New macro PSA_KEY_LIFETIME_IS_READ_ONLY
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index dccb173..46e2a7e 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -1895,6 +1895,26 @@
(PSA_KEY_LIFETIME_GET_PERSISTENCE(lifetime) == \
PSA_KEY_PERSISTENCE_VOLATILE)
+/** Whether a key lifetime indicates that the key is read-only.
+ *
+ * Read-only keys cannot be created or destroyed through the PSA Crypto API.
+ * They must be created through platform-specific means that bypass the API.
+ *
+ * Some platforms may offer ways to destroy read-only keys. For example,
+ * a platform with multiple levels of privilege may expose a key to an
+ * application without allowing that application to destroy the key, in
+ * which case it may show the key a view of the key metadata where the
+ * lifetime is read-only.
+ *
+ * \param lifetime The lifetime value to query (value of type
+ * ::psa_key_lifetime_t).
+ *
+ * \return \c 1 if the key is read-only, otherwise \c 0.
+ */
+#define PSA_KEY_LIFETIME_IS_READ_ONLY(lifetime) \
+ (PSA_KEY_LIFETIME_GET_PERSISTENCE(lifetime) == \
+ PSA_KEY_PERSISTENCE_READ_ONLY)
+
/** Construct a lifetime from a persistence level and a location.
*
* \param persistence The persistence level