[Openvpn-devel] [PATCH 01/02] Add support for PolarSSL 1.1.x branch

[Igor Novgorodov]

Continuing to struggle with making OpenVPN as tiny as possible :)
The attached patch adds checking for PolarSSL version on 
crypto_polarssl.c and depending
on which version we are using (1.0.x or 1.1.x) chooses a new shiny 
havege_random() function,
or an old ugly while{} loop hack to generate randomness.
--- a/crypto_polarssl.c
+++ b/crypto_polarssl.c
@@ -41,6 +41,7 @@
 #include <polarssl/md5.h>
 #include <polarssl/cipher.h>
 #include <polarssl/havege.h>
+#include <polarssl/version.h>

 /*
  *
@@ -157,25 +158,24 @@
 rand_bytes (uint8_t *output, int len)
 {
   static havege_state hs = {0};
-  static bool hs_initialised = false;
-  const int int_size = sizeof(int);

-  if (!hs_initialised)
-    {
-      /* Initialise PolarSSL RNG */
-      havege_init(&hs);
-      hs_initialised = true;
-    }
+  /* Initialise PolarSSL RNG */
+  havege_init(&hs);
+#if (POLARSSL_VERSION_MAJOR >= 1 && POLARSSL_VERSION_MINOR >= 1)
+  havege_random(&hs, output, len);
+#else
+  const int int_size = sizeof(int);

   while (len > 0)
     {
-      const int blen   = min_int (len, int_size);
-      const int rand_int       = havege_rand(&hs);
+      const int blen    = min_int (len, int_size);
+      const int rand_int        = havege_rand(&hs);

       memcpy (output, &rand_int, blen);
       output += blen;
       len -= blen;
     }
+#endif
   return 1;
 }