Version 5.5.1¶

• The newhope plugin implements the post-quantum NewHope key exchange algorithm
  proposed in their 2015 paper by Erdem Alkim, Léo Ducas, Thomas Pöppelmann and
  Peter Schwabe.

• The libstrongswan crypto factory now offers the registration of Extended
  Output Functions (XOFs). Currently supported XOFs are SHAKE128 and SHAKE256
  implemented by the sha3 plugin, ChaCHa20 implemented by the chapoly plugin
  and the more traditional MGF1 Mask Generation Functions based on the SHA-1,
  SHA-256 and SHA-512 hash algorithms implemented by the new mgf1 plugin.

• By default, the "outbound" FWD policies, introduced with 5.5.0, are not installed anymore.
  They may be enabled via the policies_fwd_out setting in swanctl.conf/vici for a specific
  CHILD_SA if its traffic would otherwise get blocked by a drop policy.
  A bug in regards to updating reqids in the kernel-netlink plugin, that was particularly a problem
  with duplicate "outbound" FWD policies, has also been fixed (175d78df60).

• XFRM policy hashing thresholds may be configured via strongswan.conf. This can significantly
  improve the performance on hosts where the number of flows exceeds the flow cache size of the
  Linux kernel. Policies covering more than a single address don't get hash-indexed by default,
  which results in wasting most of the cycles in xfrm_policy_lookup_bytype() and the called
  xfrm_policy_match(). Since Linux 3.18 the kernel can hash the first n-bit of a policy subnet to
  perform indexed lookups. With correctly chosen thresholds this can completely eliminate the
  performance impact of policy lookups.
  Note: Due to a bug in Linux 3.19 through 4.7, the kernel crashes with a NULL pointer dereference
  if a socket policy (used by strongSwan to exempt IKE traffic from IPsec tunnels) is installed while
  hash thresholds are changed. See ac9759a532 for details and a workaround.

• The NetworkManager integration has been updated to support NM 1.2.
  The directory from which CA certificates are loaded if no certificate is configured in the GUI can
  now be configured via strongswan.conf using the new charon-nm.ca_dir setting.

• IKE fragmentation is now enabled by default with the default fragment size set to 1280 bytes
  for both IP address families.

• A DELETE is sent when a rekeyed IKEv1 SA is deleted. This fixes issues with peers that continue
  to send DPDs on the old SA and then delete all SAs if no response is received (see #2090).
  Also, when terminating IKEv1 SAs, DELETEs for all CHILD_SAs are now sent before sending one for
  the IKE_SA and destroying it.

• The pki tool, with help of the pkcs1 or openssl plugins, can parse private keys in any of the
  supported formats without having to know the exact type. So instead of having to specify rsa or
  ecdsa explicitly the keyword priv may be used to indicate a private key of any type.
  Similarly, swanctl can load any type of private key from the swanctl/private directory.

• The pki tool can handle RSASSA-PKCS1v1.5-with-SHA-3 signatures using the
  sha3 and gmp plugins.

• The VICI flush-certs command flushes certificates from the volatile certificate cache.
  Optionally the type of the certificates to be flushed (e.g. type = x509_crl) can be specified.

• When setting charon.cache_crls = yes in strongswan.conf the vici plugin saves regular,
  base and delta CRLs to disk.
  Fetched CRLs are now also cached if the checked certificate has been revoked.

• The serial number for delta CRLs generated by pki --signcrl is now based on
  the given base CRL again (was broken since 4.6.3).

• Delta CRLs are now properly cached in-memory (and on disk) together with their base. Before this
  the presence of a delta CRL might have required that the base be refetched every time.

• When verifying trust chains with pki --verify local CRLs may now be specified with the
  new --crl argument.

• IKE and ESP/AH proposals configured as strings in ipsec.conf and swanctl.conf (or VICI) are now
  checked to avoid invalid proposals. For instance, the presence of DH, PRF and encryption algorithms
  for IKE proposal are now enforced and AEAD and regular encryption algorithms are not allowed in
  the same proposal anymore. Also fixed is the mapping of the aes*gmac keywords to an integrity
  algorithm in AH proposals.

• Unmarked packets may now be matched by setting 0/0xffffffff as XFRM mark (33d3ffde25).

• The maximum registered log level is now determined correctly if loggers implementing only
  log or vlog are mixed (dac15e03c8).

• In addition to the existing ike_keys and child_keys hooks on listener_t two new hooks
  allow listeners to receive the derived IKE and CHILD_SA keys (ike|child_derived_keys).

• The check for libatomic has been improved (6e19a1f5f2).

• The use of AES-GCM with BoringSSL has been fixed (c72c6e9225).

• libtpmtss: In the TSS2 API the function TeardownSocketTcti() was replaced by
  tss2_tcti_finalize().

• The results of leak-detective are now evaluated in our testing environment, which
  lead to the fixing of several memory leaks.

• No key and self-signed certificate is generated by starter anymore if ipsec.secrets does not exist.

• The long unmaintained Maemo plugin and frontend have been removed.