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Added a selftest about SPA resistance

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This commit is contained in:
Manuel Pégourié-Gonnard
2012-11-13 20:57:00 +01:00
committed by Paul Bakker
parent 9674fd0d5e
commit b4a310b472
4 changed files with 98 additions and 1 deletions
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82
library/ecp.c
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@ -38,6 +38,14 @@
#include "polarssl/ecp.h"
#include <limits.h>
#if defined(POLARSSL_SELF_TEST)
/*
* Counts of point addition and doubling operations.
* Used to test resistance of point multiplication to SPA/timing attacks.
*/
unsigned long add_count, dbl_count;
#endif
/*
* Initialize (the components of) a point
*/
@ -505,6 +513,10 @@ static int ecp_double_jac( const ecp_group *grp, ecp_point *R,
int ret;
mpi T1, T2, T3, X, Y, Z;
#if defined(POLARSSL_SELF_TEST)
dbl_count++;
#endif
if( mpi_cmp_int( &P->Z, 0 ) == 0 )
return( ecp_set_zero( R ) );
@ -567,6 +579,10 @@ static int ecp_add_mixed( const ecp_group *grp, ecp_point *R,
int ret;
mpi T1, T2, T3, T4, X, Y, Z;
#if defined(POLARSSL_SELF_TEST)
add_count++;
#endif
/*
* Trivial cases: P == 0 or Q == 0
* (Check Q first, so that we know Q != 0 when we compute -Q.)
@ -738,7 +754,71 @@ cleanup:
*/
int ecp_self_test( int verbose )
{
return( verbose++ );
int ret;
size_t i;
ecp_group grp;
ecp_point R;
mpi m;
unsigned long add_c_prev, dbl_c_prev;
char *exponents[] =
{
"400000000000000000000000000000000000000000000000",
"7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF",
"555555555555555555555555555555555555555555555555",
"5EA6F389A38B8BC81E767753B15AA5569E1782E30ABE7D25",
"000000000000000000000000000000000000000000000010",
};
ecp_group_init( &grp );
ecp_point_init( &R );
mpi_init( &m );
MPI_CHK( ecp_use_known_dp( &grp, POLARSSL_ECP_DP_SECP192R1 ) );
if( verbose != 0 )
printf( " ECP test #1 (SPA resistance): " );
add_count = 0;
dbl_count = 0;
MPI_CHK( mpi_read_string( &m, 16, exponents[0] ) );
MPI_CHK( ecp_mul( &grp, &R, &m, &grp.G ) );
for( i = 1; i < sizeof( exponents ) / sizeof( exponents[0] ); i++ )
{
add_c_prev = add_count;
dbl_c_prev = dbl_count;
add_count = 0;
dbl_count = 0;
MPI_CHK( mpi_read_string( &m, 16, exponents[i] ) );
MPI_CHK( ecp_mul( &grp, &R, &m, &grp.G ) );
if( add_count != add_c_prev || dbl_count != dbl_c_prev )
{
if( verbose != 0 )
printf( "failed (%zu)\n", i );
ret = 1;
goto cleanup;
}
}
if( verbose != 0 )
printf( "passed\n" );
cleanup:
if( ret < 0 && verbose != 0 )
printf( "Unexpected error, return code = %08X\n", ret );
ecp_group_free( &grp );
ecp_point_free( &R );
mpi_free( &m );
if( verbose != 0 )
printf( "\n" );
return( ret );
}
#endif