Attest: Implement API to get attestation public key

Implement non-secure interface function for IPC and library models and
secure interface function to get the public part of the attestation
key pair.
Add public key getter secure function / service to Initial Attestation
partition manifest.

Change-Id: Idae5f5d5d645afa6d3c7e62e9169387e57932137
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/interface/src/tfm_initial_attestation_func_api.c b/interface/src/tfm_initial_attestation_func_api.c
index c391f61..7292df5 100644
--- a/interface/src/tfm_initial_attestation_func_api.c
+++ b/interface/src/tfm_initial_attestation_func_api.c
@@ -9,6 +9,7 @@
 #include "tfm_veneers.h"
 #include "tfm_ns_interface.h"
 #include "psa/client.h"
+#include "psa/crypto_types.h"
 
 #define IOVEC_LEN(x) (sizeof(x)/sizeof(x[0]))
 
@@ -56,3 +57,25 @@
                             (uint32_t)in_vec,  IOVEC_LEN(in_vec),
                             (uint32_t)out_vec, IOVEC_LEN(out_vec));
 }
+
+enum psa_attest_err_t
+tfm_initial_attest_get_public_key(uint8_t         *public_key,
+                                  size_t           public_key_buf_size,
+                                  size_t          *public_key_len,
+                                  psa_ecc_curve_t *elliptic_curve_type)
+{
+    int32_t res;
+
+    psa_outvec out_vec[] = {
+        {.base = public_key,          .len = public_key_buf_size},
+        {.base = elliptic_curve_type, .len = sizeof(*elliptic_curve_type)},
+        {.base = public_key_len,      .len = sizeof(*public_key_len)}
+    };
+
+    res = tfm_ns_interface_dispatch(
+                        (veneer_fn)tfm_initial_attest_get_public_key_veneer,
+                        (uint32_t)NULL,  0,
+                        (uint32_t)out_vec, IOVEC_LEN(out_vec));
+
+    return (enum psa_attest_err_t)res;
+}