Documentation update for MBEDTLS_ECP_NO_FALLBACK

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
This commit is contained in:
Steven Cooreman 2021-01-21 13:58:31 +01:00
parent 97b4984657
commit 6226a12acc
2 changed files with 18 additions and 14 deletions

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@ -1,4 +1,4 @@
Features
* Automatic fallback to a software implementation of ECP when ECP_xxx_ALT
accelerator hooks are in use can now be turned off through setting the new
configuration flag MBEDTLS_ECP_NO_FALLBACK.
* Automatic fallback to a software implementation of ECP when
MBEDTLS_ECP_xxx_ALT accelerator hooks are in use can now be turned off
through setting the new configuration flag MBEDTLS_ECP_NO_FALLBACK.

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@ -485,7 +485,7 @@
* alternative.
*
* The original implementation can in addition be removed by setting the
* MBEDTLS_ECP_NO_FALLBACK, in which case any function for which the
* MBEDTLS_ECP_NO_FALLBACK option, in which case any function for which the
* corresponding MBEDTLS_ECP__FUNCTION_NAME__ALT macro is defined will not be
* able to fallback to curves not supported by the alternative implementation.
*
@ -502,16 +502,20 @@
* called before and after each point operation and provide an opportunity to
* implement optimized set up and tear down instructions.
*
* Example: In case you uncomment MBEDTLS_ECP_INTERNAL_ALT and
* MBEDTLS_ECP_DOUBLE_JAC_ALT, mbed TLS will still provide the ecp_double_jac
* function, but will use your mbedtls_internal_ecp_double_jac if the group is
* supported (your mbedtls_internal_ecp_grp_capable function returns 1 when
* receives it as an argument). If the group is not supported then the original
* implementation is used, unless disabled by MBEDTLS_ECP_NO_FALLBACK. The
* other functions and the definition of mbedtls_ecp_group and
* mbedtls_ecp_point will not change, so your implementation of
* mbedtls_internal_ecp_double_jac and mbedtls_internal_ecp_grp_capable must be
* compatible with this definition.
* Example: In case you set MBEDTLS_ECP_INTERNAL_ALT and
* MBEDTLS_ECP_DOUBLE_JAC_ALT, mbed TLS will still provide the ecp_double_jac()
* function, but will use your mbedtls_internal_ecp_double_jac() if the group
* for the operation is supported by your implementation (i.e. your
* mbedtls_internal_ecp_grp_capable() function returns 1 for this group). If the
* group is not supported by your implementation, then the original mbed TLS
* implementation of ecp_double_jac() is used instead, unless this fallback
* behaviour is disabled by setting MBEDTLS_ECP_NO_FALLBACK (in which case
* ecp_double_jac() will return MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE).
*
* The function prototypes and the definition of mbedtls_ecp_group and
* mbedtls_ecp_point will not change based on MBEDTLS_ECP_INTERNAL_ALT, so your
* implementation of mbedtls_internal_ecp__function_name__ must be compatible
* with their definitions.
*
* Uncomment a macro to enable alternate implementation of the corresponding
* function.