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Questions[strongswan](server)

Martin Hope
Oleg
Asked: 2020-06-10 06:37:13 +0800 CST
  • 4

I am running a strongSwan (U5.3.5/K4.4.0-62-generic) VPN server on Ubuntu 16.04.

Ususally, when I want to examine traffic on a server, I simply run something like the following:

tcpdump -ni eth0 "tcp port 80" -w log.pcap

On the VPN server it doesn't help me too much though. I only catch "regular" traffic, and no IPSEC traffic. I imagine it's because IPSEC operates one layer below TCP. But I would still like to capture some packets for inspection on Wireshark.

How can I accomplish that?

tcpdump ipsec strongswan
Martin Hope
Roberto Manfreda
Asked: 2020-03-07 15:24:24 +0800 CST
  • 4

I'm trying to setting a VPN on Linux Mint 19.2.

I'm using the network-manager-strongswan so I added this file named VPN under /etc/NetworkManager/system-connections/ 

[connection]
id=VPN
uuid=be1d4fd1-bbaa-4aa9-9fdc-e293bf16fe67
type=vpn
autoconnect=false
permissions=
timestamp=1582680217

[vpn]
address=vpn********.it
certificate=
encap=yes
ipcomp=no
method=eap
password-flags=0
proposal=no
user=user
virtual=yes
service-type=org.freedesktop.NetworkManager.strongswan

[vpn-secrets]
password=password

[ipv4]
dns-search=
ignore-auto-dns=true
ignore-auto-routes=true
method=auto

[ipv6]
addr-gen-mode=stable-privacy
dns-search=
ip6-privacy=0
method=ignore

The connection is fine, I can access using ssh on the private network. The big issue is that after the connection I can't surf the internet, connecting to the vpn lock all other addresses.
I added the ignore-auto-routes flag in the config so why my connection is locked?

ip a output* 

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:3c:de:1b brd ff:ff:ff:ff:ff:ff
    inet yy.16.209.132/24 brd yy.16.209.255 scope global dynamic noprefixroute ens33
       valid_lft 1656sec preferred_lft 1656sec
    inet yy.26.199.18/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::216e:bcc0:3b4f:44b2/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

route -n output 

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         yy.16.209.2    0.0.0.0         UG    20100  0        0 ens33
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 ens33
yy.16.209.0    0.0.0.0         255.255.255.0   U     100    0        0 ens33
yy.26.199.18   0.0.0.0         255.255.255.255 UH    50     0        0 ens33
yy.26.199.18   0.0.0.0         255.255.255.255 UH    100    0        0 ens33

ip xfrm policy output NO VPN 

src yy.16.209.0/24 dst yy.16.209.0/24 
    dir fwd priority 175423 
src yy.16.209.0/24 dst yy.16.209.0/24 
    dir in priority 175423 
src yy.16.209.0/24 dst yy.16.209.0/24 
    dir out priority 175423 
src 169.254.0.0/16 dst 169.254.0.0/16 
    dir fwd priority 183615 
src 169.254.0.0/16 dst 169.254.0.0/16 
    dir in priority 183615 
src 169.254.0.0/16 dst 169.254.0.0/16 
    dir out priority 183615 
src fe80::/64 dst fe80::/64 
    dir fwd priority 134463 
src fe80::/64 dst fe80::/64 
    dir in priority 134463 
src fe80::/64 dst fe80::/64 
    dir out priority 134463 
src yy.26.199.18/32 dst 0.0.0.0/0 
    dir out priority 383615 
    tmpl src yy.16.209.132 dst xx.xx.124.58
        proto esp spi 0xc57cfb3f reqid 7 mode tunnel
src 0.0.0.0/0 dst yy.26.199.18/32 
    dir fwd priority 383615 
    tmpl src xx.xx.124.58 dst yy.16.209.132
        proto esp reqid 7 mode tunnel
src 0.0.0.0/0 dst yy.26.199.18/32 
    dir in priority 383615 
    tmpl src xx.xx.124.58 dst yy.16.209.132
        proto esp reqid 7 mode tunnel
src ::1/128 dst ::1/128 
    dir fwd priority 68927 
src ::1/128 dst ::1/128 
    dir in priority 68927 
src ::1/128 dst ::1/128 
    dir out priority 68927 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0

ip xfrm policy output UNDER VPN 

src yy.26.199.18/32 dst 0.0.0.0/0 
    dir out priority 383615 
    tmpl src yy.16.209.132 dst xx.xx.124.58
        proto esp spi 0xc787ea42 reqid 2 mode tunnel
src 0.0.0.0/0 dst yy.26.199.18/32 
    dir fwd priority 383615 
    tmpl src xx.xx.124.58 dst yy.16.209.132
        proto esp reqid 2 mode tunnel
src 0.0.0.0/0 dst yy.26.199.18/32 
    dir in priority 383615 
    tmpl src xx.xx.124.58 dst yy.16.209.132
        proto esp reqid 2 mode tunnel
src fe80::/64 dst fe80::/64 
    dir fwd priority 134463 
src fe80::/64 dst fe80::/64 
    dir in priority 134463 
src fe80::/64 dst fe80::/64 
    dir out priority 134463 
src ::1/128 dst ::1/128 
    dir fwd priority 68927 
src ::1/128 dst ::1/128 
    dir in priority 68927 
src ::1/128 dst ::1/128 
    dir out priority 68927 
src yy.16.209.0/24 dst yy.16.209.0/24 
    dir fwd priority 175423 
src yy.16.209.0/24 dst yy.16.209.0/24 
    dir in priority 175423 
src yy.16.209.0/24 dst yy.16.209.0/24 
    dir out priority 175423 
src 169.254.0.0/16 dst 169.254.0.0/16 
    dir fwd priority 183615 
src 169.254.0.0/16 dst 169.254.0.0/16 
    dir in priority 183615 
src 169.254.0.0/16 dst 169.254.0.0/16 
    dir out priority 183615 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket in priority 0 
src 0.0.0.0/0 dst 0.0.0.0/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0 
src ::/0 dst ::/0 
    socket in priority 0 
src ::/0 dst ::/0 
    socket out priority 0

Diffing the outputs I can see this piece is added while the VPN is connected:

src yy.26.199.18/32 dst 0.0.0.0/0 
    dir out priority 383615 
    tmpl src yy.16.209.132 dst xx.xx.124.58
        proto esp spi 0xc787ea42 reqid 2 mode tunnel
src 0.0.0.0/0 dst yy.26.199.18/32 
    dir fwd priority 383615 
    tmpl src xx.xx.124.58 dst yy.16.209.132
        proto esp reqid 2 mode tunnel
src 0.0.0.0/0 dst yy.26.199.18/32 
    dir in priority 383615 
    tmpl src xx.xx.124.58 dst yy.16.209.132
        proto esp reqid 2 mode tunnel

I tried a lot of things but with no luck.

  • tried to increase the Metric for yy.26.199.18 to 1050 and 1100.
  • route del default && ip route add default via yy.26.199.18 dev ens33
  • Tried to delete the route entries yy.26.199.18 but nothing changes

and a lot of others stupid stuff.

So I want to use my connection for the "normal internet" while routing specific addresses through VPN.
It is possible?

vpn networkmanager ip-routing strongswan linuxmint
Martin Hope
sunknudsen
Asked: 2019-06-04 16:53:14 +0800 CST
  • 6

I would like clients to try reconnecting indefinitely if server is down so when it comes back, the client simply reconnects.

Client ipsec.conf

conn %default
    ike=aes256gcm16-sha384-modp3072!
    esp=aes256gcm16-sha384-modp3072!

conn ikev2
    auto=start
    [email protected]
    leftsourceip=%config
    leftauth=eap-tls
    leftcert=vpn-client.crt
    right=my-vpn.com
    rightid=my-vpn.com
    rightsubnet=0.0.0.0/0
    rightauth=pubkey
strongswan
Martin Hope
Christian
Asked: 2018-04-06 00:21:38 +0800 CST
  • 4

I've been asked to deploy an IPSEC server for a project and after doing some research, StrongSwan looks like a good candidate. Since this project requires top security, I decided to install the latest version of StrongSwan (5.6.2) as it seems to fix a few security issues and what-not.

So I've spent the past few days working out how to configure it, which I have been able to do using /etc/ipsec.conf, however, on reading StrongSwan's website, is now a legacy way of setting it up.

The recommended way of configuring strongSwan is via the powerful vici interface and the swanctl command line tool. The swanctl.conf configuration file used by swanctl is stored together with certificates and corresponding private keys in the swanctl directory. Global strongSwan settings as well as plugin-specific configurations are defined in strongswan.conf.

Alternatively the legacy ipsec stroke interface and its ipsec.conf and ipsec.secrets configuration files may be used.

So now I am in the process of trying to change the configuration to use a file stored in /etc/swanctl/conf.d instead...

So my question is this:

Does anyone know how to build StrongSwan from source and have it start with the Server (Ubuntu 16.04) and use the new configuration method?

My configure line looks like this

./configure --prefix=/usr --sysconfdir=/etc \
  --enable-systemd --enable-swanctl \
  --disable-charon --disable-stroke --disable-scepclient \
  --enable-gcm --enable-eap-tls

but this still doesnt start with the Server, nor can I find any strongswan or strongswan-swanctl for startup.

My current ipsec.conf looks like this

conn %default
 auto=add
 forceencaps=yes
 keyexchange=ikev2
 keyingtries=1
 ike=aes256-sha256-modp2048!
 esp=aes256-sha256,aes128-sha256!
 dpdaction=clear
 inactivity=120s
 leftsendcert=always
 leftcert=vpn-server-cert.pem
 leftsubnet=10.0.0.0/20
 leftid=@vpnserver
 rightsourceip=172.16.0.0/12
 eap_identity=%identity

conn ikev2-cert
 rightauth=eap-tls

which 'I think' translates to this

connections {
   rw {
      version = 2
      send_certreq = yes
      proposals = aes256-sha256-modp2048!
      encap = yes
      dpd_delay = 30s
      local {
         auth = eap-tls 
         certs = vpn-server-cert.pem
         id = vpnserver
      }
      remote {
         auth = eap-tls 
      }
      children {
         net {
            local_ts  = 172.16.0.0/12 
            esp_proposals = aes256-sha256,aes128-sha256!
            inactivity = 120s
         }
      }
   }
}
strongswan
Martin Hope
Olivia
Asked: 2016-09-18 23:57:36 +0800 CST
  • 4

After many days of searching on Google, through Serverfault, and even on the StrongSwan website, I have been unsuccessful in attempting to get StrongSwan IPSec/IKEv2 VPN working on OS X 10.11.5 and iOS 10. I have been very successful in getting it to work on Windows 10 Pro Insider Preview and Android - neither of which are relevant to my travel arrangements where I will only have a Mac notebook and iOS 10 devices.

I have two StrongSwan VPN Servers setup - one in London and one in San Francisco, both with nearly identical configurations.

Having followed https://raymii.org/s/tutorials/IPSEC_vpn_with_Ubuntu_16.04.html I was able to quickly setup both servers and issue a single client certificate for Windows 10 Pro Insider Preview and Android. However, when I copy the p12s of the two servers over to OS X and iOS to create the VPNs I am presented with questions I didn't get what the other two operating systems.

I can seem to find a definitive answer on what is a "Remote ID" and "Local ID" and how does this pertain to me establishing a certificate based authenticated connection to the SwanStrong VPN Server?

From what little I have been able to find I have learned the following:

  • Local ID must match the CN or SAN specified in the certificate (i.e. [email protected])
  • Remote ID is required by both OS X and iOS but I have no idea what to put in this input field
  • Unlike Windows and Android which connected seamlessly with encryption, OS X and iOS both get stuck at "Connecting" or will quickly cycle to "Disconnecting" perpetually

This is one of the StrongSwan server configurations (the one I have been testing against):

# ipsec.conf - strongSwan IPsec configuration file

config setup
    charondebug="ike 2, knl 2, cfg 2, net 2, esp 2, dmn 2,  mgr 2"

conn %default
    keyexchange=ikev2
    ike=aes128-sha1-modp1024,aes128-sha1-modp1536,aes128-sha1-modp2048,aes128-s$
    esp=aes128-aes256-sha1-sha256-modp2048-modp4096-modp1024,aes128-sha1,aes128$
    dpdaction=clear
    dpddelay=300s
    authby=pubkey
    left=%any
    leftid=subdomain5.subdomain4.subdomain3.subdomain2.subdomain.domain.net
    leftsubnet=0.0.0.0/0
    leftcert=vpnHostCert.der
    leftsendcert=always
    right=%any
    rightsourceip=172.11.22.0/24,2002:25f7:7489:3::/112
    rightdns=8.8.8.8,2001:4860:4860::8888

conn IPSec-IKEv2
    keyexchange=ikev2
    auto=add

How can I correctly provision the VPN Tunnel on OS X 10.11.5 and iOS 10 with the same certificates used by Windows and Android?

vpn mac-osx ipsec ios strongswan