Build enclave using libgmp

nguyen__hieu — Fri, 03 Nov 2017 18:25:10 GMT

Hi everyone

I am now want to implement some functions running inside SGX enclave. My functions will based on some cryptographic libraries like libgmp, libpbc (Paired-Based Cryptography library). I don't know if those libraries can be used inside SGX enclave or not because when I try to build my enclave with -lgmp option I got an error like "/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/libgmp.a(memory.o): relocation R_X86_64_32 against `.rodata.str1.8' can not be used when making a shared object; recompile with -fPIC".

Thanks for your help!

Hello,In SGX SDK, Only those

dai_c_ — Mon, 06 Nov 2017 00:47:48 GMT

Hello,In SGX SDK, Only those libraries in sgxsdk/include can be used in enclave

Libgmp is a trivial library

nguyen__hieu — Mon, 06 Nov 2017 04:34:29 GMT

Libgmp is a trivial library which supports a lot of cryptography function but it is not supported in SGX enclave. It 's too bad to hear that

I have posted an article and

JohnMechalas — Wed, 10 Oct 2018 15:44:43 GMT

I have posted an article and sample code on using libgmp in an enclave.

Hi john,

islam__md_monirul — Thu, 31 Jan 2019 18:23:44 GMT

Hi john,

I was trying to build trusted gmp library for SGX enclave, following your above-mentioned article, so I downloaded the modified package from given github link in the article and tried to configure and build it, but I get errors and warnings after executing the make command. The errors are given below:

In file included from nextprime.c:56:0:
gmp-impl.h:292:3: error: expected identifier or ‘(’ before ‘do’
   do {     \
   ^
/opt/intel/sgxsdk/include/tlibc/string.h:65:22: note: in expansion of macro ‘memset’
void * _TLIBC_CDECL_ memset(void *, int, size_t);
                      ^~~~~~
gmp-impl.h:298:5: error: expected identifier or ‘(’ before ‘while’
   } while (0)
     ^
/opt/intel/sgxsdk/include/tlibc/string.h:65:22: note: in expansion of macro ‘memset’
void * _TLIBC_CDECL_ memset(void *, int, size_t);
                      ^~~~~~
In file included from nextprime.c:57:0:
/opt/intel/sgxsdk/include/tlibc/string.h:87:80: warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, strcat, char *, const char *);
                                                                               ^
/opt/intel/sgxsdk/include/tlibc/string.h:88:80: warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, strcpy, char *, const char *);
                                                                               ^
/opt/intel/sgxsdk/include/tlibc/string.h:120:72: warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
_TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, strdup, const char *);
                                                                        ^
/opt/intel/sgxsdk/include/tlibc/string.h:121:87: warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
EPRECATED_FUNCTION_(char * _TLIBC_CDECL_, stpcpy, char *dest, const char *src);
                                                                               ^
In file included from nextprime.c:56:0:
nextprime.c: In function ‘__gmp_nextprime’:
gmp-impl.h:294:25: warning: pointer targets in initialization differ in signedness [-Wpointer-sign]
     char *__memset__p = (p); \
                         ^
nextprime.c:97:3: note: in expansion of macro ‘memset’
   memset (ps->s, 0, SIEVESIZE);
   ^~~~~~
Makefile:1259: recipe for target 'libsgx_tgmp_a-nextprime.o' failed
make[2]: *** [libsgx_tgmp_a-nextprime.o] Error 1
make[2]: Leaving directory '/home/user/Desktop/sgx-gmp-github'
Makefile:1350: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/user/Desktop/sgx-gmp-github'
Makefile:1024: recipe for target 'all' failed
make: *** [all] Error 2

Following is the section of gmp-impl.h file in which system detected errors:

#if ! HAVE_MEMSET
#define memset(p, c, n)           \
do {                   \
    ASSERT ((n) >= 0);           \
    char *__memset__p = (p);       \
    int   __i;               \
    for (__i = 0; __i < (n); __i++)   \
      __memset__p[__i] = (c);       \
} while (0)

Following is the section of string.h file:

/*
* Deprecated C99.
*/

_TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, strcat, char *, const char *);
_TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, strcpy, char *, const char *);

/*
* Deprecated Non-C99.
*/
_TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, strdup, const char *);
_TLIBC_DEPRECATED_FUNCTION_(char * _TLIBC_CDECL_, stpcpy, char *dest, const char *src);

__END_DECLS

Thanks!

Any help regarding the above

islam__md_monirul — Wed, 06 Feb 2019 08:09:05 GMT

Any help regarding the above issue?

Apologies for the long delay.

JohnMechalas — Fri, 16 Aug 2019 04:20:48 GMT

Apologies for the long delay. I don't normally monitor this forum so I missed your reply. I encourage you, and others, to file issues with the repo directly on GitHub as that will notify me.

My guess is that there have been changes in the SGX SDK that are causing a conflict with libgmp's code. I'll take a look at this

topic I have posted an article and in Intel® Software Guard Extensions (Intel® SGX)

Build enclave using libgmp

Hello,In SGX SDK, Only those

Libgmp is a trivial library

I have posted an article and

Hi john,

Any help regarding the above

Apologies for the long delay.