Made headers compatible with C++.

inc/bearssl_hash.h

@@ -29,6 +29,10 @@
 #include <stdint.h>
 #include <string.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** \file bearssl_hash.h
  *
  * # Hash Functions
@@ -1335,4 +1339,8 @@ void br_ghash_pwr8(void *y, const void *h, const void *data, size_t len);
  */
 br_ghash br_ghash_pwr8_get(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif