This library implements SPDM 1.2 secure sessions.
This is not an official Google product.
On Debian and Ubuntu install the following packages:
$ sudo apt install libmbedtls-dev libtss2-dev cmake
Note that mbedtls and libtss2 are only needed for tests. The core spdm-lite library does not take a direct dependency on any external libraries.
$ cmake -B build
$ cmake --build build
$ ctest --test-dir build
Requesters are expected to call spdm_establish_session, and then
spdm_dispatch_app_request for each subsequent message sent over the secure
session. Requesters can tear down the session by calling spdm_end_session.
Requesters are expected to initialize and provide an SpdmDispatchRequestCtx,
which provides both a function pointer used to dispatch messages to the
Responder, as well as scratch memory used for staging encrypted requests and
responses. The scratch memory should be as large as
(max request or response size + SPDM_SECURE_MESSAGE_OVERHEAD)
See samples/requester_app.c which illustrates how this can be done.
Responders are expected to call spdm_dispatch_request upon receipt of an SPDM
request. The transport binding used by the Responder must indicate whether or
not the given SPDM request is encrypted.
In addition, Responders are expected to provide a callback function of type
spdm_app_dispatch_request_fn, which will be invoked upon receipt of a
vendor-defined command sent within an established secure session.
This implementation currently only supports one active session at a time.
See samples/responder_app.c which illustrates how this can be done.
This implementation requires mutual authentication. Certificate exchange is out
of scope. As SPDM 1.2 currently does not support a mechanism for exchanging raw
public keys, this implementation provides a pair of custom vendor-defined
commands for this purpose. See common/vendor_defined_pub_key.h for the message
structure.
Requesters and Responders are expected to implement an instance of
SpdmCryptoSpec.
These instances contain function pointers for low-level crypto primitives, as well as serialization and deserialization functions for asymmetric public keys.
Users should override SPDM_MAX_SERIALIZED_ASYM_PUB_KEY_SIZE in
include/spdm_lite/common/config.h when providing a public key serialization
routine.
This library does not implement timing-related functionality.
This library parses SPDM messages using
EverParse. See
everparse/SPDM.3d for a description of each message, expressed in EverParse's
Dependent Data Description language.
everparse/build.sh will generate the parser functions.
everparse/SPDMWrapper.{h,c} contains manually-created wrapper functions to
better integrate with the type system used in spdm-lite.
- Endian conversion
- Error codes / debug messages
- Max message size enforcement
- Customizable algorithm negotiation routine
- GET_CERTIFICATE / KEY_UPDATE / HEARTBEAT / CHUNK_SEND etc.