The pre-master secret is currently constructed at the time of
instantiating the TLS connection. This precludes the use of key
exchange mechanisms such as Ephemeral Diffie-Hellman (DHE), which
require a ServerKeyExchange message to exchange additional key
material before the pre-master secret can be constructed.
Allow for the use of such cipher suites by deferring generation of the
master secret until the point of sending the ClientKeyExchange
message.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Record the root of trust used at the point that a certificate is
validated, redefine validation as checking a certificate against a
specific root of trust, and pass an explicit root of trust when
creating a TLS connection.
This allows a custom TLS connection to be used with a custom root of
trust, without causing any validated certificates to be treated as
valid for normal purposes.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Use the existing certificate store to automatically append any
available issuing certificates to the selected client certificate.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Restructure the use of add_tls() to insert a TLS filter onto an
existing interface. This allows for the possibility of using
add_tls() to start TLS on an existing connection (as used in several
protocols which will negotiate the choice to use TLS before the
ClientHello is sent).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Record the session ID (if any) provided by the server and attempt to
reuse it for any concurrent connections to the same server.
If multiple connections are initiated concurrently (e.g. when using
PeerDist) then defer sending the ClientHello for all but the first
connection, to allow time for the first connection to potentially
obtain a session ID (and thereby speed up the negotiation for all
remaining connections).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
In TLS terminology a session conceptually spans multiple individual
connections, and essentially represents the stored cryptographic state
(master secret and cipher suite) required to establish communication
without going through the certificate and key exchange handshakes.
Rename tls_session to tls_connection in order to make the name
tls_session available to represent the session state.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Support renegotiation with servers supporting RFC5746. This allows
for the use of per-directory client certificates.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add support for SHA-224, SHA-384, and SHA-512 as digest algorithms in
X.509 certificates, and allow the choice of public-key, cipher, and
digest algorithms to be configured at build time via config/crypto.h.
Originally-implemented-by: Tufan Karadere <tufank@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expand the concept of the X.509 cache to provide the functionality of
a certificate store. Certificates in the store will be automatically
used to complete certificate chains where applicable.
The certificate store may be prepopulated at build time using the
CERT=... build command line option. For example:
make bin/ipxe.usb CERT=mycert1.crt,mycert2.crt
Certificates within the certificate store are not implicitly trusted;
the trust list is specified using TRUST=... as before. For example:
make bin/ipxe.usb CERT=root.crt TRUST=root.crt
This can be used to embed the full trusted root certificate within the
iPXE binary, which is potentially useful in an HTTPS-only environment
in which there is no HTTP server from which to automatically download
cross-signed certificates or other certificate chain fragments.
This usage of CERT= extends the existing use of CERT= to specify the
client certificate. The client certificate is now identified
automatically by checking for a match against the private key. For
example:
make bin/ipxe.usb CERT=root.crt,client.crt TRUST=root.crt KEY=client.key
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TLS servers are not obliged to implement the RFC3546 maximum fragment
length extension, and many common servers (including OpenSSL, as used
in Apache's mod_ssl) do not do so. iPXE may therefore have to cope
with TLS records of up to 16kB. Allocations for 16kB have a
non-negligible chance of failing, causing the TLS connection to abort.
Fix by maintaining the received record as a linked list of I/O
buffers, rather than a single contiguous buffer. To reduce memory
pressure, we also decrypt in situ, and deliver the decrypted data via
xfer_deliver_iob() rather than xfer_deliver_raw().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The default maximum plaintext fragment length for TLS is 16kB, which
is a substantial amount of memory for iPXE to have to allocate for a
temporary decryption buffer.
Reduce the memory footprint of TLS connections by requesting a maximum
fragment length of 2kB.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At present, certificate chain validation is treated as an
instantaneous process that can be carried out using only data that is
already in memory. This model does not allow for validation to
include non-instantaneous steps, such as downloading a cross-signing
certificate, or determining certificate revocation status via OCSP.
Redesign the internal representation of certificate chains to allow
chains to outlive the scope of the original source of certificates
(such as a TLS Certificate record).
Allow for certificates to be cached, so that each certificate needs to
be validated only once.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Simplify code by recording the active handshake digest algorithm as a
session parameter. (Note that we must still accumulate digests for
all supported algorithms, since we don't know which digest will
eventually be used until we receive the Server Hello.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TLSv1.1 and earlier use a hybrid of MD5 and SHA-1 to generate digests
over the handshake messages. Formalise this as a separate digest
algorithm "md5+sha1".
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Advertise support for TLS version 1.1, and be prepared to downgrade to
TLS version 1.0. Tested against Apache with mod_gnutls, using the
GnuTLSPriorities directive to force specific protocol versions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Remove data-xfer as an interface type, and replace data-xfer
interfaces with generic interfaces supporting the data-xfer methods.
Filter interfaces (as used by the TLS layer) are handled using the
generic pass-through interface capability. A side-effect of this is
that deliver_raw() no longer exists as a data-xfer method. (In
practice this doesn't lose any efficiency, since there are no
instances within the current codebase where xfer_deliver_raw() is used
to pass data to an interface supporting the deliver_raw() method.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown