Introduce psa_key_handle_is_null inline function

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 22bf0e7..5fee0d7 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -158,7 +158,7 @@
     mbedtls_pk_init( &pk );
 
     key = pk_psa_genkey();
-    if( key == 0 )
+    if( psa_key_handle_is_null( key ) )
         goto exit;
 
     TEST_ASSERT( mbedtls_pk_setup_opaque( &pk, key ) == 0 );
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 3c4d7c8..fbd7195 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -5761,7 +5761,7 @@
     mbedtls_free( second_export );
     psa_key_derivation_abort( &operation );
     psa_destroy_key( base_key );
-    if( handle == 0 )
+    if( psa_key_handle_is_null( handle ) )
     {
         /* In case there was a test failure after creating the persistent key
          * but while it was not open, try to re-open the persistent key
diff --git a/tests/suites/test_suite_psa_crypto_init.function b/tests/suites/test_suite_psa_crypto_init.function
index fd4ff21..c9fdcd1 100644
--- a/tests/suites/test_suite_psa_crypto_init.function
+++ b/tests/suites/test_suite_psa_crypto_init.function
@@ -197,7 +197,7 @@
     psa_set_key_type( &attributes, PSA_KEY_TYPE_RAW_DATA );
     status = psa_import_key( &attributes, data, sizeof( data ), &handle );
     TEST_EQUAL( status, PSA_ERROR_BAD_STATE );
-    TEST_EQUAL( handle, 0 );
+    TEST_ASSERT( psa_key_handle_is_null( handle ) );
 }
 /* END_CASE */
 
diff --git a/tests/suites/test_suite_psa_crypto_persistent_key.function b/tests/suites/test_suite_psa_crypto_persistent_key.function
index a50eac4..34b88a7 100644
--- a/tests/suites/test_suite_psa_crypto_persistent_key.function
+++ b/tests/suites/test_suite_psa_crypto_persistent_key.function
@@ -177,7 +177,7 @@
     /* Check key slot storage is removed */
     TEST_EQUAL( psa_is_key_present_in_storage( key_id ), 0 );
     TEST_EQUAL( psa_open_key( key_id, &handle ), PSA_ERROR_DOES_NOT_EXIST );
-    TEST_EQUAL( handle, 0 );
+    TEST_ASSERT( psa_key_handle_is_null( handle ) );
 
     /* Shutdown and restart */
     PSA_DONE();
diff --git a/tests/suites/test_suite_psa_crypto_se_driver_hal.function b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
index 68a803e..a1d542d 100644
--- a/tests/suites/test_suite_psa_crypto_se_driver_hal.function
+++ b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
@@ -674,7 +674,7 @@
                                          buffer, sizeof( buffer ), &length ) );
 
     SMOKE_ASSERT( psa_copy_key( handle, &attributes, &handle2 ) );
-    if( handle2 != 0 )
+    if( ! psa_key_handle_is_null( handle2 ) )
         PSA_ASSERT( psa_close_key( handle2 ) );
 
     SMOKE_ASSERT( psa_mac_sign_setup( &mac_operation, handle, PSA_ALG_CMAC ) );
diff --git a/tests/suites/test_suite_psa_crypto_slot_management.function b/tests/suites/test_suite_psa_crypto_slot_management.function
index bee5835..39491a0 100644
--- a/tests/suites/test_suite_psa_crypto_slot_management.function
+++ b/tests/suites/test_suite_psa_crypto_slot_management.function
@@ -152,7 +152,7 @@
     psa_set_key_type( &attributes, type );
     PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
                                 &handle ) );
-    TEST_ASSERT( handle != 0 );
+    TEST_ASSERT( ! psa_key_handle_is_null( handle ) );
     PSA_ASSERT( psa_get_key_attributes( handle, &attributes ) );
     TEST_EQUAL( psa_get_key_type( &attributes ), type );
 
@@ -210,7 +210,7 @@
     psa_set_key_enrollment_algorithm( &attributes, alg2 );
     PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
                                 &handle ) );
-    TEST_ASSERT( handle != 0 );
+    TEST_ASSERT( ! psa_key_handle_is_null( handle ) );
 
 #if defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
     TEST_EQUAL( psa_open_key( wrong_owner_id, &invalid_handle ),
@@ -342,7 +342,7 @@
     psa_set_key_algorithm( &attributes, 0 );
     PSA_ASSERT( psa_import_key( &attributes, material1, sizeof( material1 ),
                                 &handle1 ) );
-    TEST_ASSERT( handle1 != 0 );
+    TEST_ASSERT( ! psa_key_handle_is_null( handle1 ) );
 
     if( reopen_policy == CLOSE_BEFORE )
         PSA_ASSERT( psa_close_key( handle1 ) );
@@ -351,7 +351,7 @@
     TEST_EQUAL( psa_import_key( &attributes, material2, sizeof( material2 ),
                                 &handle2 ),
                 PSA_ERROR_ALREADY_EXISTS );
-    TEST_EQUAL( handle2, 0 );
+    TEST_ASSERT( psa_key_handle_is_null( handle2 ) );
 
     if( reopen_policy == CLOSE_AFTER )
         PSA_ASSERT( psa_close_key( handle1 ) );
@@ -394,7 +394,7 @@
     PSA_ASSERT( psa_crypto_init( ) );
 
     TEST_EQUAL( psa_open_key( id, &handle ), expected_status );
-    TEST_EQUAL( handle, 0 );
+    TEST_ASSERT( psa_key_handle_is_null( handle ) );
 
 exit:
     PSA_DONE( );
@@ -422,7 +422,7 @@
     TEST_EQUAL( psa_import_key( &attributes, material, sizeof( material ),
                                 &handle ),
                 expected_status );
-    TEST_EQUAL( handle, 0 );
+    TEST_ASSERT( psa_key_handle_is_null( handle ) );
 
 exit:
     PSA_DONE( );
@@ -631,7 +631,7 @@
     TEST_EQUAL( psa_copy_key( source_handle,
                               &attributes, &new_handle ),
                 PSA_ERROR_ALREADY_EXISTS );
-    TEST_EQUAL( new_handle , 0 );
+    TEST_ASSERT( psa_key_handle_is_null( new_handle ) );
 
     /* Test that the target slot is unaffected. */
     PSA_ASSERT( psa_get_key_attributes( target_handle, &attributes2 ) );
@@ -691,7 +691,7 @@
     PSA_ASSERT( psa_import_key( &attributes,
                                 material, sizeof( material ),
                                 &valid_handle ) );
-    TEST_ASSERT( valid_handle != 0 );
+    TEST_ASSERT( ! psa_key_handle_is_null( valid_handle ) );
 
     /* Construct an invalid handle as specified in the test case data. */
     switch( handle_construction )
@@ -766,7 +766,7 @@
         if( status == PSA_ERROR_INSUFFICIENT_MEMORY )
             break;
         PSA_ASSERT( status );
-        TEST_ASSERT( handles[i] != 0 );
+        TEST_ASSERT( ! psa_key_handle_is_null( handles[i] ) );
         for( j = 0; j < i; j++ )
             TEST_ASSERT( handles[i] != handles[j] );
     }