Add a facility to configure entropy sources
Add a function to configure entropy sources. For testing only.
Use it to test that the library initialization fails properly if there is no
entropy source.
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 4c0ac12..f4c87d3 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -43,6 +43,7 @@
#include "psa/crypto.h"
+#include "psa_crypto_invasive.h"
/* Include internal declarations that are useful for implementing persistently
* stored keys. */
#include "psa_crypto_storage.h"
@@ -155,6 +156,8 @@
typedef struct
{
+ void (* entropy_init )( mbedtls_entropy_context *ctx );
+ void (* entropy_free )( mbedtls_entropy_context *ctx );
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
key_slot_t key_slots[PSA_KEY_SLOT_COUNT];
@@ -4437,6 +4440,17 @@
/* Module setup */
/****************************************************************/
+psa_status_t mbedtls_psa_crypto_configure_entropy_sources(
+ void (* entropy_init )( mbedtls_entropy_context *ctx ),
+ void (* entropy_free )( mbedtls_entropy_context *ctx ) )
+{
+ if( global_data.rng_state != RNG_NOT_INITIALIZED )
+ return( PSA_ERROR_BAD_STATE );
+ global_data.entropy_init = entropy_init;
+ global_data.entropy_free = entropy_free;
+ return( PSA_SUCCESS );
+}
+
void mbedtls_psa_crypto_free( void )
{
psa_key_slot_t key;
@@ -4457,7 +4471,7 @@
if( global_data.rng_state != RNG_NOT_INITIALIZED )
{
mbedtls_ctr_drbg_free( &global_data.ctr_drbg );
- mbedtls_entropy_free( &global_data.entropy );
+ global_data.entropy_free( &global_data.entropy );
}
/* Wipe all remaining data, including configuration.
* In particular, this sets all state indicator to the value
@@ -4474,10 +4488,15 @@
if( global_data.initialized != 0 )
return( PSA_SUCCESS );
- mbedtls_zeroize( &global_data, sizeof( global_data ) );
+ /* Set default configuration if
+ * mbedtls_psa_crypto_configure_entropy_sources() hasn't been called. */
+ if( global_data.entropy_init == NULL )
+ global_data.entropy_init = mbedtls_entropy_init;
+ if( global_data.entropy_free == NULL )
+ global_data.entropy_free = mbedtls_entropy_free;
/* Initialize the random generator. */
- mbedtls_entropy_init( &global_data.entropy );
+ global_data.entropy_init( &global_data.entropy );
mbedtls_ctr_drbg_init( &global_data.ctr_drbg );
global_data.rng_state = RNG_INITIALIZED;
ret = mbedtls_ctr_drbg_seed( &global_data.ctr_drbg,
diff --git a/library/psa_crypto_invasive.h b/library/psa_crypto_invasive.h
new file mode 100644
index 0000000..642652a
--- /dev/null
+++ b/library/psa_crypto_invasive.h
@@ -0,0 +1,79 @@
+/**
+ * \file psa_crypto_invasive.h
+ *
+ * \brief PSA cryptography module: invasive interfaces for test only.
+ *
+ * The interfaces in this file are intended for testing purposes only.
+ * They MUST NOT be made available to clients over IPC in integrations
+ * with isolation, and they SHOULD NOT be made available in library
+ * integrations except when building the library for testing.
+ */
+/*
+ * 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)
+ */
+
+#ifndef PSA_CRYPTO_INVASIVE_H
+#define PSA_CRYPTO_INVASIVE_H
+
+#if defined(MBEDTLS_CONFIG_FILE)
+#include MBEDTLS_CONFIG_FILE
+#else
+#include "mbedtls/config.h"
+#endif
+
+#include "psa/crypto.h"
+
+#include "mbedtls/entropy.h"
+
+/** \brief Configure entropy sources.
+ *
+ * This function may only be called before a call to psa_crypto_init(),
+ * or after a call to mbedtls_psa_crypto_free() and before any
+ * subsequent call to psa_crypto_init().
+ *
+ * This function is only intended for test purposes. The functionality
+ * it provides is also useful for system integrators, but
+ * system integrators should configure entropy drivers instead of
+ * breaking through to the Mbed TLS API.
+ *
+ * \param entropy_init Function to initialize the entropy context
+ * and set up the desired entropy sources.
+ * It is called by psa_crypto_init().
+ * By default this is mbedtls_entropy_init().
+ * This function cannot report failures directly.
+ * To indicate a failure, set the entropy context
+ * to a state where mbedtls_entropy_func() will
+ * return an error.
+ * \param entropy_free Function to free the entropy context
+ * and associated resources.
+ * It is called by mbedtls_psa_crypto_free().
+ * By default this is mbedtls_entropy_free().
+ *
+ * \retval PSA_SUCCESS
+ * Success.
+ * \retval PSA_ERROR_NOT_PERMITTED
+ * The caller does not have the permission to configure
+ * entropy sources.
+ * \retval PSA_ERROR_BAD_STATE
+ * The library has already been initialized.
+ */
+psa_status_t mbedtls_psa_crypto_configure_entropy_sources(
+ void (* entropy_init )( mbedtls_entropy_context *ctx ),
+ void (* entropy_free )( mbedtls_entropy_context *ctx ) );
+
+#endif /* PSA_CRYPTO_INVASIVE_H */