Attest: Support kid parameter in COSE_Mac0 structure header
Add a HAL API tfm_plat_get_symmetric_iak_id() to fetch kid from
platform.
Implement an example of this HAL API.
Add attest_get_symmetric_iak_id() to pass the kid value to token
generation of symmetric key algorithm based Initial Attestation.
Change-Id: I642f7a03f1738c8fe77f11fc2ae91652fc01df29
Signed-off-by: David Hu <david.hu@arm.com>
diff --git a/platform/include/tfm_plat_crypto_keys.h b/platform/include/tfm_plat_crypto_keys.h
index f9934cd..035fd38 100644
--- a/platform/include/tfm_plat_crypto_keys.h
+++ b/platform/include/tfm_plat_crypto_keys.h
@@ -104,6 +104,25 @@
size_t buf_len,
size_t *key_len,
psa_algorithm_t *key_alg);
+
+#ifdef INCLUDE_COSE_KEY_ID
+/**
+ * \brief Get the key identifier of the symmetric Initial Attestation Key as the
+ * 'kid' parameter in COSE Header.
+ *
+ * \note This `kid` parameter is included in COSE Header. Please don't confuse
+ * it with that `kid` in COSE_Key structure.
+ *
+ * \param[out] kid_buf The buffer to be written with key id
+ * \param[in] buf_len The length of kid_buf
+ * \param[out] kid_len The length of key id
+ *
+ * \return Returns error code specified in \ref tfm_plat_err_t.
+ */
+enum tfm_plat_err_t tfm_plat_get_symmetric_iak_id(void *kid_buf,
+ size_t buf_len,
+ size_t *kid_len);
+#endif
#else /* SYMMETRIC_INITIAL_ATTESTATION */
/**
* \brief Get the initial attestation key