Move legacy definitions to crypto_extra.h

Types and functions that are not used in the attribute-based key
creation API are now implementation-specific extensions, kept around
until we finish transitioning to the new API.
diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index efd1b76..f2cf051 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -202,6 +202,115 @@
 /* FIXME Deprecated. Remove this as soon as all the tests are updated. */
 #define PSA_ALG_SELECT_RAW                      ((psa_algorithm_t)0x31000001)
 
+/** \defgroup policy Key policies
+ * @{
+ *
+ * The functions in this section are legacy interfaces where the properties
+ * of a key object are set after allocating a handle, in constrast with the
+ * preferred interface where key objects are created atomically from
+ * a structure that represents the properties.
+ */
+
+/** \def PSA_KEY_POLICY_INIT
+ *
+ * This macro returns a suitable initializer for a key policy object of type
+ * #psa_key_policy_t.
+ */
+#ifdef __DOXYGEN_ONLY__
+/* This is an example definition for documentation purposes.
+ * Implementations should define a suitable value in `crypto_struct.h`.
+ */
+#define PSA_KEY_POLICY_INIT {0}
+#endif
+
+/** Return an initial value for a key policy that forbids all usage of the key.
+ */
+static psa_key_policy_t psa_key_policy_init(void);
+
+/** \brief Set the standard fields of a policy structure.
+ *
+ * Note that this function does not make any consistency check of the
+ * parameters. The values are only checked when applying the policy to
+ * a key slot with psa_set_key_policy().
+ *
+ * \param[in,out] policy The key policy to modify. It must have been
+ *                       initialized as per the documentation for
+ *                       #psa_key_policy_t.
+ * \param usage          The permitted uses for the key.
+ * \param alg            The algorithm that the key may be used for.
+ */
+void psa_key_policy_set_usage(psa_key_policy_t *policy,
+                              psa_key_usage_t usage,
+                              psa_algorithm_t alg);
+
+/** \brief Retrieve the usage field of a policy structure.
+ *
+ * \param[in] policy    The policy object to query.
+ *
+ * \return The permitted uses for a key with this policy.
+ */
+psa_key_usage_t psa_key_policy_get_usage(const psa_key_policy_t *policy);
+
+/** \brief Retrieve the algorithm field of a policy structure.
+ *
+ * \param[in] policy    The policy object to query.
+ *
+ * \return The permitted algorithm for a key with this policy.
+ */
+psa_algorithm_t psa_key_policy_get_algorithm(const psa_key_policy_t *policy);
+
+/** \brief Set the usage policy on a key slot.
+ *
+ * This function must be called on an empty key slot, before importing,
+ * generating or creating a key in the slot. Changing the policy of an
+ * existing key is not permitted.
+ *
+ * Implementations may set restrictions on supported key policies
+ * depending on the key type and the key slot.
+ *
+ * \param handle        Handle to the key whose policy is to be changed.
+ * \param[in] policy    The policy object to query.
+ *
+ * \retval #PSA_SUCCESS
+ *         Success.
+ *         If the key is persistent, it is implementation-defined whether
+ *         the policy has been saved to persistent storage. Implementations
+ *         may defer saving the policy until the key material is created.
+ * \retval #PSA_ERROR_INVALID_HANDLE
+ * \retval #PSA_ERROR_ALREADY_EXISTS
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE
+ * \retval #PSA_ERROR_HARDWARE_FAILURE
+ * \retval #PSA_ERROR_TAMPERING_DETECTED
+ * \retval #PSA_ERROR_BAD_STATE
+ *         The library has not been previously initialized by psa_crypto_init().
+ *         It is implementation-dependent whether a failure to initialize
+ *         results in this error code.
+ */
+psa_status_t psa_set_key_policy(psa_key_handle_t handle,
+                                const psa_key_policy_t *policy);
+
+/** \brief Get the usage policy for a key slot.
+ *
+ * \param handle        Handle to the key slot whose policy is being queried.
+ * \param[out] policy   On success, the key's policy.
+ *
+ * \retval #PSA_SUCCESS
+ * \retval #PSA_ERROR_INVALID_HANDLE
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE
+ * \retval #PSA_ERROR_HARDWARE_FAILURE
+ * \retval #PSA_ERROR_TAMPERING_DETECTED
+ * \retval #PSA_ERROR_BAD_STATE
+ *         The library has not been previously initialized by psa_crypto_init().
+ *         It is implementation-dependent whether a failure to initialize
+ *         results in this error code.
+ */
+psa_status_t psa_get_key_policy(psa_key_handle_t handle,
+                                psa_key_policy_t *policy);
+
+/**@}*/
+
 /** \defgroup to_handle Key creation to allocated handle
  * @{
  *
@@ -248,6 +357,51 @@
                             psa_key_id_t id,
                             psa_key_handle_t *handle);
 
+/** Allocate a key slot for a transient key, i.e. a key which is only stored
+ * in volatile memory.
+ *
+ * The allocated key slot and its handle remain valid until the
+ * application calls psa_close_key() or psa_destroy_key() or until the
+ * application terminates.
+ *
+ * \param[out] handle   On success, a handle to a volatile key slot.
+ *
+ * \retval #PSA_SUCCESS
+ *         Success. The application can now use the value of `*handle`
+ *         to access the newly allocated key slot.
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
+ *         There was not enough memory, or the maximum number of key slots
+ *         has been reached.
+ */
+psa_status_t psa_allocate_key(psa_key_handle_t *handle);
+
+/**
+ * \brief Get basic metadata about a key.
+ *
+ * \param handle        Handle to the key slot to query.
+ * \param[out] type     On success, the key type (a \c PSA_KEY_TYPE_XXX value).
+ *                      This may be a null pointer, in which case the key type
+ *                      is not written.
+ * \param[out] bits     On success, the key size in bits.
+ *                      This may be a null pointer, in which case the key size
+ *                      is not written.
+ *
+ * \retval #PSA_SUCCESS
+ * \retval #PSA_ERROR_INVALID_HANDLE
+ * \retval #PSA_ERROR_DOES_NOT_EXIST
+ *         The handle is to a key slot which does not contain key material yet.
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE
+ * \retval #PSA_ERROR_HARDWARE_FAILURE
+ * \retval #PSA_ERROR_TAMPERING_DETECTED
+ * \retval #PSA_ERROR_BAD_STATE
+ *         The library has not been previously initialized by psa_crypto_init().
+ *         It is implementation-dependent whether a failure to initialize
+ *         results in this error code.
+ */
+psa_status_t psa_get_key_information(psa_key_handle_t handle,
+                                     psa_key_type_t *type,
+                                     size_t *bits);
+
 /** \brief Retrieve the lifetime of an open key.
  *
  * \param handle        Handle to query.