Add mbedtls_mpi_core_add_if() tests for when inputs are aliased
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 8278939..6f5e349 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -1767,12 +1767,13 @@
* We generated test data such that B was always >= A, so that's how many
* limbs each of these need.
*/
- a = mbedtls_calloc( B.n, sizeof(mbedtls_mpi_uint) );
- b = mbedtls_calloc( B.n, sizeof(mbedtls_mpi_uint) );
- x = mbedtls_calloc( B.n, sizeof(mbedtls_mpi_uint) );
- d = mbedtls_calloc( B.n, sizeof(mbedtls_mpi_uint) );
+ size_t limbs = B.n;
+ a = mbedtls_calloc( limbs, sizeof(mbedtls_mpi_uint) );
+ b = mbedtls_calloc( limbs, sizeof(mbedtls_mpi_uint) );
+ x = mbedtls_calloc( limbs, sizeof(mbedtls_mpi_uint) );
+ d = mbedtls_calloc( limbs, sizeof(mbedtls_mpi_uint) );
- size_t bytes = B.n * sizeof(mbedtls_mpi_uint);
+ size_t bytes = limbs * sizeof(mbedtls_mpi_uint);
TEST_ASSERT( a != NULL );
TEST_ASSERT( b != NULL );
@@ -1789,30 +1790,42 @@
/* 1a) a + b: d = a; d += b, cond = 0 => there should be no carry */
memcpy( d, a, bytes );
- TEST_EQUAL( 0, mbedtls_mpi_core_add_if( d, b, B.n, 0 ) );
+ TEST_EQUAL( 0, mbedtls_mpi_core_add_if( d, b, limbs, 0 ) );
/* 1b) and d should be unchanged */
ASSERT_COMPARE( d, bytes, a, bytes );
/* 2a) a + b: d = a; d += b, cond = 1 => we should get the correct carry */
- TEST_EQUAL( carry, mbedtls_mpi_core_add_if( d, b, B.n, 1 ) );
+ TEST_EQUAL( carry, mbedtls_mpi_core_add_if( d, b, limbs, 1 ) );
/* 2b) and d should have the correct result */
ASSERT_COMPARE( d, bytes, x, bytes );
/* 3a) b + a: d = b; d += a, cond = 0 => there should be no carry */
memcpy( d, b, bytes );
- TEST_EQUAL( 0, mbedtls_mpi_core_add_if( d, a, B.n, 0 ) );
+ TEST_EQUAL( 0, mbedtls_mpi_core_add_if( d, a, limbs, 0 ) );
/* 3b) and d should be unchanged */
ASSERT_COMPARE( d, bytes, b, bytes );
/* 4a) b + a: d = b; d += a, cond = 1 => we should get the correct carry */
- TEST_EQUAL( carry, mbedtls_mpi_core_add_if( d, a, B.n, 1 ) );
+ TEST_EQUAL( carry, mbedtls_mpi_core_add_if( d, a, limbs, 1 ) );
/* 4b) and d should have the correct result */
ASSERT_COMPARE( d, bytes, x, bytes );
+ /* 5) a + b where a and b are aliased - only when a == b */
+ if ( A.n == B.n && memcmp( A.p, B.p, bytes ) == 0 )
+ {
+ /* 5a) cond = 0 => no carry, and no change to b */
+ TEST_EQUAL( 0, mbedtls_mpi_core_add_if( b, b, limbs, 0 ) );
+ ASSERT_COMPARE( b, bytes, B.p, bytes );
+
+ /* 5b) cond = 1 => correct carry, and correct result in b */
+ TEST_EQUAL( carry, mbedtls_mpi_core_add_if( b, b, limbs, 1 ) );
+ ASSERT_COMPARE( b, bytes, x, bytes );
+ }
+
exit:
mbedtls_free( a );
mbedtls_free( b );