From b0d46deef6e6ed62301ea6aa7c0f2d42cc669ef2 Mon Sep 17 00:00:00 2001
From: Jon Shallow <supjps-libcoap@jpshallow.com>
Date: Fri, 12 Feb 2021 15:20:35 +0000
Subject: [PATCH] coap_prng.c: Fix missing coap_prng_impl function.

PR #590 unfortunately broke the standard builds.
---
 src/coap_prng.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/coap_prng.c b/src/coap_prng.c
index c825dbd6..888a9f03 100644
--- a/src/coap_prng.c
+++ b/src/coap_prng.c
@@ -39,14 +39,21 @@ coap_prng_impl( unsigned char *buf, size_t len ) {
         return 1;
 }
 
-#endif
+#endif /* _WIN32 */
 
 static int
 coap_prng_default(void *buf, size_t len) {
 #ifdef HAVE_GETRANDOM
   return getrandom(buf, len, 0);
 #else /* !HAVE_GETRANDOM */
+#if defined(_WIN32)
   return coap_prng_impl(buf,len);
+#else /* !_WIN32 */
+  unsigned char *dst = (unsigned char *)buf;
+  while (len--)
+    *dst++ = rand() & 0xFF;
+  return 1;
+#endif /* !_WIN32 */
 #endif /* !HAVE_GETRANDOM */
 }