Add proper allocation of restart context
We'll need to store MPIs and other things that allocate memory in this
context, so we need a place to free it. We can't rely on doing it before
returning from ecp_mul() as we might return MBEDTLS_ERR_ECP_IN_PROGRESS (thus
preserving the context) and never be called again (for example, TLS handshake
aborted for another reason). So, ecp_group_free() looks like a good place to
do this, if the restart context is part of struct ecp_group.
This means it's not possible to use the same ecp_group structure in different
threads concurrently, but:
- that's already the case (and documented) for other reasons
- this feature is precisely intended for environments that lack threading
An alternative option would be for the caller to have to allocate/free the
restart context and pass it explicitly, but this means creating new functions
that take a context argument, and putting a burden on the user.
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index c8daef9..74e2387 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -145,6 +145,10 @@
}
while( ret != 0 );
+ /* Do we leak memory when not finishing an operation? */
+ ret = mbedtls_ecp_mul( &grp, &R, &dB, &R, NULL, NULL );
+ TEST_ASSERT( ret == 0 || ret == MBEDTLS_ERR_ECP_IN_PROGRESS );
+
exit:
mbedtls_ecp_group_free( &grp ); mbedtls_ecp_point_free( &R );
mbedtls_mpi_free( &dA ); mbedtls_mpi_free( &xA ); mbedtls_mpi_free( &yA );