Demo, CN=raspi4.example.com"

Feb 19 11:00:34 raspi5 charon-systemd[21165]:   using trusted ca certificate "C=US, O=TNC Demo, CN=TNC Demo CA"

Feb 19 11:00:34 raspi5 charon-systemd[21165]:   reached self-signed root ca with a path length of 0

Feb 19 11:00:34 raspi5 charon-systemd[21165]: authentication of 'raspi4.example.com' with ECDSA_WITH_SHA256_DER successful

Feb 19 11:00:34 raspi5 charon-systemd[21165]: IKE_SA ecc[2] established between 10.10.0.105[C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com]...10.10.0.104[raspi4.example.com]

Feb 19 11:00:34 raspi5 charon-systemd[21165]: scheduling reauthentication in 10180s

Feb 19 11:00:34 raspi5 charon-systemd[21165]: maximum IKE_SA lifetime 11260s

Feb 19 11:00:34 raspi5 charon-systemd[21165]: CHILD_SA ecc{2} established with SPIs c2c16cd0_i c47ea6f6_o and TS 10.10.0.105/32 === 10.10.0.104/32

Feb 19 11:00:34 raspi5 charon-systemd[21165]: received AUTH_LIFETIME of 9880s, scheduling reauthentication in 8800s

Feb 19 11:00:34 raspi5 charon-systemd[21165]: peer supports MOBIKE

</pre>

The establed IKE and CHILD SAs are displayed

<pre>

 swanctl --list-sas

</pre>

<pre>

ecc: #2, ESTABLISHED, IKEv2, b7f2652777b0996a_i* 12282b5964ff0658_r

  local  'C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com' @ 10.10.0.105[4500]

  remote 'raspi4.example.com' @ 10.10.0.104[4500]

  AES_CBC-128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/CURVE_25519

  established 126s ago, reauth in 8674s

  ecc: #2, reqid 2, INSTALLED, TRANSPORT, ESP:AES_CBC-128/HMAC_SHA2_256_128

    installed 126s ago, rekeying in 3252s, expires in 3834s

    in  c2c16cd0,    320 bytes,     5 packets,     2s ago

    out c47ea6f6,    320 bytes,     5 packets,     2s ago

    local  10.10.0.105/32

    remote 10.10.0.104/32

</pre>

The IKE and CHILD SAs are terminated

<pre>

swanctl --terminate --ike ecc

</pre>

<pre>

Feb 19 11:04:32 raspi5 charon-systemd[21165]: vici terminate IKE_SA 'ecc'

Feb 19 11:04:32 raspi5 charon-systemd[21165]: deleting IKE_SA ecc[2] between 10.10.0.105[C=US, O=TNC Demo, OU=AIK ECC, CN=raspi5.example.com]...10.10.0.104[raspi4.example.com]

Feb 19 11:04:32 raspi5 charon-systemd[21165]: sending DELETE for IKE_SA ecc[2]

Feb 19 11:04:32 raspi5 charon-systemd[21165]: generating INFORMATIONAL request 2 [ D ]

Feb 19 11:04:32 raspi5 charon-systemd[21165]: sending packet: from 10.10.0.105[4500] to 10.10.0.104[4500] (80 bytes)

Feb 19 11:04:32 raspi5 charon-systemd[21165]: received packet: from 10.10.0.104[4500] to 10.10.0.105[4500] (80 bytes)

Feb 19 11:04:32 raspi5 charon-systemd[21165]: parsed INFORMATIONAL response 2 [ ]

Feb 19 11:04:32 raspi5 charon-systemd[21165]: IKE_SA deleted

</pre>