The compiler complains that "taking address of packed member ... of
class or structure 'ip6_hdr' may result in an unaligned pointer value".
We don't care if the address is aligned as we explicitly use untoh16()
to convert the read value.
If an IPsec SA is actually replaced with a rekeying its entry in the
manager is freed. That means that when the hard expire is triggered a
new entry might be found at the cached pointer location. So we have
to make sure we trigger the expire only if we found the right SA.
We could use SPI and addresses for the lookup, but this here requires
a bit less memory and is just a small change. Another option would be to
somehow cancel the queued job, but our scheduler doesn't allow that at
the moment.
Fixes#2399.
We don't attempt to parse the transport headers for fragments, not even
for the initial fragment (it's not guaranteed they contain the header,
depending on the number and type of extension headers).
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.
Tobias Brunner