The manifest syntax stays exactly the same, including 0 and 1
integers to denote boolean values (this is done for ease of porting
and can be fixed in future commits). The only visible change is
surrounding strings in the manifest with quotes (requirement of
TOML). All manifests and Makefiles of our tests and example apps are
ported to the new TOML syntax. Documentation is updated.
Also move parse_size_str() to a more appropriate atoi.c file.
This is in preparation for replacing the old ad-hoc manifest
syntax with the TOML syntax.
Protected files (PF) are a new type of file that can be specified in
the manifest (SGX only). They are encrypted on disk and transparently
decrypted when accessed by the Graphene payload.
Other features:
- data is integrity protected (tamper resistance)
- file swap protection (a PF can only be accessed when in a specific path)
- transparency (Graphene payload sees PFs as regular files, no need to modify
the payload)
See Linux-SGX/protected-files directory for implementation. PF format is
based on protected files from the SGX SDK:
https://github.com/intel/linux-sgx/tree/master/sdk/protected_fs
The following new manifest elements are added:
sgx.protected_files_key = <16-byte hex value>
sgx.protected_files.<name> = file:<host path>
sgx.protected_files_key specifies the encryption key and is only a temporary
implementation. This key should be provisioned with local/remote attestation
in the future.
Paths specifying PF entries can be files or directories. If a directory is
specified, all files/directories within are registered as protected
recursively (and are expected to be encrypted in the PF format).
Linux-SGX/tools directory contains the pf_crypt utility that converts files
to/from the protected format.
This patch fixes the following compile error:
string/memcpy.c: In function \u2018memcpy\u2019:
string/memcpy.c:32:16: warning: dereferencing \u2018void *\u2019 pointer
*d++ = *src++;
^~~~~~
string/memcpy.c:32:14: error: void value not ignored as it ought to be
*d++ = *src++;
Graphene used its own implementations of memory-handling functions like
memcmp(), memcpy(), etc. These implementations were copied from Glibc
and contained complicated code from year 2004. Modern HW and compilers
do better job at optimizing simple C implementations of these functions.
Thus, this commit replaces old implementations with simple ones taken
from Musl libc and adapted to our code style.
One particular optimization is made to memcpy() on x86-64. memcpy() is
heavily used in Linux-SGX PAL to copy data in/out of SGX enclave.
Experiments with Redis 5.0 show perf improvement of using "rep movsb" at
3-5% for 4KB payloads over the previous implementation based on Glibc.
We don't need this micro-optimization which just obfuscates the sources
for negligible performance gains. (Un)likeliness of branches in almost
all cases should be derived from profiling, not from hand-written hints,
using profile-guided optimization.
Before argv[0] was treated specially and was changed to a value
from manifest file. Now this happens only if binary was run as
a manifest i.e. `./pal_loader path_to_manifest_file`.
Plenty of bugfixes for Linux kernel later than 3.5 and Ubuntu later than 10.10.
More organized code to improve portability.
Regression tests for Pal to test completeness of implementation.
Vijay Dhanraj