Unit test function for mbedtls_ecp_muladd

Write a simple unit test for mbedtls_ecp_muladd().

Add just one pair of test cases. #2 fails since PR #3512. Thanks to
Philippe Antoine (catenacyber) for the test case, found by ecfuzzer.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_ecp.data b/tests/suites/test_suite_ecp.data
index 408a9b7..59dfa4f 100644
--- a/tests/suites/test_suite_ecp.data
+++ b/tests/suites/test_suite_ecp.data
@@ -458,6 +458,14 @@
 depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
 ecp_test_mul_rng:MBEDTLS_ECP_DP_CURVE25519:"5AC99F33632E5A768DE7E81BF854C27C46E3FBF2ABBACD29EC4AFF517369C660"
 
+ECP point muladd secp256r1 #1
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_muladd:MBEDTLS_ECP_DP_SECP256R1:"01":"04e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e0e1ff20e1ffe120e1e1e173287170a761308491683e345cacaebb500c96e1a7bbd37772968b2c951f0579":"01":"04e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1ffffffff20e120e1e1e1e13a4e135157317b79d4ecf329fed4f9eb00dc67dbddae33faca8b6d8a0255b5ce":"04fab65e09aa5dd948320f86246be1d3fc571e7f799d9005170ed5cc868b67598431a668f96aa9fd0b0eb15f0edf4c7fe1be2885eadcb57e3db4fdd093585d3fa6"
+
+ECP point muladd secp256r1 #2
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_muladd:MBEDTLS_ECP_DP_SECP256R1:"01":"04e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1ffffffff20e120e1e1e1e13a4e135157317b79d4ecf329fed4f9eb00dc67dbddae33faca8b6d8a0255b5ce":"01":"04e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e1e0e1ff20e1ffe120e1e1e173287170a761308491683e345cacaebb500c96e1a7bbd37772968b2c951f0579":"04fab65e09aa5dd948320f86246be1d3fc571e7f799d9005170ed5cc868b67598431a668f96aa9fd0b0eb15f0edf4c7fe1be2885eadcb57e3db4fdd093585d3fa6"
+
 ECP test vectors Curve448 (RFC 7748 6.2, after decodeUCoordinate)
 depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
 ecp_test_vec_x:MBEDTLS_ECP_DP_CURVE448:"eb7298a5c0d8c29a1dab27f1a6826300917389449741a974f5bac9d98dc298d46555bce8bae89eeed400584bb046cf75579f51d125498f98":"a01fc432e5807f17530d1288da125b0cd453d941726436c8bbd9c5222c3da7fa639ce03db8d23b274a0721a1aed5227de6e3b731ccf7089b":"ad997351b6106f36b0d1091b929c4c37213e0d2b97e85ebb20c127691d0dad8f1d8175b0723745e639a3cb7044290b99e0e2a0c27a6a301c":"0936f37bc6c1bd07ae3dec7ab5dc06a73ca13242fb343efc72b9d82730b445f3d4b0bd077162a46dcfec6f9b590bfcbcf520cdb029a8b73e":"9d874a5137509a449ad5853040241c5236395435c36424fd560b0cb62b281d285275a740ce32a22dd1740f4aa9161cec95ccc61a18f4ff07"
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 4ee75a6..8d47eda 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -752,6 +752,52 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED */
+void ecp_muladd( int id,
+                 data_t *u1_bin, data_t *P1_bin,
+                 data_t *u2_bin, data_t *P2_bin,
+                 data_t *expected_result )
+{
+    /* Compute R = u1 * P1 + u2 * P2 */
+    mbedtls_ecp_group grp;
+    mbedtls_ecp_point P1, P2, R;
+    mbedtls_mpi u1, u2;
+    uint8_t actual_result[MBEDTLS_ECP_MAX_PT_LEN];
+    size_t len;
+
+    mbedtls_ecp_group_init( &grp );
+    mbedtls_ecp_point_init( &P1 );
+    mbedtls_ecp_point_init( &P2 );
+    mbedtls_ecp_point_init( &R );
+    mbedtls_mpi_init( &u1 );
+    mbedtls_mpi_init( &u2 );
+
+    TEST_EQUAL( 0, mbedtls_ecp_group_load( &grp, id ) );
+    TEST_EQUAL( 0, mbedtls_mpi_read_binary( &u1, u1_bin->x, u1_bin->len ) );
+    TEST_EQUAL( 0, mbedtls_mpi_read_binary( &u2, u2_bin->x, u2_bin->len ) );
+    TEST_EQUAL( 0, mbedtls_ecp_point_read_binary( &grp, &P1,
+                                                  P1_bin->x, P1_bin->len ) );
+    TEST_EQUAL( 0, mbedtls_ecp_point_read_binary( &grp, &P2,
+                                                  P2_bin->x, P2_bin->len ) );
+
+    TEST_EQUAL( 0, mbedtls_ecp_muladd( &grp, &R, &u1, &P1, &u2, &P2 ) );
+    TEST_EQUAL( 0, mbedtls_ecp_point_write_binary(
+                    &grp, &R, MBEDTLS_ECP_PF_UNCOMPRESSED,
+                    &len, actual_result, sizeof( actual_result ) ) );
+
+    ASSERT_COMPARE( expected_result->x, expected_result->len,
+                    actual_result, len );
+
+exit:
+    mbedtls_ecp_group_free( &grp );
+    mbedtls_ecp_point_free( &P1 );
+    mbedtls_ecp_point_free( &P2 );
+    mbedtls_ecp_point_free( &R );
+    mbedtls_mpi_free( &u1 );
+    mbedtls_mpi_free( &u2 );
+}
+/* END_CASE */
+
 /* BEGIN_CASE */
 void ecp_fast_mod( int id, char * N_str )
 {