[crypto] Generalise X.509 cache to a full certificate store
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>
[crypto] Allow certificate chains to be long-lived data structures
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>
Michael Brown