Diff: targets/TARGET_NUVOTON/TARGET_M2351/trng_api.c

Revision:

187:0387e8f68319

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/trng_api.c	Thu Sep 06 13:40:20 2018 +0100
@@ -0,0 +1,89 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017-2018 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"
+#include "crypto-misc.h"
+
+
+/*
+ * Get Random number generator.
+ */
+
+#define PRNG_KEY_SIZE  (0x20UL)
+
+static void trng_get(unsigned char *pConversionData)
+{
+    uint32_t *p32ConversionData;
+
+    p32ConversionData = (uint32_t *)pConversionData;
+
+    PRNG_Open(CRYPTO_MODBASE(), PRNG_KEY_SIZE_256, 1, us_ticker_read());
+    crypto_prng_prestart();
+    PRNG_Start(CRYPTO_MODBASE());
+    crypto_prng_wait();
+
+    PRNG_Read(CRYPTO_MODBASE(), p32ConversionData);
+}
+
+void trng_init(trng_t *obj)
+{
+    (void)obj;
+    
+    /* Init crypto module */
+    crypto_init();
+    
+    PRNG_ENABLE_INT(CRYPTO_MODBASE());
+}
+
+void trng_free(trng_t *obj)
+{
+    (void)obj;
+    
+    PRNG_DISABLE_INT(CRYPTO_MODBASE());
+    
+    /* Uninit crypto module */
+    crypto_uninit();
+}
+
+int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
+{
+    (void)obj;
+    unsigned char tmpBuff[PRNG_KEY_SIZE];
+    size_t cur_length = 0;
+    
+    while (length >= sizeof(tmpBuff)) {
+        trng_get(output);
+        output += sizeof(tmpBuff);
+        cur_length += sizeof(tmpBuff);
+        length -= sizeof(tmpBuff);
+    }
+    if (length > 0) {
+        trng_get(tmpBuff);
+        memcpy(output, tmpBuff, length);
+        cur_length += length;
+        crypto_zeroize(tmpBuff, sizeof(tmpBuff));
+    }
+    *output_length = cur_length;
+    return 0;
+}
+
+#endif