From 02b5705aa37613d83c97aa2f84b8d66b10b60d3d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Tue, 15 Jun 2021 11:29:26 +0200 Subject: [PATCH] Simplify internal code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We know that Montgomery multiplication will never be called without an RNG, so make that clear from the beginning of the function. Signed-off-by: Manuel Pégourié-Gonnard --- library/ecp.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/library/ecp.c b/library/ecp.c index b7a3854757..8f6e9886b8 100644 --- a/library/ecp.c +++ b/library/ecp.c @@ -2384,6 +2384,9 @@ static int ecp_mul_mxz( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, mbedtls_mpi PX; mbedtls_ecp_point_init( &RP ); mbedtls_mpi_init( &PX ); + if( f_rng == NULL ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + /* Save PX and read from P before writing to R, in case P == R */ MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &PX, &P->X ) ); MBEDTLS_MPI_CHK( mbedtls_ecp_copy( &RP, P ) ); @@ -2397,8 +2400,7 @@ static int ecp_mul_mxz( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, MOD_ADD( RP.X ); /* Randomize coordinates of the starting point */ - if( f_rng != NULL ) - MBEDTLS_MPI_CHK( ecp_randomize_mxz( grp, &RP, f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( ecp_randomize_mxz( grp, &RP, f_rng, p_rng ) ); /* Loop invariant: R = result so far, RP = R + P */ i = mbedtls_mpi_bitlen( m ); /* one past the (zero-based) most significant bit */ @@ -2430,9 +2432,7 @@ static int ecp_mul_mxz( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, * * Avoid the leak by randomizing coordinates before we normalize them. */ - if( f_rng != NULL ) - MBEDTLS_MPI_CHK( ecp_randomize_mxz( grp, R, f_rng, p_rng ) ); - + MBEDTLS_MPI_CHK( ecp_randomize_mxz( grp, R, f_rng, p_rng ) ); MBEDTLS_MPI_CHK( ecp_normalize_mxz( grp, R ) ); cleanup: