Added support for getrandom()/getentropy(), and a fix for the RDRAND bug on AMD CPU...

[BearSSL] / src / inner.h

diff --git a/src/inner.h b/src/inner.h
index 1b52673..07e1d0a 100644 (file)
--- a/src/inner.h
+++ b/src/inner.h
@@ -114,6 +114,10 @@
 #define BR_64   1
 #elif defined(__x86_64__) || defined(_M_X64)
 #define BR_64   1
+#elif defined(__aarch64__) || defined(_M_ARM64)
+#define BR_64   1
+#elif defined(__mips64)
+#define BR_64   1
 #endif
 #endif
 
@@ -305,9 +309,20 @@
  * values are documented on:
  *    https://sourceforge.net/p/predef/wiki/OperatingSystems/
  *
- * TODO: enrich the list of detected system. Also add detection for
- * alternate system calls like getentropy(), which are usually
- * preferable when available.
+ * Win32's CryptGenRandom() should be available on Windows systems.
+ *
+ * /dev/urandom should work on all Unix-like systems (including macOS X).
+ *
+ * getentropy() is present on Linux (Glibc 2.25+), FreeBSD (12.0+) and
+ * OpenBSD (5.6+). For OpenBSD, there does not seem to be easy to use
+ * macros to test the minimum version, so we just assume that it is
+ * recent enough (last version without getentropy() has gone out of
+ * support in May 2015).
+ *
+ * Ideally we should use getentropy() on macOS (10.12+) too, but I don't
+ * know how to test the exact OS version with preprocessor macros.
+ *
+ * TODO: enrich the list of detected system.
  */
 
 #ifndef BR_USE_URANDOM
@@ -324,6 +339,15 @@
 #endif
 #endif
 
+#ifndef BR_USE_GETENTROPY
+#if (defined __linux__ \
+       && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25))) \
+       || (defined __FreeBSD__ && __FreeBSD__ >= 12) \
+       || defined __OpenBSD__
+#define BR_USE_GETENTROPY   1
+#endif
+#endif
+
 #ifndef BR_USE_WIN32_RAND
 #if defined _WIN32 || defined _WIN64
 #define BR_USE_WIN32_RAND   1