EAP-TTLS Start packets are empty by default, but can still be sent with
the L flag set. When attempting to reassemble a message we should not
fail if the length of the message is 0, and just treat it as any other
unfragmented message with the L flag set.
Seeing that some authenticators can't handle TLS session caching
properly, allow the EAP-TLS-based methods session caching support to be
disabled per-network using a method specific FastReauthentication setting.
Defaults to true.
With the previous commit, authentication should succeed at least every
other attempt. I'd also expect that EAP-TLS is not usually affected
because there's no phase2, unlike with EAP-PEAP/EAP-TTLS.
If we have a TLS session cached from this attempt or a previous
successful connection attempt but the overall EAP method fails, forget
the session to improve the chances that authentication succeeds on the
next attempt considering that some authenticators strangely allow
resumption but can't handle it all the way to EAP method success.
Logically the session resumption in the TLS layers on the server should
be transparent to the EAP layers so I guess those may be failed
attempts to further optimise phase 2 when the server thinks it can
already trust the client.
The PEAP RFC wants implementations to enforce that Phase2 methods have
been successfully completed prior to accepting a successful result TLV.
However, when TLS session resumption is used, some servers will skip
phase2 methods entirely and simply send a Result TLV with a success
code. This results in iwd (erroneously) rejecting the authentication
attempt.
Fix this by marking phase2 method as successful if session resumption is
being used.
Use l_tls_set_session_cache() to enable session cache/resume in the
TLS-based EAP methods. Sessions for all 802.1x networks are stored in
one l_settings object.
eap_{get,set}_peer_id() API is added for the upper layers to set the
identifier of the authenticator (or the supplicant if we're the
authenticator, if there's ever a use case for that.)
eap-tls-common.c can't call storage_eap_tls_cache_{load,sync}()
or known_networks_watch_add() (to handle known network removals) because
it's linked into some executables that don't have storage.o,
knownnetworks.o or common.o so an upper layer (station.c) will call
eap_tls_set_session_cache_ops() and eap_tls_forget_peer() as needed.
After one of the eap-tls-common-based methods succeeds keep the TLS
tunnel instance until the method is freed, rather than free it the
moment the method succeeds. This fixes repeated method runs where until
now each next run would attempt to create a new TLS tunnel instance
but would have no authentication data (CA certificate, client
certificate, private key and private key passphrase) since those are
were by the old l_tls object from the moment of the l_tls_set_auth_data()
call.
Use l_tls_reset() to reset the TLS state after method success, followed
by a new l_tls_start() when the reauthentication starts.
- Mostly problems with whitespace:
- Use of spaces instead of tabs
- Stray spaces before closing ')
- Missing spaces
- Missing 'void' from function declarations & definitions that
take no arguments.
- Wrong indentation level
Switch EAP-TLS-ClientCert and EAP-TLS-ClientKey to use
l_cert_load_container_file for file loading so that the file format is
autodetected. Add new setting EAP-TLS-ClientKeyBundle for loading both
the client certificate and private key from one file.
As requested move the client certificate and private key loading from
eap-tls-common.c to eap-tls.c. No man page change needed because those
two settings weren't documented in it in the first place.
Replace the usage of eap_send_response() in the method implementations
with a new eap_method_respond that skips the redundant "type" parameter.
The new eap_send_packet is used inside eap_method_respond and will be
reused for sending request packets in authenticator side EAP methods.
iwd would fail to connect using EAP-TLS when no CA certificate was
provided as it checked for successful loading of the CA certificate
instead of the client certificate when attempting to load the client
certificate.
Windows Server 2008 - Network Policy Server (NPS) generates an invalid
Compound MAC for Cryptobinding TLV when is used within PEAPv0 due to
incorrect parsing of the message containing TLS Client Hello.
Setting L bit and including TLS Message Length field, even for the
packets that do not require fragmentation, corrects the issue. The
redundant TLS Message Length field in unfragmented packets doesn't
seem to affect the other server implementations.
Relax the pre-check for local user certificate. Before we used to check
that the CA provided (if any) was used to verify both the peer identity
and the local certificate chain. However, there seem to be networks
that use different CAs to sign AP/Radius certificates and certificates
issued to users.
Drop the ca_certs argument from l_certchain_verify, but keep the call
there to make sure the certificate chain is indeed a chain as a sanity
check.
Refactoring was required to allow for embedded certs. The existing
eap_tls_state object was changed to hold the cert types (l_queue,
l_certchain, l_key) rather than the file path, since there may not
actually be separate PEM files.
Care was taken to properly manage the memory of these objects.
Since the TLS object takes ownership when setting auth data or the
CA certs all error cases must be handled properly to free these
objects after they are loaded and in addition they must be set to
NULL so that the cleanup doesn't double free them.
If everything goes to plan, we load all the PEMs in settings_load,
provide these objects to the TLS APIs, and then NULL out the
pointers (TLS now owns this memory). If anything fails between
settings_load and l_tls_start we must free these objects.
A special format must be used to indicate that a PEM is embedded
inside the settings file. First, the l_settings format should be
followed for the PEM itself, e.g.
[@pem@my_ca_cert]
<CA Cert data>
This PEM can then be referenced by "embed:my_ca_cert", e.g.
EAP-TLS-CACert=embed:my_ca_cert
Any other value not starting with "embed:" will be treated as a file
path.
Allow users to provide a glob string that the contents of the server
certificate's subject DN should be matched against as a primitive
protection against rogue APs using certificates purchased from
commercial CAs trusted by the client. If the network uses an AP
certificate emitted by a commerical CA and the clients are configured
to trust those CAs so that the client configurations don't have to be
updated when the AP renews its certificate, this new option can be used
to check if the CN in the AP certificate's DN matches the known domain
name. This logic assumes that the commercial CAs provide enough
assurance that only the owner of the domain can buy a certificate with
that domain in the CN field.
The format of this option is similar to apple's TLSTrustedServerNames
and wpa_supplicant's domain_match/domain_suffix_match format, the exact
syntax is documented in ell/tls.c.
The Hotspot 2.0 spec introduces 'Anonymous EAP-TLS' as a new EAP method
to be used with OSEN/Hotspot. The protocol details of this aren't
relevant to this patch, but one major difference is that it uses the
expanded EAP type rather than the TLS type. Since the common TLS code
was written with only EAP_TYPE_TLS in mind the vendor ID/type cause the
EAP packet to be malformed when using the expanded EAP type.
To handle this the common TLS code now checks the EAP type, and if its
expanded we shift the payload 7 bytes further to account for the extra
header data.
Replace existing uses of memset to clear secrets with explicit_bzero to
make sure it doesn't get optimized away. This has some side effects as
documented in gcc docs but is still recommended.
In eap_secret_info_free make sure we clear both strings in the case of
EAP_SECRET_REMOTE_USER_PASSWORD secrets.
In the methods' check_settings do a more complete early check for
possible certificate / private key misconfiguration, including check
that the certificate and the private key are always present or absent
together and that they actually match each other. Do this by encrypting
and decrypting a small buffer because we have no better API for that.
Stop using l_pem_load_certificate which has been removed from ell, use
the same functions to load certificate files to validate them as those
used by the TLS implementation itself.
Check that the TLS logic has verified the server is trusted by the CA if
one was configured. This is more of an assert as ell intentionally only
allows empty certificate chains from the peer in server mode (if a CA
certficate is set) although this could be made configurable.
