random numbers for fe310

1 files changed, 27 insertions, 0 deletions

diff --git a/fw/fe310/eos/rng.c b/fw/fe310/eos/rng.c
new file mode 100644
index 0000000..317941d
--- /dev/null
+++ b/fw/fe310/eos/rng.c
@@ -0,0 +1,27 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "net.h"
+
+int getentropy(unsigned char *b, size_t sz) {
+    unsigned char type;
+    unsigned char *buffer;
+    uint16_t len;
+    int rv;
+
+    buffer = eos_net_alloc();
+
+    type = EOS_NET_MTYPE_RNG;
+    len = sizeof(uint16_t);
+    buffer[0] = sz >> 8;
+    buffer[1] = sz;
+
+    rv = eos_net_xchg(&type, buffer, &len);
+    if (rv || (len != sz)) rv = -1;
+
+    if (!rv) memcpy(b, buffer, sz);
+    eos_net_free(buffer, 1);
+
+    return rv;
+}