Diff: targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c

Revision:

149:156823d33999

Child:

153:fa9ff456f731

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,100 @@
+/*
+ *  Hardware entropy collector for NUC472's RNGA
+ *
+ *  Copyright (C) 2006-2015, 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 DEVICE_TRNG
+
+#include <stdlib.h>
+#include <string.h>
+#include "cmsis.h"
+#include "NUC472_442.h"
+#include "us_ticker_api.h"
+#include "trng_api.h"
+
+/*
+ * Get Random number generator.
+ */
+static volatile int  g_PRNG_done;
+
+void CRYPTO_IRQHandler()
+{
+    if (PRNG_GET_INT_FLAG()) {
+        g_PRNG_done = 1;
+        PRNG_CLR_INT_FLAG();
+    }
+} 
+
+static void trng_get(unsigned char *pConversionData)
+{
+    uint32_t *p32ConversionData;
+
+    p32ConversionData = (uint32_t *)pConversionData;
+
+    PRNG_Open(PRNG_KEY_SIZE_256, 1, us_ticker_read());
+    PRNG_Start();
+    while (!g_PRNG_done);
+
+    PRNG_Read(p32ConversionData);
+}
+
+void trng_init(trng_t *obj)
+{
+    (void)obj;
+    /* Unlock protected registers */
+    SYS_UnlockReg();    
+    /* Enable IP clock */
+    CLK_EnableModuleClock(CRPT_MODULE);
+    
+    /* Lock protected registers */
+    SYS_LockReg();
+    
+    NVIC_EnableIRQ(CRPT_IRQn);
+    PRNG_ENABLE_INT();
+}
+
+void trng_free(trng_t *obj)
+{
+    (void)obj;
+    PRNG_DISABLE_INT();
+    NVIC_DisableIRQ(CRPT_IRQn);
+}
+
+int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
+{
+    (void)obj;
+
+    *output_length = 0;
+    if (length < 32) {
+        unsigned char tmpBuff[32];
+        trng_get(tmpBuff);
+        memcpy(output, &tmpBuff, length);
+        *output_length = length;
+    } else {
+        for (int i = 0; i < (length/32); i++) {
+            trng_get(output);
+            *output_length += 32;
+            output += 32;
+        }
+    }
+
+    return 0;
+}
+ 
+#endif
+