Tobias Frauenschläger
29506d2cac
The non-recursive automake "distdir" recipe inlines the entire $(DISTFILES)
list into a single shell command. Enumerating every IDE integration file
individually made that list large enough (~123 KB) that the recipe exceeded
the Linux MAX_ARG_STRLEN (128 KB) single-argument exec limit, so "make dist"
failed with:
/bin/bash: Argument list too long
make[2]: *** [distdir-am] Error 127
Replace the per-file EXTRA_DIST enumeration of the IDE directories with one
wholesale "EXTRA_DIST += IDE/<dir>" entry per directory (automake copies the
tree recursively). This collapses ~745 file entries into ~52 directory
entries and shrinks the top-level DISTFILES from ~123 KB to ~97 KB, well
under the limit.
The set of distributed IDE files is unchanged: a before/after "make dist"
diff shows no project file added or removed (only the now-unused include.am
build fragments are gone). Three directories that intentionally omit some
tracked files (apple-universal, MPLABX16, Renesas - private IDE configs,
.gitkeep placeholders, helper scripts) stay enumerated file-by-file.
Static Library: Building libwolfssl.sgx.static.lib.a for use with SGX Enclaves
Requirements:
This code was created to use Intel's SGX hardware. It is expected that the user has gone through the steps of both turning on the hardware in bios if needed and has installed the necessary software from Intel to make use of the hardware. (https://software.intel.com/en-us/sgx) If these steps have not been done then it is expected that the user is familiar with simulation software being used in place of hardware.
Security:
If not already in use, it is recommended that SP (single precision) RSA and ECC code is used. This will help mitigate potential side channel attacks. To use SP code check that wolfcrypt/src/sp_c32.c and wolfcrypt/src/sp_c64.c are compiled and add HAVE_WOLFSSL_SP=1 to the build command to define the necessary macros.
Overview and Build:
This project creates a static library to then link with Enclaves. A simple example of an Enclave linking to the created wolfSSL library can be found in wolfssl-examples on github. This project has been tested with gcc 5.4.0 on Ubuntu 16.04. When building with tests the file wolfssl/options.h is expected, in downloaded bundles from wolfssl.com this file exists but when building from a cloned version of wolfSSL from GitHub then the file needs created. This is done either through cd wolfssl && ./autogen.sh && ./configure && ./config.status or by cd wolfssl && touch wolfssl/options.h.
To create the static library, simply call make:
make -f sgx_t_static.mk all
To clean the static library and compiled objects use the provided clean script:
clean.sh
This will create a local static library, libwolfssl.sgx.static.lib.a, that can be linked with SGX enclaves to access wolfSSL APIs using SGX hardware.
Customization:
To enable wolfssl debug, add CFLAGS=-DDEBUG_WOLFSSL.
To enable wolfssl benchmark tests with enclave, specify: HAVE_WOLFSSL_BENCHMARK at build
To enable wolfcrypt testsuite with enclave, specify: HAVE_WOLFSSL_TEST at build
To enable SP code, specify: HAVE_WOLFSSL_SP at build
For example:
make -f sgx_t_static.mk CFLAGS=-DDEBUG_WOLFSSL HAVE_WOLFSSL_BENCHMARK=1 HAVE_WOLFSSL_TEST=1 HAVE_WOLFSSL_SP=1
NOTE: This more customized step has been provided for easier execution in the
script build.sh
Limitations:
Single Threaded (multiple threaded applications have not been tested)
AES-NI use with SGX has not been added in yet