0

Here is the situation :

  • GW installed on CentOS7 with Strongswan 5.7.2 with these plugins loaded :

charon pkcs11 tpm aesni aes des rc2 sha2 sha1 md4 md5 mgf1 random nonce x509 revocation constraints acert pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem openssl gcrypt fips-prf gmp curve25519 chapoly xcbc cmac hmac ctr ccm gcm curl attr kernel-netlink resolve socket-default farp stroke vici updown eap-identity eap-sim eap-aka eap-aka-3gpp eap-aka-3gpp2 eap-md5 eap-gtc eap-mschapv2 eap-dynamic eap-radius eap-tls eap-ttls eap-peap xauth-generic xauth-eap xauth-pam xauth-noauth dhcp led duplicheck unity counters

  • the same CA authority has signed all of the certificates (for the GW and for the identity of the client)

  • clients are in roadwarrior mode, on Windows 10

  • ipsec.conf :

# VPN connections
conn %default
        mobike=yes
        esp=aes256gcm128-sha512-modp4096,aes256-sha1-modp1024!
        ike=aes256gcm128-sha512-modp4096,aes256-sha384-modp1024!
        eap_identity=%any
        keyexchange=ikev2
        forceencaps=yes
        auto=add

conn IKEv2-eap
        leftauth=pubkey
        leftfirewall=yes
        leftcert=gwCert.pem
        leftsubnet=0.0.0.0/0
        right=%any
        rightsourceip=10.3.0.0/24
        rightsendcert=never
        rightdns=134.158.128.2,134.158.128.6
        rightauth=eap-tls
        eap_identity=%identity
  • ipsec.secrets :
# ipsec.secrets - strongSwan IPsec secrets file
: RSA gwKey.pem
  • GW certificate :
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 62767 (0xf52f)
    Signature Algorithm: sha1WithRSAEncryption
        Issuer: C=FR, O=Organization, CN=IntermediateAuthority
        Validity
            Not Before: May 20 13:26:11 2019 GMT
            Not After : May 19 13:26:11 2021 GMT
        Subject: C=FR, O=Organization, OU=OUnit, CN=vpn.domain.tld/emailAddress=contact@domain.tld
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    ...
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Basic Constraints: critical
                CA:FALSE
            Netscape Cert Type:
                SSL Client, SSL Server
            X509v3 Key Usage: critical
                Digital Signature, Non Repudiation, Key Encipherment
            X509v3 Extended Key Usage:
                TLS Web Server Authentication, TLS Web Client Authentication
            Netscape Comment:
                Certificat serveur IntermediateAuthority
            X509v3 Subject Key Identifier:
                ...
            X509v3 Authority Key Identifier:
                keyid:...
                DirName:/C=FR/O=Organization/CN=RootAuthority
                serial:03

            X509v3 Subject Alternative Name:
                email:contact@domain.tld
            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crls.domain.tld/IntermediateAuthority/getder.crl

    Signature Algorithm: sha1WithRSAEncryption
         ...
  • client certificate :
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 62711 (0xf4f7)
    Signature Algorithm: sha1WithRSAEncryption
        Issuer: C=FR, O=Organization, CN=IntermediateAuthority
        Validity
            Not Before: May 15 08:58:59 2019 GMT
            Not After : May 14 08:58:59 2021 GMT
        Subject: C=FR, O=Organization, OU=OUnit, CN=My Name/emailAddress=contact@domain.tld
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    ...
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Basic Constraints: critical
                CA:FALSE
            Netscape Cert Type:
                SSL Client, S/MIME, Object Signing
            X509v3 Key Usage: critical
                Digital Signature, Non Repudiation, Key Encipherment
            Netscape Comment:
                Certificat IntermediateAuthority.
            X509v3 Subject Key Identifier:
                ...
            X509v3 Authority Key Identifier:
                keyid:...
                DirName:/C=FR/O=Organization/CN=RootAuthority
                serial:03

            X509v3 Subject Alternative Name:
                email:contact@domain.tld
            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crls.domain.tld/IntermediateAuthority/getder.crl

    Signature Algorithm: sha1WithRSAEncryption
         ...
  • charon.log :
May 21 10:27:04 00[DMN] Starting IKE charon daemon (strongSwan 5.7.2, Linux 3.10.0-957.12.2.el7.x86_64, x86_64)
May 21 10:27:04 00[CFG] PKCS11 module '<name>' lacks library path
May 21 10:27:04 00[LIB] openssl FIPS mode(2) - enabled
May 21 10:27:04 00[CFG] loading ca certificates from '/etc/strongswan/ipsec.d/cacerts'
May 21 10:27:04 00[CFG]   loaded ca certificate "C=FR, O=Organization, CN=IntermediateAuthority" from '/etc/strongswan/ipsec.d/cacerts/ca-std.pem'
May 21 10:27:04 00[CFG]   loaded ca certificate "C=FR, O=Organization, CN=RootAuthority" from '/etc/strongswan/ipsec.d/cacerts/ca.pem'
May 21 10:27:04 00[CFG] loading aa certificates from '/etc/strongswan/ipsec.d/aacerts'
May 21 10:27:04 00[CFG] loading ocsp signer certificates from '/etc/strongswan/ipsec.d/ocspcerts'
May 21 10:27:04 00[CFG] loading attribute certificates from '/etc/strongswan/ipsec.d/acerts'
May 21 10:27:04 00[CFG] loading crls from '/etc/strongswan/ipsec.d/crls'
May 21 10:27:04 00[CFG] loading secrets from '/etc/strongswan/ipsec.secrets'
May 21 10:27:04 00[CFG]   loaded RSA private key from '/etc/strongswan/ipsec.d/private/gwKey.pem'
May 21 10:27:04 00[CFG]   loaded EAP secret for user
May 21 10:27:04 00[CFG]   loaded EAP secret for My Name
May 21 10:27:04 00[CFG] opening triplet file /etc/strongswan/ipsec.d/triplets.dat failed: No such file or directory
May 21 10:27:04 00[CFG] loaded 0 RADIUS server configurations
May 21 10:27:04 00[CFG] HA config misses local/remote address
May 21 10:27:04 00[CFG] no script for ext-auth script defined, disabled
May 21 10:27:04 00[LIB] loaded plugins: charon pkcs11 tpm aesni aes des rc2 sha2 sha1 md4 md5 mgf1 random nonce x509 revocation constraints acert pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem openssl gcrypt fips-prf gmp curve25519 chapoly xcbc cmac hmac ctr ccm gcm curl attr kernel-netlink resolve socket-default farp stroke vici updown eap-identity eap-sim eap-aka eap-aka-3gpp eap-aka-3gpp2 eap-md5 eap-gtc eap-mschapv2 eap-dynamic eap-radius eap-tls eap-ttls eap-peap xauth-generic xauth-eap xauth-pam xauth-noauth dhcp led duplicheck unity counters
May 21 10:27:04 00[JOB] spawning 16 worker threads
May 21 10:27:04 05[CFG] received stroke: add connection 'IKEv2-eap'
May 21 10:27:04 05[CFG] adding virtual IP address pool 10.3.0.0/24
May 21 10:27:04 05[CFG]   loaded certificate "C=FR, O=Organization, OU=OUnit, CN=vpn.domain.tld, E=contact@domain.tld" from 'gwCert.pem'
May 21 10:27:04 05[CFG]   id '%any' not confirmed by certificate, defaulting to 'C=FR, O=Organization, OU=OUnit, CN=vpn.domain.tld, E=contact@domain.tld'
May 21 10:27:04 05[CFG] added configuration 'IKEv2-eap'
May 21 10:27:11 12[NET] <1> received packet: from 172.10.128.210[500] to 172.10.130.248[500] (624 bytes)
May 21 10:27:11 12[ENC] <1> parsed IKE_SA_INIT request 0 [ SA KE No N(FRAG_SUP) N(NATD_S_IP) N(NATD_D_IP) V V V V ]
May 21 10:27:11 12[IKE] <1> received MS NT5 ISAKMPOAKLEY v9 vendor ID
May 21 10:27:11 12[IKE] <1> received MS-Negotiation Discovery Capable vendor ID
May 21 10:27:11 12[IKE] <1> received Vid-Initial-Contact vendor ID
May 21 10:27:11 12[ENC] <1> received unknown vendor ID: 01:52:8b:bb:c0:06:96:12:18:49:ab:9a:1c:5b:2a:51:00:00:00:02
May 21 10:27:11 12[IKE] <1> 172.10.128.210 is initiating an IKE_SA
May 21 10:27:11 12[CFG] <1> selected proposal: IKE:AES_CBC_256/HMAC_SHA2_384_192/PRF_HMAC_SHA2_384/MODP_1024
May 21 10:27:11 12[IKE] <1> faking NAT situation to enforce UDP encapsulation
May 21 10:27:11 12[ENC] <1> generating IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) N(MULT_AUTH) ]
May 21 10:27:11 12[NET] <1> sending packet: from 172.10.130.248[500] to 172.10.128.210[500] (320 bytes)
May 21 10:27:11 15[NET] <1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (588 bytes)
May 21 10:27:11 15[ENC] <1> parsed IKE_AUTH request 1 [ EF(1/3) ]
May 21 10:27:11 15[ENC] <1> received fragment #1 of 3, waiting for complete IKE message
May 21 10:27:11 15[NET] <1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (588 bytes)
May 21 10:27:11 15[ENC] <1> parsed IKE_AUTH request 1 [ EF(2/3) ]
May 21 10:27:11 15[ENC] <1> received fragment #2 of 3, waiting for complete IKE message
May 21 10:27:11 16[NET] <1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (332 bytes)
May 21 10:27:11 16[ENC] <1> parsed IKE_AUTH request 1 [ EF(3/3) ]
May 21 10:27:11 16[ENC] <1> received fragment #3 of 3, reassembled fragmented IKE message (1320 bytes)
May 21 10:27:11 16[ENC] <1> parsed IKE_AUTH request 1 [ IDi CERTREQ N(MOBIKE_SUP) CPRQ(ADDR DNS NBNS SRV) SA TSi TSr ]
May 21 10:27:11 16[IKE] <1> received cert request for "C=FR, O=Organization, CN=IntermediateAuthority"
May 21 10:27:11 16[IKE] <1> received cert request for "C=FR, O=Organization, CN=RootAuthority"
May 21 10:27:11 16[IKE] <1> received 47 cert requests for an unknown ca
May 21 10:27:11 16[CFG] <1> looking for peer configs matching 172.10.130.248[%any]...172.10.128.210[172.10.128.210]
May 21 10:27:11 16[CFG] <IKEv2-eap|1> selected peer config 'IKEv2-eap'
May 21 10:27:11 16[IKE] <IKEv2-eap|1> initiating EAP_IDENTITY method (id 0x00)
May 21 10:27:11 16[IKE] <IKEv2-eap|1> peer supports MOBIKE
May 21 10:27:11 16[IKE] <IKEv2-eap|1> authentication of 'C=FR, O=Organization, OU=OUnit, CN=vpn.domain.tld, E=contact@domain.tld' (myself) with RSA signature successful
May 21 10:27:11 16[IKE] <IKEv2-eap|1> sending end entity cert "C=FR, O=Organization, OU=OUnit, CN=vpn.domain.tld, E=contact@domain.tld"
May 21 10:27:11 16[ENC] <IKEv2-eap|1> generating IKE_AUTH response 1 [ IDr CERT AUTH EAP/REQ/ID ]
May 21 10:27:11 16[ENC] <IKEv2-eap|1> splitting IKE message (1656 bytes) into 2 fragments
May 21 10:27:11 16[ENC] <IKEv2-eap|1> generating IKE_AUTH response 1 [ EF(1/2) ]
May 21 10:27:11 16[ENC] <IKEv2-eap|1> generating IKE_AUTH response 1 [ EF(2/2) ]
May 21 10:27:11 16[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (1244 bytes)
May 21 10:27:11 16[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (492 bytes)
May 21 10:27:11 15[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (104 bytes)
May 21 10:27:11 15[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 2 [ EAP/RES/ID ]
May 21 10:27:11 15[IKE] <IKEv2-eap|1> received EAP identity 'My Name'
May 21 10:27:11 15[IKE] <IKEv2-eap|1> initiating EAP_TLS method (id 0xC9)
May 21 10:27:11 15[ENC] <IKEv2-eap|1> generating IKE_AUTH response 2 [ EAP/REQ/TLS ]
May 21 10:27:11 15[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (88 bytes)
May 21 10:27:11 07[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (248 bytes)
May 21 10:27:11 07[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 3 [ EAP/RES/TLS ]
May 21 10:27:11 07[TLS] <IKEv2-eap|1> negotiated TLS 1.2 using suite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
May 21 10:27:11 07[TLS] <IKEv2-eap|1> sending TLS server certificate 'C=FR, O=Organization, OU=OUnit, CN=vpn.domain.tld, E=contact@domain.tld'
May 21 10:27:11 07[TLS] <IKEv2-eap|1> sending TLS intermediate certificate 'C=FR, O=Organization, CN=IntermediateAuthority'
May 21 10:27:11 07[TLS] <IKEv2-eap|1> sending TLS cert request for 'C=FR, O=Organization, CN=IntermediateAuthority'
May 21 10:27:11 07[TLS] <IKEv2-eap|1> sending TLS cert request for 'C=FR, O=Organization, CN=RootAuthority'
May 21 10:27:11 07[ENC] <IKEv2-eap|1> generating IKE_AUTH response 3 [ EAP/REQ/TLS ]
May 21 10:27:11 07[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (1112 bytes)
May 21 10:27:11 05[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (88 bytes)
May 21 10:27:11 05[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 4 [ EAP/RES/TLS ]
May 21 10:27:11 05[ENC] <IKEv2-eap|1> generating IKE_AUTH response 4 [ EAP/REQ/TLS ]
May 21 10:27:11 05[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (1112 bytes)
May 21 10:27:11 08[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (88 bytes)
May 21 10:27:11 08[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 5 [ EAP/RES/TLS ]
May 21 10:27:11 08[ENC] <IKEv2-eap|1> generating IKE_AUTH response 5 [ EAP/REQ/TLS ]
May 21 10:27:11 08[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (744 bytes)
May 21 10:27:11 09[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (588 bytes)
May 21 10:27:11 09[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 6 [ EF(1/3) ]
May 21 10:27:11 09[ENC] <IKEv2-eap|1> received fragment #1 of 3, waiting for complete IKE message
May 21 10:27:11 09[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (588 bytes)
May 21 10:27:11 09[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 6 [ EF(2/3) ]
May 21 10:27:11 09[ENC] <IKEv2-eap|1> received fragment #2 of 3, waiting for complete IKE message
May 21 10:27:11 09[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (492 bytes)
May 21 10:27:11 09[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 6 [ EF(3/3) ]
May 21 10:27:11 09[ENC] <IKEv2-eap|1> received fragment #3 of 3, reassembled fragmented IKE message (1480 bytes)
May 21 10:27:11 09[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 6 [ EAP/RES/TLS ]
May 21 10:27:11 09[ENC] <IKEv2-eap|1> generating IKE_AUTH response 6 [ EAP/REQ/TLS ]
May 21 10:27:11 09[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (88 bytes)
May 21 10:27:11 13[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (588 bytes)
May 21 10:27:11 13[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 7 [ EF(1/3) ]
May 21 10:27:11 13[ENC] <IKEv2-eap|1> received fragment #1 of 3, waiting for complete IKE message
May 21 10:27:11 13[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (588 bytes)
May 21 10:27:11 13[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 7 [ EF(2/3) ]
May 21 10:27:11 13[ENC] <IKEv2-eap|1> received fragment #2 of 3, waiting for complete IKE message
May 21 10:27:11 13[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (316 bytes)
May 21 10:27:11 13[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 7 [ EF(3/3) ]
May 21 10:27:11 13[ENC] <IKEv2-eap|1> received fragment #3 of 3, reassembled fragmented IKE message (1304 bytes)
May 21 10:27:11 13[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 7 [ EAP/RES/TLS ]
May 21 10:27:11 13[TLS] <IKEv2-eap|1> received TLS peer certificate 'C=FR, O=Organization, OU=OUnit, CN=My Name, E=contact@domain.tld'
May 21 10:27:11 13[TLS] <IKEv2-eap|1> received TLS intermediate certificate 'C=FR, O=Organization, CN=IntermediateAuthority'
May 21 10:27:11 13[TLS] <IKEv2-eap|1> no trusted certificate found for 'My Name' to verify TLS peer
May 21 10:27:11 13[TLS] <IKEv2-eap|1> sending fatal TLS alert 'certificate unknown'
May 21 10:27:11 13[ENC] <IKEv2-eap|1> generating IKE_AUTH response 7 [ EAP/REQ/TLS ]
May 21 10:27:11 13[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (104 bytes)
May 21 10:27:11 06[NET] <IKEv2-eap|1> received packet: from 172.10.128.210[4500] to 172.10.130.248[4500] (88 bytes)
May 21 10:27:11 06[ENC] <IKEv2-eap|1> parsed IKE_AUTH request 8 [ EAP/RES/TLS ]
May 21 10:27:11 06[IKE] <IKEv2-eap|1> EAP method EAP_TLS failed for peer 172.10.128.210
May 21 10:27:11 06[ENC] <IKEv2-eap|1> generating IKE_AUTH response 8 [ EAP/FAIL ]
May 21 10:27:11 06[NET] <IKEv2-eap|1> sending packet: from 172.10.130.248[4500] to 172.10.128.210[4500] (88 bytes)
  • hostname GW : vpn.domain.tld

The issue is my Windows client mount tunnel but doesn't accept auth probably because of these lines in charon.log :

May 21 10:27:11 13[TLS] <IKEv2-eap|1> received TLS peer certificate 'C=FR, O=Organization, OU=OUnit, CN=My Name, E=contact@domain.tld'
May 21 10:27:11 13[TLS] <IKEv2-eap|1> received TLS intermediate certificate 'C=FR, O=Organization, CN=IntermediateAuthority'
May 21 10:27:11 13[TLS] <IKEv2-eap|1> no trusted certificate found for 'My Name' to verify TLS peer
May 21 10:27:11 13[TLS] <IKEv2-eap|1> sending fatal TLS alert 'certificate unknown'

What's wrong in my configuration ?

migrated from security.stackexchange.com May 21 at 8:53

This question came from our site for information security professionals.

0

The EAP identity sent by the client ("My Name" apparently) does not match either the full subject distinguished name (DN) or the value and type of any subjectAlternativeName (SAN) extension. Since strongSwan doesn't match identities against parts of the DN e.g. the CN relative distinguished name (RDN) - not even for EAP-TLS - no certificate is found to confirm the identity.

Two possible solutions:

  1. If the client allows it, make it send a different identity e.g. the full DN, or the email address, which is contained as SAN in the certificate. I think that's not possible with Windows clients, though.

  2. If the client always sends the value of the CN RDN as EAP identity, you need to change the client certificate:

    • Either change the CN to match one of the SANs, in this case you could set it to the email address (if necessary, the person's name could be encoded in the S - for surname - and G - for given name - RDNs in the DN).
    • The alternative is to add a dNSName SAN with the value "My Name" i.e. matching the CN value. While that's technically not a valid domain name (due to the space) it should match the EAP identity because that's parsed as identity of type ID_FQDN by strongSwan (that's its fallback type).
  • Thx. I can't modify certs because it's not my service which is in charge of PKI. Now I understand and I think I will use mschapv2 instead. – DSX May 21 at 14:29
  • You could also try to use machine certificate authentication instead of EAP-TLS (which uses user-specific certificates), that should work better with Windows clients as they'll use the full subject DN as IKE identity. – ecdsa May 22 at 7:47

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