Hi,

I am working on adding HW acceleration to a NXP Kinetis MCU, but the HW accelerator happens to implement many operations which are defined in bignum.c, like "mbedtls_mpi_exp_mod", "mbedtls_mpi_gcd", "mbedtls_mpi_inv_mod" and so on. The bignum clients for me would be ecp.c and ecp_curves.c (as well as ecdh and ecdsa), and while I can override some of those using _ALT macros, for bignum it seems not possible to do so, short of not defining MBEDLTS_BIGNUM_C and all associated dependency issues.

Also bignum itself also has other call paths that happen to use the functions I am trying to accelerate, which are themselves called by other files. Since I am using an open-source OSS and can't just override stuff in a fork, so I would like to know if there is some technical reason for an option like "MBEDTLS_BIGNUM_ALT" not being available and if such change would be acceptable?

Fabio