Plug in the entry point for public key export through driver

Including test.

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 97b522d..8a2e413 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1656,14 +1656,24 @@
             /* Exporting private -> private */
             return( psa_internal_export_key_buffer( slot, data, data_size, data_length ) );
         }
+
         /* Need to export the public part of a private key,
-         * so conversion is needed */
+         * so conversion is needed. Try the accelerators first. */
+        psa_status_t status = psa_driver_wrapper_export_public_key( slot,
+                                                                    data,
+                                                                    data_size,
+                                                                    data_length );
+
+        if( status != PSA_ERROR_NOT_SUPPORTED ||
+            psa_key_lifetime_is_external( slot->attr.lifetime ) )
+            return( status );
+
         if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
         {
 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
     defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
             mbedtls_rsa_context *rsa = NULL;
-            psa_status_t status = psa_load_rsa_representation(
+            status = psa_load_rsa_representation(
                                     slot->attr.type,
                                     slot->data.key.data,
                                     slot->data.key.bytes,
@@ -1692,7 +1702,7 @@
 #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
     defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
             mbedtls_ecp_keypair *ecp = NULL;
-            psa_status_t status = psa_load_ecp_representation(
+            status = psa_load_ecp_representation(
                                     slot->attr.type,
                                     slot->data.key.data,
                                     slot->data.key.bytes,
diff --git a/library/psa_crypto_driver_wrappers.c b/library/psa_crypto_driver_wrappers.c
index 4040b36..c3ea6f1 100644
--- a/library/psa_crypto_driver_wrappers.c
+++ b/library/psa_crypto_driver_wrappers.c
@@ -438,6 +438,59 @@
 #endif /* PSA_CRYPTO_DRIVER_PRESENT */
 }
 
+psa_status_t psa_driver_wrapper_export_public_key( const psa_key_slot_t *slot,
+                                                   uint8_t *data,
+                                                   size_t data_size,
+                                                   size_t *data_length )
+{
+#if defined(PSA_CRYPTO_ACCELERATOR_DRIVER_PRESENT)
+    psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
+    psa_key_location_t location = PSA_KEY_LIFETIME_GET_LOCATION(slot->attr.lifetime);
+    psa_key_attributes_t attributes = {
+      .core = slot->attr
+    };
+
+    switch( location )
+    {
+        case PSA_KEY_LOCATION_LOCAL_STORAGE:
+            /* Key is stored in the slot in export representation, so
+             * cycle through all known transparent accelerators */
+#if defined(PSA_CRYPTO_DRIVER_TEST)
+            status = test_transparent_export_public_key( &attributes,
+                                                         slot->data.key.data,
+                                                         slot->data.key.bytes,
+                                                         data,
+                                                         data_size,
+                                                         data_length );
+            /* Declared with fallback == true */
+            if( status != PSA_ERROR_NOT_SUPPORTED )
+                return( status );
+#endif /* PSA_CRYPTO_DRIVER_TEST */
+            /* Fell through, meaning no accelerator supports this operation */
+            return( PSA_ERROR_NOT_SUPPORTED );
+        /* Add cases for opaque driver here */
+#if defined(PSA_CRYPTO_DRIVER_TEST)
+        case PSA_CRYPTO_TEST_DRIVER_LIFETIME:
+            return( test_opaque_export_public_key( &attributes,
+                                                   slot->data.key.data,
+                                                   slot->data.key.bytes,
+                                                   data,
+                                                   data_size,
+                                                   data_length ) );
+#endif /* PSA_CRYPTO_DRIVER_TEST */
+        default:
+            /* Key is declared with a lifetime not known to us */
+            return( status );
+    }
+#else /* PSA_CRYPTO_ACCELERATOR_DRIVER_PRESENT */
+    (void) slot;
+    (void) data;
+    (void) data_size;
+    (void) data_length;
+    return( PSA_ERROR_NOT_SUPPORTED );
+#endif /* PSA_CRYPTO_ACCELERATOR_DRIVER_PRESENT */
+}
+
 /*
  * Cipher functions
  */
diff --git a/library/psa_crypto_driver_wrappers.h b/library/psa_crypto_driver_wrappers.h
index b0b483b..6b51437 100644
--- a/library/psa_crypto_driver_wrappers.h
+++ b/library/psa_crypto_driver_wrappers.h
@@ -55,6 +55,11 @@
                                               size_t data_length,
                                               size_t *bits );
 
+psa_status_t psa_driver_wrapper_export_public_key( const psa_key_slot_t *slot,
+                                                   uint8_t *data,
+                                                   size_t data_size,
+                                                   size_t *data_length );
+
 /*
  * Cipher functions
  */