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.
This commit is contained in:
Hanno Becker
2019-07-17 11:21:02 +01:00
parent 505be8be4d
commit a5cedbcd3f
30 changed files with 247 additions and 177 deletions

View File

@@ -100,7 +100,7 @@ int main( int argc, char *argv[] )
unsigned char diff;
const mbedtls_cipher_info_t *cipher_info;
const mbedtls_md_info_t *md_info;
mbedtls_md_handle_t md_info;
mbedtls_cipher_context_t cipher_ctx;
mbedtls_md_context_t md_ctx;
#if defined(_WIN32_WCE)
@@ -192,7 +192,7 @@ int main( int argc, char *argv[] )
}
md_info = mbedtls_md_info_from_string( argv[5] );
if( md_info == NULL )
if( md_info == MBEDTLS_MD_INVALID_HANDLE )
{
mbedtls_fprintf( stderr, "Message Digest '%s' not found\n", argv[5] );
goto exit;