Introduce MD handle type
As has been previously done for ciphersuites, this commit introduces
a zero-cost abstraction layer around the type
mbedtls_md_info const *
whose valid values represent implementations of message digest algorithms.
Access to a particular digest implementation can be requested by name or
digest ID through the API mbedtls_md_info_from_xxx(), which either returns
a valid implementation or NULL, representing failure.
This commit replaces such uses of `mbedtls_md_info const *` by an abstract
type `mbedtls_md_handle_t` whose valid values represent digest implementations,
and which has a designated invalid value MBEDTLS_MD_INVALID_HANDLE.
The purpose of this abstraction layer is to pave the way for builds which
support precisely one digest algorithm. In this case, mbedtls_md_handle_t
can be implemented as a two-valued type, with one value representing the
invalid handle, and the unique valid value representing the unique enabled
digest.
diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index 2b86566..88e3290 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -693,13 +693,16 @@
if( todo.hmac_drbg )
{
mbedtls_hmac_drbg_context hmac_drbg;
- const mbedtls_md_info_t *md_info;
+ mbedtls_md_handle_t md_info;
mbedtls_hmac_drbg_init( &hmac_drbg );
#if defined(MBEDTLS_SHA1_C)
- if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 ) ) == NULL )
+ if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 ) ) ==
+ MBEDTLS_MD_INVALID_HANDLE )
+ {
mbedtls_exit(1);
+ }
if( mbedtls_hmac_drbg_seed( &hmac_drbg, md_info, myrand, NULL, NULL, 0 ) != 0 )
mbedtls_exit(1);
@@ -715,8 +718,11 @@
#endif
#if defined(MBEDTLS_SHA256_C)
- if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ) ) == NULL )
+ if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ) ) ==
+ MBEDTLS_MD_INVALID_HANDLE )
+ {
mbedtls_exit(1);
+ }
if( mbedtls_hmac_drbg_seed( &hmac_drbg, md_info, myrand, NULL, NULL, 0 ) != 0 )
mbedtls_exit(1);