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.
This new flag gives the kernel-interface a hint how it should priorize the
use of newly installed SAs during rekeying.
Consider the following rekey procedure in IKEv2:
Initiator --- Responder
I1 -------CREATE-------> R1
I2 <------CREATE--------
-------DELETE-------> R2
I3 <------DELETE--------
SAs are always handled as pairs, the following happens at the SA level:
* Initiator starts the exchange at I1
* Responder installs new SA pair at R1
* Initiator installs new SA pair at I2
* Responder removes old SA pair at R2
* Initiator removes old SA pair at I3
This makes sure SAs get installed/removed overlapping during rekeying. However,
to avoid any packet loss, it is crucial that the new outbound SA gets
activated at the correct position:
* as exchange initiator, in I2
* as exchange responder, in R2
This should guarantee that we don't use the new outbound SA before the peer
could install its corresponding inbound SA.
The new parameter allows the kernel backend to install the new SA with
appropriate priorities, i.e. it should:
* as exchange inititator, have the new outbound SA installed with higher
priority than the old SA
* as exchange responder, have the new outbound SA installed with lower
priority than the old SA
While we could split up the SA installation at the responder, this approach
has another advantage: it allows the kernel backend to switch SAs based on
other criteria, for example when receiving traffic on the new inbound SA.
The TKM credential encoder creates fingerprints of type
KEYID_PUBKEY_INFO_SHA1 and KEYID_PUBKEY_SHA1 using
CRED_PART_RSA_PUB_ASN1_DER.
This makes the pkcs1 plugin unnecessary.
Load complete kernel_netlink plugin instead. Registering the TKM
specific plugins first still ensures that the correct ipsec plugin
is used.
Lazy initialize the RNG_WEAK plugin to avoid the unsatisfiable
soft dependency on startup.
An ALERT_KEEP_ON_CHILD_SA_FAILURE alert is issued when child SA establishment
fails but the corresponding IKE SA is not destroyed. To allow later creation
of child SAs the ISA context must be signaled that the implicity first child SA
creation was skipped.
The IKE and EES sockets are now read from strongswan.conf. They can be
specified like this:
charon-tkm {
ike_socket = /tmp/tkm.rpc.ike
ees_socket = /tmp/tkm.rpc.ees
}
The socket names given above are used by default if none are configured.
The TKM credential set extends the in-memory credential set. It
provides a private key enumerator which is used to instantiate private
key proxy objects on-demand. This allows the usage of private keys with
arbitrary identifiers.
Pass the reqid (of the first child config of an IKE SA) as remote identity id
when calling cc_set_user_certificate. May lead to the usage of the wrong id in
case an IKE SA has multiple child configurations/reqids.
This must be replaced with a proper lookup once the configuration backend is
implemented and provides remote identity ids to charon-tkm.
The key currently imitates the private key of alice@strongswan.org by
returning it's fingerprint in the get_fingerprint function.
This associates the private key with alice's X.509 cert and charon will
use it to create a signature over the local AUTH octets of the test
connection.
The private key serves as a proxy to the TKM ike_isa_sign operation and
extracts the required information from the auth octets chunk passed on
by the keymat.
Store the ISA context id and the initial message in the auth octets
chunk using the sign_info_t struct. Charon will pass on this information
to the TKM private key sign operation where it is extracted.
The key unconditionally returns TRUE for the verify operation if it is called
with a supported signature algorithm. All such verification operations are
performed by the TKM (e.g. trustchain or auth octets verification) anyway, so
this is safe.
The IKE init message sent to us by the peer is needed for authentication
in the authorization hook. Store the message as chunk in the keymat and
provide a getter to make it available.
Extract peer certificate information and build a TKM certificate chain
context in the authorize hook of the tkm_listener_t. The cc context will
be used for ISA authentication using certificates.
The Esa Event Service can be used to trigger ESP SA (ESA) events such as
acquire or expire. The incoming events are forwarded to the hydra kernel
interface for processing.
The responsibility to reset an authenticated endpoint context is passed
from a parent IKE SA keymat to the new keymat by including it in the ISA
info data contained in the skd chunk. The last IKE SA to be destroyed
will also reset the associated AE context.
A child SA is being rekeyed if the esa information passed to the add_sa
function contains nonces. If it also contains a valid Diffie-Hellman
context id PFS is used.
The fact that the encr_r encryption key is passed to add_sa in the
inbound case can be used to determine if we are initiator or not by
inspecting the is_encr_r flag of the esa information struct.
Add additional fields to the esa_info_t struct so the necessary data can
be passed from the keymat to the kernel ipsec interface, where ESA
creation and key generation using the TKM takes place.
The information is used during the inbound add_sa call to create an ESP
SA. This makes the hack of storing the local SPI in a kernel interface
variable between subsequent add_sa calls unnecessary.
An SAD entry is added after successfull creation of a TKM ESA context
in the add_sa() function. The corresponding entry is removed in
del_sa() using the SAD, src, dst, spi and protocol parameters.
Explicitly register kernel netlink net implementation and avoid loading
the whole kernel-netlink plugin since the kernel netlink ipsec part is
unwanted.
Since the TKM handles all relevant key material, charon-tkm must not
have access to it anymore. Thus the ike_dh_get_shared_secret operation
is not available anymore.
ESP SAs are created when adding CHILD SAs via the kernel ipsec
interface.
The encr_i key is used to transfer the context id of the parent IKE SA
from the keymat to the TKM kernel ipsec interface.
The existing kernel netlink ipsec interface is currently used as proxy
to perform the actual work. It will be gradually removed as the TKM
implements the needed features.
To make the chunk map more robust it now stores a clone of the data
chunk given on insertion. The entry struct is needed to properly free
the allocated chunk after use.
Use the message hook to save the AUTHENTICATION payload of an incoming
IKE_AUTH message.
The AUTH payload will be passed on to the TKM ike_isa_auth operation in
the authorize hook.
Create and initialize AEAD transforms with keys derived by the TKM.
Return these transforms in the get_aead function.
IKE keys used by charon are derived by TKM now.
Forward incoming calls to default ikev2 keymat instance. This is needed
to make a stepwise migration to TKM keymat possible. It will be removed
once the corresponding parts are implemented in the TKM.
Instead of storing the acquired context ids in a linked list, use an
array of booleans for the job. A boolean value of true in the array
designates an available context id.
The tkm_diffie_hellman_t plugin acquires a DH context from the Trusted
Key Manager and uses it to get a DH public value and the calculated
shared secret. Proper context handling is still missing though, the
plugin currently uses context ID 1.
The get_shared_secret function will be removed as soon as the TKM
specific keymat is ready.
Analogous to charon-nm the charon-tkm daemon is a specialized charon
instance used in combination with the trusted key manager (TKM) written
in Ada.
The charon-tkm is basically a copy of the charon-nm code which will
register it's own TKM specific plugins.
The daemon binary is built using the gprbuild utility. This is needed
because it uses the tkm-rpc Ada library and consequently the Ada
runtime. gprbuild takes care of the complete binding and linker steps
required to properly initialize the Ada runtime.
Tobias Brunner