The commit mentioned below adds an AES-GCM default proposal for ESP. That
proposal does not include any ESN or non-ESN transform to indicate if
extended sequence numbers are supported.
A standards-compliant peer will include one or more ESN support transforms,
and will be unable to select this proposal due to a proposal mismatch.
Fix the default AES-GCM proposal by adding a NO_ESN algorithm. While ESN has
been supported in the Linux kernel for a while, having it in the default
proposal can be problematic with kernel-libipsec or on other platforms.
Fixes: c7bef954ee ("proposal: Add AES-GCM to the ESP default AEAD proposal")
Closesstrongswan/strongswan#868
This avoids having to call strip_dh() in child_cfg_t::get_proposals().
It also inverts the ALLOW_PRIVATE flag (i.e. makes it SKIP_PRIVATE) so
nothing has to be supplied to clone complete proposals.
During proposal selection with ike/child_cfgs a couple of boolean
variables can be set (e.g. private, prefer_self, strip_dh). To simplify
the addition of new parameters, these functions now use a set of flags
instead of indiviual boolean values.
Signed-off-by: Thomas Egerer <[email protected]>
This algorithm uses a fixed-length key and we MUST NOT send a key length
attribute when proposing such algorithms.
While we could accept transforms with key length this would only work as
responder, as original initiator it wouldn't because we won't know if a
peer requires the key length. And as exchange initiator (e.g. for
rekeyings), while being original responder, we'd have to go to great
lengths to store the condition and modify the sent proposal to patch in
the key length. This doesn't seem worth it for only a partial fix.
This means, however, that ChaCha20/Poly1305 can't be used with previous
releases (5.3.3 an newer) that don't contain this fix.
Fixes#2614.
Fixes: 3232c0e64e ("Merge branch 'chapoly'")
This way there will be a mismatch if one of the proposals contains
transform types not contained in the other (the fix list of transform
types used previously resulted in a match if unknown transform types
were contained in one of the proposals). Merging the sets of types
makes comparing proposals with optional transform types easier (e.g.
DH for ESP with MODP_NONE).
This allows us to use it without having to initialize libcharon, which
was required for the logging (we probably could have included debug.h
instead of daemon.h to workaround that but this seems more correct).
Tobias Brunner