feat(rmmd): el3 token sign during attestation
Add required SMCs by RMM to push attestation signing requests to EL3
and get responses. EL3 may then choose to push these requests to a HES
as suitable for a platform. This patch also supports the new
RMM_EL3_FEATURES interface, that RMM can use to query for support for
HES based signing. The new interface exposes a feature register with
different bits defining different discoverable features. This new
interface is available starting the 0.4 version of the RMM-EL3
interface, causing the version to bump up. This patch also adds a
platform port for FVP that implements the platform hooks required to
enable the new SMCs, but it does not push to a HES and instead copies a
zeroed buffer in EL3.
Change-Id: I69c110252835122a9533e71bdcce10b5f2a686b2
Signed-off-by: Raghu Krishnamurthy <raghupathyk@nvidia.com>
diff --git a/include/services/rmmd_svc.h b/include/services/rmmd_svc.h
index 635c28e..0cc8628 100644
--- a/include/services/rmmd_svc.h
+++ b/include/services/rmmd_svc.h
@@ -129,8 +129,43 @@
/* 0x1B3 */
#define RMM_ATTEST_GET_PLAT_TOKEN SMC64_RMMD_EL3_FID(U(3))
+/* Starting RMM-EL3 interface version 0.4 */
+#define RMM_EL3_FEATURES SMC64_RMMD_EL3_FID(U(4))
+#define RMM_EL3_FEAT_REG_0_IDX U(0)
+/* Bit 0 of FEAT_REG_0 */
+/* 1 - the feature is present in EL3 , 0 - the feature is absent */
+#define RMM_EL3_FEAT_REG_0_EL3_TOKEN_SIGN_MASK U(0x1)
+
+/*
+ * Function codes to support attestation where EL3 is used to sign
+ * realm attestation tokens. In this model, the private key is not
+ * exposed to the RMM.
+ * The arguments to this SMC are:
+ * arg0 - Function ID.
+ * arg1 - Opcode, one of:
+ * RMM_EL3_TOKEN_SIGN_PUSH_REQ_OP,
+ * RMM_EL3_TOKEN_SIGN_PULL_RESP_OP,
+ * RMM_EL3_TOKEN_SIGN_GET_RAK_PUB_OP
+ * arg2 - Pointer to buffer with request/response structures,
+ * which is in the RMM<->EL3 shared buffer.
+ * arg3 - Buffer size of memory pointed by arg2.
+ * arg4 - ECC Curve, when opcode is RMM_EL3_TOKEN_SIGN_GET_RAK_PUB_OP
+ * The return arguments are:
+ * ret0 - Status/Error
+ * ret1 - Size of public key if opcode is RMM_EL3_TOKEN_SIGN_GET_RAK_PUB_OP
+ */
+#define RMM_EL3_TOKEN_SIGN SMC64_RMMD_EL3_FID(U(5))
+
+/* Opcodes for RMM_EL3_TOKEN_SIGN */
+#define RMM_EL3_TOKEN_SIGN_PUSH_REQ_OP U(1)
+#define RMM_EL3_TOKEN_SIGN_PULL_RESP_OP U(2)
+#define RMM_EL3_TOKEN_SIGN_GET_RAK_PUB_OP U(3)
+
/* ECC Curve types for attest key generation */
-#define ATTEST_KEY_CURVE_ECC_SECP384R1 0
+#define ATTEST_KEY_CURVE_ECC_SECP384R1 U(0)
+
+/* Identifier for the hash algorithm used for attestation signing */
+#define EL3_TOKEN_SIGN_HASH_ALG_SHA384 U(1)
/*
* RMM_BOOT_COMPLETE originates on RMM when the boot finishes (either cold
@@ -153,7 +188,7 @@
* Increase this when a bug is fixed, or a feature is added without
* breaking compatibility.
*/
-#define RMM_EL3_IFC_VERSION_MINOR (U(3))
+#define RMM_EL3_IFC_VERSION_MINOR (U(4))
#define RMM_EL3_INTERFACE_VERSION \
(((RMM_EL3_IFC_VERSION_MAJOR << 16) & 0x7FFFF) | \