Trusted images may always be executed. Untrusted images may be
executed only if the current image trust requirement allows untrusted
images.
Images can be marked as trusted using image_trust(), and marked as
untrusted using image_untrust().
The current image trust requirement can be changed using
image_set_trust(). It is possible to make the change permanent, in
which case any future attempts to change the image trust requirement
will fail.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The Cryptographic Message Syntax (PKCS#7) provides a format for
encapsulating digital signatures of arbitrary binary blobs. A
signature can be generated using
openssl cms -sign -in <file to sign> -binary -noattr \
-signer <signer>.crt -inkey <signer>.key -certfile <CA>.crt \
-outform DER -out <signature>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The concept of an OID-identified algorithm as defined in X.509 is used
in some other standards (e.g. PKCS#7). Generalise this functionality
and provide it as part of the ASN.1 core.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
OIDs are theoretically part of a global hierarchy. However, the
hierarchy is sufficiently disorganised as to be essentially
meaningless for all purposes other than guaranteeing uniqueness.
Ignore the hierarchical nature of OIDs and treat them as opaque.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow a client certificate and corresponding private key to be
specified at build time using the syntax
make CERT=/path/to/certificate KEY=/path/to/key
The build process uses openssl to convert the files into DER format,
and includes them within the client certificate store in
clientcert.c. The build process will prompt for the private key
password if applicable.
Note that the private key is stored unencrypted, and so the resulting
iPXE binary (and the temporary files created during the build process)
should be treated as being equivalent to an unencrypted private key
file.
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>
bigint_mod_multiply() and bigint_mod_exp() require a fixed amount of
temporary storage for intermediate results. (The amount of temporary
storage required depends upon the size of the integers involved.)
When performing calculations for 4096-bit RSA the amount of temporary
storage space required will exceed 2.5kB, which is too much to
allocate on the stack. Avoid this problem by forcing the caller to
allocate temporary storage.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
RSA requires modular exponentiation using arbitrarily large integers.
Given the sizes of the modulus and exponent, all required calculations
can be done without any further dynamic storage allocation. The x86
architecture allows for efficient large integer support via inline
assembly using the instructions that take advantage of the carry flag
(e.g. "adcl", "rcrl").
This implemention is approximately 80% smaller than the (more generic)
AXTLS implementation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
All axTLS files are now vanilla versions of the upstream axTLS files,
with one minor exception: the unused "ctx" parameter of
bi_int_divide() has been marked with "__unused" to avoid a compilation
error.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Both HMAC_DRBG using SHA-1 and HMAC_DRBG using SHA-256 are Approved
algorithms in ANS X9.82 for our chosen security strength of 128 bits.
However, general recommendations (see e.g. NIST SP800-57) are to use a
larger hash function in preference to SHA-1.
Since SHA-256 is required anyway for TLSv1.2 support, there is no code
size penalty for switching HMAC_DRBG to also use SHA-256.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 Part 4 (April 2011 Draft) Section 13.3.4.2 states that "When
using the derivation function based on a hash function, the output
length of the hash function shall meet or exceed the security strength
indicated by the min_entropy parameter in the Get_entropy_input call",
although this criteria is missing from the pseudocode provided in the
same section.
Add a test for this condition, and upgrade from SHA-1 to SHA-256 since
SHA-1 has an output length of 160 bits, which is insufficient for
generating the (128 * 3/2 = 192) bits required when instantiating the
128-bit strength DRBG.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace MD5 implementation with one which is around 20% smaller. This
implementation has been verified using the existing MD5 self-tests.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace SHA-1 implementation from AXTLS with a dedicated iPXE
implementation which is around 40% smaller. This implementation has
been verified using the existing SHA-1 self-tests (including the NIST
SHA-1 test vectors).
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>
Allow packet transmission to be deferred pending successful ARP
resolution. This avoids the time spent waiting for a higher-level
protocol (e.g. TCP or TFTP) to attempt retransmission.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some PXE stacks (observed with a QLogic 8242) will always try to
prepend a link-layer header, even if the caller uses P_UNKNOWN to
indicate that the link-layer header has already been filled in. This
results in an invalid packet being transmitted.
Work around these faulty PXE stacks where possible by stripping the
existing link-layer header and allowing the PXE stack to (re)construct
the link-layer header itself.
Originally-fixed-by: Buck Huppmann <buckh@pobox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some iSCSI targets respond to a PDU before receiving the padding
bytes. If the target responds quickly enough, this can cause iPXE to
start processing a new TX PDU before the padding bytes have been sent,
which results in a protocol violation.
Fix by always transmitting the padding bytes along with the data
segment.
Originally-fixed-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Abstract out the generic line-handling portions of the syslog
putchar() routine, to allow use by other console types.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Separate out the core HTTP functionality (which is shared by both HTTP
and HTTPS) from the provision of the "http://" URI opener. This
allows for builds that support only "https://" URIs.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
RSA requires the generation of random non-zero bytes (i.e. a sequence
of random numbers in the range [0x01,0xff]). ANS X9.82 provides
various Approved methods for converting random bits into random
numbers. The simplest such method is the Simple Discard Method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved Sources of Entropy Input (SEI).
One such SEI uses an entropy source as the Source of Entropy Input,
condensing each entropy source output after each GetEntropy call.
This can be implemented relatively cheaply in iPXE and avoids the need
to allocate potentially very large buffers.
(Note that the terms "entropy source" and "Source of Entropy Input"
are not synonyms within the context of ANS X9.82.)
Use the iPXE API mechanism to allow entropy sources to be selected at
compilation time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Treat an empty (zeroed) DRBG as invalid. This ensures that a DRBG
that has not yet been instantiated (or that has been uninstantiated)
will refuse to attempt to generate random bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved derivation functions for use in
distributing entropy throughout a buffer. One such derivation
function is Hash_df, which can be implemented using the existing iPXE
SHA-1 functionality.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE exposes some extended capabilities via the PXE FILE API to allow
NBPs such as pxelinux to use protocols other than TFTP. Provide an
equivalent interface as a UEFI protocol so that EFI binaries may also
take advantage of iPXE's extended capabilities.
This can be used with a patched version of elilo, for example:
http://comments.gmane.org/gmane.comp.boot-loaders.elilo.general/147
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies that an Approved DRBG must consist of an Approved
algorithm wrapped inside an envelope which handles entropy gathering,
prediction resistance, automatic reseeding and other housekeeping
tasks.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Cryptographic random number generation requires an entropy source,
which is used as the input to a Deterministic Random Bit Generator
(DRBG).
iPXE does not currently have a suitable entropy source. Provide a
dummy source to allow the DRBG code to be implemented.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved algorithms for use in a
Deterministic Random Bit Generator (DRBG). One such algorithm is
HMAC_DRBG, which can be implemented using the existing iPXE SHA-1 and
HMAC functionality. This algorithm provides a maximum security
strength of 128 bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
All users of imgdownload() require registration of the image, so make
registration an integral part of imgdownload() itself and simplify the
"action" parameter to be one of image_select(), image_exec() et al.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This self-test mechanism is inspired by Perl's Test::Simple and
similar modules. The aim is to encourage the use of self-tests by
making it as easy as possible to create self-test code
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE currently uses the last four bytes of the MAC address as the DHCP
transaction identifier. Reduce the probability of collisions by
generating a random transaction identifier.
Originally-implemented-by: Amos Kong <akong@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TCP currently neglects to allow sufficient space for its own headers
when allocating I/O buffers. This problem is masked by the fact that
the maximum link-layer header size (802.11) is substantially larger
than the common Ethernet link-layer header.
Fix by allowing sufficient space for any TCP headers, as well as the
network-layer and link-layer headers.
Reported-by: Scott K Logan <logans@cottsay.net>
Debugged-by: Scott K Logan <logans@cottsay.net>
Tested-by: Scott K Logan <logans@cottsay.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The version field of an X.509 certificate appears to be optional.
Reported-by: Sebastiano Manusia <Sebastiano.Manusia@chuv.ch>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the link layer to directly report whether or not a packet is
multicast or broadcast at the time of calling pull(), rather than
relying on heuristics to determine this at a later stage.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some processes execute only once, and exist solely in order to defer
execution until after the relevant instantiator method has returned.
Such processes do not need to be automatically rescheduled when
executing.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Give the step() method a pointer to the containing object, rather than
a pointer to the process. This is consistent with the operation of
interface methods, and allows a single function to serve as both an
interface method and a process step() method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow TX errors to be recorded against a network device even when the
packet didn't make it as far as netdev_tx().
Inspired-by: Dominik Russenberger <dominik.russenberger@terreactive.ch>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expose the multiple-SAN-drive capability of the iPXE core via the iPXE
command line by adding commands to hook and unhook additional drives.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Standardise on using init_editstring() to initialise an embedded
editable string, to match the coding style used by other embedded
objects.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A scriptlet is a single iPXE command that can be stored in
non-volatile option storage and used to override the default
"autoboot" behaviour without having to reflash the iPXE image.
For example, a scriptlet could contain
autoboot || reboot
to instruct iPXE to reboot the system if booting fails.
Unlike an embedded image, the presence of a scriptlet does not inhibit
the initial "Press Ctrl-B..." prompt. This allows the user to recover
from setting a faulty scriptlet.
Originally-implemented-by: Glenn Brown <glenn@myri.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Make the allocators used by malloc and linux_umalloc valgrindable.
Include valgrind headers in the codebase to avoid a build dependency
on valgrind.
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Improve the appearance of the "config" user interface by ensuring that
settings appear in some kind of logical order.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
