1279 Commits

Author SHA1 Message Date
Michael Brown b66e27d9b2 [ipv6] Expose router address for DHCPv6 leased addresses
The DHCPv6 protocol does not itself provide a router address or a
prefix length.  This information is instead obtained from the router
advertisements.

Our IPv6 minirouting table construction logic will first construct an
entry for each advertised prefix, and later update the entry to
include an address assigned within that prefix via stateful DHCPv6 (if
applicable).

This logic fails if the address assigned via stateful DHCPv6 does not
fall within any of the advertised prefixes (e.g. if the network is
configured to use DHCPv6-assigned /128 addresses with no advertised
on-link prefixes).  We will currently treat this situation as
equivalent to having a manually assigned address with no corresponding
router address or prefix length: the routing table entry will use the
default /64 prefix length and will not include the router address.

DHCPv6 is triggered only in response to a router advertisement with
the "Managed Address Configuration (M)" or "Other Configuration (O)"
flags set, and a router address is therefore available at the point
that we initiate DHCPv6.

Record the router address when initiating DHCPv6, and expose this
router address as part of the DHCPv6 settings block.  This allows the
routing table entry for any address assigned via stateful DHCPv6 to
correctly include the router address, even if the assigned address
does not fall within an advertised prefix.

Also provide a fixed /128 prefix length as part of the DHCPv6 settings
block.  When an address assigned via stateful DHCPv6 does not fall
within an advertised prefix, this will cause the routing table entry
to have a /128 prefix length as expected.  (When such an address does
fall within an advertised prefix, it will continue to use the
advertised prefix length.)

Originally-fixed-by: Guvenc Gulce <guevenc.guelce@sap.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-06-27 13:43:37 +01:00
Michael Brown 77acf6b41f [ipv4] Support small subnets with no directed broadcast address
In a small subnet (with a /31 or /32 subnet mask), all addresses
within the subnet are valid host addresses: there is no separate
network address or directed broadcast address.

The logic used in iPXE to determine whether or not to use a link-layer
broadcast address will currently fail in these subnets.  In a /31
subnet, the higher of the two host addresses (i.e. the address with
all host bits set) will be treated as a broadcast address.  In a /32
subnet, the single valid host address will be treated as a broadcast
address.

Fix by adding the concept of a host mask, defined such that an address
in the local subnet with all of the mask bits set to zero represents
the network address, and an address in the local subnet with all of
the mask bits set to one represents the directed broadcast address.
For most subnets, this is simply the inverse of the subnet mask.  For
small subnets (/31 or /32) we can obtain the desired behaviour by
setting the host mask to all ones, so that only the local broadcast
address 255.255.255.255 will be treated as a broadcast address.

Originally-fixed-by: Lukas Stockner <lstockner@genesiscloud.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-06-26 05:01:58 -07:00
Pavel Krotkiy 59f27d6935 [netdevice] Add "linktype" setting
Add a new setting to provide access to the link layer protocol type
from scripts.  This can be useful in order to skip configuring
interfaces based on their link layer protocol or, conversely,
configure only selected interface types (Ethernet, IPoIB, etc.)

Example script:

    set idx:int32 0
    :loop
    isset ${net${idx}/mac} || exit 0
    iseq ${net${idx}/linktype} IPoIB && goto try_next ||
    autoboot net${idx} ||
    :try_next
    inc idx && goto loop

Signed-off-by: Pavel Krotkiy <porsh@nebius.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-04-03 12:53:46 +01:00
Michael Brown 764e34f15a [http] Add error table entry for HTTP 404 Not Found error
Add an abbreviated "Not found" error message for an HTTP 404 status
code, so that any automatic attempt to download a non-existent
autoexec.ipxe script produces only a minimal error message.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-03-29 14:46:13 +00:00
Michael Brown afae881782 [tftp] Add error table entry for TFTP "file not found" error code
Add an abbreviated "Not found" error message for a TFTP "file not
found" error code, so that any automatic attempt to download a
non-existent autoexec.ipxe script produces only a minimal error
message.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-03-29 14:46:13 +00:00
Michael Brown 43e385091a [eap] Add support for the MS-CHAPv2 authentication method
Add support for EAP-MSCHAPv2 (note that this is not the same as
PEAP-MSCHAPv2), controllable via the build configuration option
EAP_METHOD_MSCHAPV2 in config/general.h.

Our model for EAP does not encompass mutual authentication: we will
starting sending plaintext packets (e.g. DHCP requests) over the link
even before EAP completes, and our only use for an EAP success is to
mark the link as unblocked.

We therefore ignore the content of the EAP-MSCHAPv2 success request
(containing the MS-CHAPv2 authenticator response) and just send back
an EAP-MSCHAPv2 success response, so that the EAP authenticator will
complete the process and send through the real EAP success packet
(which will, in turn, cause us to unblock the link).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-02-23 16:37:07 +00:00
Michael Brown 25ffcd79bf [eap] Allow MD5-Challenge authentication method to be disabled
RFC 3748 states that implementations must support the MD5-Challenge
method.  However, some network environments may wish to disable it as
a matter of policy.

Allow support for MD5-Challenge to be controllable via the build
configuration option EAP_METHOD_MD5 in config/general.h.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-02-23 16:24:44 +00:00
Michael Brown 834f319f87 [eap] Add progress debug messages
Add debug messages for each EAP Request and Response, and to show the
list of methods offered when sending a Nak.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-02-23 16:17:07 +00:00
Michael Brown 929f06a76d [crypto] Allow for multiple cross-signed certificate download attempts
Certificates issued by Let's Encrypt have two options for their chain
of trust: the chain can either terminate in the self-signed ISRG Root
X1 root certificate, or in an intermediate ISRG Root X1 certificate
that is signed in turn by the self-signed DST Root CA X3 root
certificate.  This is a historical artifact: when Let's Encrypt first
launched as a project, the chain ending in DST Root CA X3 was used
since existing clients would not have recognised the ISRG Root X1
certificate as a trusted root certificate.

The DST Root CA X3 certificate expired in September 2021, and so is no
longer trusted by clients (such as iPXE) that validate the expiry
times of all certificates in the certificate chain.

In order to maintain usability of certificates on older Android
devices, the default certificate chain provided by Let's Encrypt still
terminates in DST Root CA X3, even though that certificate has now
expired.  On newer devices which include ISRG Root X1 as a trusted
root certificate, the intermediate version of ISRG Root X1 in the
certificate chain is ignored and validation is performed as though the
chain had terminated in the self-signed ISRG Root X1 root certificate.
On older Android devices which do not include ISRG Root X1 as a
trusted root certificate, the validation succeeds since Android
chooses to ignore expiry times for root certificates and so continues
to trust the DST Root CA X3 root certificate.

This backwards compatibility hack unfortunately breaks the cross-
signing mechanism used by iPXE, which assumes that the certificate
chain will always terminate in a non-expired root certificate.

Generalise the validator's cross-signed certificate download mechanism
to walk up the certificate chain in the event of a failure, attempting
to find a replacement cross-signed certificate chain starting from the
next level up.  This allows the validator to step over the expired
(and hence invalidatable) DST Root CA X3 certificate, and instead
download the cross-signed version of the ISRG Root X1 certificate.

This generalisation also gives us the ability to handle servers that
provide a full certificate chain including their root certificate:
iPXE will step over the untrusted public root certificate and attempt
to find a cross-signed version of it instead.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-02-15 13:13:08 +00:00
Michael Brown 943d75b557 [crypto] Add x509_is_self_signed() helper function
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-02-15 12:45:58 +00:00
Michael Brown 0cc0f47443 [tls] Tidy up error handling flow in tls_send_plaintext()
Coverity reported that tls_send_plaintext() failed to check the return
status from tls_generate_random(), which could potentially result in
uninitialised random data being used as the block initialisation
vector (instead of intentionally random data).

Add the missing return status check, and separate out the error
handling code paths (since on the successful exit code path there will
be no need to free either the plaintext or the ciphertext anyway).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-31 13:49:35 +00:00
Michael Brown b234226dbc [tls] Add support for Ephemeral Elliptic Curve Diffie-Hellman key exchange
Add support for the Ephemeral Elliptic Curve Diffie-Hellman (ECDHE)
key exchange algorithm.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-30 16:16:31 +00:00
Michael Brown 8e2469c861 [tls] Split out Diffie-Hellman parameter signature verification
DHE and ECDHE use essentially the same mechanism for verifying the
signature over the Diffie-Hellman parameters, though the format of the
parameters is different between the two methods.

Split out the verification of the parameter signature so that it may
be shared between the DHE and ECDHE key exchange algorithms.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-30 16:06:45 +00:00
Michael Brown 989dbe0bc4 [tls] Generate key material after sending ClientKeyExchange
The construction of the key material for the pending cipher suites
from the TLS master secret must happen regardless of which key
exchange algorithm is in use, and the key material is not required to
send the ClientKeyExchange handshake (which is sent before changing
cipher suites).

Centralise the call to tls_generate_keys() after performing key
exchange via the selected algorithm.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-30 15:25:38 +00:00
Michael Brown 6f70e8be83 [tls] Restructure construction of ClientHello message
Define an individual local structure for each extension and a single
structure for the list of extensions.  This makes it viable to add
extensions such as the Supported Elliptic Curves extension, which must
not be present if the list of curves is empty.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-30 13:38:15 +00:00
Michael Brown 6d29415c89 [libc] Make static_assert() available via assert.h
Expose static_assert() via assert.h and migrate link-time assertions
to build-time assertions where possible.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-16 13:35:08 +00:00
Michael Brown 08fcb0e8fb [eap] Add support for the MD5-Challenge authentication type
RFC 3748 states that support for MD5-Challenge is mandatory for EAP
implementations.  The MD5 and CHAP code is already included in the
default build since it is required by iSCSI, and so this does not
substantially increase the binary size.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-10 16:22:32 +00:00
Michael Brown c6226f104e [eap] Add support for sending an EAP identity
Allow the ${netX/username} setting to be used to specify an EAP
identity to be returned in response to a Request-Identity, and provide
a mechanism for responding with a NAK to indicate which authentication
types we support.

If no identity is specified then fall back to the current behaviour of
not sending any Request-Identity response, so that switches will time
out and switch to MAC Authentication Bypass (MAB) if applicable.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-10 16:03:10 +00:00
Michael Brown 0abb3e85e5 [eap] Ignore any received EAP responses
EAP responses (including our own) may be broadcast by switches but are
not of interest to us and can be safely ignored if received.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2024-01-10 16:02:32 +00:00
Michael Brown 595b1796f6 [eapol] Limit number of EAPoL-Start packets transmitted per attempt
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-11-07 13:51:16 +00:00
Michael Brown 1bd01b761f [eapol] Delay EAPoL-Start while waiting for EAP to complete
EAP exchanges may take a long time to reach a final status, especially
when relying upon MAC Authentication Bypass (MAB).  Our current
behaviour of sending EAPoL-Start every few seconds until a final
status is obtained can prevent these exchanges from ever completing.

Fix by redefining the EAP supplicant state to allow EAPoL-Start to be
suppressed: either temporarily (while waiting for a full EAP exchange
to complete, in which case we need to eventually resend EAPoL-Start if
the final Success or Failure packet is lost), or permanently (while
waiting for the potentially very long MAC Authentication Bypass
timeout period).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-11-07 13:31:20 +00:00
Michael Brown 8b14652e50 [eapol] Send EAPoL-Start packets to trigger EAP authentication
We have no way to force a link-layer restart in iPXE, and therefore no
way to explicitly trigger a restart of EAP authentication.  If an iPXE
script has performed some action that requires such a restart
(e.g. registering a device such that the port VLAN assignment will be
changed), then the only means currently available to effect the
restart is to reboot the whole system.  If iPXE is taking over a
physical link already used by a preceding bootloader, then even a
reboot may not work.

In the EAP model, the supplicant is a pure responder and never
initiates transmissions.  EAPoL extends this to include an EAPoL-Start
packet type that may be sent by the supplicant to (re)trigger EAP.

Add support for sending EAPoL-Start packets at two-second intervals on
links that are open and have reached physical link-up, but for which
EAP has not yet completed.  This allows "ifclose ; ifopen" to be used
to restart the EAP process.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-09-19 23:16:58 +01:00
Michael Brown 56cc61a168 [eap] Define a supplicant model for EAP and EAPoL
Extend the EAP model to include a record of whether or not EAP
authentication has completed (successfully or otherwise), and to
provide a method for transmitting EAP responses.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-09-18 12:07:28 +01:00
Michael Brown cac3a584dc [fcoe] Use driver-private data to hold FCoE port structure
Simplify the FCoE code by using driver-private data to hold the FCoE
port for each network device, instead of using a separate allocation.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-09-14 13:25:19 +01:00
Michael Brown 8b1d34badf [ipv6] Use driver-private data to hold link-local IPv6 settings block
Simplify the IPv6 link-local settings code by using driver-private
data to hold the settings block, instead of using a separate
allocation.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-09-13 23:02:54 +01:00