psa: Add initializers for MAC operation objects
Add new initializers for MAC operation objects and use them in our tests
and library code. Prefer using the macro initializers due to their
straightforwardness.
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 694fdf4..f94830d 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -929,11 +929,50 @@
/** The type of the state data structure for multipart MAC operations.
*
+ * Before calling any function on a MAC operation object, the application must
+ * initialize it by any of the following means:
+ * - Set the structure to all-bits-zero, for example:
+ * \code
+ * psa_mac_operation_t operation;
+ * memset(&operation, 0, sizeof(operation));
+ * \endcode
+ * - Initialize the structure to logical zero values, for example:
+ * \code
+ * psa_mac_operation_t operation = {0};
+ * \endcode
+ * - Initialize the structure to the initializer #PSA_MAC_OPERATION_INIT,
+ * for example:
+ * \code
+ * psa_mac_operation_t operation = PSA_MAC_OPERATION_INIT;
+ * \endcode
+ * - Assign the result of the function psa_mac_operation_init()
+ * to the structure, for example:
+ * \code
+ * psa_mac_operation_t operation;
+ * operation = psa_mac_operation_init();
+ * \endcode
+ *
* This is an implementation-defined \c struct. Applications should not
* make any assumptions about the content of this structure except
* as directed by the documentation of a specific implementation. */
typedef struct psa_mac_operation_s psa_mac_operation_t;
+/** \def PSA_MAC_OPERATION_INIT
+ *
+ * This macro returns a suitable initializer for a MAC operation object of type
+ * #psa_mac_operation_t.
+ */
+#ifdef __DOXYGEN_ONLY__
+/* This is an example definition for documentation purposes.
+ * Implementations should define a suitable value in `crypto_struct.h`.
+ */
+#define PSA_MAC_OPERATION_INIT {0}
+#endif
+
+/** Return an initial value for a MAC operation object.
+ */
+static psa_mac_operation_t psa_mac_operation_init(void);
+
/** Start a multipart MAC calculation operation.
*
* This function sets up the calculation of the MAC
@@ -944,6 +983,8 @@
* The sequence of operations to calculate a MAC is as follows:
* -# Allocate an operation object which will be passed to all the functions
* listed here.
+ * -# Initialize the operation object with one of the methods described in the
+ * documentation for #psa_mac_operation_t, e.g. PSA_MAC_OPERATION_INIT.
* -# Call psa_mac_sign_setup() to specify the algorithm and key.
* The key remains associated with the operation even if the content
* of the key slot changes.
@@ -954,14 +995,16 @@
* calculating the MAC value and retrieve it.
*
* The application may call psa_mac_abort() at any time after the operation
- * has been initialized with psa_mac_sign_setup().
+ * has been initialized.
*
* After a successful call to psa_mac_sign_setup(), the application must
* eventually terminate the operation through one of the following methods:
* - A failed call to psa_mac_update().
* - A call to psa_mac_sign_finish() or psa_mac_abort().
*
- * \param[out] operation The operation object to use.
+ * \param[in,out] operation The operation object to set up. It must have
+ * been initialized as per the documentation for
+ * #psa_mac_operation_t and not yet in use.
* \param handle Handle to the key to use for the operation.
* \param alg The MAC algorithm to compute (\c PSA_ALG_XXX value
* such that #PSA_ALG_IS_MAC(alg) is true).
@@ -996,6 +1039,8 @@
* The sequence of operations to verify a MAC is as follows:
* -# Allocate an operation object which will be passed to all the functions
* listed here.
+ * -# Initialize the operation object with one of the methods described in the
+ * documentation for #psa_mac_operation_t, e.g. PSA_MAC_OPERATION_INIT.
* -# Call psa_mac_verify_setup() to specify the algorithm and key.
* The key remains associated with the operation even if the content
* of the key slot changes.
@@ -1007,14 +1052,16 @@
* the expected value.
*
* The application may call psa_mac_abort() at any time after the operation
- * has been initialized with psa_mac_verify_setup().
+ * has been initialized.
*
* After a successful call to psa_mac_verify_setup(), the application must
* eventually terminate the operation through one of the following methods:
* - A failed call to psa_mac_update().
* - A call to psa_mac_verify_finish() or psa_mac_abort().
*
- * \param[out] operation The operation object to use.
+ * \param[in,out] operation The operation object to set up. It must have
+ * been initialized as per the documentation for
+ * #psa_mac_operation_t and not yet in use.
* \param handle Handle to the key to use for the operation.
* \param alg The MAC algorithm to compute (\c PSA_ALG_XXX value
* such that #PSA_ALG_IS_MAC(\p alg) is true).
diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index 4a6e168..efc30b8 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -123,6 +123,13 @@
} ctx;
};
+#define PSA_MAC_OPERATION_INIT {0, 0, 0, 0, 0, 0, 0, {0}}
+static inline struct psa_mac_operation_s psa_mac_operation_init( void )
+{
+ const struct psa_mac_operation_s v = PSA_MAC_OPERATION_INIT;
+ return( v );
+}
+
struct psa_cipher_operation_s
{
psa_algorithm_t alg;