RFC 4303 reserves the SPIs between 1 and 255 for future use. This also
avoids an overflow and a division by zero if spi_min is 0 and spi_max is
0xffffffff.
An example are the fallback drop policies installed when updating SAs.
We ignore such policies in add_policy() so there is no point in attempting
to remove them. Since they use different priorities than regular policies
this did not result in policies getting deleted unintentionally but there
was an irritating log message on level 2 that indicated otherwise.
Since we don't use the kernel-netlink plugin anymore and the headers
in the NDK are reasonably recent, we don't need this anymore (at least
when building the app).
Fixes#1172.
Due to the nonce, the ESP key material is four bytes longer than needed for
the actual AES key. The crypto plugins, however, register their AES-CTR
implementations with the AES key length, so the lookup here failed.
For IKEv2 the key material is allocated after creating a crypter instance
with the negotiated AES key size. The length of the actual key material is
retrieved via get_key_size(), which adds the four bytes to the AES key length.
Fixes#1124.
Real AEADs directly provide a suitable IV generator, but traditional crypters
do not. For some (stream) ciphers, we should use sequential IVs, for which
we pass an appropriate generator to the AEAD wrapper.
The IPv6 length field denotes the payload length after the 40 bytes header.
Fixes: 293515f95c ("libipsec: remove extra RFC4303 TFC padding appended to inner payload")
The salt, or often called implicit nonce, varies between AEAD algorithms and
their use in protocols. For IKE and ESP, GCM uses 4 bytes, while CCM uses
3 bytes. With TLS, however, AEAD mode uses 4 bytes for both GCM and CCM.
Our GCM backends currently support 4 bytes and CCM 3 bytes only. This is fine
until we go for CCM mode support in TLS, which requires 4 byte nonces.
The flag is required to convince libtool on Cygwin to build DLLs. But on
Windows these shared libraries can not have undefined symbols, so we have to
link them explicitly to the libraries they reference.
For plugins this is currently not done, so only the monolithic build is
supported. The plugin loader wouldn't be able to load DLLs anyway, as
it tries to load files that don't exist on Cygwin.
INCLUDES are now deprecated and throw warnings when using automake 1.13.
We now also differentiate AM_CPPFLAGS and AM_CFLAGS, where includes and
defines are passed to AM_CPPFLAGS only.
Tobias Brunner