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Strongswan a Cisco ASA con múltiples subredes derechas

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Strongswan a Cisco ASA con múltiples subredes derechas

Tengo un túnel ikev2, iniciado a la izquierda desde una caja de ubuntu con strongswan yendo a cisco asa. El uso de ASA para ASA en múltiples redes funciona, pero no puedo conseguirlo con strongswan.

#config setup
    # strictcrlpolicy=yes
    # uniqueids = no
config setup
    charondebug="all"
    uniqueids=yes
    strictcrlpolicy=yes
# Add connections here.
conn host2
    left=8.8.8.8 #Changed from real for this example
    leftsubnet=172.27.1.0/20
    right=8.8.4.4 # changed
    rightsubnet=192.168.1.0/24,192.168.2.0/24
    ike=aes256-sha512-modp2048s256
    esp=aes256-sha512
    keyingtries=0
    ikelifetime=1h
    lifetime=8h
    dpddelay=30
    dpdtimeout=120
    dpdaction=restart
    authby=secret
    auto=add
    keyexchange=ikev2
    type=tunnel

después de conectarse: política ip xfm

src 192.168.1.0/24 dst 8.8.8.8/32
    dir fwd priority 185664
    tmpl src 4.4.4.4 dst 8.8.8.8
        proto esp reqid 1 mode tunnel
src 192.168.1.0/24 dst 8.8.8.8/32
    dir in priority 185664
    tmpl src 4.4.4.4 dst 8.8.8.8
        proto esp reqid 1 mode tunnel
src 8.8.8.8/32 dst 192.168.1.0/24
    dir out priority 185664
    tmpl src 8.8.8.8 dst 4.4.4.4
        proto esp reqid 1 mode tunnel
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


$ipsec statusall
Status of IKE charon daemon (strongSwan 5.5.1, Linux 4.13.0-37-generic, x86_64):
  uptime: 119 seconds, since Mar 23 09:08:33 2018
  malloc: sbrk 2297856, mmap 532480, used 1224384, free 1073472
  worker threads: 11 of 16 idle, 5/0/0/0 working, job queue: 0/0/0/0, scheduled: 2
  loaded plugins: charon test-vectors unbound ldap pkcs11 aes rc2 sha2 sha1 md4 md5 mgf1 rdrand random nonce x509 revocation constraints acert pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey dnscert ipseckey pem gcrypt af-alg fips-prf gmp chapoly xcbc cmac hmac ctr ccm ntru bliss curl soup mysql sqlite attr kernel-netlink resolve socket-default farp stroke updown eap-identity eap-sim eap-sim-pcsc eap-aka eap-aka-3gpp2 eap-simaka-pseudonym eap-simaka-reauth eap-md5 eap-gtc eap-dynamic eap-radius eap-tls eap-ttls eap-peap eap-tnc xauth-eap xauth-pam xauth-noauth tnc-tnccs tnccs-20 tnccs-11 tnccs-dynamic dhcp whitelist lookip error-notify certexpire led radattr addrblock unity
Listening IP addresses:
  8.8.8.8
  172.27.1.3
Connections:
       host2:  8.8.8.8...4.4.4.4  IKEv2
       host2:   local:  [8.8.8.8] uses pre-shared key authentication
       host2:   remote: [4.4.4.4] uses pre-shared key authentication
       host2:   child:  8.8.8.8/32 === 192.168.1.0/24 192.168.2.0/24 
TUNNEL
Security Associations (1 up, 0 connecting):
       host2[1]: ESTABLISHED 115 seconds ago, 8.8.8.8[8.8.8.8]...4.4.4.4[4.4.4.4]
   host2[1]: IKEv2 SPIs: 1f4ce050e3e482ac_i* 35d68fd4c114ef25_r, pre-shared key reauthentication in 2 hours
   host2[1]: IKE proposal: AES_CBC_256/HMAC_SHA2_512_256/PRF_HMAC_SHA2_512/MODP_2048_256
   host2{1}:  INSTALLED, TUNNEL, reqid 1, ESP SPIs: ca77e9b9_i a6993362_o
   host2{1}:  AES_CBC_256/HMAC_SHA1_96, 0 bytes_i, 0 bytes_o, rekeying in 40 minutes
   host2{1}:   8.8.8.8/32 === 192.168.2.0/24

El ASA después de una conexión exitosa:

asa-fw1# show crypto ipsec sa peer 8.8.4.4 | include ident
  local ident (addr/mask/prot/port): (192.168.2.0/255.255.255.0/0/0)
  remote ident (addr/mask/prot/port): (172.27.1.0/255.255.240.0/0/0)

Y un túnel diferente entre 2 ASA:

      local ident (addr/mask/prot/port): (10.1.2.0/255.255.255.252/0/0)
      remote ident (addr/mask/prot/port) : (192.168.10.2/255.255.255.255/0/0)
      local ident (addr/mask/prot/port): (192.168.1.0/255.255.255.0/0/0)
      remote ident (addr/mask/prot/port): (192.168.10.2/255.255.255.255/0/0)
      local ident (addr/mask/prot/port): (192.168.2.0/255.255.255.0/0/0)
      remote ident (addr/mask/prot/port): (192.168.10.2/255.255.255.255/0/0)
      local ident (addr/mask/prot/port): (192.168.4.0/255.255.255.0/0/0)
      remote ident (addr/mask/prot/port): (192.168.10.2/255.255.255.255/0/0)

También intenté colocar subredes derechas adicionales por su cuenta, como las siguientes:

conn host2
    left=8.8.8.8 #Changed from real for this example
    leftsubnet=172.27.1.0/20
    right=4.4.4.4 # changed
    rightsubnet=192.168.1.0/24
    ike=aes256-sha512-modp2048s256
    esp=aes256-sha512
    keyingtries=0
    ikelifetime=1h
    lifetime=8h
    dpddelay=30
    dpdtimeout=120
    dpdaction=restart
    authby=secret
    auto=add
    keyexchange=ikev2
    type=tunnel

conn host2-2
    also=host2
    rightsubnet=192.168.2.0/24

después de la conexión:

$ipsec statusall
Status of IKE charon daemon (strongSwan 5.5.1, Linux 4.13.0-37-generic, x86_64):
  uptime: 52 seconds, since Mar 23 09:02:22 2018
  malloc: sbrk 2293760, mmap 532480, used 1203936, free 1089824
  worker threads: 11 of 16 idle, 5/0/0/0 working, job queue: 0/0/0/0, 
scheduled: 2
  loaded plugins: charon test-vectors unbound ldap pkcs11 aes rc2 sha2 sha1 md4 md5 mgf1 rdrand random nonce x509 revocation constraints acert pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey dnscert ipseckey pem gcrypt af-alg fips-prf gmp chapoly xcbc cmac hmac ctr ccm ntru bliss curl soup mysql sqlite attr kernel-netlink resolve socket-default farp stroke updown eap-identity eap-sim eap-sim-pcsc eap-aka eap-aka-3gpp2 eap-simaka-pseudonym eap-simaka-reauth eap-md5 eap-gtc eap-dynamic eap-radius eap-tls eap-ttls eap-peap eap-tnc xauth-eap xauth-pam xauth-noauth tnc-tnccs tnccs-20 tnccs-11 tnccs-dynamic dhcp whitelist lookip error-notify certexpire led radattr addrblock unity
Listening IP addresses:
  8.8.8.8
  172.27.1.3
Connections:
       host2:  8.8.8.8...4.4.4.4  IKEv2
       host2:   local:  [8.8.8.8] uses pre-shared key authentication
       host2:   remote: [4.4.4.4] uses pre-shared key authentication
       host2:   child:  8.8.8.8/32 === 192.168.1.0/24 TUNNEL
      host2-2:   child:  8.8.8.8/32 === 192.168.2.0/24 TUNNEL
Security Associations (1 up, 0 connecting):
       host2[1]: ESTABLISHED 50 seconds ago, 
8.8.8.8[8.8.8.8]...4.4.4.4[4.4.4.4]
   host2[1]: IKEv2 SPIs: 98cf15596219b433_i* 8177dc2c8f0605d8_r, pre-shared key reauthentication in 2 hours
   host2[1]: IKE proposal: AES_CBC_256/HMAC_SHA2_512_256/PRF_HMAC_SHA2_512/MODP_2048_256
  host2-2{1}:  INSTALLED, TUNNEL, reqid 1, ESP SPIs: ccc8bf25_i 1cec9278_o
  host2-2{1}:  AES_CBC_256/HMAC_SHA1_96, 336 bytes_i (4 pkts, 40s ago), 336 bytes_o (4 pkts, 40s ago), rekeying in 41 minutes
  host2-2{1}:   8.8.8.8/32 === 192.168.2.0/24

y la política ip xfrm:

src 192.168.2.0/24 dst 8.8.8.8/32
    dir fwd priority 185664 
    tmpl src 4.4.4.4 dst 8.8.8.8
        proto esp reqid 1 mode tunnel
src 192.168.2.0/24 dst 8.8.8.8/32
    dir in priority 185664
    tmpl src 4.4.4.4 dst 8.8.8.8
        proto esp reqid 1 mode tunnel
 src 8.8.8.8/32 dst 192.168.2.0/24
    dir out priority 185664
    tmpl src 8.8.8.8 dst 4.4.4.4
        proto esp reqid 1 mode tunnel
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

Cuando uso el método anterior, puedo acceder a 192.168.2.0 pero ya no a 192.168.1.0.
De todos modos, la política xfrm es la misma y solo puedo acceder a 192.168.2.0/24.

Intenté generar tráfico a las subredes sin éxito. ¿Alguien puede ayudarme a determinar por qué solo puedo acceder a UNA subred remota en el lado derecho?

Respuesta1

La respuesta es simple, Cisco ASAno admite múltiples selectores de tráfico por CHILD_SA. Por lo tanto, debe negociar CHILD_SA individuales para cada combinación de subred local y remota que desee crear un túnel. Es decir, algo como:

conn host2
    ...
    rightsubnet=192.168.1.0/24
    ...

conn host2-2
    also=host2
    rightsubnet=192.168.2.0/24

conn host2-3
    also=host2
    rightsubnet=192.168.3.0/24

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