Provide a public PKCS#11 mechanism enumerator

src/libstrongswan/plugins/pkcs11/pkcs11_library.c

@@ -613,6 +613,89 @@ METHOD(pkcs11_library_t, create_object_enumerator, enumerator_t*,
 	return &enumerator->public;
 }
 
+/**
+ * Enumerator over mechanisms
+ */
+typedef struct {
+	/* implements enumerator_t */
+	enumerator_t public;
+	/* PKCS#11 library */
+	pkcs11_library_t *lib;
+	/* slot of token */
+	CK_SLOT_ID slot;
+	/* mechanism type list */
+	CK_MECHANISM_TYPE_PTR mechs;
+	/* number of mechanism types */
+	CK_ULONG count;
+	/* current mechanism */
+	CK_ULONG current;
+} mechanism_enumerator_t;
+
+METHOD(enumerator_t, enumerate_mech, bool,
+	mechanism_enumerator_t *this, CK_MECHANISM_TYPE* type,
+	CK_MECHANISM_INFO *info)
+{
+	CK_RV rv;
+
+	if (this->current >= this->count)
+	{
+		return FALSE;
+	}
+	if (info)
+	{
+		rv = this->lib->f->C_GetMechanismInfo(this->slot,
+											  this->mechs[this->current], info);
+		if (rv != CKR_OK)
+		{
+			DBG1(DBG_CFG, "C_GetMechanismInfo() failed: %N", ck_rv_names, rv);
+			return FALSE;
+		}
+	}
+	*type = this->mechs[this->current++];
+	return TRUE;
+}
+
+METHOD(enumerator_t, destroy_mech, void,
+	mechanism_enumerator_t *this)
+{
+	free(this->mechs);
+	free(this);
+}
+
+METHOD(pkcs11_library_t, create_mechanism_enumerator, enumerator_t*,
+	private_pkcs11_library_t *this, CK_SLOT_ID slot)
+{
+	mechanism_enumerator_t *enumerator;
+	CK_RV rv;
+
+	INIT(enumerator,
+		.public = {
+			.enumerate = (void*)_enumerate_mech,
+			.destroy = _destroy_mech,
+		},
+		.lib = &this->public,
+		.slot = slot,
+	);
+
+	rv = enumerator->lib->f->C_GetMechanismList(slot, NULL, &enumerator->count);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GetMechanismList() failed: %N", ck_rv_names, rv);
+		free(enumerator);
+		return enumerator_create_empty();
+	}
+	enumerator->mechs = malloc(sizeof(CK_MECHANISM_TYPE) * enumerator->count);
+	enumerator->lib->f->C_GetMechanismList(slot, enumerator->mechs,
+										   &enumerator->count);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GetMechanismList() failed: %N", ck_rv_names, rv);
+		destroy_mech(enumerator);
+		return enumerator_create_empty();
+	}
+	return &enumerator->public;
+}
+
 METHOD(pkcs11_library_t, destroy, void,
 	private_pkcs11_library_t *this)
 {
@@ -761,6 +844,7 @@ pkcs11_library_t *pkcs11_library_create(char *name, char *file)
 		.public = {
 			.get_name = _get_name,
 			.create_object_enumerator = _create_object_enumerator,
+			.create_mechanism_enumerator = _create_mechanism_enumerator,
 			.destroy = _destroy,
 		},
 		.name = name,

src/libstrongswan/plugins/pkcs11/pkcs11_library.h

@@ -62,6 +62,18 @@ struct pkcs11_library_t {
 			CK_SESSION_HANDLE session, CK_ATTRIBUTE_PTR tmpl, CK_ULONG tcount,
 			CK_ATTRIBUTE_PTR attr, CK_ULONG acount);
 
+	/**
+	 * Create an enumerator over supported mechanisms of a token.
+	 *
+	 * The resulting enumerator enumerates over the mechanism type, and if
+	 * a non-NULL pointer is given, over the mechanism info details.
+	 *
+	 * @param slot		slot of the token
+	 * @return			enumerator over (CK_MECHANISM_TYPE, CK_MECHANISM_INFO)
+	 */
+	enumerator_t* (*create_mechanism_enumerator)(pkcs11_library_t *this,
+												 CK_SLOT_ID slot);
+
 	/**
 	 * Destroy a pkcs11_library_t.
 	 */

src/libstrongswan/plugins/pkcs11/pkcs11_manager.c

@@ -84,54 +84,31 @@ static void lib_entry_destroy(lib_entry_t *entry)
  */
 static void print_mechs(lib_entry_t *entry, CK_SLOT_ID slot)
 {
-	CK_MECHANISM_TYPE_PTR mechs;
+	enumerator_t *enumerator;
+	CK_MECHANISM_TYPE type;
 	CK_MECHANISM_INFO info;
-	CK_ULONG count;
-	CK_RV rv;
-	int i;
 
-	rv = entry->lib->f->C_GetMechanismList(slot, NULL, &count);
+	enumerator = entry->lib->create_mechanism_enumerator(entry->lib, slot);
-	if (rv != CKR_OK)
+	while (enumerator->enumerate(enumerator, &type, &info))
 	{
-		DBG1(DBG_CFG, "C_GetMechanismList() failed: %N", ck_rv_names, rv);
+		DBG2(DBG_CFG, "      %N %lu-%lu [ %s%s%s%s%s%s%s%s%s%s%s%s%s]",
-		return;
+			ck_mech_names, type,
+			info.ulMinKeySize, info.ulMaxKeySize,
+			info.flags & CKF_HW ? "HW " : "",
+			info.flags & CKF_ENCRYPT ? "ENCR " : "",
+			info.flags & CKF_DECRYPT ? "DECR " : "",
+			info.flags & CKF_DIGEST ? "DGST " : "",
+			info.flags & CKF_SIGN ? "SIGN " : "",
+			info.flags & CKF_SIGN_RECOVER ? "SIGN_RCVR " : "",
+			info.flags & CKF_VERIFY ? "VRFY " : "",
+			info.flags & CKF_VERIFY_RECOVER ? "VRFY_RCVR " : "",
+			info.flags & CKF_GENERATE ? "GEN " : "",
+			info.flags & CKF_GENERATE_KEY_PAIR ? "GEN_KEY_PAIR " : "",
+			info.flags & CKF_WRAP ? "WRAP " : "",
+			info.flags & CKF_UNWRAP ? "UNWRAP " : "",
+			info.flags & CKF_DERIVE ? "DERIVE " : "");
 	}
-	mechs = malloc(sizeof(CK_MECHANISM_TYPE) * count);
+	enumerator->destroy(enumerator);
-	entry->lib->f->C_GetMechanismList(slot, mechs, &count);
-	if (rv != CKR_OK)
-	{
-		DBG1(DBG_CFG, "C_GetMechanismList() failed: %N", ck_rv_names, rv);
-		return;
-	}
-	for (i = 0; i < count; i++)
-	{
-		rv = entry->lib->f->C_GetMechanismInfo(slot, mechs[i], &info);
-		if (rv == CKR_OK)
-		{
-			DBG2(DBG_CFG, "      %N %lu-%lu [ %s%s%s%s%s%s%s%s%s%s%s%s%s]",
-				ck_mech_names, mechs[i],
-				info.ulMinKeySize, info.ulMaxKeySize,
-				info.flags & CKF_HW ? "HW " : "",
-				info.flags & CKF_ENCRYPT ? "ENCR " : "",
-				info.flags & CKF_DECRYPT ? "DECR " : "",
-				info.flags & CKF_DIGEST ? "DGST " : "",
-				info.flags & CKF_SIGN ? "SIGN " : "",
-				info.flags & CKF_SIGN_RECOVER ? "SIGN_RCVR " : "",
-				info.flags & CKF_VERIFY ? "VRFY " : "",
-				info.flags & CKF_VERIFY_RECOVER ? "VRFY_RCVR " : "",
-				info.flags & CKF_GENERATE ? "GEN " : "",
-				info.flags & CKF_GENERATE_KEY_PAIR ? "GEN_KEY_PAIR " : "",
-				info.flags & CKF_WRAP ? "WRAP " : "",
-				info.flags & CKF_UNWRAP ? "UNWRAP " : "",
-				info.flags & CKF_DERIVE ? "DERIVE " : "");
-		}
-		else
-		{
-			DBG1(DBG_CFG, "C_GetMechanismList(%N) failed: %N",
-				 ck_mech_names, mechs[i], ck_rv_names, rv);
-		}
-	}
-	free(mechs);
 }
 
 /**