Add support for CC trng

add support for HW entropy source

Author: Ron Eldor

targets/TARGET_CRYPTOCELL310/objects_cryptocell.h

@@ -0,0 +1,44 @@
+ /*
+  *  objects_cryptocell.h
+  *
+  *  Copyright (C) 2017, 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.
+  *
+  */
+
+#ifndef MBED_OBJECTS_CRYPTOCELL_H
+#define MBED_OBJECTS_CRYPTOCELL_H
+#include "sns_silib.h"
+
+typedef struct  trng_s
+{
+    /* parameters defining TRNG */
+    CRYS_RND_mode_t TrngMode;
+
+    /* allowed ring oscillator lengths: bits 0,1,2,3  */
+    uint32_t  RoscsAllowed;
+
+    /* sampling interval: count of ring oscillator cycles between
+       consecutive bits sampling */
+    uint32_t  SubSamplingRatio;
+
+    uint32_t  SubSamplingRatio1;
+    uint32_t  SubSamplingRatio2;
+    uint32_t  SubSamplingRatio3;
+    uint32_t  SubSamplingRatio4;
+
+}CRYS_RND_Params_t;
+
+#endif // MBED_OBJECTS_CRYPTOCELL_H

targets/TARGET_CRYPTOCELL310/trng.c

@@ -0,0 +1,89 @@
+ /*
+  *  trng.c
+  *
+  *  Copyright (C) 2017, 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.
+  *
+  */
+
+#if defined(DEVICE_TRNG)
+
+#include <string.h>
+#include "trng_api.h"
+
+extern CRYS_RND_State_t     rndState;
+extern CRYS_RND_WorkBuff_t  rndWorkBuff;
+
+/* Implementation that should never be optimized out by the compiler */
+static void mbedtls_zeroize( void *v, size_t n ) {
+    volatile unsigned char *p = (unsigned char*)v;
+    while( n-- ) *p++ = 0;
+}
+
+CRYSError_t RNG_PLAT_SetUserRngParameters(
+                         CRYS_RND_State_t  *pRndState,
+                         CRYS_RND_Params_t *pTrngParams);
+
+CRYSError_t LLF_RND_GetTrngSource(
+                         CRYS_RND_State_t  *rndState_ptr,
+                         CRYS_RND_Params_t *trngParams_ptr,
+                         SaSiBool_t        isContinued,
+                         uint32_t          *entropySize_ptr,
+                         uint32_t          **sourceOut_ptr_ptr,
+                         uint32_t          *sourceOutSize_ptr,
+                         uint32_t          *rndWorkBuff_ptr);
+
+
+void trng_init(trng_t *obj)
+{
+    RNG_PLAT_SetUserRngParameters(&rndState, obj);
+}
+
+void trng_free(trng_t *obj)
+{
+    (void)obj;
+}
+
+
+int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *outputLength)
+{
+    (void)obj;
+    int ret;
+    uint32_t entropySizeBits;
+    uint32_t *entrSource_ptr;
+    uint32_t actualLength;
+
+    ret = LLF_RND_GetTrngSource(
+                &rndState ,    /*in/out*/
+                obj,       /*in/out*/
+                0,       /*in*/
+                &entropySizeBits,  /*in/out*/
+                &entrSource_ptr,   /*out*/
+                &actualLength,  /*out*/
+                (uint32_t*)&rndWorkBuff.crysRndWorkBuff /*in*/);
+    if ( ret != 0 )
+        return -1;
+
+    if ( length < actualLength )
+        actualLength = length;
+
+    *outputLength = actualLength;
+
+    memcpy( output, entrSource_ptr + CRYS_RND_TRNG_SRC_INNER_OFFSET_WORDS, *outputLength );
+    mbedtls_zeroize( entrSource_ptr + CRYS_RND_TRNG_SRC_INNER_OFFSET_WORDS, *outputLength );
+    return 0;
+}
+
+#endif //DEVICE_TRNG

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF51/objects.h

@@ -47,6 +47,13 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
+#if DEVICE_CRYPTOCELL
+#include "objects_cryptocell.h"
+#else
+struct trng_s {
+    uint32_t placeholder;
+};
+#endif
 
 struct serial_s {
     uint32_t placeholder; // struct is unused by nRF5x API implementation
@@ -85,10 +92,6 @@ struct flash_s {
     uint32_t placeholder;
 };
 
-struct trng_s {
-    uint32_t placeholder;
-};
-
 #include "gpio_object.h"
 
 #ifdef __cplusplus

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF51/trng_api.c

@@ -41,6 +41,7 @@
 #include "hal/trng_api.h"
 #include "hal/lp_ticker_api.h"
 
+#if !defined(DEVICE_CRYPTOCELL)
 #include "nrf_drv_rng.h"
 
 #define DEFAULT_TIMEOUT_US (1000*1000)
@@ -179,4 +180,5 @@ int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_l
     return (*output_length == 0) ? -1 : 0;
 }
 
+#endif/* !DEVICE_CRYPTOCELL */
 #endif