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/include/mbedtls/ecjpake.h b/include/mbedtls/ecjpake.h
index 3d8d02a..00e752b 100644
--- a/include/mbedtls/ecjpake.h
+++ b/include/mbedtls/ecjpake.h
@@ -75,7 +75,7 @@
*/
typedef struct mbedtls_ecjpake_context
{
- const mbedtls_md_info_t *md_info; /**< Hash to use */
+ mbedtls_md_handle_t md_info; /**< Hash to use */
mbedtls_ecp_group grp; /**< Elliptic curve */
mbedtls_ecjpake_role role; /**< Are we client or server? */
int point_format; /**< Format for point export */