tree f4baf4576762c56f71038b54aba2eeacf23fa548
parent 4d8c836cdc4559d862337c5b2ecc9ca5d1e7810f
author Eric Adamson <eadamson@fastmail.fm> 1581477480 -0500
committer Eric Adamson <eadamson@fastmail.fm> 1584928630 -0400

Remove temporary allocation in mbedtls_mpi_sub_abs

In cases where X == B the code now no longer requires an extra call to
mbedtls_calloc if X->n >= A->n.  This reduces calls to mbedtls_calloc in
test_suite_ecdsa by 52% and in test_suite_ecdh by 36%.

This does not update mpi_sub_hlp - in mpi_montmul this translates to a
performance decrease for rsa and dhm since in all cases X == A.

Signed-off-by: Eric Adamson <eadamson@fastmail.fm>