Add macro for error code addition

Adds a macro (`MBEDTLS_ERR_ADD`) to add error codes together and check that the
result will not be corrupted. This additional check is only enabled during
testing when `MBEDTLS_TEST_HOOKS` is defined.

Also includes a reference usage example in `rsa.c` where two high-level error
codes could be incorrectly added together under the right conditions. This now
ensures that when this error occurs during testing it will be correctly
reported.

Signed-off-by: Chris Jones <christopher.jones@arm.com>
This commit is contained in:
Chris Jones 2021-01-08 17:04:59 +00:00
parent 528b0a6b18
commit 96ae73b0ea
6 changed files with 49 additions and 1 deletions

View file

@ -1085,7 +1085,7 @@ cleanup:
mbedtls_mpi_free( &I );
if( ret != 0 && ret >= -0x007f )
return( MBEDTLS_ERR_RSA_PRIVATE_FAILED + ret );
return( MBEDTLS_ERR_ADD( MBEDTLS_ERR_RSA_PRIVATE_FAILED, ret ) );
return( ret );
}