lib/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-07-28 00:21:48 +03:00
Code Activity

bignum_mod_raw: Added modular negation.

Browse Source 
This patch adds the `mpi_mod_raw_neg()` method.

Co-authored-by: Hanno Becker <hanno.becker@arm.com>
Co-authored-by: Minos Galanakis <minos.galanakis@arm.com>

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
This commit is contained in:
Minos Galanakis
2022-12-07 18:06:05 +00:00
parent 98be95563d
commit 21fe8bdeac
2 changed files with 30 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
library/bignum_mod_raw.c
View File

@ -182,6 +182,18 @@ int mbedtls_mpi_mod_raw_from_mont_rep( mbedtls_mpi_uint *X,
mbedtls_free( T );
return( 0 );
}
void mbedtls_mpi_mod_raw_neg( mbedtls_mpi_uint *X,
const mbedtls_mpi_uint *A,
const mbedtls_mpi_mod_modulus *m )
{
mbedtls_mpi_core_sub( X, m->p, A, m->limbs );
/* If A=0 initially, then X=N now. Detect this by
* subtracting N and catching the carry. */
mbedtls_mpi_uint borrow = mbedtls_mpi_core_sub( X, X, m->p, m->limbs );
(void) mbedtls_mpi_core_add_if( X, m->p, m->limbs, (unsigned) borrow );
}
/* END MERGE SLOT 7 */
/* BEGIN MERGE SLOT 8 */