3.8. Implementación de una VPN IPsec compatible con FIPS

Procedimiento

1. Instale los paquetes de libreswan:

   # yum install libreswan

2. Si está reinstalando Libreswan, elimine su antigua base de datos NSS:

   # systemctl stop ipsec
   # rm /etc/ipsec.d/*db

3. Inicie el servicio ipsec, y habilite el servicio para que se inicie automáticamente al arrancar:

   # systemctl enable ipsec --now

4. Configure el cortafuegos para permitir los puertos 500 y 4500/UDP para los protocolos IKE, ESP y AH añadiendo el servicio ipsec:

   # firewall-cmd --add-service="ipsec"
   # firewall-cmd --runtime-to-permanent

5. Cambie el sistema al modo FIPS en RHEL 8:

   # fips-mode-setup --enable

6. Reinicie su sistema para permitir que el kernel cambie al modo FIPS:

   # reboot

Pasos de verificación

1. Para confirmar que Libreswan funciona en modo FIPS:

   # ipsec whack --fipsstatus
   000 FIPS mode enabled

2. También puede comprobar las entradas de la unidad ipsec en el diario systemd:

   $ journalctl -u ipsec
   ...
   Jan 22 11:26:50 localhost.localdomain pluto[3076]: FIPS Product: YES
   Jan 22 11:26:50 localhost.localdomain pluto[3076]: FIPS Kernel: YES
   Jan 22 11:26:50 localhost.localdomain pluto[3076]: FIPS Mode: YES

3. Para ver los algoritmos disponibles en el modo FIPS:

   # ipsec pluto --selftest 2>&1 | head -11
   FIPS Product: YES
   FIPS Kernel: YES
   FIPS Mode: YES
   NSS DB directory: sql:/etc/ipsec.d
   Initializing NSS
   Opening NSS database "sql:/etc/ipsec.d" read-only
   NSS initialized
   NSS crypto library initialized
   FIPS HMAC integrity support [enabled]
   FIPS mode enabled for pluto daemon
   NSS library is running in FIPS mode
   FIPS HMAC integrity verification self-test passed

4. Para consultar los algoritmos desactivados en el modo FIPS:

   # ipsec pluto --selftest 2>&1 | grep disabled
   Encryption algorithm CAMELLIA_CTR disabled; not FIPS compliant
   Encryption algorithm CAMELLIA_CBC disabled; not FIPS compliant
   Encryption algorithm SERPENT_CBC disabled; not FIPS compliant
   Encryption algorithm TWOFISH_CBC disabled; not FIPS compliant
   Encryption algorithm TWOFISH_SSH disabled; not FIPS compliant
   Encryption algorithm NULL disabled; not FIPS compliant
   Encryption algorithm CHACHA20_POLY1305 disabled; not FIPS compliant
   Hash algorithm MD5 disabled; not FIPS compliant
   PRF algorithm HMAC_MD5 disabled; not FIPS compliant
   PRF algorithm AES_XCBC disabled; not FIPS compliant
   Integrity algorithm HMAC_MD5_96 disabled; not FIPS compliant
   Integrity algorithm HMAC_SHA2_256_TRUNCBUG disabled; not FIPS compliant
   Integrity algorithm AES_XCBC_96 disabled; not FIPS compliant
   DH algorithm MODP1024 disabled; not FIPS compliant
   DH algorithm MODP1536 disabled; not FIPS compliant
   DH algorithm DH31 disabled; not FIPS compliant

5. Para listar todos los algoritmos y cifrados permitidos en el modo FIPS:

   # ipsec pluto --selftest 2>&1 | grep ESP | grep FIPS | sed "s/^.*FIPS//"
   {256,192,*128}  aes_ccm, aes_ccm_c
   {256,192,*128}  aes_ccm_b
   {256,192,*128}  aes_ccm_a
   [*192]  3des
   {256,192,*128}  aes_gcm, aes_gcm_c
   {256,192,*128}  aes_gcm_b
   {256,192,*128}  aes_gcm_a
   {256,192,*128}  aesctr
   {256,192,*128}  aes
   {256,192,*128}  aes_gmac
   sha, sha1, sha1_96, hmac_sha1
   sha512, sha2_512, sha2_512_256, hmac_sha2_512
   sha384, sha2_384, sha2_384_192, hmac_sha2_384
   sha2, sha256, sha2_256, sha2_256_128, hmac_sha2_256
   aes_cmac
   null
   null, dh0
   dh14
   dh15
   dh16
   dh17
   dh18
   ecp_256, ecp256
   ecp_384, ecp384
   ecp_521, ecp521