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/library/ecjpake.c b/library/ecjpake.c
index b276514..ea28e6d 100644
--- a/library/ecjpake.c
+++ b/library/ecjpake.c
@@ -63,7 +63,7 @@
{
ECJPAKE_VALIDATE( ctx != NULL );
- ctx->md_info = NULL;
+ ctx->md_info = MBEDTLS_MD_INVALID_HANDLE;
mbedtls_ecp_group_init( &ctx->grp );
ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;
@@ -86,7 +86,7 @@
if( ctx == NULL )
return;
- ctx->md_info = NULL;
+ ctx->md_info = MBEDTLS_MD_INVALID_HANDLE;
mbedtls_ecp_group_free( &ctx->grp );
mbedtls_ecp_point_free( &ctx->Xm1 );
@@ -119,8 +119,11 @@
ctx->role = role;
- if( ( ctx->md_info = mbedtls_md_info_from_type( hash ) ) == NULL )
+ if( ( ctx->md_info = mbedtls_md_info_from_type( hash ) ) ==
+ MBEDTLS_MD_INVALID_HANDLE )
+ {
return( MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE );
+ }
MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &ctx->grp, curve ) );
@@ -140,7 +143,7 @@
{
ECJPAKE_VALIDATE_RET( ctx != NULL );
- if( ctx->md_info == NULL ||
+ if( ctx->md_info == MBEDTLS_MD_INVALID_HANDLE ||
ctx->grp.id == MBEDTLS_ECP_DP_NONE ||
ctx->s.p == NULL )
{
@@ -190,7 +193,7 @@
/*
* Compute hash for ZKP (7.4.2.2.2.1)
*/
-static int ecjpake_hash( const mbedtls_md_info_t *md_info,
+static int ecjpake_hash( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,
@@ -240,7 +243,7 @@
/*
* Parse a ECShnorrZKP (7.4.2.2.2) and verify it (7.4.2.3.3)
*/
-static int ecjpake_zkp_read( const mbedtls_md_info_t *md_info,
+static int ecjpake_zkp_read( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,
@@ -312,7 +315,7 @@
/*
* Generate ZKP (7.4.2.3.2) and write it as ECSchnorrZKP (7.4.2.2.2)
*/
-static int ecjpake_zkp_write( const mbedtls_md_info_t *md_info,
+static int ecjpake_zkp_write( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,
@@ -373,7 +376,7 @@
* Parse a ECJPAKEKeyKP (7.4.2.2.1) and check proof
* Output: verified public key X
*/
-static int ecjpake_kkp_read( const mbedtls_md_info_t *md_info,
+static int ecjpake_kkp_read( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,
@@ -410,7 +413,7 @@
* Generate an ECJPAKEKeyKP
* Output: the serialized structure, plus private/public key pair
*/
-static int ecjpake_kkp_write( const mbedtls_md_info_t *md_info,
+static int ecjpake_kkp_write( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,
@@ -447,7 +450,7 @@
* Read a ECJPAKEKeyKPPairList (7.4.2.3) and check proofs
* Ouputs: verified peer public keys Xa, Xb
*/
-static int ecjpake_kkpp_read( const mbedtls_md_info_t *md_info,
+static int ecjpake_kkpp_read( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,
@@ -480,7 +483,7 @@
* Generate a ECJPAKEKeyKPPairList
* Outputs: the serialized structure, plus two private/public key pairs
*/
-static int ecjpake_kkpp_write( const mbedtls_md_info_t *md_info,
+static int ecjpake_kkpp_write( mbedtls_md_handle_t md_info,
const mbedtls_ecp_group *grp,
const int pf,
const mbedtls_ecp_point *G,