dhm: remove unused variable (and improve comment)
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/dhm.c b/library/dhm.c
index 3c65bc8..941a89d 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -345,9 +345,6 @@
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
int ret;
- mbedtls_mpi R;
-
- mbedtls_mpi_init(&R);
/*
* Don't use any blinding the first time a particular X is used,
@@ -382,13 +379,11 @@
/* Vi = random( 2, P-2 ) */
MBEDTLS_MPI_CHK(dhm_random_below(&ctx->Vi, &ctx->P, f_rng, p_rng));
- /* Vf = Vi^-X mod P */
+ /* Vf = Vi^-X = (Vi^-1)^X mod P */
MBEDTLS_MPI_CHK(mbedtls_mpi_gcd_modinv_odd(NULL, &ctx->Vf, &ctx->Vi, &ctx->P));
MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP));
cleanup:
- mbedtls_mpi_free(&R);
-
return ret;
}