On Wed, Aug 4, 2021 at 9:23 AM Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: > > The Security Protocol and Data Model (SPDM) defines messages, > data objects and sequences for performing message exchanges between > devices over various transports and physical media. > > As the kernel supports several possible transports (mctp, PCI DOE) > introduce a library than can in turn be used with all those transports. > > There are a large number of open questions around how we do this that > need to be resolved. These include: > * Key chain management > - Current approach is to use a keychain provide as part of per transport > initialization for the root certificates which are assumed to be > loaded into that keychain, perhaps in an initrd script. > - Each SPDM instance then has its own keychain to manage its > certificates. It may make sense to drop this, but that looks like it > will make a lot of the standard infrastructure harder to use. > * ECC algorithms needing ASN1 encoded signatures. I'm struggling to find > any specification that actual 'requires' that choice vs raw data, so my > guess is that this is a question of existing usecases (x509 certs seem > to use this form, but CHALLENGE_AUTH SPDM seems to use raw data). > I'm not sure whether we are better off just encoding the signature in > ASN1 as currently done in this series, or if it is worth a tweaking > things in the crypto layers. > * Lots of options in actual implementation to look at. > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > --- > lib/Kconfig | 3 + > lib/Makefile | 2 + > lib/spdm.c | 1196 ++++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 1201 insertions(+) > > diff --git a/lib/Kconfig b/lib/Kconfig > index ac3b30697b2b..0aa2fef6a592 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -704,3 +704,6 @@ config PLDMFW > > config ASN1_ENCODER > tristate > + > +config SPDM > + tristate > diff --git a/lib/Makefile b/lib/Makefile > index 2cc359ec1fdd..566166d6936e 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -282,6 +282,8 @@ obj-$(CONFIG_PERCPU_TEST) += percpu_test.o > obj-$(CONFIG_ASN1) += asn1_decoder.o > obj-$(CONFIG_ASN1_ENCODER) += asn1_encoder.o > > +obj-$(CONFIG_SPDM) += spdm.o > + > obj-$(CONFIG_FONT_SUPPORT) += fonts/ > > hostprogs := gen_crc32table > diff --git a/lib/spdm.c b/lib/spdm.c > new file mode 100644 > index 000000000000..3ce2341647f8 > --- /dev/null > +++ b/lib/spdm.c > @@ -0,0 +1,1196 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * DMTF Security Protocol and Data Model > + * > + * Copyright (C) 2021 Huawei > + * Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > + */ > + > +#include <linux/asn1_encoder.h> > +#include <linux/asn1_ber_bytecode.h> > +#include <linux/bitfield.h> > +#include <linux/cred.h> > +#include <linux/dev_printk.h> > +#include <linux/digsig.h> > +#include <linux/idr.h> > +#include <linux/key.h> > +#include <linux/module.h> > +#include <linux/random.h> > +#include <linux/spdm.h> > + > +#include <crypto/akcipher.h> > +#include <crypto/hash.h> > +#include <crypto/public_key.h> > +#include <keys/asymmetric-type.h> > +#include <keys/user-type.h> > +#include <asm/unaligned.h> > + > +/* > + * Todo > + * - Secure channel setup. > + * - Multiple slot support. > + * - Measurement support (over secure channel or within CHALLENGE_AUTH. > + * - Support more core algorithms (not CMA does not require them, but may use > + * them if present. > + * - Extended algorithm, support. > + */ > +/* > + * Discussions points > + * 1. Worth adding an SPDM layer around a transport layer? I came here to say yes to this question. I am seeing interest in SPDM outside of a DOE transport. Hope to find my way back to testing these bits out soon...
