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https://github.com/stefanberger/libtpms
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be5fabf155
Windows 2019 Server padds the TPM_ContextLoad() command with additional bytes up to TPM_PT_MAX_OBJECT_CONTEXT for the TPMS_CONTEXT part. Since libtpms does not use an OBJECT to serialize the keys (anymore) it now uses less bytes than the MAXimum of TPM_PT_MAX_OBJECT_CONTEXT bytes and the padding leaves some unconsumed bytes that end up failing the command since no left-over bytes are allowed in any command. When unconsumed bytes are left in TPMS_CONTEXT_Unmarshal() we check that the original passed in size was that of TPM_PT_MAX_OBJECT_CONTEXT and only then consume the additional padding bytes. Luckily only one command calls TPMS_CONTEXT_Unmarshal() so that no unwanted side effects should occur anywhere else, such as no bytes left for unmarshalling the next structure. The wisdom behind the padding is not quite clear but it feels like ill-fixing the code to work around a Windows 2019 server bug... This patch fixes issed #217 Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> |
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| debian | ||
| dist | ||
| include | ||
| m4 | ||
| man | ||
| src | ||
| tests | ||
| .gitignore | ||
| .travis.yml | ||
| autogen.sh | ||
| bootstrap.sh | ||
| CHANGES | ||
| configure.ac | ||
| CREDITS | ||
| DCO1.1.txt | ||
| INSTALL | ||
| libtpms.pc.in | ||
| LICENSE | ||
| Makefile.am | ||
| README | ||
What is libtpms?
----------------
Libtpms is a library that targets the integration of TPM functionality
into hypervisors, primarily into Qemu. Libtpms provides a very narrow
public API for this purpose so that integration is possible. Only the
minimum of necessary APIs are made publicly available.
It is assumed that the user of libtpms is familiar with the concepts
of the Trusted Platform Module (TPM). For the interaction with libtpms
it is necessary to know how to construct valid TPM commands and to
be able to parse their results. It is not within the scope of libtpms's
documentation to provide background on this. See the section on references
below.
What files does the libtpms package provide?
--------------------------------------------
The main libtpms package provides the following files:
/usr/lib64/libtpms.so.0
/usr/lib64/libtpms.so.0.5.1
/usr/share/doc/libtpms-0.5.1
/usr/share/doc/libtpms-0.5.1/CHANGES
/usr/share/doc/libtpms-0.5.1/LICENSE
/usr/share/doc/libtpms-0.5.1/README
Applications can link with -ltpms.
What files does the libtpms development package provide?
--------------------------------------------------------
The libtpms development package (libtpms-devel) provides the following
include files for applications to use:
tpm_error.h
tpm_library.h
tpm_memory.h
tpm_nvfilename.h
tpm_tis.h
tpm_types.h
These files contain the data structures, data types and API calls supported
by libtpms. It is recommended to not use any other API calls than those
provided in these include files.
All APIs are described in man pages. The man pages are part of the libtpms
development package as well:
TPMLIB_DecodeBlob
TPMLIB_GetTPMProperty
TPMLIB_GetVersion
TPMLIB_MainInit
TPMLIB_Process
TPMLIB_RegisterCallbacks
TPMLIB_Terminate
TPMLIB_VolatileAll_Store
TPM_Free
TPM_IO_Hash_Data
TPM_IO_Hash_End
TPM_IO_Hash_Start
TPM_IO_TpmEstablished_Get
TPM_Malloc
TPM_Realloc
How to contribute?
------------------
The mailing list for libtpms is libtpms@googlegroups.com.
For patch submissions, please use a Signed-off-by: <your email> to indicate
agreement to the DCO1.1.txt.
Fuzzing
-------
Initial fuzzing is possible with clang & libfuzzer.
You have to configure the project with --enable-fuzzer
(--enable-sanitizer can also help spot more issues). Then you can
build fuzz and run it with the testing corpus.
Fuzz testing is known to work with Fedora 28 or later. It requires that the
'clang' package is installed.
Ex:
$ ./configure --with-openssl --with-tpm2 --enable-sanitizers --enable-fuzzer \
CC=clang CXX=clang++
$ make && make -C tests fuzz
$ tests/run-fuzzer.sh
oss-fuzz builds with its own fuzzer flags, and set $LIB_FUZZING_ENGINE
to be linked with. The script run by oss-fuzz is tests/oss-fuzz.sh.
Maintainers
-----------
libtpms is currently being maintained by Stefan Berger <stefanb@us.ibm.com>.
References:
-----------
Documentation about the Trusted Platform Module (TPM) can be downloaded
from the Trusted Computing Group's website at
http://www.trustedcomputinggroup.org