Diff: targets/TARGET_NUVOTON/TARGET_M480/trng_api.c

Revision:

172:7d866c31b3c5

Child:

179:b0033dcd6934

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NUVOTON/TARGET_M480/trng_api.c	Thu Aug 31 17:27:04 2017 +0100
@@ -0,0 +1,99 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2015-2016 Nuvoton
+ *
+ * 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 "us_ticker_api.h"
+#include "trng_api.h"
+
+/*
+ * Get Random number generator.
+ */
+static volatile int  g_PRNG_done;
+volatile int  g_AES_done;
+
+void CRYPTO_IRQHandler()
+{
+    if (PRNG_GET_INT_FLAG()) {
+        g_PRNG_done = 1;
+        PRNG_CLR_INT_FLAG();
+    } else	if (AES_GET_INT_FLAG()) {
+        g_AES_done = 1;
+        AES_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 (unsigned i = 0; i < (length/32); i++) {
+            trng_get(output);
+            *output_length += 32;
+            output += 32;
+        }
+    }
+
+    return 0;
+}
+
+#endif
+