Disable the use of MD5 as an OID-identifiable algorithm. Note that
the MD5 algorithm implementation will still be present in the build,
since it is used implicitly by various cryptographic components such
as HTTP digest authentication; this commit removes it only from the
list of OID-identifiable algorithms.
It would be appropriate to similarly disable the use of SHA-1 by
default, but doing so would break the use of OCSP since several OCSP
responders (including the current version of openca-ocspd) are not
capable of interpreting the hashAlgorithm field and so will fail if
the client uses any algorithm other than the configured default.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
There are many ways in which the object for a cryptographic algorithm
may be included, even if not explicitly enabled in config/crypto.h.
For example: the MD5 algorithm is required by TLSv1.1 or earlier, by
iSCSI CHAP authentication, by HTTP digest authentication, and by NTLM
authentication.
In the current implementation, inclusion of an algorithm for any
reason will result in the algorithm's ASN.1 object identifier being
included in the "asn1_algorithms" table, which consequently allows the
algorithm to be used for any ASN1-identified purpose. For example: if
the MD5 algorithm is included in order to support HTTP digest
authentication, then iPXE would accept a (validly signed) TLS
certificate using an MD5 digest.
Split the ASN.1 object identifiers into separate files that are
required only if explicitly enabled in config/crypto.h. This allows
an algorithm to be omitted from the "asn1_algorithms" table even if
the algorithm implementation is dragged in for some other purpose.
The end result is that only the algorithms that are explicitly enabled
in config/crypto.h can be used for ASN1-identified purposes such as
signature verification.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The supported ciphers and digest algorithms may already be specified
via config/crypto.h. Extend this to allow a minimum TLS protocol
version to be specified.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some CAs provide non-functional OCSP servers, and some clients are
forced to operate on networks without access to the OCSP servers.
Allow the user to explicitly disable the use of OCSP checks by
undefining OCSP_CHECK in config/crypto.h.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a build option CROSSCERT in config/crypto.h to allow the
default cross-signed certificate source to be configured at build
time. The ${crosscert} setting may still be used to reconfigure the
cross-signed certificate source at runtime.
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>
Allow named configurations to be specified via the CONFIG=... build
parameter. For headers in config/*.h which support named
configurations, the following files will be included when building
with CONFIG=<name>:
- config/defaults/<platform>.h (e.g. config/defaults/pcbios.h)
- config/<header>.h
- config/<name>/<header>.h (only if the directory config/<name> exists)
- config/local/<header>.h (autocreated if necessary)
- config/local/<name>/<header>.h (autocreated if necessary)
This mechanism allows for predefined named configurations to be
checked in to the source tree, as a directory config/<name> containing
all of the required header files.
The mechanism also allows for users to define multiple local
configurations, by creating header files in the directory
config/local/<name>.
Note that the config/*.h files which are used only to configure
internal iPXE APIs (e.g. config/ioapi.h) cannot be modified via a
named configuration. This avoids rebuilding the entire iPXE codebase
whenever switching to a different named configuration.
Inspired-by: Robin Smidsrød <robin@smidsrod.no>
Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown