Add new PSA Crypto Storage backend implementation using ITS APIs

The new file is conditionally compiled with the new mbedtls
configuration option that  Mbed OS would set by default -
`MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C`.

-

library/CMakeLists.txt

@@ -56,6 +56,7 @@ set(src_crypto
     psa_crypto.c
     psa_crypto_storage.c
     psa_crypto_storage_file.c
+    psa_crypto_storage_its.c
     ripemd160.c
     rsa.c
     rsa_internal.c

library/Makefile

@@ -84,6 +84,7 @@ OBJS_CRYPTO=	aes.o		aesni.o		arc4.o		\
 		psa_crypto.o					\
 		psa_crypto_storage.o				\
 		psa_crypto_storage_file.o			\
+		psa_crypto_storage_its.o			\
 		ripemd160.o	rsa_internal.o	rsa.o  		\
 		sha1.o		sha256.o	sha512.o	\
 		threading.o	timing.o	version.o	\

library/psa_crypto_storage_its.c

@@ -0,0 +1,184 @@
+/*
+ *  PSA storage backend for persistent keys using psa_its APIs.
+ */
+/*  Copyright (C) 2018, ARM Limited, All Rights Reserved
+ *  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.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if defined(MBEDTLS_CONFIG_FILE)
+#include MBEDTLS_CONFIG_FILE
+#else
+#include "mbedtls/config.h"
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C)
+
+#include "psa/crypto.h"
+#include "psa_crypto_storage_backend.h"
+#include "psa_prot_internal_storage.h"
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#endif
+
+static psa_status_t its_to_psa_error( psa_its_status_t ret )
+{
+    switch( ret )
+    {
+        case PSA_ITS_SUCCESS:
+            return( PSA_SUCCESS );
+
+        case PSA_ITS_ERROR_KEY_NOT_FOUND:
+            return( PSA_ERROR_EMPTY_SLOT );
+
+        case PSA_ITS_ERROR_STORAGE_FAILURE:
+            return( PSA_ERROR_STORAGE_FAILURE );
+
+        case PSA_ITS_ERROR_INSUFFICIENT_SPACE:
+            return( PSA_ERROR_INSUFFICIENT_STORAGE );
+
+        case PSA_ITS_ERROR_INVALID_KEY:
+        case PSA_PS_ERROR_OFFSET_INVALID:
+        case PSA_ITS_ERROR_INCORRECT_SIZE:
+        case PSA_ITS_ERROR_BAD_POINTER:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+        case PSA_ITS_ERROR_FLAGS_NOT_SUPPORTED:
+            return( PSA_ERROR_NOT_SUPPORTED );
+
+        case PSA_ITS_ERROR_WRITE_ONCE:
+            return( PSA_ERROR_OCCUPIED_SLOT );
+
+        default:
+            return( PSA_ERROR_UNKNOWN_ERROR );
+    }
+}
+
+static uint32_t psa_its_identifier_of_slot( psa_key_slot_t key )
+{
+    return( key );
+}
+
+psa_status_t psa_crypto_storage_load( const psa_key_slot_t key, uint8_t *data,
+                                      size_t data_size )
+{
+    psa_its_status_t ret;
+    psa_status_t status;
+    uint32_t data_identifier = psa_its_identifier_of_slot( key );
+    struct psa_its_info_t data_identifier_info;
+
+    ret = psa_its_get_info( data_identifier, &data_identifier_info );
+    status = its_to_psa_error( ret );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    ret = psa_its_get( data_identifier, 0, data_size, data );
+    status = its_to_psa_error( ret );
+
+    return( status );
+}
+
+int psa_is_key_present_in_storage( const psa_key_slot_t key )
+{
+    psa_its_status_t ret;
+    uint32_t data_identifier = psa_its_identifier_of_slot( key );
+    struct psa_its_info_t data_identifier_info;
+
+    ret = psa_its_get_info( data_identifier, &data_identifier_info );
+
+    if( ret == PSA_ITS_ERROR_KEY_NOT_FOUND )
+        return( 0 );
+    return( 1 );
+}
+
+psa_status_t psa_crypto_storage_store( const psa_key_slot_t key,
+                                       const uint8_t *data,
+                                       size_t data_length )
+{
+    psa_its_status_t ret;
+    psa_status_t status;
+    uint32_t data_identifier = psa_its_identifier_of_slot( key );
+    struct psa_its_info_t data_identifier_info;
+
+    if( psa_is_key_present_in_storage( key ) == 1 )
+        return( PSA_ERROR_OCCUPIED_SLOT );
+
+    ret = psa_its_set( data_identifier, data_length, data, 0 );
+    status = its_to_psa_error( ret );
+    if( status != PSA_SUCCESS )
+    {
+        return( PSA_ERROR_STORAGE_FAILURE );
+    }
+
+    ret = psa_its_get_info( data_identifier, &data_identifier_info );
+    status = its_to_psa_error( ret );
+    if( status != PSA_SUCCESS )
+    {
+        goto exit;
+    }
+
+    if( data_identifier_info.size != data_length )
+    {
+        status = PSA_ERROR_STORAGE_FAILURE;
+        goto exit;
+    }
+
+exit:
+    if( status != PSA_SUCCESS )
+        psa_its_remove( data_identifier );
+    return( status );
+}
+
+psa_status_t psa_destroy_persistent_key( const psa_key_slot_t key )
+{
+    psa_its_status_t ret;
+    uint32_t data_identifier = psa_its_identifier_of_slot( key );
+    struct psa_its_info_t data_identifier_info;
+
+    ret = psa_its_get_info( data_identifier, &data_identifier_info );
+    if( ret == PSA_ITS_ERROR_KEY_NOT_FOUND )
+        return( PSA_SUCCESS );
+
+    if( psa_its_remove( data_identifier ) != PSA_ITS_SUCCESS )
+        return( PSA_ERROR_STORAGE_FAILURE );
+
+    ret = psa_its_get_info( data_identifier, &data_identifier_info );
+    if( ret != PSA_ITS_ERROR_KEY_NOT_FOUND )
+        return( PSA_ERROR_STORAGE_FAILURE );
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_crypto_storage_get_data_length( const psa_key_slot_t key,
+                                                 size_t *data_length )
+{
+    psa_its_status_t ret;
+    psa_status_t status;
+    uint32_t data_identifier = psa_its_identifier_of_slot( key );
+    struct psa_its_info_t data_identifier_info;
+
+    ret = psa_its_get_info( data_identifier, &data_identifier_info );
+    status = its_to_psa_error( ret );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    *data_length = (size_t) data_identifier_info.size;
+
+    return( PSA_SUCCESS );
+}
+
+#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C */

visualc/VS2010/mbedTLS.vcxproj

@@ -291,6 +291,7 @@
     <ClCompile Include="..\..\library\psa_crypto.c" />
     <ClCompile Include="..\..\library\psa_crypto_storage.c" />
     <ClCompile Include="..\..\library\psa_crypto_storage_file.c" />
+    <ClCompile Include="..\..\library\psa_crypto_storage_its.c" />
     <ClCompile Include="..\..\library\ripemd160.c" />
     <ClCompile Include="..\..\library\rsa.c" />
     <ClCompile Include="..\..\library\rsa_internal.c" />