From 7a28e99fa09471689995d766d04e05a84668fc02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?=
 <manuel.pegourie-gonnard@arm.com>
Date: Tue, 16 Oct 2018 11:22:45 +0200
Subject: [PATCH] Expand test to ensure no assumption on output

The functions don't require the caller to preserve the content of the output
parameter - let's ensure that they don't assume that.
---
 tests/suites/test_suite_ecp.function | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 65736f3653..65c487ef88 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -2,6 +2,10 @@
 #include "mbedtls/ecp.h"
 
 #define ECP_PF_UNKNOWN     -1
+
+#define ECP_PT_RESET( x )           \
+    mbedtls_ecp_point_free( x );    \
+    mbedtls_ecp_point_init( x );
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -78,13 +82,14 @@ void ecp_test_vect_restart( int id,
      */
     mbedtls_ecp_restart_ctx ctx;
     mbedtls_ecp_group grp;
-    mbedtls_ecp_point R;
+    mbedtls_ecp_point R, P;
     mbedtls_mpi dA, xA, yA, dB, xZ, yZ;
     int cnt_restarts;
     int ret;
 
     mbedtls_ecp_restart_init( &ctx );
-    mbedtls_ecp_group_init( &grp ); mbedtls_ecp_point_init( &R );
+    mbedtls_ecp_group_init( &grp );
+    mbedtls_ecp_point_init( &R ); mbedtls_ecp_point_init( &P );
     mbedtls_mpi_init( &dA ); mbedtls_mpi_init( &xA ); mbedtls_mpi_init( &yA );
     mbedtls_mpi_init( &dB ); mbedtls_mpi_init( &xZ ); mbedtls_mpi_init( &yZ );
 
@@ -103,6 +108,7 @@ void ecp_test_vect_restart( int id,
     /* Base point case */
     cnt_restarts = 0;
     do {
+        ECP_PT_RESET( &R );
         ret = mbedtls_ecp_mul_restartable( &grp, &R, &dA, &grp.G, NULL, NULL, &ctx );
     } while( ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restarts );
 
@@ -114,9 +120,11 @@ void ecp_test_vect_restart( int id,
     TEST_ASSERT( cnt_restarts <= max_restarts );
 
     /* Non-base point case */
+    mbedtls_ecp_copy( &P, &R );
     cnt_restarts = 0;
     do {
-        ret = mbedtls_ecp_mul_restartable( &grp, &R, &dB, &R, NULL, NULL, &ctx );
+        ECP_PT_RESET( &R );
+        ret = mbedtls_ecp_mul_restartable( &grp, &R, &dB, &P, NULL, NULL, &ctx );
     } while( ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restarts );
 
     TEST_ASSERT( ret == 0 );
@@ -130,13 +138,14 @@ void ecp_test_vect_restart( int id,
      * This test only makes sense when we actually restart */
     if( min_restarts > 0 )
     {
-        ret = mbedtls_ecp_mul_restartable( &grp, &R, &dB, &R, NULL, NULL, &ctx );
+        ret = mbedtls_ecp_mul_restartable( &grp, &R, &dB, &P, NULL, NULL, &ctx );
         TEST_ASSERT( ret == MBEDTLS_ERR_ECP_IN_PROGRESS );
     }
 
 exit:
     mbedtls_ecp_restart_free( &ctx );
-    mbedtls_ecp_group_free( &grp ); mbedtls_ecp_point_free( &R );
+    mbedtls_ecp_group_free( &grp );
+    mbedtls_ecp_point_free( &R ); mbedtls_ecp_point_free( &P );
     mbedtls_mpi_free( &dA ); mbedtls_mpi_free( &xA ); mbedtls_mpi_free( &yA );
     mbedtls_mpi_free( &dB ); mbedtls_mpi_free( &xZ ); mbedtls_mpi_free( &yZ );
 }
@@ -183,6 +192,7 @@ void ecp_muladd_restart( int id, char *xR_str, char *yR_str,
 
     cnt_restarts = 0;
     do {
+        ECP_PT_RESET( &R );
         ret = mbedtls_ecp_muladd_restartable( &grp, &R,
                                               &u1, &grp.G, &u2, &Q, &ctx );
     } while( ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restarts );