| Change the API to allow adding critical extensions to CSRs | |
| ------------------------------------------------------------------ | |
| This affects applications that call the `mbedtls_x509write_csr_set_extension` | |
| function. | |
| The API is changed to include the parameter `critical` which allow to mark an | |
| extension included in a CSR as critical. To get the previous behaviour pass | |
| `0`. |