bignum_mod_raw: Refactored Montgomery conversion functions
This patch updates the `mbedtls_mpi_mod_raw_conv_xx()` methods
as follows:
* Renamed for simplicity: conv_fwd -> from_mont_rep, conv_inv -> to_mont_rep.
* Uncoupled the dependency on the legaly bignum interface.
* `mbedtls_mpi` is no longer used for temporary buffer allocation.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index 97f7731..b43add7 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -127,26 +127,38 @@
/* END MERGE SLOT 6 */
/* BEGIN MERGE SLOT 7 */
-int mbedtls_mpi_mod_raw_conv_inv( mbedtls_mpi_uint *X,
- const mbedtls_mpi_mod_modulus *modulus )
+int mbedtls_mpi_mod_raw_to_mont_rep( mbedtls_mpi_uint *X,
+ const mbedtls_mpi_mod_modulus *m )
{
- mbedtls_mpi_uint one = 1;
- mbedtls_mpi T;
- mbedtls_mpi_init( &T );
- mbedtls_mpi_core_montmul( X, X, &one, 1, m->p, m->limbs,
- m->rep.mont.mm, T.p );
- mbedtls_mpi_free( &T );
+ mbedtls_mpi_uint *T;
+ const size_t t_limbs = m->limbs * 2 + 1;
+
+ if( ( T = (mbedtls_mpi_uint *) mbedtls_calloc( t_limbs, ciL ) ) == NULL )
+ return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+
+ mbedtls_mpi_core_montmul( X, X, m->rep.mont.rr, m->limbs, m->p, m->limbs,
+ m->rep.mont.mm, T );
+
+ mbedtls_platform_zeroize( T, t_limbs * ciL );
+ mbedtls_free( T );
return( 0 );
}
-int mbedtls_mpi_mod_raw_conv_fwd( mbedtls_mpi_uint *X,
- const mbedtls_mpi_mod_modulus *modulus )
+int mbedtls_mpi_mod_raw_from_mont_rep( mbedtls_mpi_uint *X,
+ const mbedtls_mpi_mod_modulus *m )
{
- mbedtls_mpi T;
- mbedtls_mpi_init( &T );
- mbedtls_mpi_core_montmul( X, X, m->rep.mont.rr, 1, m->p, m->limbs,
- m->rep.mont.mm, T.p );
- mbedtls_mpi_free( &T );
+ const mbedtls_mpi_uint one = 1;
+ const size_t t_limbs = m->limbs * 2 + 1;
+ mbedtls_mpi_uint *T;
+
+ if( ( T = (mbedtls_mpi_uint *) mbedtls_calloc( t_limbs, ciL ) ) == NULL )
+ return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+
+ mbedtls_mpi_core_montmul( X, X, &one, 1, m->p, m->limbs,
+ m->rep.mont.mm, T );
+
+ mbedtls_platform_zeroize( T, t_limbs * ciL );
+ mbedtls_free( T );
return( 0 );
}
/* END MERGE SLOT 7 */