Add support for PSA crypto driver size_function
Updated get_expected_key_size in psa_crypto_driver_wrappers to properly
handle using the new size_function from PSA crypto drivers. Created
initial infrastructure to support size_function for the PSA crypto
drivers.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
diff --git a/library/psa_crypto_driver_wrappers.c b/library/psa_crypto_driver_wrappers.c
index d41209b..a8dcc06 100644
--- a/library/psa_crypto_driver_wrappers.c
+++ b/library/psa_crypto_driver_wrappers.c
@@ -256,23 +256,51 @@
size_t *expected_size )
{
size_t buffer_size = 0;
- if( PSA_KEY_LIFETIME_GET_LOCATION( attributes->core.lifetime ) == PSA_KEY_LOCATION_LOCAL_STORAGE )
- {
- buffer_size = PSA_KEY_EXPORT_MAX_SIZE( attributes->core.type,
- attributes->core.bits );
+ psa_key_location_t location = PSA_KEY_LIFETIME_GET_LOCATION( attributes->core.lifetime );
+ psa_key_type_t key_type = attributes->core.type;
+ size_t key_bits = attributes->core.bits;
- if( buffer_size == 0 )
+ switch( location )
+ {
+ case PSA_KEY_LOCATION_LOCAL_STORAGE:
+ buffer_size = PSA_KEY_EXPORT_MAX_SIZE( key_type, key_bits );
+
+ if( buffer_size == 0 )
+ return( PSA_ERROR_NOT_SUPPORTED );
+
+ *expected_size = buffer_size;
+ return( PSA_SUCCESS );
+
+#if defined(PSA_CRYPTO_DRIVER_TEST)
+ case PSA_CRYPTO_TEST_DRIVER_LIFETIME:
+ /* TBD: opaque driver support: need to calculate size through a
+ * driver-defined size function, since the size of an opaque (wrapped)
+ * key will be different for each implementation. */
+#ifdef TEST_KEY_CONTEXT_SIZE_FUNCTION
+ *expected_size = test_size_function( key_type, key_bits );
+ return( PSA_SUCCESS );
+#else /* TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION */
+ if( PSA_KEY_TYPE_IS_KEY_PAIR( key_type ) )
+ {
+ *expected_size = TEST_DRIVER_KEY_CONTEXT_BASE_SIZE
+ + TEST_DRIVER_KEY_CONTEXT_PUBLIC_KEY_SIZE;
+ }
+ else if( PSA_KEY_TYPE_IS_PUBLIC_KEY( attributes->core.type ) )
+ {
+ *expected_size = TEST_DRIVER_KEY_CONTEXT_BASE_SIZE
+ + TEST_DRIVER_KEY_CONTEXT_SYMMETRIC_FACTOR
+ * ( ( key_bits + 7 ) / 8 );
+ }
+ else
+ {
+ return( PSA_ERROR_NOT_SUPPORTED );
+ }
+ return( PSA_SUCCESS );
+#endif /* TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION */
+#endif /* PSA_CRYPTO_DRIVER_TEST */
+
+ default:
return( PSA_ERROR_NOT_SUPPORTED );
-
- *expected_size = buffer_size;
- return( PSA_SUCCESS );
- }
- else
- {
- /* TBD: opaque driver support: need to calculate size through a
- * driver-defined size function, since the size of an opaque (wrapped)
- * key will be different for each implementation. */
- return( PSA_ERROR_NOT_SUPPORTED );
}
}
#endif /* PSA_CRYPTO_DRIVER_PRESENT */
diff --git a/tests/include/test/drivers/size.h b/tests/include/test/drivers/size.h
new file mode 100644
index 0000000..4e5b591
--- /dev/null
+++ b/tests/include/test/drivers/size.h
@@ -0,0 +1,87 @@
+/*
+ * Test driver for context size functions
+ */
+/* Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef PSA_CRYPTO_TEST_DRIVERS_SIZE_H
+#define PSA_CRYPTO_TEST_DRIVERS_SIZE_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(PSA_CRYPTO_DRIVER_TEST)
+#include <psa/crypto_driver_common.h>
+
+typedef struct {
+ unsigned int context;
+} test_driver_key_context_t;
+
+/** \def TEST_DRIVER_KEY_CONTEXT_BASE_SIZE
+ *
+ * This macro returns the base size for the key context. It should include
+ * the size for any driver context information stored with each key.
+ */
+#define TEST_DRIVER_KEY_CONTEXT_BASE_SIZE sizeof(test_driver_key_context_t)
+
+/** \def TEST_DRIVER_KEY_CONTEXT_KEY_PAIR_SIZE
+ *
+ * Number of bytes included in every key context for a key pair.
+ */
+
+#define TEST_DRIVER_KEY_CONTEXT_KEY_PAIR_SIZE 0
+
+/** \def TEST_DRIVER_KEY_CONTEXT_PUBLIC_KEY_SIZE
+ *
+ * Number of bytes included in every key context for a public key.
+ */
+#define TEST_DRIVER_KEY_CONTEXT_PUBLIC_KEY_SIZE 0
+
+/** \def TEST_DRIVER_KEY_CONTEXT_SYMMETRIC_FACTOR
+ *
+ * Every key context for a symmetric key includes this many times the key size.
+ */
+#define TEST_DRIVER_KEY_CONTEXT_SYMMETRIC_FACTOR 0
+
+/** \def TEST_DRIVER_KEY_CONTEXT_STORE_PUBLIC_KEY
+ *
+ * If this is true for a key pair, the key context includes space for the public key.
+ * If this is false, no additional space is added for the public key.
+ */
+#define TEST_DRIVER_KEY_CONTEXT_STORE_PUBLIC_KEY 0
+
+/** \def TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION
+ *
+ * If TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION is defined, the test driver
+ * provides a size_function entry point, otherwise, it does not.
+ *
+ * Some opaque drivers have the need to support a custom size for the storage
+ * of key and context information. The size_function provides the ability to
+ * provide that customization.
+ */
+//#define TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION
+
+#ifdef TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION
+size_t test_size_function(
+ const psa_key_type_t key_type,
+ const size_t key_bits );
+#endif /* TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION */
+
+#endif /* PSA_CRYPTO_DRIVER_TEST */
+#endif /* PSA_CRYPTO_TEST_DRIVERS_KEYGEN_H */
diff --git a/tests/include/test/drivers/test_driver.h b/tests/include/test/drivers/test_driver.h
index 7ee8e5e..ee59742 100644
--- a/tests/include/test/drivers/test_driver.h
+++ b/tests/include/test/drivers/test_driver.h
@@ -25,5 +25,6 @@
#include "test/drivers/signature.h"
#include "test/drivers/keygen.h"
#include "test/drivers/cipher.h"
+#include "test/drivers/size.h"
#endif /* PSA_CRYPTO_TEST_DRIVER_H */
diff --git a/tests/src/drivers/size.c b/tests/src/drivers/size.c
new file mode 100644
index 0000000..05f8a98
--- /dev/null
+++ b/tests/src/drivers/size.c
@@ -0,0 +1,47 @@
+/*
+ * Test driver for retrieving key context size.
+ * Only used by opaque drivers.
+ */
+/* Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_DRIVERS) && defined(PSA_CRYPTO_DRIVER_TEST)
+#include "psa/crypto.h"
+#include "psa_crypto_core.h"
+#include "mbedtls/error.h"
+
+#include "test/drivers/size.h"
+
+#include <string.h>
+
+#ifdef TEST_KEY_CONTEXT_SIZE_FUNCTION
+size_t test_size_function(
+ const psa_key_type_t key_type,
+ const size_t key_bits )
+{
+ (void) key_type;
+ (void) key_bits;
+ return 0;
+}
+#endif /*TEST_KEY_CONTEXT_SIZE_FUNCTION */
+
+#endif /* MBEDTLS_PSA_CRYPTO_DRIVERS && PSA_CRYPTO_DRIVER_TEST */