[rng] Choose HMAC_DRBG using SHA-256 as the DRBG algorithm
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>
[rng] Use SHA-256 for Hash_df, and validate the hash function strength
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>
[i386] Use memory address constraints in __bswap_16s() and __bswap_64s()
Minimise code size by forcing the use of memory addresses for
__bswap_16s() and __bswap_64s(). (__bswap_32s() cannot avoid loading the
value into a register.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fix a strict-aliasing error on certain versions of gcc.
Reported-by: Marko Myllynen <myllynen@redhat.com>
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>
[i386] Optimise byte-swapping functions and provide __bswap_{16,32,64}s()
Use the "bswap" instruction to shrink the size of byte-swapping code,
and provide the in-place variants __bswap_{16,32,64}s.
"bswap" is available only on 486 and later processors. (We already
assume the presence of "cpuid" and "rdtsc", which are available only
on Pentium and later processors.)
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>
[undi] Allow underlying PXE stack to construct link-layer header
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>
[iscsi] Send any padding inline with the data segment
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>
As RFC 2616 10.3.4 explains, a 303 status is the proper HTTP 1.1
behavior for what most HTTP 1.0 clients did with code 302.
Signed-off-by: Jason Lunz <lunz@acm.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[syslog] Separate out generic line-based console functionality
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>
[syslog] Disable console when no syslog server is defined
Explicitly disable the syslog console when no syslog server is
defined, rather than (ab)using the socket family address as an
equivalent console-enabled flag.
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>
The RTC-based entropy source uses the nanosecond-scale CPU TSC to
measure the time between two 1kHz interrupts generated by the CMOS
RTC. In a physical machine these clocks are driven from independent
crystals, resulting in some observable clock drift. In a virtual
machine, the CMOS RTC is typically emulated using host-OS
constructions such as SIGALRM.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Separate out the list of self-tests from the self-test infrastructure.
This allows tests to be run individually. For example:
make bin/sha1_test.iso
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[rng] Add get_random_nz() function required by RSA algorithm
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 that the start-up tests shall consist of at least
one full cycle of the continuous tests.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown